Phys. Lett. B 728 (2014) 85-94 The \CP-violating charge asymmetry in $B^{\pm}\rightarrow \phi K^{\pm}$
decays is measured in a sample of $pp$ collisions at 7 TeV centre-of-mass
energy, corresponding ...to an integrated luminosity of 1.0 fb$^{-1}$ collected by
the LHCb experiment. The result is $\mathcal{A}_{CP}(B^{\pm}\rightarrow \phi
K^{\pm}) = \rm 0.022\pm 0.021 \pm 0.009$, where the first uncertainty is
statistical and the second systematic. In addition, a search for the
$B^{\pm}\rightarrow \phi \pi^{\pm}$ decay mode is performed, using the
$B^{\pm}\rightarrow \phi K^{\pm}$ decay rate for normalization. An upper limit
on the branching fraction $\mathcal{B}(B^{\pm}\rightarrow \phi \pi^{\pm})<
1.5\times 10^{-7}$ is set at 90% confidence level.
An analysis of the decay B0 -> J/psi K*(892)0 is presented using data, corresponding to an integrated luminosity of 1.0fb^-1, collected in pp collisions at a centre-of-mass energy of 7TeV with the ...LHCb detector. The polarisation amplitudes and the corresponding phases are measured to be |A_{\parallel}|^2 = 0.227 +- 0.004 (stat.) +- 0.011 (syst.), |A_{\perp}|^2 = 0.201 +- 0.004 (stat.) +- 0.008 (syst.), \delta_{\parallel} rad = -2.94 +- 0.02 (stat.) +- 0.03 (syst.), \delta_{\perp} rad = 2.94 +- 0.02 (stat.) +- 0.02 (syst.). Comparing B0 -> J/psi K*(892)0 and \bar{B}0 -> J/psi \bar{K}*(892)0 decays, no evidence for direct CP violation is found.
JHEP 1311 (2013) 094 The decay $B_c\rightarrow J/\psi K^+ K^- \pi^+$ is observed for the first
time, using proton-proton collisions collected with the LHCb detector
corresponding to an integrated ...luminosity of 3fb$^{-1}$. A signal yield of
$78\pm14$ decays is reported with a significance of 6.2 standard deviations.
The ratio of the branching fraction of $\B_c \rightarrow J/\psi K^+ K^- \pi^+$
decays to that of $B_c \rightarrow J/\psi \pi^+$ decays is measured to be
$0.53\pm 0.10\pm0.05$, where the first uncertainty is statistical and the
second is systematic.
JHEP 02 (2014) 072 The production of $J/\psi$ mesons with rapidity $1.5<y<4.0$ or $-5.0<y<-2.5$
and transverse momentum $p_\mathrm{T}<14 \mathrm{GeV}/c$ is studied with the
LHCb detector in ...proton-lead collisions at a nucleon-nucleon centre-of-mass
energy $\sqrt{s_{NN}}=5 \mathrm{TeV}$. The analysis is based on a data sample
corresponding to an integrated luminosity of about $1.6 \mathrm{nb}^{-1}$. For
the first time the nuclear modification factor and forward-backward production
ratio are determined separately for prompt $J/\psi$ mesons and $J/\psi$ from
$b$-hadron decays. Clear suppression of prompt $J/\psi$ production with respect
to proton-proton collisions at large rapidity is observed, while the production
of $J/\psi$ from $b$-hadron decays is less suppressed. These results show good
agreement with available theoretical predictions. The measurement shows that
cold nuclear matter effects are important for interpretations of the related
quark-gluon plasma signatures in heavy-ion collisions.
Physics Letters B 727 (2013), pp. 403-411 First observation of the decay Bs -> D0bar phi is reported using pp collision
data, corresponding to an integrated luminosity of 1.0 fb^-1, collected by the
...LHCb experiment at a centre-of-mass energy of 7 TeV. The significance of the
signal is 6.2 standard deviations. The branching fraction is measured relative
to that of the decay Bs -> D0bar K*0bar to be 0.069 +/- 0.013 (stat) +/- 0.007
(syst). The first measurement of the ratio of branching fractions for the
decays Bs -> D0bar K*0bar and Bd->D0bar K*0 is found to be 7.8 +/- 0.7 (stat)
+/- 0.3 (syst) +/- 0.6 (f_s/f_d), where the last uncertainty is due to the
ratio of the Bs and Bd fragmentation fractions.
Phys. Rev. Lett. 111, 191801 (2013) We present a measurement of form-factor independent angular observables in
the decay \mbox{$B^0\to K^{*}(892)^{0}\mu^+ \mu^-$}. The analysis is based on a
data ...sample corresponding to an integrated luminosity of 1.0fb$^{-1}$,
collected by the LHCb experiment in $pp$ collisions at a center-of-mass energy
of 7TeV. Four observables are measured in six bins of the dimuon invariant mass
squared, $q^2$, in the range $0.1<q^2<19.0$GeV$^{2}$/c$^{4}$. Agreement with
Standard Model predictions is found for 23 of the 24 measurements. A local
discrepancy, corresponding to $3.7$ Gaussian standard deviations, is observed
in one $q^2$ bin for one of the observables. Considering the 24 measurements as
independent, the probability to observe such a discrepancy, or larger, in one
is $0.5\%$.
