EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH (CERN)

 CERN-PH-EP-2015-223 LHCb-PAPER-2015-032 25 January 2016

Study of the production of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
5.36378pt\overline{\kern-5.36378ptB}{}}{}^{0}}$ hadrons in $pp$ collisions and
first measurement of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ branching fraction

The LHCb collaboration†††Authors are listed at the end of this paper.

The product of the ${{\mathchar 28931\relax}^{0}_{b}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$) differential production
cross-section and the branching fraction of the decay ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*}}(892)^{0}$) is
measured as a function of the beauty hadron transverse momentum, $p_{\rm T}$,
and rapidity, $y$. The kinematic region of the measurements is $\mbox{$p_{\rm
T}$}<20{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and $2.0<y<4.5$. The measurements
use a data sample corresponding to an integrated luminosity of
$3\mbox{\,fb}^{-1}$ collected by the LHCb detector in $pp$ collisions at
centre-of-mass energies $\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV}$ in 2011 and
$\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV}$ in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}$, the branching fraction of the decay
${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ is measured to be

${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})=(3.17\pm 0.04\pm 0.07\pm 0.34^{+0.45}_{-0.28})\times
10^{-4},$

where the first uncertainty is statistical, the second is systematic, the
third is due to the uncertainty on the branching fraction of the decay
${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*}}(892)^{0}$, and
the fourth is due to the knowledge of $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}$. The sum of the asymmetries in the production
and decay between ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$ is also
measured as a function of $p_{\rm T}$ and $y$. The previously published
branching fraction of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}}$, relative to that of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$, is updated. The branching fractions of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{}P_{c}^{+}(\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}){{K}^{-}}$ are determined.

Published in Chin. Phys. C40 (2016) 011001

© CERN on behalf of the LHCb collaboration, licence CC-BY-4.0.

##  1 Introduction

In quantum chromodynamics (QCD) the production process of $b$ hadrons can be
divided into two steps, assuming factorisation: a hard process for $b$
production and a soft process to describe hadronisation. The hard process can
be predicted by perturbative calculations in QCD; the soft process is
parameterised by the fragmentation function, which has large uncertainties due
to non-perturbative QCD contributions. The study of the production of ${b}$
hadrons tests the factorisation ansatz. The ground state of the $b$-baryon
family, ${{\mathchar 28931\relax}^{0}_{b}}$, has a wide range of decay modes.
The study of its production and decays can offer complementary information to
that obtained from the study of $B$ mesons. The kinematic dependence of the
production of ${{\mathchar 28931\relax}^{0}_{b}}$ baryons relative to that of
$B$ mesons can test differences in the ${b}$ quark hadronisation process
between the two [1, 2]. Furthermore, the asymmetry of heavy flavoured baryons
and antibaryons produced in $pp$ collisions is an important input for various
asymmetry measurements. Leading-order QCD calculations predict equal
production cross-sections for heavy baryons and heavy anti-baryons, while
measurements at the ISR showed that ${\mathchar 28931\relax}^{+}_{c}$
production is favoured in $pp$ collisions at forward rapidity, $y$ [3, 4]. The
CMS experiment measured the ${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}$
production ratio in $pp$ collisions at $7\mathrm{\,Te\kern-1.00006ptV}$, and
no asymmetry was observed, but the large uncertainties preclude definitive
conclusions [5]. Measurements at LHCb can provide further tests of existing
mechanisms, e.g., the string drag effect or the leading quark effect [6].

Measurements of ${{\mathchar 28931\relax}^{0}_{b}}$ production to date have
mostly been based on semileptonic decays and the hadronic decays ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{\mathchar 28931\relax}$ and ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{\mathchar 28931\relax}^{+}_{c}}{{\pi}^{-}}$
(charge-conjugation is implied throughout the paper unless otherwise
specified). Using semileptonic decays, the LHCb experiment measured the ratio
of ${\mathchar 28931\relax}^{0}_{b}$ baryon production to light $B$ meson
production, $f_{{{\mathchar 28931\relax}^{0}_{b}}}/(f_{u}+f_{d})$ [7]. The
kinematic dependence of the ratio of ${\mathchar 28931\relax}^{0}_{b}$ to
${\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ production,
$f_{{{\mathchar 28931\relax}^{0}_{b}}}/f_{d}$, was measured using ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{\mathchar 28931\relax}^{+}_{c}}{{\pi}^{-}}$
and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{D}^{+}}{{\pi}^{-}}$
decays, and the absolute branching fraction ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{\mathchar 28931\relax}^{+}_{c}}{{\pi}^{-}})$
was determined [8].

In this paper, the ${\mathchar 28931\relax}^{0}_{b}$ candidates are
reconstructed in the decay channel ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$, which was first observed by LHCb in 2013 [9]. Compared
with the open-charm decays of ${{\mathchar 28931\relax}^{0}_{b}}$ baryons,
this channel has higher trigger efficiencies, especially in the region of low
transverse momentum, $p_{\rm T}$. Two pentaquark-charmonium states
$P_{c}(4380)^{+}$ and $P_{c}(4450)^{+}$ were observed by LHCb [10] in the
amplitude analysis of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay. The measurement of the absolute branching fraction
of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ in the current paper allows the pentaquark branching
fractions to be determined. Other ${\mathchar 28931\relax}^{0}_{b}$ decays
with a charmonium meson in the final state, such as the Cabibbo-suppressed
decay ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}}$ [11], can use the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay as a reference to measure their absolute branching
fractions.

The product of the ${{\mathchar 28931\relax}^{0}_{b}}$ (${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$) differential production cross-
section and the branching fraction of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$) decay is
measured as a function of $p_{\rm T}$ and $y$, where ${{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ indicates the ${{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*}}(892)^{0}$ meson throughout the
text. The kinematic region of these measurements is $\mbox{$p_{\rm
T}$}<20{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and $2.0<y<4.5$ for the $b$
hadron. The production ratio of the two $b$ hadrons, defined as

$R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}\equiv\frac{\sigma({{\mathchar
28931\relax}^{0}_{b}}){\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})}{\sigma({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}){\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})},$ (1)

is determined, taking advantage of the cancellation of some uncertainties in
both experimental measurements and theoretical calculations. Here,
$\sigma({{\mathchar 28931\relax}^{0}_{b}})$ and $\sigma({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}})$ represent the production
cross-sections of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ hadrons in $pp$ collisions.
The branching fraction ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ is calculated from this result using previous
measurements of $f_{{{\mathchar 28931\relax}^{0}_{b}}}/f_{d}$ [7, 8] and
${\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$ [12]. The
kinematic dependence of the sum of the asymmetries in the production and
decay, $a_{\rm p+d}\equiv a_{\rm prod}+a_{\rm decay}$, between ${{\mathchar
28931\relax}^{0}_{b}}$ and ${{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$ is
studied using ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern 1.00006pt\overline{\kern-1.00006pt\mathchar
28931\relax}}{}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{\overline{p}}{{K}^{+}}$ decays. Furthermore, using the measurement of
${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$, the branching fractions of the decays ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}}$ and ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{}P_{c}^{+}(\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}){{K}^{-}}$ are determined.

The measurements in this paper are based on a data sample corresponding to an
integrated luminosity of $3\mbox{\,fb}^{-1}$, collected by the LHCb experiment
in $pp$ collisions at centre-of-mass energies
$\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV}$ in 2011 and
$\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV}$ in 2012. Separate measurements are
performed for each of the two centre-of-mass energies.

##  2 Detector and simulation

The LHCb detector [13, 14] is a single-arm forward spectrometer covering the
pseudorapidity range $2<\eta<5$, designed for the study of particles
containing $b$ or $c$ quarks. The detector includes a high-precision tracking
system consisting of a silicon-strip vertex detector surrounding the $pp$
interaction region [15], a large-area silicon-strip detector located upstream
of a dipole magnet with a bending power of about $4{\rm\,Tm}$, and three
stations of silicon-strip detectors and straw drift tubes [16] placed
downstream of the magnet. The tracking system provides a measurement of
momentum, $p$, of charged particles with a relative uncertainty that varies
from 0.5% at low momentum to 1.0% at
200${\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. The minimum distance of a track to
a primary vertex (PV), the impact parameter (IP), is measured with a
resolution of $(15+29/\mbox{$p_{\rm T}$}){\,\upmu\rm m}$, where $p_{\rm T}$ is
the component of the momentum transverse to the beam, in
${\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. Different types of charged hadrons are
distinguished using information from two ring-imaging Cherenkov detectors
[17]. Photons, electrons and hadrons are identified by a calorimeter system
consisting of scintillating-pad and preshower detectors, an electromagnetic
calorimeter and a hadronic calorimeter. Muons are identified by a system
composed of alternating layers of iron and multiwire proportional chambers
[18]. The online event selection is performed by a trigger [19], which
consists of a hardware stage, based on information from the calorimeter and
muon systems, followed by a software stage, which applies a full event
reconstruction. In the hardware trigger, events are selected by requiring at
least one high-$p_{\rm T}$ track that is consistent with a muon hypothesis. In
the software trigger, two well-reconstructed muons are required to form a
vertex with good fit $\chi^{2}$ and to have an invariant mass consistent with
that of the ${J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}$ meson [20]. The
trigger also requires a significant displacement between the
${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}$ vertex and the associated PV
of the $pp$ collision.

