EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH (CERN)

 CERN-PH-EP-2014-185 LHCb-PAPER-2014-043 10 October 2014

Observation of $B^{0}_{s}\rightarrow K^{*\pm}K^{\mp}$ and evidence for
$B^{0}_{s}\rightarrow K^{*-}\pi^{+}$ decays

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

Measurements of the branching fractions of $B^{0}_{s}\rightarrow
K^{*\pm}K^{\mp}$ and $B^{0}_{s}\rightarrow K^{*\pm}\pi^{\mp}$ decays are
performed using a data sample corresponding to $1.0\ {\rm fb}^{-1}$ of proton-
proton collision data collected with the LHCb detector at a centre-of-mass
energy of $7\mathrm{\,Te\kern-1.00006ptV}$, where the $K^{*\pm}$ mesons are
reconstructed in the ${{K}^{0}_{\rm\scriptscriptstyle S}}\pi^{\pm}$ final
state. The first observation of the $B^{0}_{s}\rightarrow K^{*\pm}K^{\mp}$
decay and the first evidence for the $B^{0}_{s}\rightarrow K^{*-}\pi^{+}$
decay are reported with branching fractions

$\displaystyle{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)$
$\displaystyle=$ $\displaystyle\left(12.7\pm 1.9\pm 1.9\right)\times
10^{-6}\,,$ $\displaystyle{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}\right)$
$\displaystyle=$ $\displaystyle~{}\left(3.3\pm 1.1\pm 0.5\right)\times
10^{-6}\,,$

where the first uncertainties are statistical and the second are systematic.
In addition, an upper limit of ${\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)<0.4\ (0.5)\times
10^{-6}$ is set at $90\,\%\ (95\,\%)$ confidence level.

Published in New J. Phys.

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

##  1 Introduction

The Standard Model (SM) of particle physics predicts that all manifestations
of $C\\!P$ violation, i.e. violation of symmetry under the combined charge
conjugation and parity operation, arise due to the single complex phase that
appears in the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix [1, 2].
Since this source is not sufficient to account for the level of the baryon
asymmetry of the Universe [3], one of the key goals of contemporary particle
physics is to search for signatures of $C\\!P$ violation that are not
consistent with the CKM paradigm.

Among the most important areas being explored in quark flavour physics is the
study of $B$ meson decays to hadronic final states that do not contain charm
quarks or antiquarks (hereafter referred to as “charmless”). As shown in Fig.
1, such decays have, in general, amplitudes that contain contributions from
both “tree” and “loop” diagrams (see, e.g., Ref. [4]). The phase differences
between the two amplitudes can lead to $C\\!P$ violation and, since particles
hypothesised in extensions to the SM may affect the loop diagrams, deviations
from the SM predictions may occur. Large $C\\!P$ violation effects, i.e.
asymmetries of ${\cal O}(10\,\%)$ or more between the rates of ${{\kern
1.79993pt\overline{\kern-1.79993ptB}{}}}$ and $B$ meson decays to $C\\!P$
conjugate final states, have been seen in
$B^{0}\rightarrow{{K}^{+}}{{\pi}^{-}}$[5, 6, 7, 8],
${{B}^{0}_{s}}\rightarrow{{K}^{-}}{{\pi}^{+}}$[7, 8], and
${{{B}^{+}}}\rightarrow{{\pi}^{+}}{{\pi}^{-}}{{K}^{+}}$,
${{K}^{+}}{{K}^{-}}{{K}^{+}}$, ${{\pi}^{+}}{{\pi}^{-}}{{\pi}^{+}}$ and
${{K}^{+}}{{K}^{-}}{{\pi}^{+}}$ decays [9, 10, 11]. However, it is hard to be
certain whether these measurements are consistent with the SM predictions due
to the presence of parameters describing the hadronic interactions that are
difficult to determine either theoretically or from data.

Figure 1: (a) Tree and (b) loop diagrams for the decay
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*+}}{{K}^{-}}$.

An interesting approach to control the hadronic uncertainties is to exploit
amplitude analysis techniques. For example, by studying the distribution of
kinematic configurations of
${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ decays across the Dalitz plot [12], the relative
phase between the $K^{*+}{{\pi}^{-}}$ and ${{K}^{0}_{\rm\scriptscriptstyle
S}}\rho^{0}$ amplitudes can be determined. This information is not accessible
in studies either of two-body decays, or of the inclusive properties of three-
body decays. Consequently, it may be possible to make more sensitive tests of
the SM by studying decays to final states having contributions from
intermediate states with one vector and one pseudoscalar meson (VP), rather
than in those with two pseudoscalars.

Several methods to test the SM with $B$ meson decays to charmless VP
($K^{*}\pi$ and $K\rho$) states have been proposed [13, 14, 15, 16, 17, 18].
The experimental inputs needed for these methods are the magnitudes and
relative phases of the decay amplitudes. Although the phases can only be
obtained from Dalitz plot analyses of $B$ meson decays to final states
containing one kaon and two pions, the magnitudes can be obtained from
simplified approaches. Dalitz plot analyses have been performed for the decays
${{{B}^{+}}}\rightarrow{{K}^{+}}{{\pi}^{+}}{{\pi}^{-}}$ [19, 20],
${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ [21, 22] and
${{B}^{0}}\rightarrow{{K}^{+}}{{\pi}^{-}}{{\pi}^{0}}$ [23]. Decays of $B$
mesons to $K^{*}K$ final states can in principle be studied with similar
methods, but the existing experimental results are less precise [24, 25, 26,
27, 28, 29]. No previous measurements of ${B}^{0}_{s}$ meson decays to
charmless VP final states exist. First results from the LHCb collaboration on
inclusive three-body charmless ${B}^{0}_{s}$ decays have recently become
available [30], but no attempt has previously been made to separate the
different resonant and nonresonant contributions to their Dalitz plots.

In this paper, the first measurements of ${B}^{0}_{s}$ meson decays to
${{K}^{*-}}{{\pi}^{+}}$ and ${{K}^{*\pm}}{{K}^{\mp}}$ final states and of the
${{B}^{0}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ rate are reported. Throughout
the remainder of the paper the symbol ${{K}^{*}}$ is used to denote the
${{K}^{*}}(892)$ resonance. Unique charge assignments of the final state
particles are specified in the expression
${{B}^{0}_{s}}\rightarrow{{K}^{*-}}{{\pi}^{+}}$ because the amplitude for
${{B}^{0}_{s}}\rightarrow{{K}^{*+}}{{\pi}^{-}}$ is expected to be negligibly
small; however, the inclusion of charge-conjugate processes is implied
throughout the paper. The branching fractions are measured relative to that of
the ${{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}$ decay, which is known from
previous measurements, ${\cal
B}\left({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)=\left(8.5\pm
0.7\right)\times 10^{-6}$ [31]. Each of the relative branching fractions for
${{B}^{0}_{s}}\rightarrow{{K}^{*\pm}}h^{\mp}$, where $h$ refers either to a
pion or kaon, are determined as

$\frac{{\cal B}\left(B^{0}_{s}\rightarrow{{K}^{*\pm}}h^{\mp}\right)}{{\cal
B}\left({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}=\frac{f_{d}}{f_{s}}\,\frac{\epsilon({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}})}{\epsilon(B^{0}_{s}\rightarrow{{K}^{*\pm}}h^{\mp})}\,\frac{N(B^{0}_{s}\rightarrow{{K}^{*\pm}}h^{\mp})}{N({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}})}\,,$
(1)

while that for ${{B}^{0}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ is determined as

$\frac{{\cal B}\left({{B}^{0}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)}{{\cal
B}\left({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}=\frac{\epsilon({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}})}{\epsilon({{B}^{0}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}})}\,\frac{N({{B}^{0}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}})}{N({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}})}\,,$
(2)

where $N$ are signal yields obtained from data, $\epsilon$ are efficiencies
obtained from simulation and corrected for known discrepancies between data
and simulation, and the ratio of fragmentation fractions $f_{s}/f_{d}=0.259\pm
0.015$ [32, 33, 34]. With this approach, several potentially large systematic
uncertainties cancel in the ratios. The ${K}^{*\pm}$ mesons are reconstructed
in their decays to ${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}$ with
${{K}^{0}_{\rm\scriptscriptstyle S}}\rightarrow{{\pi}^{+}}{{\pi}^{-}}$ and
therefore the final states ${{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}}h^{\mp}$, as well as the data sample, are identical to those
studied in Ref. [30].