Phys. Rev. Lett. 111, 151801 (2013) A measurement of the $C\P$ asymmetry in $B^+ \rightarrow K^+ \mu^+ \mu^-$
decays is presented using $pp$ collision data, corresponding to an integrated
luminosity ...of 1.0${\,fb}^{-1}$, recorded by the LHCb experiment during 2011 at
a centre-of-mass energy of 7 TeV. The measurement is performed in seven bins of
$\mu^+ \mu^-$ invariant mass squared in the range
${0.05<q^{2}<22.00{\mathrm{GeV^2/}c^4}}$, excluding the ${J/\psi}$ and
$\psi{(2S)}$ resonance regions. Production and detection asymmetries are
corrected for using the $B^+ \rightarrow J/\psi K^+$ decay as a control mode.
Averaged over all the bins, the $C\P$ asymmetry is found to be ${{\cal A}_{C\P}
= 0.000\pm 0.033{(stat.)} \pm0.005 {(syst.)} \pm 0.007{}(J/\psi K^+)}$, where
the third uncertainty is due to the $C\P$ asymmetry of the control mode. This
is consistent with the Standard Model prediction.
Eur. Phys. C (2013) 73:2655 The $B^0_s$ and $B^0$ mixing frequencies, $\Delta m_s$ and $\Delta m_d$, are
measured using a data sample corresponding to an integrated luminosity of 1.0
fb^{-1} ...collected by the LHCb experiment in $pp$ collisions at a centre of mass
energy of 7 TeV during 2011. Around 1.8x10^6 candidate events are selected of
the type $B^0_{(s)} \to D^-_{(s)} \mu^+$ (+ anything), where about half are
from peaking and combinatorial backgrounds. To determine the B decay times, a
correction is required for the momentum carried by missing particles, which is
performed using a simulation-based statistical method. Associated production of
muons or mesons allows us to tag the initial-state flavour and so to resolve
oscillations due to mixing. We obtain \Delta m_s = (17.93 \pm 0.22 (stat) \pm
0.15 (syst)) ps^{-1}, \Delta m_d = (0.503 \pm 0.011 (stat) \pm 0.013 (syst))
ps^{-1}. The hypothesis of no oscillations is rejected by the equivalent of 5.8
standard deviations for $B^0_s$ and 13.0 standard deviations for $B^0$. This is
the first observation of $B^0_s$ mixing to be made using only semileptonic
decays.
Physics Letters B 726 (2013) pp. 646-655 An analysis of $B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+$ and $B^+ \to
K_{\rm \scriptscriptstyle S}^0 K^+$ decays is performed with the LHCb
experiment. ...The $pp$ collision data used correspond to integrated luminosities
of $1{\,fb}^{-1}$ and $2{\,fb}^{-1}$ collected at centre-of-mass energies of
$\sqrt{s}=7\mathrm{\,Te\kern -0.1em V}$ and $\sqrt{s}=8\mathrm{\,Te\kern -0.1em
V}$, respectively. The ratio of branching fractions and the direct {\it CP}
asymmetries are measured to be $\mathcal{B}(B^+ \to K_{\rm \scriptscriptstyle
S}^0 K^+)/\mathcal{B}(B^+ \to K_{\rm \scriptscriptstyle S}^0 \pi^+) = 0.064 \pm
0.009\textrm{(stat.)} \pm 0.004\textrm{(syst.)}$, $\mathcal{A}^{\it CP}(B^+ \to
K_{\rm \scriptscriptstyle S}^0 \pi^+) = -0.022 \pm 0.025\textrm{(stat.)} \pm
0.010\textrm{(syst.)}$ and $\mathcal{A}^{\it CP}(B^+ \to K_{\rm
\scriptscriptstyle S}^0 K^+) = -0.21 \pm 0.14\textrm{(stat.)} \pm
0.01\textrm{(syst.)}$. The data sample taken at $\sqrt{s}=7\mathrm{\,Te\kern
-0.1em V}$ is used to search for $B_c^+ \to K_{\rm \scriptscriptstyle S}^0 K^+$
decays and results in the upper limit $(f_c\cdot\mathcal{B}(B_c^+ \to K_{\rm
\scriptscriptstyle S}^0 K^+))/(f_u\cdot\mathcal{B}(B^+ \to K_{\rm
\scriptscriptstyle S}^0 \pi^+)) < 5.8\times10^{-2}\textrm{at 90% confidence
level}$, where $f_c$ and $f_u$ denote the hadronisation fractions of a
$\bar{b}$ quark into a $B_c^+$ or a $B^+$ meson, respectively.
J. High Energy Phys. 10 (2013) 005 The results of a search for the rare two-body charmless baryonic decays $B^0
\to p \bar{p}$ and $B_s^0 \to p \bar{p}$ are reported. The analysis uses a data
sample, ...corresponding to an integrated luminosity of 0.9 fb$^{-1}$, of $pp$
collision data collected by the LHCb experiment at a centre-of-mass energy of 7
TeV. An excess of $B^0 \to p \bar{p}$ candidates with respect to background
expectations is seen with a statistical significance of 3.3 standard
deviations. This is the first evidence for a two-body charmless baryonic $B^0$
decay. No significant $B_s^0 \to p \bar{p}$ signal is observed, leading to an
improvement of three orders of magnitude over previous bounds. If the excess
events are interpreted as signal, the 68.3% confidence level intervals on the
branching fractions are {eqnarray} \cal{B}(B^0 \to p \bar{p}) & = & (1.47
\,^{+0.62}_{-0.51} \,^{+0.35}_{-0.14}) \times 10^{-8} \,, *{0.3cm}
\cal{B}(B_s^0 \to p \bar{p}) & = & (2.84 \,^{+2.03}_{-1.68} \,^{+0.85}_{-0.18})
\times 10^{-8} \,, {eqnarray} where the first uncertainty is statistical and
the second is systematic.