In the simulation, $pp$ collisions are generated using Pythia [21, 22] with a
specific LHCb configuration [23]. Decays of hadronic particles are described
by EvtGen [24], in which final-state radiation is generated using Photos [25].
The interaction of the generated particles with the detector, and its
response, are implemented using the Geant4 toolkit [26, 27] as described in
Ref. [28]. The physics models used by LHCb in Geant4 for hadronic interactions
have been tested against experimental data from COMPAS [20], and good
agreement was observed.111Data files are courtesy of the COMPAS Group, IHEP,
Protvino, Russia.

##  3 Event selection

Candidates for ${{\mathchar 28931\relax}^{0}_{b}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$) hadrons are reconstructed in
the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$) decay
channel, where the ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}$ mesons are
reconstructed in the dimuon final state, and ${{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ candidates are reconstructed
from ${{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}\rightarrow{{K}^{-}}{{\pi}^{+}}$
decays. Since the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decays have
the same topology, a similar event selection is adopted for both.

An offline selection is applied after the trigger and is divided into two
steps: a preselection and a multivariate selection based on a boosted decision
tree (BDT) [29, 30, 31, 32]. In the preselection, each track of the
${\mathchar 28931\relax}^{0}_{b}$ (${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$) candidate is required to be of
good quality [14, 33, 34, 35]. Identified muons are required to have $p_{\rm
T}$ greater than $550{\mathrm{\,Me\kern-1.00006ptV\\!/}c}$, while hadrons are
required to have $p_{\rm T}$ greater than
$250{\mathrm{\,Me\kern-1.00006ptV\\!/}c}$. The muons should be inconsistent
with originating from any PV, as determined by their impact parameter. Each
${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}$ candidate is required to have
a good vertex fit $\chi^{2}$ and an invariant mass within
${}_{-48}^{+43}{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$ of the known
${J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}$ mass [20]. Particle
identification (PID) requirements are imposed on the final-state tracks. For
the kaon and proton in the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay, the sum of the kaon and proton $p_{\rm T}$ should
be larger than $1{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. Each ${\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}$ candidate is required to have
a good vertex fit $\chi^{2}$ and to have $p_{\rm T}$ greater than
$1{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. The invariant mass of the
reconstructed ${{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ is
required to be within $\pm 70{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$ of the
${{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ mass [20]. Each $b$
hadron candidate must have a good vertex fit $\chi^{2}$, be consistent with
originating from the PV, and have a decay time greater than $0.2{\rm\,ps}$.

Some non-combinatorial backgrounds exist in the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ data sample, originating from ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{K}^{-}}{{\pi}^{+}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}_{s}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{K}^{-}}{{K}^{+}}$ decays with the ${{\pi}^{+}}$ and ${{K}^{+}}$
misidentified as a proton. In order to suppress these events, the invariant
mass is recalculated by interpreting the proton candidate as a pion or a kaon,
and the two relevant invariant mass regions are vetoed:
$m({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{K}^{-}}{{\pi}^{+}})\in[5250,5310]{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$
and $m({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{K}^{+}}{{K}^{-}})\in[5340,5400]{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$.
After the mass vetoes these background contributions are reduced to a
negligible level.

After the preselection, the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$) candidates
are filtered with the BDT to further suppress combinatorial background. For
the decays ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$, the same BDT
classifier is applied. Independent BDT classifiers are used for the 2011 and
2012 samples. In the BDT training a simulated ${{\mathchar
28931\relax}^{0}_{b}}$ sample is used as the signal. The background is taken
from the lower, $(5420,5560){\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$, and
upper, $(5680,5820){\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$, sidebands of the
${\mathchar 28931\relax}^{0}_{b}$ invariant mass distribution in data. Events
in the sidebands are randomly divided into two parts, one for the training and
the other for the test. No overtraining is observed. The following information
is used by the BDT classifier: the kinematic properties and the impact
parameters of the tracks; and the vertex quality, the decay length and the
impact parameter of the reconstructed $b$ hadron candidate. The variables used
for the training are chosen based on their power to discriminate signal from
background and on the similarity of their distributions for ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decays. The
threshold for the BDT response is chosen to maximise $S/\sqrt{S+B}$, where $B$
represents the number of background events estimated from the sideband region
and $S$ the number of signal events in the mass peak.

##  4 Cross-section and branching fraction determination

The product of the differential production cross-section of each $b$ hadron
and the corresponding branching fraction is calculated as

${\mathrm{d}^{2}\sigma\over\mathrm{d}\mbox{$p_{\rm T}$}\,\mathrm{d}y}~{}{\cal
B}=\frac{N(\mbox{$p_{\rm T}$},y)}{{\varepsilon}(\mbox{$p_{\rm
T}$},y)~{}\mathcal{L}~{}{\cal B}_{{\rm inter}}~{}\Delta\mbox{$p_{\rm
T}$}~{}\Delta y},$ (2)

where $N(\mbox{$p_{\rm T}$},y)$ and ${\varepsilon}(\mbox{$p_{\rm T}$},y)$ are
respectively the signal yield and the efficiency as functions of $p_{\rm T}$
and $y$ of the $b$ hadron, $\Delta\mbox{$p_{\rm T}$}$ and $\Delta y$ are the
bin widths, $\mathcal{L}$ is the integrated luminosity, ${\cal B}$ is the
absolute branching fraction of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$) decay, and
${\cal B}_{{\rm inter}}$ represents the branching fractions of the
intermediate decays:

${\cal B}_{{\rm inter}}\equiv\begin{cases}{\cal
B}({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}})\qquad{\kern 78.00014pt}\mbox{for
{${\mathchar 28931\relax}^{0}_{b}$}},\\\ {\cal
B}({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}})~{}{\cal B}({{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}\rightarrow{{K}^{-}}{{\pi}^{+}})\qquad\mbox{for
{${\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$}}.\end{cases}$

The luminosity is measured with van der Meer scans and a beam-gas imaging
method [36]. The 2011 and 2012 data samples correspond to $1019\pm
17\mbox{\,pb}^{-1}$ and $2056\pm 23\mbox{\,pb}^{-1}$, respectively. The
branching fraction ${\cal B}({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}})=(5.961\pm 0.033)\%$ [20], while ${\cal
B}({{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}\rightarrow{{K}^{-}}{{\pi}^{+}})$
is taken to be $2/3$ assuming isospin symmetry. The branching fraction ${\cal
B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})=(1.29\pm
0.05\pm 0.13)\times 10^{-3}$ as measured by Belle [12] is used in preference
to the world average value, since in the Belle result the S-wave component is
subtracted.

##  5 Signal determination

The signal yields of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decays are
determined from unbinned extended maximum likelihood fits to the invariant
mass distributions of the reconstructed $b$ hadron candidates in each $p_{\rm
T}$ and $y$ bin. In order to improve the mass resolution, the $b$ hadron is
refitted with constraints [37] that it originates from the PV and that the
reconstructed ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}$ mass equals its
known mass [20].

Figure 1 shows, as an example of one of the fit results, the invariant mass
distributions of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ candidates in the kinematic
region $\mbox{$p_{\rm T}$}\in[6,7]{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and
$y\in[3.0,3.5]$ for the 2012 data sample. The signal shape in the fits is
modelled by a double-sided Crystal Ball (DSCB) function, an empirical function
comprising a Gaussian core together with power-law tails on both sides. The
mean and the mass resolution of the DSCB function are free in the fits, while
the tail parameters are determined from simulation in each kinematic bin
according to the empirical function given in Ref. [38]. The combinatorial
background is modelled by an exponential function whose parameters are left
free in the fits.

In the fits to the ${{\mathchar 28931\relax}^{0}_{b}}$ mass distribution,
there is a contribution from the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay in which the proton is misidentified as a kaon and
the kaon is misidentified as a proton. This background is denoted as the
doubly misidentified background, and it is modelled by a DSCB function. All
parameters of this DSCB function are fixed from the simulation study,
including: the difference between the mean of this DSCB function and that of
the signal shape; the ratio of the mass resolution between these two DSCB; the
yield fraction relative to the ${{\mathchar 28931\relax}^{0}_{b}}$ signal
channel; and the tail parameters.

In the ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ sample, in
addition to the combinatorial background, there are two further sources of
background. One is the decay
${{B}^{0}_{s}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$, which populates the upper
sideband of the invariant mass distribution, and is modelled with a DSCB
function. The tail parameters of this DSCB function are the same as those of
the ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ signal shape and
the remaining parameters are free in the fits. The other comes from partially
reconstructed $B$ mesons and is described by the tail of a Gaussian function.
The associated mean and width are free parameters in the fits.

According to a previous LHCb measurement [39], the fraction of the ${{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ meson contribution in the
${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decay is
calculated as $(89.9\pm 0.4\pm 1.3)\%$, where the remainder is due to the
S-wave component in the ${{K}^{-}}{{\pi}^{+}}$ system and its interference
with the ${{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ meson. The
fitted ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ yields are
subtracted with this number to remove the components from S-wave and its
interference.

