A measurement of the cross-section for Z-boson production in the forward region of pp collisions at 8TeV centre-of-mass energy is presented. The measurement is based on a sample of \(\rm Z\rightarrow ...e^+e^-\) decays reconstructed using the LHCb detector, corresponding to an integrated luminosity of 2.0fb\(^{-1}\). The acceptance is defined by the requirements \(2.0<\eta<4.5\) and \(p_{\rm T}>20\)GeV for the pseudorapidities and transverse momenta of the leptons. Their invariant mass is required to lie in the range 60--120GeV. The cross-section is determined to be $$ \sigma({\rm pp\to Z\to e^+e^-})=93.81\pm0.41({\rm stat})\pm1.48({\rm syst})\pm1.14({\rm lumi})\;{\rm pb}\,,$$ where the first uncertainty is statistical and the second reflects all systematic effects apart from that arising from the luminosity, which is given as the third uncertainty. Differential cross-sections are presented as functions of the Z-boson rapidity and of the angular variable \(\phi^*\), which is related to the Z-boson transverse momentum.
A model-dependent amplitude analysis of \(B^{\pm} \rightarrow D K^{\pm}\) with \(D \rightarrow K_S^0 \pi^+ \pi^-\) decays is performed using proton-proton collision data, corresponding to an ...integrated luminosity of \(1\) fb\(^{-1}\), recorded by LHCb at a centre-of-mass energy of \(7\) TeV in \(2011\). Values of the \(CP\) violation observables \(x_{\pm}\) and \(y_{\pm}\), which are sensitive to the CKM angle \(\gamma\), are measured to be \begin{align*} x_- &= +0.027 \pm 0.044 ^{+0.010}_{-0.008} \pm 0.001, \\ y_- &= +0.013 \pm 0.048 ^{+0.009}_{-0.007} \pm 0.003, \\ x_+ &= -0.084 \pm 0.045 \pm 0.009 \pm 0.005, \\ y_+ &= -0.032 \pm 0.048 ^{+0.010}_{-0.009} \pm 0.008, \end{align*} where the first uncertainty is statistical, the second systematic and the third arises from the uncertainty of the \(D \rightarrow K_S^0 \pi^+ \pi^-\) amplitude model. The value of \(\gamma\) is determined to be \((84^{+49}_{-42})^\circ\), including all sources of uncertainty. Neutral \(D\) meson mixing is found to have negligible effect.
Measurements of the branching fractions of \(B^0_s \to K^{*\pm}K^\mp\) and \(B^0_s \to K^{*\pm}\pi^\mp\) 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 \(7\mathrm{\,TeV}\), where the \(K^{*\pm}\) mesons are reconstructed in the \(K^0_{\rm S}\pi^\pm\) final state. The first observation of the \(B^0_s \to K^{*\pm}K^\mp\) decay and the first evidence for the \(B^0_s \to K^{*-}\pi^+\) decay are reported with branching fractions \begin{eqnarray} {\cal B}(B^0_s \to K^{*\pm}K^\mp) & = & (12.7\pm1.9\pm1.9) \times 10^{-6}, \\ {\cal B}(B^0_s \to K^{*-}\pi^+) & = & ~(3.3\pm1.1\pm0.5) \times 10^{-6}, \end{eqnarray} where the first uncertainties are statistical and the second are systematic. In addition, an upper limit of \({\cal B}(B^0 \to K^{*\pm}K^\mp) < 0.4 \ (0.5) \times 10^{-6}\) is set at \(90\,% \ (95\,%)\) confidence level.
We report on measurements of the time-dependent CP violating observables in \(B^0_s\rightarrow D^{\mp}_s K^{\pm}\) decays using a dataset corresponding to 1.0 fb\(^{-1}\) of pp collisions recorded ...with the LHCb detector. We find the CP violating observables \(C_f=0.53\pm0.25\pm0.04\), \(A^{\Delta\Gamma}_f=0.37\pm0.42\pm0.20\), \(A^{\Delta\Gamma}_{\bar{f}}=0.20\pm0.41\pm0.20\), \(S_f=-1.09\pm0.33\pm0.08\), \(S_{\bar{f}}=-0.36\pm0.34\pm0.08\), where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the \(B^0_s\) mixing phase \(-2\beta_s\) leads to the first extraction of the CKM angle \(\gamma\) from \(B^0_s \rightarrow D^{\mp}_s K^{\pm}\) decays, finding \(\gamma\) = (115\(_{-43}^{+28}\))\(^\circ\) modulo 180\(^\circ\) at 68% CL, where the error contains both statistical and systematic uncertainties.
Production of \(\Upsilon\) mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy \(\sqrt{s_{NN}}=5 \mathrm{TeV}\) is studied with the LHCb detector. The analysis is based on a ...data sample corresponding to an integrated luminosity of \(1.6 \mathrm{nb}^{-1}\). The \(\Upsilon\) mesons of transverse momenta up to \(15 \mathrm{GeV}/c\) are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is \(1.5<y<4.0\) (forward region) and \(-5.0<y<-2.5\) (backward region). The forward-backward production ratio and the nuclear modification factor for \(\Upsilon(1S)\) mesons are determined. The data are compatible with the predictions for a suppression of \(\Upsilon(1S)\) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt \(J/\psi\) mesons.
