JHEP 10 (2016) 030 A measurement of the cross-section for $W \to e\nu$ production in $pp$
collisions is presented using data corresponding to an integrated luminosity of
$2\,$fb$^{-1}$ collected by ...the LHCb experiment at a centre-of-mass energy of
$\sqrt{s}=8\,$TeV. The electrons are required to have more than $20\,$GeV of
transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The
inclusive $W$ production cross-sections, where the $W$ decays to $e\nu$, are
measured to be \begin{equation*} \sigma_{W^{+} \to e^{+}\nu_{e}}=1124.4\pm
2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb}, \end{equation*} \begin{equation*}
\sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm
\phantom{0}9.4\,\mathrm{pb}, \end{equation*} where the first uncertainties are
statistical, the second are systematic, the third are due to the knowledge of
the LHC beam energy and the fourth are due to the luminosity determination.
Differential cross-sections as a function of the electron pseudorapidity are
measured. The $W^{+}/W^{-}$ cross-section ratio and production charge asymmetry
are also reported. Results are compared with theoretical predictions at
next-to-next-to-leading order in perturbative quantum chromodynamics. Finally,
in a precise test of lepton universality, the ratio of $W$ boson branching
fractions is determined to be \begin{equation*} \mathcal{B}(W \to
e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{equation*} where
the first uncertainty is statistical and the second is systematic.
JHEP 1609 (2016) 153 The ratio of branching fractions $R_{K/\pi} \equiv \mathcal{B}(B_{c}^{+} \to
J/\psi K^{+})/\mathcal{B}(B_{c}^{+} \to J/\psi\pi^{+})$ is measured with $pp$
collision data ...collected by the LHCb experiment at centre-of-mass energies of 7
TeV and 8 TeV, corresponding to an integrated luminosity of
3${\mbox{fb}^{-1}}$. It is found to be $ R_{K/\pi} = 0.079\pm0.007\pm0.003$,
where the first uncertainty is statistical and the second is systematic. This
measurement is consistent with the previous LHCb result, while the
uncertainties are significantly reduced.
Phys. Lett. B762 (2016) 253-262 A time-dependent angular analysis of $B_s^0\to\psi(2S)\phi$ decays is
performed using data recorded by the LHCb experiment. The data set corresponds
to an integrated ...luminosity of 3.0\invfb collected during Run 1 of the LHC. The
CP-violating phase and decay-width difference of the $B_s^0$ system are
measured to be $\phi_s = 0.23^{+0.29}_{-0.28} \pm 0.02$ rad and $\Delta\Gamma_s
= 0.066^{+0.041}_{-0.044} \pm 0.007$ ps$^{-1}$, respectively, where the first
uncertainty is statistical and the second systematic. This is the first time
that $\phi_s$ and $\Delta\Gamma_s$ have been measured in a decay containing the
$\psi(2S)$ resonance.
Physics Letters B 762C (2016) pp. 484-492 Using a data set corresponding to an integrated luminosity of $3 fb^{-1}$,
collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies
of ...7 and 8 TeV, the effective lifetime in the $B^0_s \rightarrow J/\psi \eta$
decay mode, $\tau_{\textrm{eff}}$, is measured to be $\tau_{\textrm{eff}} =
1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)}$ ps. Assuming $CP$
conservation, $\tau_{\textrm{eff}}$ corresponds to the lifetime of the light
$B_s^0$ mass eigenstate. This is the first measurement of the effective
lifetime in this decay mode.
The first observation of the decay $\eta_{c}(2S) \to p \bar p$ is reported
using proton-proton collision data corresponding to an integrated luminosity of
$3.0\rm \, fb^{-1}$ recorded by the LHCb ...experiment at centre-of-mass energies
of 7 and 8 TeV. The $\eta_{c}(2S)$ resonance is produced in the decay $B^{+}
\to c\bar c K^{+}$. The product of branching fractions normalised to that for
the $J/\psi$ intermediate state, ${\cal R}_{\eta_{c}(2S)}$, is measured to be
\begin{align*} {\cal R}_{\eta_{c}(2S)}\equiv\frac{{\mathcal B}(B^{+} \to
\eta_{c}(2S) K^{+}) \times {\mathcal B}(\eta_{c}(2S) \to p \bar p)}{{\mathcal
B}(B^{+} \to J/\psi K^{+}) \times {\mathcal B}(J/\psi\to p \bar p)} =~& (1.58
\pm 0.33 \pm 0.09)\times 10^{-2}, \end{align*} where the first uncertainty is
statistical and the second systematic. No signals for the decays $B^{+} \to
X(3872) (\to p \bar p) K^{+}$ and $B^{+} \to \psi(3770) (\to p \bar p) K^{+}$
are seen, and the 95\% confidence level upper limits on their relative
branching ratios are % found to be ${\cal R}_{X(3872)}<0.25\times10^{-2}$ and
${\cal R}_{\psi(3770))}<0.10$. In addition, the mass differences between the
$\eta_{c}(1S)$ and the $J/\psi$ states, between the $\eta_{c}(2S)$ and the
$\psi(2S)$ states, and the natural width of the $\eta_{c}(1S)$ are measured as
\begin{align*} M_{J/\psi} - M_{\eta_{c}(1S)} =~& 110.2 \pm 0.5 \pm 0.9 \rm \,
MeV, M_{\psi(2S)} -M_{\eta_{c}(2S)} =~ & 52.5 \pm 1.7 \pm 0.6 \rm \, MeV,
\Gamma_{\eta_{c}(1S)} =~& 34.0 \pm 1.9 \pm 1.3 \rm \, MeV. \end{align*}
JHEP 09 (2016) 136 A measurement of the production cross-section of Z bosons in pp collisions at
$\sqrt{s} = 13$ TeV is presented using dimuon and dielectron final states in
LHCb data. The ...cross-section is measured for leptons with pseudorapidities in
the range $2.0 < \eta < 4.5$, transverse momenta $p_\text{T} > 20$ GeV and
dilepton invariant mass in the range $60<m(\ell\ell)<120$ GeV. The integrated
cross-section from averaging the two final states is
\begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm
7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the
second is due to systematic effects, and the third is due to the luminosity
determination. In addition, differential cross-sections are measured as
functions of the Z boson rapidity, transverse momentum and the angular variable
$\phi^*_\eta$.