Figure 1: Fit to the (left) ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and (right) ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.79997pt\overline{\kern-1.79997ptK}{}}{}^{*0}}$ invariant mass
distributions with $\mbox{$p_{\rm
T}$}\in[6,7]{\mathrm{\,Ge\kern-0.90005ptV\\!/}c}$ and $y\in[3.0,3.5]$ for the
2012 data sample. The hatched (red) area represents the signals, the filled
(green) area ${{B}^{0}_{s}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.79997pt\overline{\kern-1.79997ptK}{}}{}^{*0}}$, and the
dashed (magenta) lines the combinatorial background. The dot-dashed (black)
lines indicate the doubly misidentified background (left) and partially
reconstructed background (right). The solid (blue) lines represent the sum of
the above components and the points with error bars show the data.

##  6 Efficiencies

The efficiency ${\varepsilon}^{{{\mathchar 28931\relax}^{0}_{b}},{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}(\mbox{$p_{\rm T}$},y)$
consists of the geometrical acceptance of the detector, the trigger
efficiency, the reconstruction and preselection efficiency, the hadron PID
efficiency, and the BDT selection efficiency. All the efficiencies are
determined from a sample of simulated signal events, except the hadron PID
efficiency, which is determined from data with tracks from the decays
${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}\rightarrow{\mu^{+}\mu^{-}}$,
${{D}^{*+}}\rightarrow{{D}^{0}}(\rightarrow{{K}^{-}}{{\pi}^{+}}){{\pi}^{+}}$
and ${{\mathchar 28931\relax}^{+}_{c}}\rightarrow{p}{{K}^{-}}{{\pi}^{+}}$.

The rich resonance structure observed in decays of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ in data [10] is not modelled in the simulation. The
simulated sample is weighted to reproduce the distributions of the BDT
training variables and the two-dimensional distribution of $m(p{{K}^{-}})$ and
$m({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{p})$ observed in the
background-subtracted data sample, which has been obtained using the sPlot
technique [40], with the $b$-hadron invariant mass as the discriminating
variable. It is found that the correlations between the discriminating
variable and the control variables are negligible.

##  7 Asymmetry determination

The observed (raw) asymmetry for ${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}$ is
defined as

$A_{\rm raw}(x)\equiv\frac{N^{{{\mathchar 28931\relax}^{0}_{b}}}(x)-N^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar
28931\relax}}{}^{0}_{b}}}(x)}{N^{{{\mathchar
28931\relax}^{0}_{b}}}(x)+N^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar 28931\relax}}{}^{0}_{b}}}(x)}.$
(3)

The symbol $N(x)$ is the signal yield in the given bin of $x$ from the fits to
the invariant mass distribution of the ${\mathchar 28931\relax}^{0}_{b}$
(${\kern 1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}$)
sample, where $x$ denotes $p_{\rm T}$ or $y$. The observed asymmetry is a sum
of several contributions: the asymmetry between the numbers of the produced
${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}$ baryons
in $pp$ collisions, $a_{\rm prod}(x)$; the decay asymmetry between the
${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and ${{\kern 1.00006pt\overline{\kern-1.00006pt\mathchar
28931\relax}}{}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{\overline{p}}{{K}^{+}}$ channels, $a_{\rm decay}(x)$; the asymmetry
between the $p$ and $\overline{p}$ detection efficiencies, $a_{\rm D}^{p}(x)$;
the asymmetry between the ${K}^{-}$ and ${K}^{+}$ detection efficiencies,
$a_{\rm D}^{K}(x)$; and the asymmetry between the PID efficiencies for
${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}$ baryons,
$a_{\rm PID}(x)$. Other possible asymmetries are neglected. Assuming that all
these asymmetries are small, the asymmetries $a_{\rm p+d}(x)$ of ${\mathchar
28931\relax}^{0}_{b}$ and ${\kern 1.00006pt\overline{\kern-1.00006pt\mathchar
28931\relax}}{}^{0}_{b}$ baryons can be calculated as

$a_{\rm p+d}(x)=A_{\rm raw}(x)-a_{\rm PID}(x)-a_{\rm D}^{p}(x)-a_{\rm
D}^{K}(x).$ (4)

The value $A_{\rm raw}(x)-a_{\rm PID}(x)$ can be calculated as

$A_{\rm raw}(x)-a_{\rm PID}(x)=\frac{N^{{{\mathchar
28931\relax}^{0}_{b}}}(x)/{\varepsilon}^{{{\mathchar
28931\relax}^{0}_{b}}}_{\rm PID}(x)-N^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar
28931\relax}}{}^{0}_{b}}}(x)/{\varepsilon}^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar 28931\relax}}{}^{0}_{b}}}_{\rm
PID}(x)}{N^{{{\mathchar 28931\relax}^{0}_{b}}}(x)/{\varepsilon}^{{{\mathchar
28931\relax}^{0}_{b}}}_{\rm PID}(x)+N^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar
28931\relax}}{}^{0}_{b}}}(x)/{\varepsilon}^{{{\kern
0.70004pt\overline{\kern-0.70004pt\mathchar 28931\relax}}{}^{0}_{b}}}_{\rm
PID}(x)},$ (5)

where ${\varepsilon}_{\rm PID}^{{{\mathchar 28931\relax}^{0}_{b}}}(x)$ and
${\varepsilon}_{\rm PID}^{{{\kern 0.70004pt\overline{\kern-0.70004pt\mathchar
28931\relax}}{}^{0}_{b}}}(x)$ represent the PID efficiencies for ${\mathchar
28931\relax}^{0}_{b}$ and ${\kern 1.00006pt\overline{\kern-1.00006pt\mathchar
28931\relax}}{}^{0}_{b}$. The kaon detection asymmetry $a_{\rm D}^{K}(x)$ as a
function of $p_{\rm T}$ and $y$ is obtained from a previous LHCb study [41].
The proton detection asymmetry $a_{\rm D}^{p}(x)$ as a function of $p_{\rm T}$
or $y$ is estimated from simulation, which uses the Geant4 model as described
in Section 2. The proton detection asymmetry as a function of $p_{\rm T}$ or
$y$ is calculated with the proton and antiproton track reconstruction
efficiencies in the corresponding kinematic bin. It is checked that the
kinematic distributions of protons and ${\mathchar 28931\relax}^{0}_{b}$
baryons in the simulation sample are consistent with those in the data sample.
As a crosscheck, the proton detection asymmetries are also estimated through a
simulation sample, where the ${\mathchar 28931\relax}^{0}_{b}$ signals are
partially reconstructed without using the proton information, and the results
are consistent.

##  8 Systematic uncertainties

Table 1:  Summary of the systematic uncertainties (%) for the production cross-sections of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$. The large uncertainties affect the bins with very few candidates.  |  ${{\mathchar 28931\relax}^{0}_{b}}$ ($7\mathrm{\,Te\kern-1.00006ptV}$) |  ${{\mathchar 28931\relax}^{0}_{b}}$ ($8\mathrm{\,Te\kern-1.00006ptV}$) |  ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ ($7\mathrm{\,Te\kern-1.00006ptV}$) |  ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ ($8\mathrm{\,Te\kern-1.00006ptV}$)
---|---|---|---|---
Uncorrelated between bins |  |  |  |
Signal shape | $0.4-15.4$ | $0.2-\kern 5.0pt6.2$ | $0.2-1.5$ | $0.2-\kern 5.0pt1.5$
Background shape | $0.0-\kern 5.0pt1.9$ | $0.0-\kern 5.0pt4.3$ | $0.0-0.9$ | $0.0-\kern 5.0pt0.9$
Simulation sample size | $4.1-16.5$ | $3.9-14.3$ | $1.7-9.5$ | $2.2-14.9$
BDT efficiency | $0.4-\kern 5.0pt2.5$ | $0.4-\kern 5.0pt2.8$ | $0.1-0.5$ | $0.1-\kern 5.0pt0.5$
Trigger efficiency | $0.0-\kern 5.0pt4.6$ | $0.0-14.9$ | $0.0-2.1$ | $0.0-\kern 5.0pt4.0$
PID efficiency | $0.4-\kern 5.0pt8.4$ | $0.4-15.8$ | $0.2-4.6$ | $0.2-\kern 5.0pt2.7$
Resonance |  |  | $0.0-1.0$ | $0.0-\kern 5.0pt1.8$
Correlated between bins |  |  |  |
Tracking efficiency | $3.0$ | $3.0$ | $3.0$ | $3.0$
Mass veto efficiency | $1.3$ | $1.9$ |  |
Luminosity | $1.7$ | $1.2$ | $1.7$ | $1.2$
${\cal B}({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}\rightarrow{\mu^{+}\mu^{-}})$ | $0.6$ | $0.6$ | $0.6$ | $0.6$
S-wave and interference in ${{K}^{-}}{{\pi}^{+}}$ |  |  | $1.4$ | $1.4$
Table 2:  Summary of the absolute systematic uncertainties (%) for the asymmetry of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern 1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$. The large uncertainties affect the bins with very few candidates.  | 2011 | 2012
---|---|---
PID efficiency | $0.4-4.4$ | $0.0-2.6$
Signal shape | $0.0-0.8$ | $0.0-0.9$
Background shape | $0.0-0.1$ | $0.0-0.3$
MC statistics | $0.7-5.4$ | $0.3-4.2$
Tracking asymmetry of proton | $0.1-1.9$ | $0.1-1.9$

Several sources of systematic uncertainties are studied in the analysis and
are summarised in Tables 1 and 2. For the production cross-section
measurements, the uncertainties originate from the determination of the signal
yields, efficiencies, branching fractions and luminosities. The total
systematic uncertainties are obtained from the sum in quadrature of all
components.