Understanding the protein composition of the follicular fluid from brown brocket deer would aid the development of a medium for in vitro embryo production, which would in turn contribute toward ...programs for species preservation. Proteomic shotgun is a sensitive tool for analysis of complex protein mixtures. Thus, this study aimed to use shotgun technique to investigate the proteome of fluid from small/medium and large follicles from brocket brown deer. The fluid was obtained by laparoscopy-guided follicular puncture from five females. Quantitative proteomic analysis was performed by multidimensional liquid chromatography coupled with mass spectrometry. A total of 226 proteins were identified in the follicular fluid, 53 and 60 of which were found only in small/medium and large follicles, respectively. One hundred and thirteen proteins were common to both groups of follicles. Quantitative analysis showed no significant differences (
P
> 0.05) in protein abundances in the follicular fluid from small/medium and large follicles. The proteins identified were classified by gene ontology terms, in silico interaction and assigned to 12 pathways indicated that proteins are involved in protein binding, catalytic activity, regulation of biological processes, extracellular matrix organization, and complement and coagulation cascades. In conclusion, these data add knowledge on the follicular development and provide original information on the follicular environment, which can contribute in the future to formulation of culture medium to use in embryo technology in brown brocket deer.
An angular analysis of the \(B^0 \rightarrow K^{*0} e^+ e^-\) decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 \({\mbox{fb}^{-1}}\), collected by the LHCb ...experiment in \(pp\) collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (\(q^2\)) interval between 0.002 and 1.120\({\mathrm{\,Ge\kern -0.1em V^2\!/}c^4}\). The angular observables \(F_{\mathrm{L}}\) and \(A_{\mathrm{T}}^{\mathrm{Re}}\) which are related to the \(K^{*0}\) polarisation and to the lepton forward-backward asymmetry, are measured to be \(F_{\mathrm{L}}= 0.16 \pm 0.06 \pm0.03\) and \(A_{\mathrm{T}}^{\mathrm{Re}} = 0.10 \pm 0.18 \pm 0.05\), where the first uncertainty is statistical and the second systematic. The angular observables \(A_{\mathrm{T}}^{(2)}\) and \(A_{\mathrm{T}}^{\mathrm{Im}}\) which are sensitive to the photon polarisation in this \(q^2\) range, are found to be \(A_{\mathrm{T}}^{(2)} = -0.23 \pm 0.23 \pm 0.05\) and \(A_{\mathrm{T}}^{\mathrm{Im}} =0.14 \pm 0.22 \pm 0.05\). The results are consistent with Standard Model predictions.
The production of \(\chi_b\) mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of \(\sqrt{s}=7\) and \(8\) TeV and ...corresponding to an integrated luminosity of 3.0 fb\(^{-1}\). The \(\chi_b\) mesons are identified through their decays to \(\Upsilon(1S)\gamma\) and \(\Upsilon(2S)\gamma\) using photons that converted to \(e^+e^-\) pairs in the detector. The relative prompt production rate of \(\chi_{b1}(1P)\) and \(\chi_{b2}(1P)\) mesons is measured as a function of the \(\Upsilon(1S)\) transverse momentum in the \(\chi_b\) rapidity range \(2.0<y<4.5\). A precise measurement of the \(\chi_b(3P)\) mass is also performed. Assuming a mass splitting between the \(\chi_{b1}(3P)\) and the \(\chi_{b2}(3P)\) states of 10.5 MeV/\(c^2\), the measured mass of the \(\chi_{b1}(3P)\) meson is \( m(\chi_{b1}(3P))= 10515.7^{+2.2}_{-3.9}(stat) ^{+1.5}_{-2.1}(syst) MeV/c^2.\)
Time-dependent \(CP\) asymmetries in the decay rates of the singly Cabibbo-suppressed decays \(D^0\rightarrow K^-K^+\) and \(D^0\rightarrow \pi^-\pi^+\) are measured in \(pp\) collision data ...corresponding to an integrated luminosity of 3.0 fb\(^{-1}\) collected by the LHCb experiment. The \(D^0\) mesons are produced in semileptonic \(b\)-hadron decays, where the charge of the accompanying muon is used to determine the initial state as \(D^0\) or \(\bar{D}^0\). The asymmetries in effective lifetimes between \(D^0\) and \(\bar{D}^0\) decays, which are sensitive to indirect \(CP\) violation, are determined to be \begin{align*} A_{\Gamma}(K^-K^+) = (-0.134 \pm 0.077 \; {}^{+0.026}_{-0.034})\% \, A_{\Gamma}(\pi^-\pi^+) = (-0.092\pm 0.145 \; {}^{+0.025}_{-0.033})\% \, \end{align*} where the first uncertainties are statistical and the second systematic. This result is in agreement with previous measurements and with the hypothesis of no indirect \(CP\) violation in \(D^0\) decays.
The resonant substructure of \(B_s^0 \rightarrow \bar{D}^0 K^- \pi^+\) decays is studied with the Dalitz plot analysis technique. The study is based on a data sample corresponding to an integrated ...luminosity of \(3.0\,{\rm fb}^{-1}\) of \(pp\) collision data recorded by LHCb. A structure at \(m(\bar{D}^0 K^-) \approx 2.86 {\rm GeV}/c^2\) is found to be an admixture of spin-1 and spin-3 resonances. The masses and widths of these states and of the \(D^*_{s2}(2573)^-\) meson are measured, as are the complex amplitudes and fit fractions for all the \(\bar{D}^0 K^-\) and \(K^-\pi^+\) components included in the amplitude model. In addition, the \(D^*_{s2}(2573)^-\) resonance is confirmed to be spin-2.