Phys. Rev. D 94, 091102 (2016) A study of $B_c^+\to K^+K^-\pi^+$ decays is performed for the first time
using data corresponding to an integrated luminosity of 3.0 $\mathrm{fb}^{-1}$
collected by the ...LHCb experiment in $pp$ collisions at centre-of-mass energies
of $7$ and $8$ TeV. Evidence for the decay $B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+$
is reported with a significance of 4.0 standard deviations, resulting in the
measurement of
$\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+)$ to
be $(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}$.
Here $\mathcal{B}$ denotes a branching fraction while $\sigma(B_c^+)$ and
$\sigma(B^+)$ are the production cross-sections for $B_c^+$ and $B^+$ mesons.
An indication of $\bar b c$ weak annihilation is found for the region
$m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2$, with a significance of
2.4 standard deviations.
Phys. Rev. D 94, 072001 (2016) The Dalitz plot analysis technique is used to study the resonant
substructures of $B^{-} \to D^{+} \pi^{-} \pi^{-}$ decays in a data sample
corresponding to 3.0 ${\rm ...fb}^{-1}$ of $pp$ collision data recorded by the
LHCb experiment during 2011 and 2012. A model-independent analysis of the
angular moments demonstrates the presence of resonances with spins 1, 2 and 3
at high $D^{+}\pi^{-}$ mass. The data are fitted with an amplitude model
composed of a quasi-model-independent function to describe the $D^{+}\pi^{-}$
S-wave together with virtual contributions from the $D^{*}(2007)^{0}$ and
$B^{*0}$ states, and components corresponding to the $D^{*}_{2}(2460)^{0}$,
$D^{*}_{1}(2680)^{0}$, $D^{*}_{3}(2760)^{0}$ and $D^{*}_{2}(3000)^{0}$
resonances. The masses and widths of these resonances are determined together
with the branching fractions for their production in $B^{-} \to D^{+} \pi^{-}
\pi^{-}$ decays. The $D^{+}\pi^{-}$ S-wave has phase motion consistent with
that expected due to the presence of the $D^{*}_{0}(2400)^{0}$ state. These
results constitute the first observations of the $D^{*}_{3}(2760)^{0}$ and
$D^{*}_{2}(3000)^{0}$ resonances.
Phys. Rev. Lett. 117, 152003 (2016) The $B_s^0\pi^\pm$ invariant mass distribution is investigated in order to
search for possible exotic meson states. The analysis is based on a data sample
recorded ...with the LHCb detector corresponding to $3$ fb$^{-1}$ of $pp$
collision data at $\sqrt{s} = 7$ and $8$ TeV. No significant excess is found,
and upper limits are set on the production rate of the claimed $X(5568)$ state
within the LHCb acceptance. Upper limits are also set as a function of the mass
and width of a possible exotic meson decaying to the $B_s^0\pi^\pm$ final
state. The same limits also apply to a possible exotic meson decaying through
the chain $B_s^{*0}\pi^\pm$, $B_s^{*0} \to B_s^0 \gamma$ where the photon is
excluded from the reconstructed decays.
Phys. Rev. Lett. 118, 022003 (2017) The first full amplitude analysis of $B^+\to J/\psi \phi K^+$ with
$J/\psi\to\mu^+\mu^-$, $\phi\to K^+K^-$ decays is performed with a data sample
of 3 fb$^{-1}$ of ...$pp$ collision data collected at $\sqrt{s}=7$ and $8$ TeV
with the LHCb detector. The data cannot be described by a model that contains
only excited kaon states decaying into $\phi K^+$, and four $J/\psi\phi$
structures are observed, each with significance over $5$ standard deviations.
The quantum numbers of these structures are determined with significance of at
least $4$ standard deviations. The lightest has mass consistent with, but width
much larger than, previous measurements of the claimed $X(4140)$ state.