Imperfect knowledge of the mass distributions for the signal and backgrounds
causes systematic uncertainties in the signal yield determination. For the
signal shape, the Apollonios function [42] and the sum of a Gaussian function
and a Crystal Ball function are tried as alternatives to the DSCB. The largest
deviation to the nominal result is taken as the uncertainty due to the model
of the signal shape.

The fits are repeated with a linear function substituted for the exponential
model for the combinatorial background. The fits are also repeated without the
double misidentified components. The maximum differences of the signal yields
from the nominal results are quoted as systematic uncertainties due to the
background shape.

Most efficiencies are estimated from simulation. The limited size of the
simulation sample leads to systematic uncertainties on the efficiencies
ranging from $1.7\%$ to $16.5\%$.

The tracking efficiency is estimated from simulation and calibrated by data
[43]. The uncertainty of the calibration is $0.4\%$ per track. Additional
systematic uncertainties are assigned to hadrons due to imperfect knowledge of
hadron interactions in the detector, $1.1\%$ for kaons, $1.4\%$ for pions and
$1.4\%$ for protons.

The BDT efficiency is estimated with the weighted simulation sample to ensure
that the distributions of the two training variables, the kinematic properties
of the tracks and the vertex quality, agree with those in data. The
uncertainties on the weights are propagated to the final results to give the
corresponding systematic uncertainty.

The trigger efficiency is determined in the simulation and validated in a
control sample of ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}}$ decays [19]. The difference of the central
values of this determination in data and the simulation in each bin is taken
as the systematic uncertainty. Uncertainties due to the limited sample size of
the simulation are added in quadrature.

The PID efficiency is estimated with a data-driven method. A sample of
${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}\rightarrow{\mu^{+}\mu^{-}}$,
${{D}^{*+}}\rightarrow{{D}^{0}}(\rightarrow{{K}^{-}}{{\pi}^{+}}){{\pi}^{+}}$
and ${{\mathchar 28931\relax}^{+}_{c}}\rightarrow p{{K}^{-}}{{\pi}^{+}}$
decays obtained without using PID information is used to evaluate the PID
efficiency. The limited sample size used to calculate the PID efficiency
introduces a systematic uncertainty in each kinematic bin. To study the bin-
by-bin migration effect, the number of the bins is doubled or halved and the
PID efficiency is recalculated. The largest deviation from the nominal result
is taken as the uncertainty.

To account for the rich and complex structure of multiple intermediate
resonances in the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay, the simulation sample is weighted in two-
dimensional bins of $m({{K}^{-}}{p})$ and
$m({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{p})$ to match the data.
Pseudoexperiments are performed to estimate the systematic uncertainties due
to the weights. The weight in each bin is varied according to its uncertainty
and the total efficiency is recalculated. The RMS of the distribution obtained
from the pseudoexperiments is taken as the systematic uncertainty. As
mentioned in Section 3, the preselection includes mass vetoes. The
preselection efficiencies are estimated from the simulation sample. A fit to
the ${\mathchar 28931\relax}^{0}_{b}$ invariant mass distribution in the
vetoed data sample is performed, which gives the number of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ signal events rejected by the vetoes. The fraction of the
vetoed signal events in the data sample is compared with that in the
simulation sample. A difference of $1.3\%$ ($1.9\%$) is observed for the 2011
(2012) sample, and this is taken as the systematic uncertainty.

The uncertainty in the determination of the integrated luminosity is $1.7\%$
($1.2\%$) for the 2011 (2012) data sample [36]. An uncertainty of $0.6\%$ is
taken on ${\cal B}({{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}})$ [20]. The fractions of the S-wave
component in the ${{K}^{-}}{{\pi}^{+}}$ system and their interference were
determined by a previous LHCb measurement, and their $1.4\%$ uncertainty [39]
is taken as a systematic uncertainty for the ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decay.

In the ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$
asymmetry measurement, all of the uncertainties mentioned above cancel in the
ratio, except for those due to the signal shape, the background shape, the
limited sample size and the PID efficiency. Since a data-driven determination
of proton detection asymmetries is not available, the difference in the
determination of the kaon detection asymmetries in data and simulation is
taken as a systematic uncertainty for the proton detection asymmetry. The
uncertainties vary from $0.1\%$ to $1.9\%$ in kinematic bins, with large
values occurring in bins of low $p_{\rm T}$ or low signal yields. In the LHCb
Geant4 physics models, the cross-sections of interactions between particles
and the material are checked with test beam data as discussed in Section 2.
There are more data for protons than for kaons. Therefore, these uncertainties
can be considered to be conservative.

##  9 Cross-section results

The product of the ${\mathchar 28931\relax}^{0}_{b}$ (${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$) double-differential cross-
section and the branching fraction of the decay ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ (${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$) is shown in
Fig. 2, and the values are listed in Tables Acknowledgements,
Acknowledgements, LABEL:tab:final_result_B011 and Acknowledgements in the
Appendix. By integrating over $y$ or $p_{\rm T}$, the single differential
production cross-sections, shown in Fig. 3, are obtained. Figure 4 shows the
$p_{\rm T}$ distribution of the ${{\mathchar 28931\relax}^{0}_{b}}$
production, fitted by a power-law function with the Tsallis parameterisation
[44, 45]:

$\frac{\mathrm{d}\sigma}{\mbox{$p_{\rm T}$}\mathrm{d}\mbox{$p_{\rm
T}$}}\propto\frac{1}{\left[1+E_{k\perp}/(TN)\right]^{N}},$ (6)

where $T$ is a temperature-like parameter, $N$ determines the power-law
behaviour at large $E_{k\perp}$, and $E_{k\perp}\equiv\sqrt{\mbox{$p_{\rm
T}$}^{2}+M^{2}}-M$ with $M$ the mass of the hadron. The fit results are

$\displaystyle T=1.12\pm 0.04~{}\mathrm{\,Ge\kern-1.00006ptV}\qquad N=7.3\pm
0.5\qquad(7\mathrm{\,Te\kern-1.00006ptV}),$ $\displaystyle T=1.13\pm
0.03~{}\mathrm{\,Ge\kern-1.00006ptV}\qquad N=7.5\pm
0.4\qquad(8\mathrm{\,Te\kern-1.00006ptV}).$

For the $7\mathrm{\,Te\kern-1.00006ptV}$ ($8\mathrm{\,Te\kern-1.00006ptV}$)
sample, the fit $\chi^{2}$ is 21.0 (10.7) for 7 (9) degrees of freedom. The
parameters $T$ and $N$ obtained from the $7\mathrm{\,Te\kern-1.00006ptV}$ and
$8\mathrm{\,Te\kern-1.00006ptV}$ samples are consistent with each other and
with the values found by CMS [5]. Other functions suggested in Ref. [46] do
not give acceptable fits to the data. In Fig. 4 the data points are placed in
the bin according to the prescription of Ref. [47].

Figure 2:  Products of production cross-sections and branching fractions as
functions of $p_{\rm T}$ in $y$ bins for (left) ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ and (right) ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$. The top
(bottom) plots represent the 2011 (2012) sample. The error bars represent the
total uncertainties.

Figure 3:  Products of production cross-sections and branching fractions as
functions of (top) $p_{\rm T}$ or (bottom) $y$. The left (right) plots
represent ${\mathchar 28931\relax}^{0}_{b}$ (${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$) hadrons. The error bars
indicate the statistical uncertainties and the hatched areas represent the
total uncertainties.  Figure 4:  Fit to the ${\mathchar 28931\relax}^{0}_{b}$
distribution with the Tsallis function.

The integrated cross-sections of the $b$ hadrons with $0<\mbox{$p_{\rm
T}$}<20{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and $2.0<y<4.5$ are measured to
be

$\displaystyle\sigma({{\mathchar
28931\relax}^{0}_{b}},~{}\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV})~{}{\cal
B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ $\displaystyle=$ $\displaystyle 6.12\pm
0.10\mathrm{\,(stat)}\pm 0.25\mathrm{\,(syst)}\rm\,nb,$
$\displaystyle\sigma({{\mathchar
28931\relax}^{0}_{b}},~{}\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV})~{}{\cal
B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ $\displaystyle=$ $\displaystyle 7.51\pm
0.08\mathrm{\,(stat)}\pm 0.31\mathrm{\,(syst)}\rm\,nb,$
$\displaystyle\sigma({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}},~{}\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV})~{}{\cal
B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$
$\displaystyle=$ $\displaystyle 53.4\pm 0.3\kern 5.0pt\mathrm{\,(stat)}\pm
2.0\kern 5.0pt\mathrm{\,(syst)}\rm\,nb,$ $\displaystyle\sigma({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}},~{}\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV})~{}{\cal
B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$
$\displaystyle=$ $\displaystyle 63.6\pm 0.2\kern 5.0pt\mathrm{\,(stat)}\pm
2.3\kern 5.0pt\mathrm{\,(syst)}\rm\,nb.$