Although the analysis shares several common features to that of the previous
publication [30], the selection is optimised independently based on the
expected level of background within the allowed
${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}$ mass window. The data
sample used is too small for a detailed Dalitz plot analysis, and therefore
only branching fractions are measured. The fit used to distinguish signal from
background is an unbinned maximum likelihood fit in the two dimensions of $B$
candidate and $K^{*}$ candidate invariant masses. This approach allows the
resonant ${B}\rightarrow{{K}^{*\pm}}h^{\mp}$ decay to be separated from other
$B$ meson decays to the ${{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}}h^{\mp}$ final state. It does not, however, account for
interference effects between the ${{K}^{*\pm}}h^{\mp}$ component and other
amplitudes contributing to the Dalitz plot; possible biases due to
interference are considered as a source of systematic uncertainty.

##  2 The LHCb detector

The analysis is based on a data sample corresponding to an integrated
luminosity of $1.0\mbox{\,fb}^{-1}$ of $pp$ collisions at a centre-of-mass
energy of $7\mathrm{\,Te\kern-1.00006ptV}$ recorded with the LHCb detector at
CERN. The LHCb detector [35] 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 (VELO) [36] surrounding
the $pp$ interaction region, 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 [37] placed
downstream. The tracking system provides a momentum measurement with relative
uncertainty that varies from 0.4 % at low momentum to 0.6 % at
100${\mathrm{\,Ge\kern-1.00006ptV\\!/}c}$. The minimum distance of a track to
a primary vertex, the impact parameter, is measured with resolution of
$20{\,\upmu\rm m}$ for tracks with large momentum transverse to the beamline
($p_{\rm T}$). Different types of charged hadrons are distinguished using
information from two ring-imaging Cherenkov detectors [38]. Photon, electron
and hadron candidates 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 [39].

The trigger [40] consists of hardware and software stages. The hadron trigger
at the hardware stage requires that there is at least one particle with
transverse energy $\mbox{$E_{\rm T}$}>3.5\mathrm{\,Ge\kern-1.00006ptV}$.
Events containing candidate signal decays are required to have been triggered
at the hardware level in one of two ways. Events in the first category are
triggered by particles from candidate signal decays that have an associated
calorimeter energy deposit above the threshold, while those in the second
category are triggered independently of the particles associated with the
signal decay. Events that do not fall into either of these categories are not
used in the subsequent analysis. The software trigger requires a two-, three-
or four-track secondary vertex with a large sum of the $p_{\rm T}$ of the
tracks and a significant displacement from the primary $pp$ interaction
vertices (PVs). A multivariate algorithm [41] is used for the identification
of secondary vertices consistent with the decay of a $b$ hadron.

Simulated events are used to study the detector response to signal decays and
to investigate potential sources of background. In the simulation, $pp$
collisions are generated using Pythia [42] with a specific LHCb configuration
[43]. Decays of hadronic particles are described by EvtGen [44], in which
final state radiation is generated using Photos [45]. The interaction of the
generated particles with the detector and its response are implemented using
the Geant4 toolkit [46, *Agostinelli:2002hh] as described in Ref. [48].

##  3 Selection requirements

The trigger and preselection requirements are identical to those in Ref. [30].
As in that analysis, and those of other final states containing
${K}^{0}_{\rm\scriptscriptstyle S}$ mesons [49, 50, 51, 52, 53], candidate
signal decays, i.e. combinations of tracks that are consistent with the signal
hypothesis, are separated into two categories: “long”, where both tracks from
the ${{K}^{0}_{\rm\scriptscriptstyle S}}\rightarrow{{\pi}^{+}}{{\pi}^{-}}$
decay contain hits in the VELO, and “downstream”, where neither does. Both
categories have associated hits in the tracking detectors downstream of the
magnet. Since long candidates have better mass, momentum and vertex
resolution, different selection requirements are imposed for the two
categories.

The two tracks originating from the $B$ decay vertex, referred to hereafter as
“bachelor” tracks, are required not to have associated hits in the muon
system. Backgrounds from decays with charm or charmonia in the intermediate
state are vetoed by removing candidates with two-body invariant mass under the
appropriate final state hypothesis within
$30{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$ of the known masses [54]. Vetoes
are applied for ${{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip
2.0mu}}\rightarrow{{\pi}^{+}}{{\pi}^{-}}$ or ${{K}^{+}}{{K}^{-}}$,
$\chi_{c0}\rightarrow{{\pi}^{+}}{{\pi}^{-}}$ or ${{K}^{+}}{{K}^{-}}$,
${{D}^{0}}\rightarrow{{K}^{-}}{{\pi}^{+}}$, ${{\pi}^{+}}{{\pi}^{-}}$ or
${{K}^{+}}{{K}^{-}}$, ${{D}^{+}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}$ or ${{K}^{0}_{\rm\scriptscriptstyle S}}{{K}^{+}}$,
${D}^{+}_{s}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{+}}$ or
${{K}^{0}_{\rm\scriptscriptstyle S}}{{K}^{+}}$ and ${{\mathchar
28931\relax}^{+}_{c}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{p}$
decays.

The largest source of potential background is from random combinations of
final state particles, hereafter referred to as combinatorial background.
Signal candidates are separated from this source of background with the output
of a neural network [55] that is trained and optimised separately for long and
downstream candidates. In the training, simulated $B^{0}_{s}\rightarrow
K^{*\pm}K^{\mp}$ decays are used to represent signal, and data from the high
mass sideband of ${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{+}}{{\pi}^{-}}$
candidates are used as a background sample (the sideband is
$40<m({{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}})-m_{B^{0}}<150{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$,
where $m_{B^{0}}$ is the known value of the $B^{0}$ mass [54]). The variables
used are: the values of the impact parameter $\chi^{2}$, defined as the
difference in $\chi^{2}$ of the associated PV with and without the considered
particle, for the bachelor tracks and the ${K}^{0}_{\rm\scriptscriptstyle S}$
and $B$ candidates; the vertex fit $\chi^{2}$ for the
${K}^{0}_{\rm\scriptscriptstyle S}$ and $B$ candidates; the angle between the
$B$ candidate flight direction and the line between the associated PV and the
decay vertex; the separation between the PV and the decay vertex divided by
its uncertainty; and the $B$ candidate $p_{\rm T}$. Some of these variables
are transformed into their logarithms or other forms that are more appropriate
for numerical handling. The consistency of the distributions of these
variables between data and simulation is confirmed for
${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ decays using the sPlot technique [56] with the $B$
candidate mass as discriminating variable.

The criteria on the outputs of the neural network are chosen to optimise the
probability to observe the $B^{0}_{s}\rightarrow K^{*\pm}K^{\mp}$ decay with
significance exceeding five standard deviations ($\sigma$) [57]. For the
optimisation, an additional requirement on the
${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}$ invariant mass,
$\left|m({{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}})-m_{K^{*\pm}}\right|<100{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$
with $m_{K^{*\pm}}$ the known ${{K}^{*}}^{\pm}$ mass, calculated with the $B$
and ${K}^{0}_{\rm\scriptscriptstyle S}$ candidates constrained to their known
masses, is imposed to select the ${{K}^{*}}^{\pm}$ dominated region of the
phase space. The requirements on the neural network output give signal
efficiencies exceeding 90 % for candidates containing long
${K}^{0}_{\rm\scriptscriptstyle S}$ candidates and exceeding 80 % for
candidates containing downstream ${K}^{0}_{\rm\scriptscriptstyle S}$
candidates, while approximately 95 % and 92 % of the background is removed
from the two categories, respectively.

Requirements are imposed on particle identification information, primarily
from the ring-imaging Cherenkov detectors [38], to separate
$K^{*\pm}{{K}^{\mp}}$ and $K^{*\pm}{{\pi}^{\mp}}$ decays. The criteria are
chosen based on optimisation of a similar figure of merit to that used to
obtain the requirement on the neural network output, and retain about 70 % of
$K^{*\pm}{{K}^{\mp}}$ and about 75 % of $K^{*\pm}{{\pi}^{\mp}}$ decays.
Candidates with tracks that are likely to be protons are rejected. After all
selection requirements are applied, below $1\,\%$ of events containing one
candidate also contain a second candidate; all such candidates are retained.

##  4 Determination of signal yields

Candidates with masses inside the fit windows of
$5000<m({{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}}h^{\mp})<5500{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$ and
$650<m({{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}})<1200{\mathrm{\,Me\kern-1.00006ptV\\!/}c^{2}}$ are used to
perform extended unbinned maximum likelihood fits to determine the signal
yields. In these fits, signal decays are separated from several categories of
background by exploiting their distributions in both
$m({{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}h^{\mp})$ and
$m({{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}})$. The mass of the
${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}h^{\mp}$ combination is
calculated assigning either the kaon or pion mass to $h^{\mp}$ according to
the outcome of the particle identification requirement. A single simultaneous
fit to both long and downstream candidates is performed. Separate fits are
performed for ${{K}^{*\pm}}{{K}^{\mp}}$ and ${{K}^{*\pm}}{{\pi}^{\mp}}$
candidates.

