A first search for Formula omitted violation in the Cabibbo-suppressed Formula omitted decay is performed using both a binned and an unbinned model-independent technique in the Dalitz plot. The ...studies are based on a sample of proton-proton collision data, corresponding to an integrated luminosity of Formula omitted, and collected by the LHCb experiment at centre-of-mass energies of 7 and Formula omitted. The data are consistent with the hypothesis of no Formula omitted violation.
Using a data sample corresponding to an integrated luminosity of 2.0 Formula omitted, collected by the LHCb experiment, the production of the Formula omitted state in proton-proton collisions at a ...centre-of-mass energy of Formula omitted Formula omitted is studied in the rapidity range Formula omitted and in the transverse momentum range Formula omitted. The cross-section for prompt production of Formula omitted mesons relative to that of the Formula omitted meson is measured using the Formula omitted Formula omitted decay mode and is found to be Formula omitted. The quoted uncertainties are, in order, statistical, systematic and due to uncertainties on the branching fractions of the Formula omitted and Formula omitted decays. The prompt Formula omitted production cross-section is determined to be Formula omitted, where the last uncertainty includes that on the Formula omitted meson cross-section. The ratio of the branching fractions of Formula omitted-hadron decays to the Formula omitted and Formula omitted states is measured to be Formula omitted, where the last uncertainty is due to those on the branching fractions of the Formula omitted and Formula omitted decays. The difference between the Formula omitted and Formula omitted masses is also determined to be Formula omitted, which is the most precise single measurement of this quantity to date.
The cross-sections of Formula omitted meson production in proton-proton collisions at Formula omitted are measured with a data sample collected by the LHCb detector corresponding to an integrated ...luminosity of Formula omitted. The production cross-sections for prompt Formula omitted mesons and those for Formula omitted mesons from b-hadron decays ( Formula omitted) are determined as functions of the transverse momentum, Formula omitted, and the rapidity, y, of the Formula omitted meson in the kinematic range Formula omitted and Formula omitted. The production cross-sections integrated over this kinematic region are sigma(promptpsi(2S),13TeV)=1.430±0.005(stat)±0.099(syst)mub,sigma(psi(2S)-from-b,13TeV)=0.426±0.002(stat)±0.030(syst)mub.A new measurement of Formula omitted production cross-sections in pp collisions at Formula omitted is also performed using data collected in 2011, corresponding to an integrated luminosity of Formula omitted. The integrated production cross-sections in the kinematic range Formula omitted and Formula omitted are sigma(promptpsi(2S),7TeV)=0.471±0.001(stat)±0.025(syst)mub,sigma(psi(2S)-from-b,7TeV)=0.126±0.001(stat)±0.008(syst)mub.All results show reasonable agreement with theoretical calculations.
The decay-time-dependent Formula omitted asymmetry in Formula omitted decays is measured using proton-proton collision data, corresponding to an integrated luminosity of Formula omitted, collected ...with the LHCb detector at a centre-of-mass energy of Formula omitted in 2015 and 2016. Using a sample of approximately 117 000 signal decays with an invariant Formula omitted mass in the vicinity of the Formula omitted resonance, the Formula omitted-violating phase Formula omitted is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the Formula omitted- Formula omitted system, Formula omitted. The difference of the average Formula omitted and Formula omitted meson decay widths, Formula omitted, is determined using in addition a sample of Formula omitted decays. The values obtained are Formula omitted, Formula omitted and Formula omitted, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of these quantities to date and are consistent with expectations based on the Standard Model and with a previous LHCb analysis of this decay using data recorded at centre-of-mass energies 7 and 8 TeV. Finally, the results are combined with recent results from Formula omitted decays obtained using the same dataset as this analysis, and with previous independent LHCb results.
Amplitude models are constructed to describe the resonance structure of Formula omitted and Formula omitted decays using pp collision data collected at centre-of-mass energies of 7 and 8 TeV with the ...LHCb experiment, corresponding to an integrated luminosity of 3.0 Formula omitted. The largest contributions to both decay amplitudes are found to come from axial resonances, with decay modes Formula omitted and Formula omitted being prominent in Formula omitted and Formula omitted, respectively. Precise measurements of the lineshape parameters and couplings of the Formula omitted, Formula omitted and Formula omitted resonances are made, and a quasi model-independent study of the Formula omitted resonance is performed. The coherence factor of the decays is calculated from the amplitude models to be Formula omitted, which is consistent with direct measurements. These models will be useful in future measurements of the unitary-triangle angle Formula omitted and studies of charm mixing and Formula omitted violation.
A search for the decay Formula omitted is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of Formula omitted, collected by the LHCb experiment ...at centre-of-mass energies of 7 and 8 Formula omitted. The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of Formula omitted at Formula omitted confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.
Using decays to Formula omitted-meson pairs, the inclusive production of charmonium states in Formula omitted-hadron decays is studied with pp collision data corresponding to an integrated luminosity ...of Formula omitted, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by Formula omitted the inclusive branching fraction of a Formula omitted hadron to a charmonium state C that decays into a pair of Formula omitted mesons, ratios Formula omitted are determined as Formula omitted, Formula omitted, Formula omitted, Formula omitted, Formula omitted and Formula omitted. Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and Formula omitted states are obtained as Formula omitted, Formula omitted and Formula omitted. Differential cross-sections as a function of transverse momentum are measured for the Formula omitted and Formula omitted states. The branching fraction of the decay Formula omitted is measured for the first time, Formula omitted. Here the third uncertainty is due to the branching fraction of the decay Formula omitted, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse Formula omitted polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the Formula omitted decays to Formula omitted and Formula omitted as Formula omitted.
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