Taking the branching fraction ${\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$ from Belle
[12], the measured ${\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$
production cross-section at $7\mathrm{\,Te\kern-1.00006ptV}$ is consistent
with the previous LHCb measurement [38]. The ratios of the ${\mathchar
28931\relax}^{0}_{b}$ and ${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ integrated production cross-
sections between $8\mathrm{\,Te\kern-1.00006ptV}$ and
$7\mathrm{\,Te\kern-1.00006ptV}$, in the kinematic range $0<\mbox{$p_{\rm
T}$}<20{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and $2.0<y<4.5$, are

$\frac{\sigma(\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV})}{\sigma(\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV})}=\begin{cases}&1.23\pm
0.02\pm 0.04\qquad\mbox{for }{{\mathchar 28931\relax}^{0}_{b}},\\\ &1.19\pm
0.01\pm 0.02\qquad\mbox{for }{{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}},\end{cases}$

where the first uncertainties are statistical and the second systematic. Many
systematic uncertainties cancel totally or partially in these ratios: the
ratio of the luminosities is known with a precision of $1.44\%$ [36]; the
tracking efficiency is considered to be fully correlated, due to the fact that
the associated systematic uncertainty is dominated by hadronic interactions of
the tracks in the detector; the mass veto efficiency, the branching fraction
of the ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{\mu^{+}\mu^{-}}$ decay, and the S-wave contribution in the
${{K}^{-}}{{\pi}^{+}}$ system are also fully correlated. All other sources are
considered uncorrelated. The ratio of the integrated production cross-sections
agrees with FONLL predictions [48, 49, 50]. Figure 5 shows the $p_{\rm T}$ and
$y$ dependence of the ratios for ${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ production cross-sections at
$8\mathrm{\,Te\kern-1.00006ptV}$ with respect to those at
$7\mathrm{\,Te\kern-1.00006ptV}$, together with linear fits to the
distributions:

$\begin{split}&{{\mathchar 28931\relax}^{0}_{b}}\begin{cases}&(1.25\pm
0.03)+(0.003\pm 0.007)(\mbox{$p_{\rm T}$}-\left\langle\mbox{$p_{\rm
T}$}\right\rangle)/({\mathrm{Ge\kern-1.00006ptV\\!/}c})\qquad\chi^{2}/\mathrm{ndf}=6.1/8,\\\
&(1.22\pm 0.03)-(0.20\pm 0.07)(y-\left\langle y\right\rangle)\hskip
95.60127pt\chi^{2}/\mathrm{ndf}=1.2/3,\end{cases}\\\ &{{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\begin{cases}&(1.21\pm
0.01)+(0.010\pm 0.003)(\mbox{$p_{\rm T}$}-\left\langle\mbox{$p_{\rm
T}$}\right\rangle)/({\mathrm{Ge\kern-1.00006ptV\\!/}c})\qquad\chi^{2}/\mathrm{ndf}=12/8,\\\
&(1.15\pm 0.01)-(0.04\pm 0.02)(y-\left\langle y\right\rangle)\hskip
95.60127pt\chi^{2}/\mathrm{ndf}=15/3,\end{cases}\end{split}$

where $\left\langle\mbox{$p_{\rm
T}$}\right\rangle=6.7~{}(6.9){\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ is the mean
$p_{\rm T}$ of ${\mathchar 28931\relax}^{0}_{b}$ (${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$) hadrons in the data sample,
$\left\langle y\right\rangle=3.1$ is the mean $y$, and ${\rm ndf}$ is the
number of degrees of freedom. The $p_{\rm T}$ dependence of the ratio agrees
with FONLL predictions, while the $y$ dependence does not.

Figure 5:  Production ratios of (left) ${{\mathchar 28931\relax}^{0}_{b}}$ and
(right) ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ at
$8\mathrm{\,Te\kern-1.00006ptV}$ and $7\mathrm{\,Te\kern-1.00006ptV}$ as
functions of the (top) $p_{\rm T}$ and (bottom) $y$ of the $b$ hadron. The
blue lines are FONLL predictions. The error bars represent uncorrelated
uncertainties, while the hatched areas show the total uncertainties. Linear
fits are also shown.

The measured values of the ratio $R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}$, defined in Eq. 1, as a
function of $p_{\rm T}$ and $y$ are shown in Fig. 6. In the region
$\mbox{$p_{\rm T}$}<5{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$, no $p_{\rm T}$
dependence of the ratio $R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}$ is observed, while the ratio
decreases for $\mbox{$p_{\rm T}$}>5{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. No
dependence with rapidity is observed. In Fig. 6 the $p_{\rm T}$ dependence of
the ratio $R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}$ is fitted with the
fragmentation function ratio $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}(\mbox{$p_{\rm T}$})$ given in Ref. [8], which is
only defined in the range $\mbox{$p_{\rm
T}$}>3{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$.

Figure 6:  Ratio $R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}$ as a function of (left)
$p_{\rm T}$ and (right) $y$ for the 2011 and 2012 samples, where the error
bars indicate statistical uncertainties and the hatched areas the total
uncertainties. The red solid (blue dashed) line in the left plot represents
the fit to the ratio $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}(\mbox{$p_{\rm T}$})$ from Ref. [8] for the 2011
(2012) data sample.

The asymmetry $a_{\rm p+d}$ between ${{\mathchar 28931\relax}^{0}_{b}}$ and
${{\kern 1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$
is shown in Fig. 7. The values are listed in Table Acknowledgements in the
Appendix. The data points are fitted with linear functions. The slope fitted
to the asymmetry as a function of $p_{\rm T}$ is consistent with zero,
$(2.3\pm 3.0)\times 10^{-3}/({\mathrm{Ge\kern-1.00006ptV\\!/}c})$ for
$7\mathrm{\,Te\kern-1.00006ptV}$ and $(3.5\pm 2.0)\times
10^{-3}/({\mathrm{Ge\kern-1.00006ptV\\!/}c})$ for
$8\mathrm{\,Te\kern-1.00006ptV}$. The fit to $a_{\rm p+d}(y)$ gives a non-zero
slope, and a combination of the results for $7\mathrm{\,Te\kern-1.00006ptV}$
and $8\mathrm{\,Te\kern-1.00006ptV}$ gives

$a_{\rm p+d}(y)=(-0.001\pm 0.007)+(0.058\pm 0.014)(y-\left\langle
y\right\rangle),$

where $\left\langle y\right\rangle=3.1$ is the average rapidity of
${{\mathchar 28931\relax}^{0}_{b}}$ hadrons in the data sample. The non-zero
slope suggests some baryon number transport from the beam particles to the
less centrally produced ${\mathchar 28931\relax}^{0}_{b}$, which leads to a
${{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$ cross-
section ratio that increases with rapidity and which can be interpreted as,
for example, a string drag effect or leading quark effect [6, 51].

Figure 7:  Asymmetries $a_{\rm p+d}$ between ${{\mathchar
28931\relax}^{0}_{b}}$ and ${{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$ as
functions of (left) $p_{\rm T}$ and (right) $y$. The error bars indicate
statistical uncertainties, and the hatched areas the total uncertainties.

##  10 Branching fraction results

The ratio $R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}$ can be calculated in bins of
$p_{\rm T}$ as:

$R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}(\mbox{$p_{\rm
T}$})=\frac{N_{\rm sig}^{{{\mathchar 28931\relax}^{0}_{b}}}(\mbox{$p_{\rm
T}$})~{}{\varepsilon}_{\rm tot}^{{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}(\mbox{$p_{\rm T}$})}{N_{\rm
sig}^{{{\kern 1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}(\mbox{$p_{\rm
T}$})~{}{\varepsilon}_{\rm tot}^{{{\mathchar
28931\relax}^{0}_{b}}}(\mbox{$p_{\rm T}$})}~{}{\cal B}({{\kern
1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}\rightarrow{{K}^{-}}{{\pi}^{+}}).$
(7)

It is related to the fragmentation fraction ratio $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}$ through

$R_{{{\mathchar 28931\relax}^{0}_{b}}/{{\kern
1.25995pt\overline{\kern-1.25995ptB}{}}{}^{0}}}(\mbox{$p_{\rm
T}$})=\frac{{\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})}{{\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})}f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}(\mbox{$p_{\rm
T}$})\equiv{}\mathcal{S}~{}f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}(\mbox{$p_{\rm T}$}),$ (8)

where $\mathcal{S}\equiv{\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})/{\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$ is a constant
factor, which can be determined from the fit in Fig. 6. The absolute branching
fraction of the decay ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ can then be measured as

${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})=\mathcal{S}~{}{\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}).$ (9)

The average of the fit results for the $7$ and
$8\mathrm{\,Te\kern-1.00006ptV}$ samples gives ${\cal S}=0.2458\pm 0.0030$,
which results in

${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})=(3.17\pm 0.04\pm 0.07\pm 0.34^{+0.45}_{-0.28})\times
10^{-4}.$

The first uncertainty is statistical, the second is systematic, the third is
due to the uncertainty on the branching fraction of the ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ decay, and the
fourth is due to the knowledge of $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}$.

In Ref. [11] the ratio ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}})/{\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ was reported. Combining this with the value of ${\cal
B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ above, the branching fraction of ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}}$ is determined as

${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}})=(2.61\pm 0.09\pm 0.13^{+0.47}_{-0.37})\times 10^{-5},$

where the first uncertainty is statistical, the second is due to the
systematic uncertainty on ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}})/{\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$, and the third is due to systematic uncertainty on
${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$.