In addition to the signal components and combinatorial background, candidates
can originate from several other $b$ hadron decays. Potential sources include:
decays of ${B}^{0}$ and ${B}^{0}_{s}$ mesons to
${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}h^{\mp}$ final states without
an intermediate ${K}^{*}$ state (referred to as “nonresonant”); misidentified
${B}^{0}_{(s)}\rightarrow{{K}^{*\pm}}h^{\mp}$ (referred to as “cross-feed”)
and ${{\mathchar 28931\relax}^{0}_{b}}\rightarrow{{K}^{*-}}{p}$ decays; decays
of $B$ mesons to charmless final states with an additional unreconstructed
pion; and ${{{B}^{+}}}\rightarrow{{\kern
1.99997pt\overline{\kern-1.99997ptD}{}}{}^{0}}h^{+}$, ${{\kern
1.99997pt\overline{\kern-1.99997ptD}{}}{}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ decays where the additional pion is not
reconstructed. Where branching fraction measurements exist [31, 54, 51], the
yields of the background sources, except that for nonresonant
${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ decays, are expected to be less than 10 % of those
for ${{B}^{0}_{s}}\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$. The branching fractions
of the other nonresonant decays have not been previously determined.

The fit includes components for both ${B}^{0}$ and ${B}^{0}_{s}$ signal and
nonresonant components, and the sources of background listed above. The signal
components are parametrised by a Crystal Ball (CB) function [58] in $B$
candidate mass and a relativistic Breit-Wigner (RBW) function in ${K}^{*}$
candidate mass. The peak positions and widths of the functions for the
dominant contribution (${B}^{0}_{s}$ for ${{K}^{*\pm}}{{K}^{\mp}}$, ${B}^{0}$
for ${{K}^{*\pm}}{{\pi}^{\mp}}$) are allowed to vary freely in the fit. The
relative positions of the ${B}^{0}$ and ${B}^{0}_{s}$ peaks in the $B$
candidate mass distribution are fixed according to the known
${B}^{0}$–${B}^{0}_{s}$ mass difference [54]. The tail parameters of the CB
function are fixed to the values found in fits to simulated signal events, as
are the relative widths of the ${B}^{0}$ and ${B}^{0}_{s}$ shapes. Cross-feed
contributions are also described by the product of CB and RBW functions with
parameters determined from simulation. The misidentification causes a shift
and a smearing of the $B$ candidate mass distribution and only small changes
to the shape in the ${K}^{*}$ candidate mass.

The $B$ candidate mass distributions for the nonresonant components are also
parametrised by a CB function, with peak positions and widths identical to
those of the signal components, but with different tail parameters that are
fixed to values obtained from simulation. Within the ${K}^{*}$ mass window
considered in the fit, the nonresonant shape can be approximated with a linear
function. All linear functions used in the fit are parametrised by their yield
and the abscissa value at which they cross zero, and are set to zero beyond
this threshold, $m_{0}$. The relative yields of nonresonant and signal
components are constrained to have the same value in the samples with long and
downstream candidates, but this ratio is allowed to be different for ${B}^{0}$
and ${B}^{0}_{s}$ decays.

Backgrounds from other $b$ hadron decays are described non-parametrically by
kernel functions [59] in the $B$ candidate mass and either RBW or linear
functions in the ${K}^{*}$ candidate mass, depending on whether or not the
decay involves a ${{K}^{*}}$ resonance. All these background shapes are
determined from simulation. To reduce the number of free parameters in the fit
to the ${{K}^{*\pm}}{{K}^{\mp}}$ sample, the yields of the backgrounds from
charmless hadronic $B$ meson decays with missing particles are fixed relative
to the yield for the ${{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}$ cross-feed
component according to expectation. The yield of the
${{{B}^{+}}}\rightarrow{{\kern
1.99997pt\overline{\kern-1.99997ptD}{}}{}^{0}}h^{+}$, ${{\kern
1.99997pt\overline{\kern-1.99997ptD}{}}{}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{+}}{{\pi}^{-}}$ component is determined from the fit to data. The
yield for the ${{\mathchar 28931\relax}^{0}_{b}}\rightarrow{{K}^{*-}}{p}$
contribution is also a free parameter in the fit to ${{K}^{*\pm}}{{K}^{\mp}}$
candidates, but is fixed to zero in the fit to ${{K}^{*\pm}}{{\pi}^{\mp}}$
candidates.

The combinatorial background is modelled with linear functions in both $B$ and
${K}^{*}$ candidate mass distributions, with parameters freely varied in the
fit to data except for the $m_{0}$ threshold in $B$ candidate mass, which is
fixed from fits to sideband data. For all components, the factorisation of the
two-dimensional probability density functions into the product of one-
dimensional functions is verified to be a good approximation using simulation
and sideband data. In total there are 20 free parameters in the fit to the
${{K}^{*\pm}}{{K}^{\mp}}$ sample: yields for ${B}^{0}$ and ${B}^{0}_{s}$
signals, cross-feed, ${\mathchar 28931\relax}^{0}_{b}$, $B\rightarrow Dh$ and
combinatorial backgrounds (all for both long and downstream categories);
ratios of yields for the ${B}^{0}$ and ${B}^{0}_{s}$ nonresonant components;
peak position and width parameters for the signal in both $B$ candidate and
${K}^{*}$ candidate mass distributions; and parameters of the linear functions
describing the combinatorial background in ${K}^{*}$ candidate mass for both
long and downstream categories. The fit to the ${{K}^{*\pm}}{{\pi}^{\mp}}$
sample has the same number of free parameters, with the ${\mathchar
28931\relax}^{0}_{b}$ background yields replaced by charmless background
yields. The stability of both fits is confirmed using simulated
pseudoexperiments.

The results of the fits are shown in Figs. 2 and 3 for the
${{K}^{*\pm}}{{K}^{\mp}}$ and ${{K}^{*\pm}}{{\pi}^{\mp}}$ final states,
respectively, and the signal yields are given in Table 1. All other fit
results are consistent with expectations.

Table 1: Yields and relative yields obtained from the fits to ${{K}^{*\pm}}{{K}^{\mp}}$ and ${{K}^{*\pm}}{{\pi}^{\mp}}$ candidates. The relative yields of nonresonant (NR) $B^{0}_{(s)}$ decays are constrained to be identical in long and downstream categories. Only statistical uncertainties are given.  Yield | ${B}^{0}$ | ${B}^{0}_{s}$
---|---|---
|  eeelongeee | downstream |  eeelongeee | downstream
$N({{K}^{*\pm}}{{K}^{\mp}})$ | $0\pm 4$ | $\phantom{1}4\pm 3$ | $40\pm 8$ | $62\pm 10$
$N({{K}^{*\pm}}{{\pi}^{\mp}})$ | $80\pm 10$ | $165\pm 16$ | $\phantom{1}5\pm 4$ | $23\pm 8\phantom{1}$
$N({{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}{{K}^{\mp}}\ \text{NR})/N({{K}^{*\pm}}{{K}^{\mp}})$ | $0.0\pm 1.0$ | $0.41\pm 0.16$
$N({{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}{{\pi}^{\mp}}\ \text{NR})/N({{K}^{*\pm}}{{\pi}^{\mp}})$ | $0.79\pm 0.14$ | $0.6\pm 0.4$

Figure 2: Results of the fit to ${{K}^{*\pm}}{{K}^{\mp}}$ candidates projected
onto (a,b) $B$ candidate and (c,d) ${K}^{*}$ candidate mass distributions, for
(a,c) long and (b,d) downstream candidates. The total fit result (solid black
line) is shown together with the data points. Components for the ${B}^{0}$
(pink dash double-dotted line) and ${B}^{0}_{s}$ (red dash dotted line)
signals are shown together with the ${B}^{0}_{s}$ nonresonant component (dark
red falling-hatched area), charmless partially reconstructed and cross-feed
background (blue long-dashed line), and combinatorial background (green long-
dash dotted line) components. The ${{{B}^{+}}}\rightarrow{{\kern
1.79997pt\overline{\kern-1.79997ptD}{}}{}^{0}}h^{+}$ background component has
a negative yield (consistent with zero) and so is not directly visible but
causes the total PDF to go below the level of the combinatorial background on
the left of the $B$ candidate mass spectrum.