Two pentaquark-charmonium states, $P_{c}(4380)^{+}$ and $P_{c}(4450)^{+}$,
were observed by LHCb in the amplitude analysis of the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay [10], and the fractions $f(P_{c}^{+})$ of the two
pentaquark-charmonium states in the ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ decay were measured. Using these fractions and the value
of ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ obtained in this analysis, the branching fractions
${\cal B}({{\mathchar 28931\relax}^{0}_{b}}\rightarrow
P_{c}^{+}{{K}^{-}}){\cal
B}(P_{c}^{+}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{p})$ are
calculated as

$\displaystyle{\cal B}({{\mathchar 28931\relax}^{0}_{b}}\rightarrow
P_{c}^{+}{{K}^{-}}){\cal
B}(P_{c}^{+}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{p})$
$\displaystyle=$ $\displaystyle f(P_{c}^{+}){\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ $\displaystyle=$ $\displaystyle\begin{cases}&(2.66\pm
0.22\pm 1.33^{+0.48}_{-0.38})\times 10^{-5}\quad{\rm for}\quad
P_{c}(4380)^{+},\\\ &(1.30\pm 0.16\pm 0.35^{+0.23}_{-0.18})\times
10^{-5}\quad{\rm for}\quad P_{c}(4450)^{+},\end{cases}$

where the first uncertainty is statistical, the second is due to the
systematic uncertainty on $f(P_{c}^{+})$, and the third is due to the
systematic uncertainty on ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$.

##  11 Conclusion

Using a data sample corresponding to an integrated luminosity of
$3\mbox{\,fb}^{-1}$ collected by the LHCb detector in 2011 and 2012, the
product of the ${\mathchar 28931\relax}^{0}_{b}$ differential production
cross-section and the branching fraction of the decay ${{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}}$ is measured as a function of the ${{\mathchar
28931\relax}^{0}_{b}}$ baryon’s transverse momentum and rapidity. The product
of the ${\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ differential
production cross-section and the branching fraction of the decay ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}$ is also
measured. The kinematic region of the measurements is $\mbox{$p_{\rm
T}$}<20{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$ and $2.0<y<4.5$.

The ratios of the cross-sections at $\sqrt{s}=8\mathrm{\,Te\kern-1.00006ptV}$
to those at $\sqrt{s}=7\mathrm{\,Te\kern-1.00006ptV}$ are calculated for
${\mathchar 28931\relax}^{0}_{b}$ and ${\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ hadrons and are compared with
FONLL predictions. The $p_{\rm T}$ dependence of the ratios is consistent with
the FONLL calculations, while the $y$ dependence is not consistent. The
production ratios of the ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$ hadrons are given for the 2011
and 2012 samples separately, and are consistent with the dependence on $p_{\rm
T}$ and $y$ of the $b$ hadron observed in a previous LHCb analysis. The
asymmetry $a_{\rm p+d}$ between ${{\mathchar 28931\relax}^{0}_{b}}$ and
${{\kern 1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$
is also measured as a function of $p_{\rm T}$ and $y$. The result suggests
some baryon number transport from the beam particles to the ${\mathchar
28931\relax}^{0}_{b}$ baryons.

Using information on the fragmentation ratio $f_{{{\mathchar
28931\relax}^{0}_{b}}}/f_{d}$ from a previous LHCb measurement, the absolute
branching fraction ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ is obtained. Using previous LHCb measurements, the
branching fractions ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{\pi}^{-}})$ and ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow P_{c}^{+}{{K}^{-}}){\cal
B}(P_{c}^{+}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}{p})$ are
determined.

## Acknowledgements

We thank J. L. Rosner for interesting discussions of asymmetry in beauty
baryon production. We express our gratitude to our colleagues in the CERN
accelerator departments for the excellent performance of the LHC. We thank the
technical and administrative staff at the LHCb institutes. We acknowledge
support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and
FINEP (Brazil); NSFC (China); CNRS/IN2P3 (France); BMBF, DFG, HGF and MPG
(Germany); INFN (Italy); FOM and NWO (The Netherlands); MNiSW and NCN
(Poland); MEN/IFA (Romania); MinES and FANO (Russia); MinECo (Spain); SNSF and
SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). The Tier1
computing centres are supported by IN2P3 (France), KIT and BMBF (Germany),
INFN (Italy), NWO and SURF (The Netherlands), PIC (Spain), GridPP (United
Kingdom). We are indebted to the communities behind the multiple open source
software packages on which we depend. We are also thankful for the computing
resources and the access to software R&D tools provided by Yandex LLC
(Russia). Individual groups or members have received support from EPLANET,
Marie Skłodowska-Curie Actions and ERC (European Union), Conseil général de
Haute-Savoie, Labex ENIGMASS and OCEVU, Région Auvergne (France), RFBR
(Russia), XuntaGal and GENCAT (Spain), Royal Society and Royal Commission for
the Exhibition of 1851 (United Kingdom).

Appendix

Table 3:  Products of ${\mathchar 28931\relax}^{0}_{b}$ production cross-
sections ($\rm pb$) and the branching fraction ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ in bins of $p_{\rm T}$ and $y$ in the 2011 data sample.
The first uncertainties are statistical and the second are systematic.

$\mbox{$p_{\rm T}$}[{\mathrm{\,Ge\kern-1.00006ptV\\!/}c}]$ | $2.0<y<2.5$ | $2.5<y<3.0$ | $3.0<y<3.5$
---|---|---|---
$0-3$ | $326\pm 42\pm 44$ | $354\pm 18\pm 23$ | $319\pm 14\pm 20$
$3-4$ | $439\pm 58\pm 54$ | $503\pm 27\pm 33$ | $486\pm 22\pm 31$
$4-5$ | $445\pm 48\pm 48$ | $425\pm 21\pm 27$ | $376\pm 17\pm 22$
$5-6$ | $411\pm 39\pm 45$ | $297\pm 15\pm 17$ | $296\pm 13\pm 17$
$6-7$ | $224\pm 23\pm 24$ | $235\pm 12\pm 14$ | $203\pm 10\pm 12$
$7-8$ | $162\pm 17\pm 16$ | $175\pm\kern 5.0pt9\pm 11$ | $145\pm 7.4\pm 9.2$
$8-9$ | $100\pm 12\pm\kern 5.0pt9$ | $109\pm 6.5\pm 7.0$ | $92.7\pm 5.5\pm 6.3$
$9-10$ | $83.2\pm 9.7\pm 8.1$ | $93.6\pm 6.0\pm 6.4$ | $63.6\pm 4.4\pm 4.6$
$10-12$ | $53.6\pm 4.6\pm 4.3$ | $39.5\pm 2.3\pm 2.4$ | $29.0\pm 1.8\pm 1.9$
$12-20$ | $11.4\pm 0.8\pm 0.7$ | $11.3\pm 0.6\pm 0.6$ | $8.6\pm 0.6\pm 0.6$
| $3.5<y<4.0$ | $4.0<y<4.5$ |
$0-3$ | $244\pm 13\pm 19$ | $221\pm 26\pm 35$ |
$3-4$ | $371\pm 21\pm 32$ | $231\pm 29\pm 38$ |
$4-5$ | $294\pm 16\pm 22$ | $138\pm 18\pm 19$ |
$5-6$ | $229\pm 12\pm 17$ | $\kern 5.0pt95\pm 14\pm 16$ |
$6-7$ | $151\pm\kern 5.0pt9\pm 12$ | $\kern 5.0pt61\pm 11\pm\kern 5.0pt8$ |
$7-8$ | $99.0\pm 6.5\pm 8.1$ | $38.4\pm 0.8\pm 6.2$ |
$8-9$ | $69.0\pm 5.3\pm 5.9$ | $37.7\pm 7.7\pm 5.9$ |
$9-10$ | $43.3\pm 4.1\pm 4.2$ | $22.8\pm 5.8\pm 4.0$ |
$10-12$ | $20.4\pm 1.9\pm 1.7$ | $\kern 5.0pt7.8\pm 1.8\pm 1.2$ |
$12-20$ | $\kern 5.0pt4.0\pm 0.4\pm 0.4$ | $\kern 5.0pt2.2\pm 0.6\pm 0.5$ |

Table 4:  Products of ${\mathchar 28931\relax}^{0}_{b}$ production cross-
sections ($\rm pb$) and the branching fraction ${\cal B}({{\mathchar
28931\relax}^{0}_{b}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{p}{{K}^{-}})$ in bins of $p_{\rm T}$ and $y$ in the 2012 data sample.
The first uncertainties are statistical and the second are systematic.  Table
6:  Products of ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}$
production cross-sections ($\rm pb$) and ${\cal B}({{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}})$ in bins of
$p_{\rm T}$ and $y$ in the 2012 data sample. The first uncertainties are
statistical and the second are systematic.  Table 7:  Asymmetries $a_{\rm
p+d}$ $(\%)$ of ${{\mathchar 28931\relax}^{0}_{b}}$ and ${{\kern
1.00006pt\overline{\kern-1.00006pt\mathchar 28931\relax}}{}^{0}_{b}}$ in bins
of $p_{\rm T}$ and $y$ for the 2011 and 2012 samples. The first uncertainties
are statistical and the second are systematic.