Figure 3: Results of the fit to ${{K}^{*\pm}}{{\pi}^{\mp}}$ candidates
projected onto (a,b) $B$ candidate and (c,d) ${K}^{*}$ candidate mass
distributions, for (a,c) long and (b,d) downstream candidates. The total fit
result (black solid line) is shown together with the data points. Components
for the ${B}^{0}$ (red dash dotted line) and ${B}^{0}_{s}$ (pink dash double-
dotted line) signals are shown together with ${B}^{0}$ (dark red falling-
hatched area) and ${B}^{0}_{s}$ (purple rising-hatched area) nonresonant
components, partially reconstructed and cross-feed background (blue long-
dashed line), and combinatorial background (green long-dash-dotted line)
components.

##  5 Systematic uncertainties

Systematic uncertainties occur due to possible imperfections in the fit model
used to determine the signal yields, and due to imperfect knowledge of the
efficiencies used to convert the yields to branching fraction results. A
summary of the systematic uncertainties is given in Table 2.

The fixed parameters in the functions describing the signal and background
components are varied within their uncertainties, and the changes in the
fitted yields are assigned as systematic uncertainties. Studies with simulated
pseudoexperiments cannot exclude biases on the yields at the level of a few
decays. An uncertainty corresponding to the size of the possible bias is
assigned. The linear approximation for the shape of the nonresonant component
in the ${K}^{*}$ candidate mass can only be valid over a restricted range.
Therefore the mass window is varied and the change in the fitted results taken
as an estimate of the corresponding uncertainty.

The largest source of systematic uncertainty arises due to imperfect
cancellation of interference effects between the P-wave ${{K}^{*}}$ signal and
the nonresonant component, in which the ${{K}^{0}_{\rm\scriptscriptstyle
S}}{{\pi}^{\pm}}$ system is predominantly S-wave. Since the efficiency is not
uniform as a function of the cosine of the decay angle,
$\cos{\theta_{{{K}^{*}}}}$, defined as the angle between the $B$ and
${K}^{0}_{\rm\scriptscriptstyle S}$ candidate momenta in the rest frame of the
${{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{\pm}}$ system, a residual
interference effect may bias the results. The size of this uncertainty is
evaluated by fitting the distribution of $\cos{\theta_{{{K}^{*}}}}$ [60]. The
distribution is reconstructed from the signal sWeights [56] obtained from the
default fit. Only the region where $\cos{\theta_{{{K}^{*}}}}$ is positive is
considered, since the efficiency variation is highly non-trivial in the
negative region. This ensures that the assigned uncertainty is conservative
since any cancellation of the interference effects between the two sides of
the distribution is neglected. In the absence of interference, the
distribution will be parabolic and pass through the origin. The bias on the
signal yield due to interference can therefore be evaluated from the constant
and linear components resulting from a fit of the distribution to a second-
order polynomial. Such fits are shown for
${{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}$ and
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ signals in Fig. 4. The
measured yields of the ${{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}$ and
${{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ signals are too small to
allow this method to be used. Therefore the same relative uncertainties are
assigned to these decays as in the corresponding ${B}^{0}$ or ${B}^{0}_{s}$
decay.

Figure 4: Background-subtracted distribution of $\cos{\theta_{{{K}^{*}}}}$ for
(a,b) ${{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}$ and (c,d)
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ signals from the samples
with (a,c) long and (b,d) downstream candidates. Results of fits with second-
order polynomial functions are shown as the solid lines.

Systematic uncertainties on the ratio of efficiencies arise due to limited
sizes of the simulation samples used to determine the acceptance and selection
efficiencies, and due to possible mismodelling of the detector response. Two
potential sources of mismodelling are the trigger and particle identification
efficiencies. These are determined from control samples and systematic
uncertainties assigned using the same procedures as described in Ref. [30].
The imperfect knowledge of the ratio of fragmentation fractions,
$f_{s}/f_{d}=0.259\pm 0.015$ [32, 33, 34], is another source of uncertainty.

Table 2: Systematic uncertainties on the relative branching fraction
measurements. The total uncertainty is obtained by combining all sources in
quadrature.

Source | $\frac{{\cal B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)}{{\cal B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$ | $\frac{{\cal B}\left({{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)}{{\cal B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$ | $\frac{{\cal B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}\right)}{{\cal B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$
---|---|---|---
| long | downstream | long | downstream | long | downstream
Fit | $0.14$ | $0.07$ | $\phantom{<\,}0.010$ | $\phantom{<\,}0.005$ | $\phantom{<\,}0.05$ | $0.04$
S-wave interference | $0.32$ | $0.14$ | $\phantom{<\,}0.001$ | $\phantom{<\,}0.002$ | $\phantom{<\,}0.04$ | $0.05$
Acceptance | $0.01$ | $0.01$ | $<0.001$ | $<0.001$ | $<0.01$ | $0.01$
Selection | $0.08$ | $0.05$ | $<0.001$ | $\phantom{<\,}0.001$ | $\phantom{<\,}0.01$ | $0.02$
Trigger | $0.03$ | $0.02$ | $<0.001$ | $\phantom{<\,}0.001$ | $<0.01$ | $0.01$
Particle identification | $0.04$ | $0.03$ | $<0.001$ | $\phantom{<\,}0.001$ | $\phantom{<\,}0.01$ | $0.01$
$f_{s}/f_{d}$ | $0.10$ | $0.08$ | — | — | $\phantom{<\,}0.01$ | $0.03$
Total | $0.37$ | $0.19$ | $\phantom{<\,}0.011$ | $\phantom{<\,}0.006$ | $\phantom{<\,}0.06$ | $0.08$

##  6 Results and conclusion

The significance of the signal strengths is determined from
$\sqrt{-2\Delta\ln{\cal L}}$, where $\Delta\ln{\cal L}$ is the change in the
log likelihood between the default fit result and that obtained when the
relevant component is fixed to zero. This calculation is performed both with
only the statistical uncertainty included, and after the likelihood function
is convolved with a Gaussian function with width corresponding to the
systematic uncertainty on the fitted yield. Combining the likelihoods from
long and downstream categories, the statistical significances for
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ and
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}$ decays are $12.5\,\sigma$
and $3.9\,\sigma$ while the corresponding values for the total significance
are $7.8\,\sigma$ and $3.4\,\sigma$, respectively. The significance of the
${{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ signal is below $2\,\sigma$.

The ratios of branching fractions of Eqs. (1,2) are obtained by correcting the
ratios of yields by the ratios of efficiencies and, where appropriate, by the
ratio of the fragmentation fractions. The particle identification efficiencies
are determined from data, using samples of kaons and pions from
${{D}^{*+}}\rightarrow{{D}^{0}}{{\pi}^{+}},{{D}^{0}}\rightarrow{{K}^{-}}{{\pi}^{+}}$
decays reweighted according to the kinematic distributions of the bachelor
tracks in ${{B}^{0}_{({s})}}\rightarrow{{K}^{*\pm}}h^{\mp}$ decays. The
relative efficiencies of the acceptance and all other selection requirements
are determined from simulation. The relative efficiencies are within 10 % of
unity.

Since the signal for ${{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ decays
is not significant, upper limits at 90 % and 95 % confidence level (CL) are
obtained by integrating the profile likelihood function in the region of
positive branching fraction. All results from the samples with long and
downstream candidates are consistent and the combined results are

$\displaystyle\frac{{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)}{{\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$ $\displaystyle=$
$\displaystyle 1.49\pm 0.22\mathrm{\,(stat)}\pm 0.18\mathrm{\,(syst)}\,,$
$\displaystyle\frac{{\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)}{{\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$ $\displaystyle=$
$\displaystyle 0.02\pm 0.02\mathrm{\,(stat)}\pm 0.01\mathrm{\,(syst)}\,,$
$\displaystyle<$ $\displaystyle 0.05\ (0.06)\ {\rm at}\ 90\,\%\ (95\,\%)\ {\rm
CL}\,,$ $\displaystyle\frac{{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}\right)}{{\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)}$ $\displaystyle=$
$\displaystyle 0.39\pm 0.13\mathrm{\,(stat)}\pm 0.05\mathrm{\,(syst)}\,.$

Multiplying the relative branching fractions by ${\cal
B}\left({{B}^{0}}\rightarrow{{K}^{*+}}{{\pi}^{-}}\right)=\left(8.5\pm
0.7\right)\times 10^{-6}$ [31] gives

$\displaystyle{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)$
$\displaystyle=$ $\displaystyle\left(12.7\pm 1.9\mathrm{\,(stat)}\pm
1.9\mathrm{\,(syst)}\right)\times 10^{-6}\,,$ $\displaystyle{\cal
B}\left({{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}\right)$
$\displaystyle=$ $\displaystyle\left(0.17\pm 0.15\mathrm{\,(stat)}\pm
0.05\mathrm{\,(syst)}\right)\times 10^{-6}\,,$ $\displaystyle<$ $\displaystyle
0.4\ (0.5)\times 10^{-6}\ {\rm at}\ 90\,\%\ (95\,\%)\ {\rm CL}\,,$
$\displaystyle{\cal
B}\left({{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}\right)$
$\displaystyle=$ $\displaystyle\left(3.3\pm 1.1\mathrm{\,(stat)}\pm
0.5\mathrm{\,(syst)}\right)\times 10^{-6}\,.$

In summary, ${{B}^{0}_{({s})}}\rightarrow{{K}^{*\pm}}h^{\mp}$ decays have been
studied using a data sample corresponding to $1.0\mbox{\,fb}^{-1}$ of $pp$
collision data at a centre-of-mass energy of $7\mathrm{\,Te\kern-1.00006ptV}$
collected with the LHCb detector. The first observation of the
${{B}^{0}_{s}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$ decay and the first
evidence for the ${{B}^{0}_{s}}\\!\rightarrow{{K}^{*-}}{{\pi}^{+}}$ decay are
obtained, and their branching fractions measured. An upper limit is set on the
branching fraction of the ${{B}^{0}}\\!\rightarrow{{K}^{*\pm}}{{K}^{\mp}}$
decay. The results are consistent with several independent theoretical
predictions [61, 62, 63], and represent an important step towards searches for
physics beyond the Standard Model in decays of $B$ mesons to charmless final
states containing one pseudoscalar and one vector meson. Dalitz plot analyses
of larger samples will allow the reduction of both statistical and systematic
uncertainties on these results. The additional sensitivity to relative phases
provided by such analyses will also permit searches for sources of $C\\!P$
violation beyond the Standard Model.

## Acknowledgements

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); SFI (Ireland);
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).