$2.0<y<2.5$ $-6.0\pm 3.3\pm 3.1$ $-7.6\pm 2.0\pm 1.2$ $2.5<y<3.0$ $-0.3\pm
1.7\pm 2.1$ $-0.3\pm 1.1\pm 0.9$ $3.0<y<3.5$ $-1.0\pm 1.6\pm 1.1$ $+0.7\pm
1.1\pm 1.0$ $3.5<y<4.0$ $+4.3\pm 2.1\pm 1.1$ $+2.4\pm 1.5\pm 1.2$ $4.0<y<4.5$
$+7.3\pm 5.4\pm 2.2$ $+8.4\pm 3.7\pm 1.9$

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LHCb collaboration

R. Aaij38, B. Adeva37, M. Adinolfi46, A. Affolder52, Z. Ajaltouni5, S. Akar6,
J. Albrecht9, F. Alessio38, M. Alexander51, S. Ali41, G. Alkhazov30, P.
Alvarez Cartelle53, A.A. Alves Jr57, S. Amato2, S. Amerio22, Y. Amhis7, L.
An3, L. Anderlini17, J. Anderson40, G. Andreassi39, M. Andreotti16,f, J.E.
Andrews58, R.B. Appleby54, O. Aquines Gutierrez10, F. Archilli38, P.
d’Argent11, A. Artamonov35, M. Artuso59, E. Aslanides6, G. Auriemma25,m, M.
Baalouch5, S. Bachmann11, J.J. Back48, A. Badalov36, C. Baesso60, W.
Baldini16,38, R.J. Barlow54, C. Barschel38, S. Barsuk7, W. Barter38, V.
Batozskaya28, V. Battista39, A. Bay39, L. Beaucourt4, J. Beddow51, F.
Bedeschi23, I. Bediaga1, L.J. Bel41, V. Bellee39, N. Belloli20,j, I.
Belyaev31, E. Ben-Haim8, G. Bencivenni18, S. Benson38, J. Benton46, A.
Berezhnoy32, R. Bernet40, A. Bertolin22, M.-O. Bettler38, M. van Beuzekom41,
A. Bien11, S. Bifani45, P. Billoir8, T. Bird54, A. Birnkraut9, A. Bizzeti17,h,
T. Blake48, F. Blanc39, J. Blouw10, S. Blusk59, V. Bocci25, A. Bondar34, N.
Bondar30,38, W. Bonivento15, S. Borghi54, M. Borsato7, T.J.V. Bowcock52, E.
Bowen40, C. Bozzi16, S. Braun11, M. Britsch10, T. Britton59, J. Brodzicka54,
N.H. Brook46, E. Buchanan46, A. Bursche40, J. Buytaert38, S. Cadeddu15, R.
Calabrese16,f, M. Calvi20,j, M. Calvo Gomez36,o, P. Campana18, D. Campora
Perez38, L. Capriotti54, A. Carbone14,d, G. Carboni24,k, R. Cardinale19,i, A.
Cardini15, P. Carniti20,j, L. Carson50, K. Carvalho Akiba2,38, G. Casse52, L.
Cassina20,j, L. Castillo Garcia38, M. Cattaneo38, Ch. Cauet9, G. Cavallero19,
R. Cenci23,s, M. Charles8, Ph. Charpentier38, M. Chefdeville4, S. Chen54,
S.-F. Cheung55, N. Chiapolini40, M. Chrzaszcz40, X. Cid Vidal38, G.
Ciezarek41, P.E.L. Clarke50, M. Clemencic38, H.V. Cliff47, J. Closier38, V.
Coco38, J. Cogan6, E. Cogneras5, V. Cogoni15,e, L. Cojocariu29, G.
Collazuol22, P. Collins38, A. Comerma-Montells11, A. Contu15,38, A. Cook46, M.
Coombes46, S. Coquereau8, G. Corti38, M. Corvo16,f, B. Couturier38, G.A.
Cowan50, D.C. Craik48, A. Crocombe48, M. Cruz Torres60, S. Cunliffe53, R.
Currie53, C. D’Ambrosio38, E. Dall’Occo41, J. Dalseno46, P.N.Y. David41, A.
Davis57, K. De Bruyn6, S. De Capua54, M. De Cian11, J.M. De Miranda1, L. De
Paula2, P. De Simone18, C.-T. Dean51, D. Decamp4, M. Deckenhoff9, L. Del
Buono8, N. Déléage4, M. Demmer9, D. Derkach65, O. Deschamps5, F. Dettori38, B.
Dey21, A. Di Canto38, F. Di Ruscio24, H. Dijkstra38, S. Donleavy52, F.
Dordei11, M. Dorigo39, A. Dosil Suárez37, D. Dossett48, A. Dovbnya43, K.
Dreimanis52, L. Dufour41, G. Dujany54, F. Dupertuis39, P. Durante38, R.
Dzhelyadin35, A. Dziurda26, A. Dzyuba30, S. Easo49,38, U. Egede53, V.
Egorychev31, S. Eidelman34, S. Eisenhardt50, U. Eitschberger9, R. Ekelhof9, L.
Eklund51, I. El Rifai5, Ch. Elsasser40, S. Ely59, S. Esen11, H.M. Evans47, T.
Evans55, A. Falabella14, C. Färber38, N. Farley45, S. Farry52, R. Fay52, D.
Ferguson50, V. Fernandez Albor37, F. Ferrari14, F. Ferreira Rodrigues1, M.
Ferro-Luzzi38, S. Filippov33, M. Fiore16,38,f, M. Fiorini16,f, M. Firlej27, C.
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Fontanelli19,i, R. Forty38, O. Francisco2, M. Frank38, C. Frei38, M.
Frosini17, J. Fu21, E. Furfaro24,k, A. Gallas Torreira37, D. Galli14,d, S.
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Pardiñas37, J. Garra Tico47, L. Garrido36, D. Gascon36, C. Gaspar38, R.
Gauld55, L. Gavardi9, G. Gazzoni5, D. Gerick11, E. Gersabeck11, M.
Gersabeck54, T. Gershon48, Ph. Ghez4, S. Gianì39, V. Gibson47, O. G. Girard39,
L. Giubega29, V.V. Gligorov38, C. Göbel60, D. Golubkov31, A. Golutvin53,31,38,
A. Gomes1,a, C. Gotti20,j, M. Grabalosa Gándara5, R. Graciani Diaz36, L.A.
Granado Cardoso38, E. Graugés36, E. Graverini40, G. Graziani17, A. Grecu29, E.
Greening55, S. Gregson47, P. Griffith45, L. Grillo11, O. Grünberg63, B. Gui59,
E. Gushchin33, Yu. Guz35,38, T. Gys38, T. Hadavizadeh55, C. Hadjivasiliou59,
G. Haefeli39, C. Haen38, S.C. Haines47, S. Hall53, B. Hamilton58, X. Han11, S.
Hansmann-Menzemer11, N. Harnew55, S.T. Harnew46, J. Harrison54, J. He38, T.
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Hulsbergen41, T. Humair53, N. Hussain55, D. Hutchcroft52, D. Hynds51, M.
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Jawahery58, F. Jing3, M. John55, D. Johnson38, C.R. Jones47, C. Joram38, B.
Jost38, N. Jurik59, S. Kandybei43, W. Kanso6, M. Karacson38, T.M. Karbach38,†,
S. Karodia51, M. Kecke11, M. Kelsey59, I.R. Kenyon45, M. Kenzie38, T. Ketel42,
B. Khanji20,38,j, C. Khurewathanakul39, S. Klaver54, K. Klimaszewski28, O.
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Krokovny34, F. Kruse9, W. Krzemien28, W. Kucewicz26,n, M. Kucharczyk26, V.
Kudryavtsev34, A. K. Kuonen39, K. Kurek28, T. Kvaratskheliya31, D.
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Langenbruch48, B. Langhans38, T. Latham48, C. Lazzeroni45, R. Le Gac6, J. van
Leerdam41, J.-P. Lees4, R. Lefèvre5, A. Leflat32,38, J. Lefrançois7, E. Lemos
Cid37, O. Leroy6, T. Lesiak26, B. Leverington11, Y. Li7, T. Likhomanenko65,64,
M. Liles52, R. Lindner38, C. Linn38, F. Lionetto40, B. Liu15, X. Liu3, D.
Loh48, I. Longstaff51, J.H. Lopes2, D. Lucchesi22,q, M. Lucio Martinez37, H.
Luo50, A. Lupato22, E. Luppi16,f, O. Lupton55, A. Lusiani23, F. Machefert7, F.
Maciuc29, O. Maev30, K. Maguire54, S. Malde55, A. Malinin64, G. Manca7, G.
Mancinelli6, P. Manning59, A. Mapelli38, J. Maratas5, J.F. Marchand4, U.
Marconi14, C. Marin Benito36, P. Marino23,38,s, J. Marks11, G. Martellotti25,
M. Martin6, M. Martinelli39, D. Martinez Santos37, F. Martinez Vidal66, D.
Martins Tostes2, A. Massafferri1, R. Matev38, A. Mathad48, Z. Mathe38, C.
Matteuzzi20, A. Mauri40, B. Maurin39, A. Mazurov45, M. McCann53, J.
McCarthy45, A. McNab54, R. McNulty12, B. Meadows57, F. Meier9, M. Meissner11,
D. Melnychuk28, M. Merk41, E Michielin22, D.A. Milanes62, M.-N. Minard4, D.S.
Mitzel11, J. Molina Rodriguez60, I.A. Monroy62, S. Monteil5, M. Morandin22, P.
Morawski27, A. Mordà6, M.J. Morello23,s, J. Moron27, A.B. Morris50, R.
Mountain59, F. Muheim50, D. Müller54, J. Müller9, K. Müller40, V. Müller9, M.
Mussini14, B. Muster39, P. Naik46, T. Nakada39, R. Nandakumar49, A. Nandi55,
I. Nasteva2, M. Needham50, N. Neri21, S. Neubert11, N. Neufeld38, M. Neuner11,
A.D. Nguyen39, T.D. Nguyen39, C. Nguyen-Mau39,p, V. Niess5, R. Niet9, N.
Nikitin32, T. Nikodem11, D. Ninci23, A. Novoselov35, D.P. O’Hanlon48, A.
Oblakowska-Mucha27, V. Obraztsov35, S. Ogilvy51, O. Okhrimenko44, R.
Oldeman15,e, C.J.G. Onderwater67, B. Osorio Rodrigues1, J.M. Otalora
Goicochea2, A. Otto38, P. Owen53, A. Oyanguren66, A. Palano13,c, F.
Palombo21,t, M. Palutan18, J. Panman38, A. Papanestis49, M. Pappagallo51, L.L.
Pappalardo16,f, C. Pappenheimer57, C. Parkes54, G. Passaleva17, G.D. Patel52,
M. Patel53, C. Patrignani19,i, A. Pearce54,49, A. Pellegrino41, G. Penso25,l,
M. Pepe Altarelli38, S. Perazzini14,d, P. Perret5, L. Pescatore45, K.
Petridis46, A. Petrolini19,i, M. Petruzzo21, E. Picatoste Olloqui36, B.
Pietrzyk4, T. Pilař48, D. Pinci25, A. Pistone19, A. Piucci11, S. Playfer50, M.
Plo Casasus37, T. Poikela38, F. Polci8, A. Poluektov48,34, I. Polyakov31, E.
Polycarpo2, A. Popov35, D. Popov10,38, B. Popovici29, C. Potterat2, E.
Price46, J.D. Price52, J. Prisciandaro39, A. Pritchard52, C. Prouve46, V.
Pugatch44, A. Puig Navarro39, G. Punzi23,r, W. Qian4, R. Quagliani7,46, B.
Rachwal26, J.H. Rademacker46, M. Rama23, M.S. Rangel2, I. Raniuk43, N.
Rauschmayr38, G. Raven42, F. Redi53, S. Reichert54, M.M. Reid48, A.C. dos
Reis1, S. Ricciardi49, S. Richards46, M. Rihl38, K. Rinnert52, V. Rives
Molina36, P. Robbe7,38, A.B. Rodrigues1, E. Rodrigues54, J.A. Rodriguez
Lopez62, P. Rodriguez Perez54, S. Roiser38, V. Romanovsky35, A. Romero
Vidal37, J. W. Ronayne12, M. Rotondo22, J. Rouvinet39, T. Ruf38, P. Ruiz
Valls66, J.J. Saborido Silva37, N. Sagidova30, P. Sail51, B. Saitta15,e, V.
Salustino Guimaraes2, C. Sanchez Mayordomo66, B. Sanmartin Sedes37, R.
Santacesaria25, C. Santamarina Rios37, M. Santimaria18, E. Santovetti24,k, A.
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Zhelezov11, A. Zhokhov31, L. Zhong3, S. Zucchelli14.

2Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil 3Center
for High Energy Physics, Tsinghua University, Beijing, China 4LAPP, Université
Savoie Mont-Blanc, CNRS/IN2P3, Annecy-Le-Vieux, France 5Clermont Université,
Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France 6CPPM,
Aix-Marseille Université, CNRS/IN2P3, Marseille, France 7LAL, Université
Paris-Sud, CNRS/IN2P3, Orsay, France 8LPNHE, Université Pierre et Marie Curie,
Université Paris Diderot, CNRS/IN2P3, Paris, France 9Fakultät Physik,
Technische Universität Dortmund, Dortmund, Germany 10Max-Planck-Institut für
Kernphysik (MPIK), Heidelberg, Germany 11Physikalisches Institut, Ruprecht-
Karls-Universität Heidelberg, Heidelberg, Germany 12School of Physics,
University College Dublin, Dublin, Ireland 13Sezione INFN di Bari, Bari, Italy
14Sezione INFN di Bologna, Bologna, Italy 15Sezione INFN di Cagliari,
Cagliari, Italy 16Sezione INFN di Ferrara, Ferrara, Italy 17Sezione INFN di
Firenze, Firenze, Italy 18Laboratori Nazionali dell’INFN di Frascati,
Frascati, Italy 19Sezione INFN di Genova, Genova, Italy 20Sezione INFN di
Milano Bicocca, Milano, Italy 21Sezione INFN di Milano, Milano, Italy
22Sezione INFN di Padova, Padova, Italy 23Sezione INFN di Pisa, Pisa, Italy
24Sezione INFN di Roma Tor Vergata, Roma, Italy 25Sezione INFN di Roma La
Sapienza, Roma, Italy 26Henryk Niewodniczanski Institute of Nuclear Physics
Polish Academy of Sciences, Kraków, Poland 27AGH - University of Science and
Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland
28National Center for Nuclear Research (NCBJ), Warsaw, Poland 29Horia Hulubei
National Institute of Physics and Nuclear Engineering, Bucharest-Magurele,
Romania 30Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia
31Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
32Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow,
Russia 33Institute for Nuclear Research of the Russian Academy of Sciences
(INR RAN), Moscow, Russia 34Budker Institute of Nuclear Physics (SB RAS) and
Novosibirsk State University, Novosibirsk, Russia 35Institute for High Energy
Physics (IHEP), Protvino, Russia 36Universitat de Barcelona, Barcelona, Spain
37Universidad de Santiago de Compostela, Santiago de Compostela, Spain
38European Organization for Nuclear Research (CERN), Geneva, Switzerland
39Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
40Physik-Institut, Universität Zürich, Zürich, Switzerland 41Nikhef National
Institute for Subatomic Physics, Amsterdam, The Netherlands 42Nikhef National
Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, The
Netherlands 43NSC Kharkiv Institute of Physics and Technology (NSC KIPT),
Kharkiv, Ukraine 44Institute for Nuclear Research of the National Academy of
Sciences (KINR), Kyiv, Ukraine 45University of Birmingham, Birmingham, United
Kingdom 46H.H. Wills Physics Laboratory, University of Bristol, Bristol,
United Kingdom 47Cavendish Laboratory, University of Cambridge, Cambridge,
United Kingdom 48Department of Physics, University of Warwick, Coventry,
United Kingdom 49STFC Rutherford Appleton Laboratory, Didcot, United Kingdom
50School of Physics and Astronomy, University of Edinburgh, Edinburgh, United
Kingdom 51School of Physics and Astronomy, University of Glasgow, Glasgow,
United Kingdom 52Oliver Lodge Laboratory, University of Liverpool, Liverpool,
United Kingdom 53Imperial College London, London, United Kingdom 54School of
Physics and Astronomy, University of Manchester, Manchester, United Kingdom
55Department of Physics, University of Oxford, Oxford, United Kingdom
56Massachusetts Institute of Technology, Cambridge, MA, United States
57University of Cincinnati, Cincinnati, OH, United States 58University of
Maryland, College Park, MD, United States 59Syracuse University, Syracuse, NY,
United States 60Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio),
Rio de Janeiro, Brazil, associated to 2 61Institute of Particle Physics,
Central China Normal University, Wuhan, Hubei, China, associated to 3
62Departamento de Fisica , Universidad Nacional de Colombia, Bogota, Colombia,
associated to 8 63Institut für Physik, Universität Rostock, Rostock, Germany,
associated to 11 64National Research Centre Kurchatov Institute, Moscow,
Russia, associated to 31 65Yandex School of Data Analysis, Moscow, Russia,
associated to 31 66Instituto de Fisica Corpuscular (IFIC), Universitat de
Valencia-CSIC, Valencia, Spain, associated to 36 67Van Swinderen Institute,
University of Groningen, Groningen, The Netherlands, associated to 41
aUniversidade Federal do Triângulo Mineiro (UFTM), Uberaba-MG, Brazil bP.N.
Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow,
Russia cUniversità di Bari, Bari, Italy dUniversità di Bologna, Bologna, Italy
eUniversità di Cagliari, Cagliari, Italy fUniversità di Ferrara, Ferrara,
Italy gUniversità di Urbino, Urbino, Italy hUniversità di Modena e Reggio
Emilia, Modena, Italy iUniversità di Genova, Genova, Italy jUniversità di
Milano Bicocca, Milano, Italy kUniversità di Roma Tor Vergata, Roma, Italy
lUniversità di Roma La Sapienza, Roma, Italy mUniversità della Basilicata,
Potenza, Italy nAGH - University of Science and Technology, Faculty of
Computer Science, Electronics and Telecommunications, Kraków, Poland oLIFAELS,
La Salle, Universitat Ramon Llull, Barcelona, Spain pHanoi University of
Science, Hanoi, Viet Nam qUniversità di Padova, Padova, Italy rUniversità di
Pisa, Pisa, Italy sScuola Normale Superiore, Pisa, Italy tUniversità degli
Studi di Milano, Milano, Italy †Deceased