## References

  * [1] N. Cabibbo, Unitary symmetry and leptonic decays, Phys. Rev. Lett. 10 (1963) 531
  * [2] M. Kobayashi and T. Maskawa, $C\\!P$ violation in the renormalizable theory of weak interaction, Prog. Theor. Phys. 49 (1973) 652
  * [3] A. Riotto and M. Trodden, Recent progress in baryogenesis, Ann. Rev. Nucl. Part. Sci. 49 (1999) 35, arXiv:hep-ph/9901362
  * [4] M. Antonelli et al., Flavor physics in the quark sector, Phys. Rept. 494 (2010) 197, arXiv:0907.5386
  * [5] BaBar collaboration, J. P. Lees et al., Measurement of $C\\!P$ asymmetries and branching fractions in charmless two-body $B$-meson decays to pions and kaons, Phys. Rev. D87 (2013) 052009, arXiv:1206.3525
  * [6] Belle collaboration, Y.-T. Duh et al., Measurements of branching fractions and direct $C\\!P$ asymmetries for $B\rightarrow K\pi$, $B\rightarrow\pi\pi$ and $B\rightarrow KK$ decays, Phys. Rev. D87 (2013) 031103, arXiv:1210.1348
  * [7] LHCb collaboration, R. Aaij et al., First observation of $CP$ violation in the decays of $B_{s}^{0}$ mesons, Phys. Rev. Lett. 110 (2013) 221601, arXiv:1304.6173
  * [8] CDF collaboration, T. A. Aaltonen et al., Measurements of direct $C\\!P$-violating asymmetries in charmless decays of bottom baryons, arXiv:1403.5586
  * [9] LHCb collaboration, R. Aaij et al., Measurement of $CP$ violation in the phase space of $B^{\pm}\rightarrow K^{\pm}\pi^{+}\pi^{-}$ and $B^{\pm}\rightarrow K^{\pm}K^{+}K^{-}$ decays, Phys. Rev. Lett. 111 (2013) 101801, arXiv:1306.1246
  * [10] LHCb collaboration, R. Aaij et al., Measurement of $CP$ violation in the phase space of $B^{\pm}\rightarrow K^{+}K^{-}\pi^{\pm}$ and $B^{\pm}\rightarrow\pi^{+}\pi^{-}\pi^{\pm}$ decays, Phys. Rev. Lett. 112 (2014) 011801, arXiv:1310.4740
  * [11] LHCb collaboration, R. Aaij et al., Measurement of $CP$ violation in the three-body phase space of charmless $B^{\pm}$ decays, arXiv:1408.5373, submitted to Phys. Rev. D
  * [12] R. H. Dalitz, On the analysis of tau-meson data and the nature of the tau-meson, Phil. Mag. 44 (1953) 1068
  * [13] M. Ciuchini, M. Pierini, and L. Silvestrini, New bounds on the Cabibbo-Kobayashi-Maskawa matrix from $B\rightarrow K\pi\pi$ Dalitz plot analyses, Phys. Rev. D74 (2006) 051301, arXiv:hep-ph/0601233
  * [14] M. Ciuchini, M. Pierini, and L. Silvestrini, Hunting the CKM weak phase with time-integrated Dalitz analyses of ${{B}^{0}_{s}}\rightarrow K\pi\pi$ decays, Phys. Lett. B645 (2007) 201, arXiv:hep-ph/0602207
  * [15] M. Gronau, D. Pirjol, A. Soni, and J. Zupan, Improved method for CKM constraints in charmless three-body $B$ and ${B}^{0}_{s}$ decays, Phys. Rev. D75 (2007) 014002, arXiv:hep-ph/0608243
  * [16] M. Gronau, D. Pirjol, A. Soni, and J. Zupan, Constraint on $\bar{\rho},\bar{\eta}$ from $B\rightarrow K^{*}\pi$, Phys. Rev. D77 (2008) 057504, arXiv:0712.3751
  * [17] I. Bediaga, G. Guerrer, and J. M. de Miranda, Extracting the quark mixing phase $\gamma$ from ${{B}^{\pm}}\rightarrow{{K}^{\pm}}{{\pi}^{+}}{{\pi}^{-}}$, ${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{+}}{{\pi}^{-}}$, and ${{\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{+}}{{\pi}^{-}}$, Phys. Rev. D76 (2007) 073011, arXiv:hep-ph/0608268
  * [18] M. Gronau, D. Pirjol, and J. Zupan, $C\\!P$ asymmetries in $B\rightarrow K\pi,K^{*}\pi,\rho K$ decays, Phys. Rev. D81 (2010) 094011, arXiv:1001.0702
  * [19] Belle collaboration, A. Garmash et al., Evidence for large direct $C\\!P$ violation in ${{B}^{\pm}}\rightarrow\rho(770)^{0}{{K}^{\pm}}$ from analysis of the three-body charmless ${{B}^{\pm}}\rightarrow{{K}^{\pm}}{{\pi}^{\pm}}{{\pi}^{\mp}}$ decays, Phys. Rev. Lett. 96 (2006) 251803, arXiv:hep-ex/0512066
  * [20] BaBar collaboration, B. Aubert et al., Evidence for direct $C\\!P$ violation from Dalitz-plot analysis of $B^{\pm}\rightarrow K^{\pm}\pi^{\mp}\pi^{\pm}$, Phys. Rev. D78 (2008) 012004, arXiv:0803.4451
  * [21] Belle collaboration, J. Dalseno et al., Time-dependent Dalitz plot measurement of $C\\!P$ parameters in $B^{0}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}\pi^{+}\pi^{-}$ decays, Phys. Rev. D79 (2009) 072004, arXiv:0811.3665
  * [22] BaBar collaboration, B. Aubert et al., Time-dependent amplitude analysis of $B^{0}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}\pi^{+}\pi^{-}$, Phys. Rev. D80 (2009) 112001, arXiv:0905.3615
  * [23] BaBar collaboration, J. P. Lees et al., Amplitude analysis of $B^{0}\rightarrow K^{+}\pi^{-}\pi^{0}$ and evidence of direct $C\\!P$ violation in $B\rightarrow K^{*}\pi$ decays, Phys. Rev. D83 (2011) 112010, arXiv:1105.0125
  * [24] BaBar collaboration, B. Aubert et al., Search for the decay of a ${B}^{0}$ or ${\kern 1.79993pt\overline{\kern-1.79993ptB}{}}{}^{0}$ meson to ${{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*0}}{{K}^{0}}$ or ${{K}^{*0}}{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{0}}$, Phys. Rev. D74 (2006) 072008, arXiv:hep-ex/0606050
  * [25] BaBar collaboration, B. Aubert et al., Search for the decay ${{{B}^{+}}}\rightarrow{{\kern 1.99997pt\overline{\kern-1.99997ptK}{}}{}^{*}}(892)^{0}{{K}^{+}}$, Phys. Rev. D76 (2007) 071103, arXiv:0706.1059
  * [26] BaBar collaboration, B. Aubert et al., Observation of the decay $B^{+}\rightarrow K^{+}K^{-}\pi^{+}$, Phys. Rev. Lett. 99 (2007) 221801, arXiv:0708.0376
  * [27] BaBar collaboration, B. Aubert et al., Search for the decay ${{{B}^{+}}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{{K}^{0}_{\rm\scriptscriptstyle S}}{{\pi}^{+}}$, Phys. Rev. D79 (2009) 051101, arXiv:0811.1979
  * [28] BaBar collaboration, P. del Amo Sanchez et al., Observation of the rare decay ${{B}^{0}}\rightarrow{{K}^{0}_{\rm\scriptscriptstyle S}}{{K}^{\pm}}{{\pi}^{\mp}}$, Phys. Rev. D82 (2010) 031101, arXiv:1003.0640
  * [29] Belle collaboration, V. Gaur et al., Evidence for the decay $B^{0}\rightarrow K^{+}K^{-}\pi^{0}$, Phys. Rev. D87 (2013) 091101, arXiv:1304.5312
  * [30] LHCb collaboration, R. Aaij et al., Study of $B_{(s)}^{0}\rightarrow K^{0}_{S}h^{+}h^{\prime-}$ decays with first observation of $B_{s}^{0}\rightarrow K^{0}_{S}K^{\pm}\pi^{\mp}$ and $B_{s}^{0}\rightarrow K^{0}_{S}\pi^{+}\pi^{-}$, JHEP 10 (2013) 143, arXiv:1307.7648
  * [31] Heavy Flavor Averaging Group, Y. Amhis et al., Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of early 2012, arXiv:1207.1158, updated results and plots available at http://www.slac.stanford.edu/xorg/hfag/
  * [32] LHCb collaboration, R. Aaij et al., Measurement of $b$ hadron production fractions in 7 TeV $pp$ collisions, Phys. Rev. D85 (2012) 032008, arXiv:1111.2357
  * [33] LHCb collaboration, R. Aaij et al., Measurement of the fragmentation fraction ratio $f_{s}/f_{d}$ and its dependence on $B$ meson kinematics, JHEP 04 (2013) 001, arXiv:1301.5286
  * [34] LHCb collaboration, Updated average $f_{s}/f_{d}$ $b$-hadron production fraction ratio for $7~{}T\kern-0.50003pteV$ $pp$ collisions, LHCb-CONF-2013-011
  * [35] LHCb collaboration, A. A. Alves Jr. et al., The LHCb detector at the LHC, JINST 3 (2008) S08005
  * [36] R. Aaij et al., Performance of the LHCb Vertex Locator, JINST 9 (2014) P09007, arXiv:1405.7808
  * [37] R. Arink et al., Performance of the LHCb Outer Tracker, JINST 9 (2014) P01002, arXiv:1311.3893
  * [38] M. Adinolfi et al., Performance of the LHCb RICH detector at the LHC, Eur. Phys. J. C73 (2013) 2431, arXiv:1211.6759
  * [39] A. A. Alves Jr. et al., Performance of the LHCb muon system, JINST 8 (2013) P02022, arXiv:1211.1346
  * [40] R. Aaij et al., The LHCb trigger and its performance in 2011, JINST 8 (2013) P04022, arXiv:1211.3055
  * [41] V. V. Gligorov and M. Williams, Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree, JINST 8 (2013) P02013, arXiv:1210.6861
  * [42] T. Sjöstrand, S. Mrenna, and P. Skands, PYTHIA 6.4 physics and manual, JHEP 05 (2006) 026, arXiv:hep-ph/0603175
  * [43] I. Belyaev et al., Handling of the generation of primary events in Gauss, the LHCb simulation framework, Nuclear Science Symposium Conference Record (NSS/MIC) IEEE (2010) 1155
  * [44] D. J. Lange, The EvtGen particle decay simulation package, Nucl. Instrum. Meth. A462 (2001) 152
  * [45] P. Golonka and Z. Was, PHOTOS Monte Carlo: a precision tool for QED corrections in $Z$ and $W$ decays, Eur. Phys. J. C45 (2006) 97, arXiv:hep-ph/0506026
  * [46] Geant4 collaboration, J. Allison et al., Geant4 developments and applications, IEEE Trans. Nucl. Sci. 53 (2006) 270
  * [47] Geant4 collaboration, S. Agostinelli et al., Geant4: a simulation toolkit, Nucl. Instrum. Meth. A506 (2003) 250
  * [48] M. Clemencic et al., The LHCb simulation application, Gauss: design, evolution and experience, J. Phys. Conf. Ser. 331 (2011) 032023
  * [49] LHCb collaboration, R. Aaij et al., Measurement of the time-dependent $CP$ asymmetry in $B^{0}\rightarrow{{J\mskip-3.0mu/\mskip-2.0mu\psi\mskip 2.0mu}}K^{0}_{S}$ decays, Phys. Lett. B721 (2013) 24, arXiv:1211.6093
  * [50] LHCb collaboration, R. Aaij et al., Measurement of the effective $B^{0}_{s}\rightarrow J/\psi K^{0}_{S}$ lifetime, Nucl. Phys. B873 (2013) 275, arXiv:1304.4500
  * [51] LHCb collaboration, R. Aaij et al., Searches for $\Lambda^{0}_{b}$ and $\Xi^{0}_{b}$ decays to $K^{0}_{S}p\pi^{-}$ and $K^{0}_{S}pK^{-}$ final states with first observation of the $\Lambda^{0}_{b}\rightarrow K^{0}_{S}p\pi^{-}$ decay, JHEP 04 (2014) 087, arXiv:1402.0770
  * [52] LHCb collaboration, R. Aaij et al., Differential branching fractions and isospin asymmetries of $B\rightarrow K^{(*)}\mu^{+}\mu^{-}$ decays, JHEP 06 (2014) 133, arXiv:1403.8044
  * [53] LHCb collaboration, R. Aaij et al., Observation of the $B^{0}_{s}\rightarrow J/\psi K_{{\rm S}}^{0}K^{\pm}\pi^{\mp}$ decay, JHEP 07 (2014) 140, arXiv:1405.3219
  * [54] Particle Data Group, J. Beringer et al., Review of particle physics, Phys. Rev. D86 (2012) 010001, and 2013 partial update for the 2014 edition
  * [55] M. Feindt and U. Kerzel, The NeuroBayes neural network package, Nucl. Instrum. Meth. A559 (2006) 190
  * [56] M. Pivk and F. R. Le Diberder, sPlot: a statistical tool to unfold data distributions, Nucl. Instrum. Meth. A555 (2005) 356, arXiv:physics/0402083
  * [57] G. Punzi, Sensitivity of searches for new signals and its optimization, in Statistical Problems in Particle Physics, Astrophysics, and Cosmology (L. Lyons, R. Mount, and R. Reitmeyer, eds.), p. 79, 2003.  arXiv:physics/0308063
  * [58] T. Skwarnicki, A study of the radiative cascade transitions between the Upsilon-prime and Upsilon resonances, PhD thesis, Institute of Nuclear Physics, Krakow, 1986, DESY-F31-86-02
  * [59] K. S. Cranmer, Kernel estimation in high-energy physics, Comput. Phys. Commun. 136 (2001) 198, arXiv:hep-ex/0011057
  * [60] LHCb collaboration, R. Aaij et al., Measurement of the charge asymmetry in $B^{\pm}\rightarrow\phi K^{\pm}$ and search for $B^{\pm}\rightarrow\phi\pi^{\pm}$ decays, Phys. Lett. B728 (2014) 85, arXiv:1309.3742
  * [61] H.-Y. Cheng and C.-K. Chua, QCD factorization for charmless hadronic ${B}^{0}_{s}$ decays revisited, Phys. Rev. D80 (2009) 114026, arXiv:0910.5237
  * [62] A. Ali et al., Charmless non-leptonic ${{B}^{0}_{s}}$ decays to $PP$, $PV$ and $VV$ final states in the pQCD approach, Phys. Rev. D76 (2007) 074018, arXiv:hep-ph/0703162
  * [63] F. Su, Y.-L. Wu, C. Zhuang, and Y.-B. Yang, Charmless ${{B}^{0}_{s}}\rightarrow PP,PV,VV$ decays based on the six-quark effective Hamiltonian with strong phase effects II, Eur. Phys. J. C72 (2012) 1914, arXiv:1107.0136

LHCb collaboration

R. Aaij41, B. Adeva37, M. Adinolfi46, A. Affolder52, Z. Ajaltouni5, S. Akar6,
J. Albrecht9, F. Alessio38, M. Alexander51, S. Ali41, G. Alkhazov30, P.
Alvarez Cartelle37, A.A. Alves Jr25,38, S. Amato2, S. Amerio22, Y. Amhis7, L.
An3, L. Anderlini17,g, J. Anderson40, R. Andreassen57, M. Andreotti16,f, J.E.
Andrews58, R.B. Appleby54, O. Aquines Gutierrez10, F. Archilli38, A.
Artamonov35, M. Artuso59, E. Aslanides6, G. Auriemma25,n, M. Baalouch5, S.
Bachmann11, J.J. Back48, A. Badalov36, W. Baldini16, R.J. Barlow54, C.
Barschel38, S. Barsuk7, W. Barter47, V. Batozskaya28, V. Battista39, A. Bay39,
L. Beaucourt4, J. Beddow51, F. Bedeschi23, I. Bediaga1, S. Belogurov31, K.
Belous35, I. Belyaev31, E. Ben-Haim8, G. Bencivenni18, S. Benson38, J.
Benton46, A. Berezhnoy32, R. Bernet40, M.-O. Bettler47, M. van Beuzekom41, A.
Bien11, S. Bifani45, T. Bird54, A. Bizzeti17,i, P.M. Bjørnstad54, T. Blake48,
F. Blanc39, J. Blouw10, S. Blusk59, V. Bocci25, A. Bondar34, N. Bondar30,38,
W. Bonivento15,38, S. Borghi54, A. Borgia59, M. Borsato7, T.J.V. Bowcock52, E.
Bowen40, C. Bozzi16, T. Brambach9, J. van den Brand42, J. Bressieux39, D.
Brett54, M. Britsch10, T. Britton59, J. Brodzicka54, N.H. Brook46, H. Brown52,
A. Bursche40, G. Busetto22,r, J. Buytaert38, S. Cadeddu15, R. Calabrese16,f,
M. Calvi20,k, M. Calvo Gomez36,p, P. Campana18,38, D. Campora Perez38, A.
Carbone14,d, G. Carboni24,l, R. Cardinale19,38,j, A. Cardini15, L. Carson50,
K. Carvalho Akiba2, G. Casse52, L. Cassina20, L. Castillo Garcia38, M.
Cattaneo38, Ch. Cauet9, R. Cenci58, M. Charles8, Ph. Charpentier38, M.
Chefdeville4, S. Chen54, S.-F. Cheung55, N. Chiapolini40, M. Chrzaszcz40,26,
K. Ciba38, X. Cid Vidal38, G. Ciezarek53, P.E.L. Clarke50, M. Clemencic38,
H.V. Cliff47, J. Closier38, V. Coco38, J. Cogan6, E. Cogneras5, L.
Cojocariu29, P. Collins38, A. Comerma-Montells11, A. Contu15, A. Cook46, M.
Coombes46, S. Coquereau8, G. Corti38, M. Corvo16,f, I. Counts56, B.
Couturier38, G.A. Cowan50, D.C. Craik48, M. Cruz Torres60, S. Cunliffe53, R.
Currie50, C. D’Ambrosio38, J. Dalseno46, P. David8, P.N.Y. David41, A.
Davis57, K. De Bruyn41, S. De Capua54, M. De Cian11, J.M. De Miranda1, L. De
Paula2, W. De Silva57, P. De Simone18, D. Decamp4, M. Deckenhoff9, L. Del
Buono8, N. Déléage4, D. Derkach55, O. Deschamps5, F. Dettori38, A. Di Canto38,
H. Dijkstra38, S. Donleavy52, F. Dordei11, M. Dorigo39, A. Dosil Suárez37, D.
Dossett48, A. Dovbnya43, K. Dreimanis52, 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. Färber11, C. Farinelli41, N.
Farley45, S. Farry52, RF Fay52, D. Ferguson50, V. Fernandez Albor37, F.
Ferreira Rodrigues1, M. Ferro-Luzzi38, S. Filippov33, M. Fiore16,f, M.
Fiorini16,f, M. Firlej27, C. Fitzpatrick39, T. Fiutowski27, M. Fontana10, F.
Fontanelli19,j, R. Forty38, O. Francisco2, M. Frank38, C. Frei38, M.
Frosini17,38,g, J. Fu21,38, E. Furfaro24,l, A. Gallas Torreira37, D.
Galli14,d, S. Gallorini22, S. Gambetta19,j, M. Gandelman2, P. Gandini59, Y.
Gao3, J. García Pardiñas37, J. Garofoli59, J. Garra Tico47, L. Garrido36, C.
Gaspar38, R. Gauld55, L. Gavardi9, G. Gavrilov30, A. Geraci21,v, E.
Gersabeck11, M. Gersabeck54, T. Gershon48, Ph. Ghez4, A. Gianelle22, S.
Giani’39, V. Gibson47, L. Giubega29, V.V. Gligorov38, C. Göbel60, D.
Golubkov31, A. Golutvin53,31,38, A. Gomes1,a, C. Gotti20, M. Grabalosa
Gándara5, R. Graciani Diaz36, L.A. Granado Cardoso38, E. Graugés36, G.
Graziani17, A. Grecu29, E. Greening55, S. Gregson47, P. Griffith45, L.
Grillo11, O. Grünberg62, B. Gui59, E. Gushchin33, Yu. Guz35,38, T. Gys38, C.
Hadjivasiliou59, G. Haefeli39, C. Haen38, S.C. Haines47, S. Hall53, B.
Hamilton58, T. Hampson46, X. Han11, S. Hansmann-Menzemer11, N. Harnew55, S.T.
Harnew46, J. Harrison54, J. He38, T. Head38, V. Heijne41, K. Hennessy52, P.
Henrard5, L. Henry8, J.A. Hernando Morata37, E. van Herwijnen38, M. Heß62, A.
Hicheur1, D. Hill55, M. Hoballah5, C. Hombach54, W. Hulsbergen41, P. Hunt55,
N. Hussain55, D. Hutchcroft52, D. Hynds51, M. Idzik27, P. Ilten56, R.
Jacobsson38, A. Jaeger11, J. Jalocha55, E. Jans41, P. Jaton39, A. Jawahery58,
F. Jing3, M. John55, D. Johnson55, C.R. Jones47, C. Joram38, B. Jost38, N.
Jurik59, M. Kaballo9, S. Kandybei43, W. Kanso6, M. Karacson38, T.M. Karbach38,
S. Karodia51, M. Kelsey59, I.R. Kenyon45, T. Ketel42, B. Khanji20, C.
Khurewathanakul39, S. Klaver54, K. Klimaszewski28, O. Kochebina7, M. Kolpin11,
I. Komarov39, R.F. Koopman42, P. Koppenburg41,38, M. Korolev32, A.
Kozlinskiy41, L. Kravchuk33, K. Kreplin11, M. Kreps48, G. Krocker11, P.
Krokovny34, F. Kruse9, W. Kucewicz26,o, M. Kucharczyk20,26,38,k, V.
Kudryavtsev34, K. Kurek28, T. Kvaratskheliya31, V.N. La Thi39, D. Lacarrere38,
G. Lafferty54, A. Lai15, D. Lambert50, R.W. Lambert42, G. Lanfranchi18, C.
Langenbruch48, B. Langhans38, T. Latham48, C. Lazzeroni45, R. Le Gac6, J. van
Leerdam41, J.-P. Lees4, R. Lefèvre5, A. Leflat32, J. Lefrançois7, S. Leo23, O.
Leroy6, T. Lesiak26, B. Leverington11, Y. Li3, T. Likhomanenko63, M. Liles52,
R. Lindner38, C. Linn38, F. Lionetto40, B. Liu15, S. Lohn38, I. Longstaff51,
J.H. Lopes2, N. Lopez-March39, P. Lowdon40, H. Lu3, D. Lucchesi22,r, H. Luo50,
A. Lupato22, E. Luppi16,f, O. Lupton55, F. Machefert7, I.V. Machikhiliyan31,
F. Maciuc29, O. Maev30, S. Malde55, A. Malinin63, G. Manca15,e, G.
Mancinelli6, A. Mapelli38, J. Maratas5, J.F. Marchand4, U. Marconi14, C. Marin
Benito36, P. Marino23,t, R. Märki39, J. Marks11, G. Martellotti25, A.
Martens8, A. Martín Sánchez7, M. Martinelli39, D. Martinez Santos42, F.
Martinez Vidal64, D. Martins Tostes2, A. Massafferri1, R. Matev38, Z. Mathe38,
C. Matteuzzi20, A. Mazurov16,f, M. McCann53, J. McCarthy45, A. McNab54, R.
McNulty12, B. McSkelly52, B. Meadows57, F. Meier9, M. Meissner11, M. Merk41,
D.A. Milanes8, M.-N. Minard4, N. Moggi14, J. Molina Rodriguez60, S. Monteil5,
M. Morandin22, P. Morawski27, A. Mordà6, M.J. Morello23,t, J. Moron27, A.-B.
Morris50, R. Mountain59, F. Muheim50, K. Müller40, M. Mussini14, B. Muster39,
P. Naik46, T. Nakada39, R. Nandakumar49, I. Nasteva2, M. Needham50, N. Neri21,
S. Neubert38, N. Neufeld38, M. Neuner11, A.D. Nguyen39, T.D. Nguyen39, C.
Nguyen-Mau39,q, M. Nicol7, V. Niess5, R. Niet9, N. Nikitin32, T. Nikodem11, A.
Novoselov35, D.P. O’Hanlon48, A. Oblakowska-Mucha27, V. Obraztsov35, S.
Oggero41, S. Ogilvy51, O. Okhrimenko44, R. Oldeman15,e, G. Onderwater65, M.
Orlandea29, J.M. Otalora Goicochea2, P. Owen53, A. Oyanguren64, B.K. Pal59, A.
Palano13,c, F. Palombo21,u, M. Palutan18, J. Panman38, A. Papanestis49,38, M.
Pappagallo51, L.L. Pappalardo16,f, C. Parkes54, C.J. Parkinson9,45, G.
Passaleva17, G.D. Patel52, M. Patel53, C. Patrignani19,j, A. Pazos Alvarez37,
A. Pearce54, A. Pellegrino41, M. Pepe Altarelli38, S. Perazzini14,d, E. Perez
Trigo37, P. Perret5, M. Perrin-Terrin6, L. Pescatore45, E. Pesen66, K.
Petridis53, A. Petrolini19,j, E. Picatoste Olloqui36, B. Pietrzyk4, T.
Pilař48, D. Pinci25, A. Pistone19, S. Playfer50, M. Plo Casasus37, F. Polci8,
A. Poluektov48,34, E. Polycarpo2, A. Popov35, D. Popov10, B. Popovici29, C.
Potterat2, E. Price46, J. Prisciandaro39, A. Pritchard52, C. Prouve46, V.
Pugatch44, A. Puig Navarro39, G. Punzi23,s, W. Qian4, B. Rachwal26, J.H.
Rademacker46, B. Rakotomiaramanana39, M. Rama18, M.S. Rangel2, I. Raniuk43, N.
Rauschmayr38, G. Raven42, S. Reichert54, M.M. Reid48, A.C. dos Reis1, S.
Ricciardi49, S. Richards46, M. Rihl38, K. Rinnert52, V. Rives Molina36, D.A.
Roa Romero5, P. Robbe7, A.B. Rodrigues1, E. Rodrigues54, P. Rodriguez Perez54,
S. Roiser38, V. Romanovsky35, A. Romero Vidal37, M. Rotondo22, J. Rouvinet39,
T. Ruf38, H. Ruiz36, P. Ruiz Valls64, J.J. Saborido Silva37, N. Sagidova30, P.
Sail51, B. Saitta15,e, V. Salustino Guimaraes2, C. Sanchez Mayordomo64, B.
Sanmartin Sedes37, R. Santacesaria25, C. Santamarina Rios37, E.
Santovetti24,l, A. Sarti18,m, C. Satriano25,n, A. Satta24, D.M. Saunders46, M.
Savrie16,f, D. Savrina31,32, M. Schiller42, H. Schindler38, M. Schlupp9, M.
Schmelling10, B. Schmidt38, O. Schneider39, A. Schopper38, M.-H. Schune7, R.
Schwemmer38, B. Sciascia18, A. Sciubba25, M. Seco37, A. Semennikov31, I.
Sepp53, N. Serra40, J. Serrano6, L. Sestini22, P. Seyfert11, M. Shapkin35, I.
Shapoval16,43,f, Y. Shcheglov30, T. Shears52, L. Shekhtman34, V. Shevchenko63,
A. Shires9, R. Silva Coutinho48, G. Simi22, M. Sirendi47, N. Skidmore46, T.
Skwarnicki59, N.A. Smith52, E. Smith55,49, E. Smith53, J. Smith47, M. Smith54,
H. Snoek41, M.D. Sokoloff57, F.J.P. Soler51, F. Soomro39, D. Souza46, B. Souza
De Paula2, B. Spaan9, A. Sparkes50, P. Spradlin51, S. Sridharan38, F.
Stagni38, M. Stahl11, S. Stahl11, O. Steinkamp40, O. Stenyakin35, S.
Stevenson55, S. Stoica29, S. Stone59, B. Storaci40, S. Stracka23,38, M.
Straticiuc29, U. Straumann40, R. Stroili22, V.K. Subbiah38, L. Sun57, W.
Sutcliffe53, K. Swientek27, S. Swientek9, V. Syropoulos42, M. Szczekowski28,
P. Szczypka39,38, D. Szilard2, T. Szumlak27, S. T’Jampens4, M. Teklishyn7, G.
Tellarini16,f, F. Teubert38, C. Thomas55, E. Thomas38, J. van Tilburg41, V.
Tisserand4, M. Tobin39, S. Tolk42, L. Tomassetti16,f, D. Tonelli38, S. Topp-
Joergensen55, N. Torr55, E. Tournefier4, S. Tourneur39, M.T. Tran39, M.
Tresch40, A. Tsaregorodtsev6, P. Tsopelas41, N. Tuning41, M. Ubeda Garcia38,
A. Ukleja28, A. Ustyuzhanin63, U. Uwer11, V. Vagnoni14, G. Valenti14, A.
Vallier7, R. Vazquez Gomez18, P. Vazquez Regueiro37, C. Vázquez Sierra37, S.
Vecchi16, J.J. Velthuis46, M. Veltri17,h, G. Veneziano39, M. Vesterinen11, B.
Viaud7, D. Vieira2, M. Vieites Diaz37, X. Vilasis-Cardona36,p, A. Vollhardt40,
D. Volyanskyy10, D. Voong46, A. Vorobyev30, V. Vorobyev34, C. Voß62, H.
Voss10, J.A. de Vries41, R. Waldi62, C. Wallace48, R. Wallace12, J. Walsh23,
S. Wandernoth11, J. Wang59, D.R. Ward47, N.K. Watson45, D. Websdale53, M.
Whitehead48, J. Wicht38, D. Wiedner11, G. Wilkinson55, M.P. Williams45, M.
Williams56, F.F. Wilson49, J. Wimberley58, J. Wishahi9, W. Wislicki28, M.
Witek26, G. Wormser7, S.A. Wotton47, S. Wright47, S. Wu3, K. Wyllie38, Y.
Xie61, Z. Xing59, Z. Xu39, Z. Yang3, X. Yuan3, O. Yushchenko35, M. Zangoli14,
M. Zavertyaev10,b, L. Zhang59, W.C. Zhang12, Y. Zhang3, A. Zhelezov11, A.
Zhokhov31, L. Zhong3, A. Zvyagin38.

1Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil
2Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
3Center for High Energy Physics, Tsinghua University, Beijing, China
4LAPP, Université de Savoie, 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
62Institut für Physik, Universität Rostock, Rostock, Germany, associated to 11
63National Research Centre Kurchatov Institute, Moscow, Russia, associated to
31
64Instituto de Fisica Corpuscular (IFIC), Universitat de Valencia-CSIC,
Valencia, Spain, associated to 36
65KVI - University of Groningen, Groningen, The Netherlands, associated to 41
66Celal Bayar University, Manisa, Turkey, associated to 38

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 Firenze, Firenze, Italy
hUniversità di Urbino, Urbino, Italy
iUniversità di Modena e Reggio Emilia, Modena, Italy
jUniversità di Genova, Genova, Italy
kUniversità di Milano Bicocca, Milano, Italy
lUniversità di Roma Tor Vergata, Roma, Italy
mUniversità di Roma La Sapienza, Roma, Italy
nUniversità della Basilicata, Potenza, Italy
oAGH - University of Science and Technology, Faculty of Computer Science,
Electronics and Telecommunications, Kraków, Poland
pLIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain
qHanoi University of Science, Hanoi, Viet Nam
rUniversità di Padova, Padova, Italy
sUniversità di Pisa, Pisa, Italy
tScuola Normale Superiore, Pisa, Italy
uUniversità degli Studi di Milano, Milano, Italy
vPolitecnico di Milano, Milano, Italy