Abstract This paper reports world averages of measurements of b-hadron, c-hadron, and $$\tau $$ τ -lepton properties obtained by the Heavy Flavour Averaging Group using results available through ...September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, $$C\!P$$ C P violation parameters, parameters of semileptonic decays, and Cabibbo–Kobayashi–Maskawa matrix elements.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).A study of ... meson production at LHCb is performed on proton-proton collision data, corresponding to 3.0...of integrated ...luminosity collected at centre-of-mass energies ... = 7 and 8 ... The fraction of ... mesons originating from ... decays is measured as a function of the ... transverse momentum in the rapidity range ... The radiative transition of the ... meson to ... is observed for the first time. The ... mass is determined to be ... ...where the first uncertainty is statistical and the second is systematic.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A measurement of the inclusive W arrow right muν production cross-section using data from pp collisions at a ...centre-of-mass energy of ... TeV is presented. The analysis is based on an integrated luminosity of about 1.0 fb-1 recorded with the LHCb detector. Results are reported for muons with a transverse momentum greater than 20 GeV/c and pseudorapidity between 2.0 and 4.5. The W + and W - production cross-sections are measured to be ... ... where the first uncertainty is statistical, the second is systematic and the third is due to the luminosity determination. Cross-section ratios and differential distributions as functions of the muon pseudorapidity are also presented. The ratio of W + to W - cross-sections in the same fiducial kinematic region is determined to be ... where the uncertainties are statistical and systematic, respectively. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Figure not available: see fulltext.
Abstract The time-dependent CP asymmetry in B 0 → K resγ → π+π− K Sγ is sensitive to the photon polarisation in the quark level process b → sγ. While this polarisation is predominantly left-handed in ...the standard model, it could be modified by the existence of new physics contributions that may possess different CP properties. In this paper, we derive the CP violation formulae for B 0 → K resγ → π+π− K Sγ including the most dominant intermediate states. We propose a new observable that could be measured in a time-dependent amplitude analysis of B 0 → π+π− K Sγ decays, providing a stringent contraint on the photon polarisation. We discuss the future prospects for obtaining such constraints from measurements at Belle II and LHCb.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).The production of ..., ... and ... mesons decaying into the dimuon final state is studied with the LHCb detector using a ...data sample corresponding to an integrated luminosity of ... collected in proton-proton collisions at a centre-of-mass energy of ... TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the ... transverse momentum and rapidity, over the ranges ... GeV/... and ... The total cross-sections in this kinematic region, assuming unpolarised production, are measured to be ... ...where the first uncertainty is statistical and the second systematic.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A search for \CP violation in Cabibbo-suppressed $D^{\pm}\rightarrow K^0_{\mathrm{S}} K^{\pm}$ and $D^{\pm}_{s}\rightarrow K^0_{\mathrm{S}} \pi^{\pm}$ decays is performed using $pp$ collision data, ...corresponding to an integrated luminosity of 3~fb$^{-1}$, recorded by the LHCb experiment. The individual $CP$-violating asymmetries are measured to be \begin{eqnarray*} \mathcal{A}_{CP}^{D^{\pm}\rightarrow K^0_{\mathrm{S}} K^{\pm}} & = & (+0.03 \pm 0.17 \pm 0.14) \% \mathcal{A}_{CP}^{D^{\pm}_{s}\rightarrow K^0_{\mathrm{S}} \pi^{\pm}} & = & (+0.38 \pm 0.46 \pm 0.17) \%, \end{eqnarray*} assuming that $CP$ violation in the Cabibbo-favoured decays is negligible. A combination of the measured asymmetries for the four decay modes $D^{\pm}_{(s)}\rightarrow K^0_{\mathrm{S}} K^{\pm}$ and $D^{\pm}_{(s)}\rightarrow K^0_{\mathrm{S}} \pi^{\pm}$ gives the sum \ \mathcal{A}_{CP}^{D^{\pm}\rightarrow K^0_{\mathrm{S}} K^{\pm}} + \mathcal{A}_{CP}^{D^{\pm}_{s}\rightarrow K^0_{\mathrm{S}} \pi^{\pm}} = (+0.41 \pm 0.49 \pm 0.26) \%. \ In all cases, the first uncertainties are statistical and the second systematic. The results represent the most precise measurements of these asymmetries to date and show no evidence for CP violation.
We present results of a search for CP violation in B0B0bar mixing with the BABAR detector. We select a sample of B0-->D*-Xl+ nu decays with a partial reconstruction method and use kaon tagging to ...assess the flavor of the other B meson in the event. We determine the CP violating asymmetry ACP = (N(B0B0) - N(B0bar B0bar))/(N(B0B0) + N(B0bar B0bar))=(0.06+-0.17+0.38-0.32)%, corresponding to delta_CP =1 - |q/p| =(0.29+-0.84+1.88 -1.61)*10^-3.
The B 0 a B A= 0 oscillation frequency I m d is measured by the LHCb experiment using a dataset corresponding to an integrated luminosity of 1.0 fb - 1 of protonaproton collisions at s = 7 TeV , and ...is found to be I m d = 0.5156 +/- 0.0051 (stat.) +/- 0.0033 (syst.) ps - 1 . The measurement is based on results from analyses of the decays B 0 a D - pi + (D - a K + pi - pi -) and B 0 a J / I K a 0 (J / I a mu + mu - , K a 0 a K + pi -) and their charge conjugated modes.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The lifetime of the ... meson is measured using semileptonic decays having a ... meson and a muon in the final state. The ...data, corresponding to an integrated luminosity of ..., are collected by the LHCb detector in ... collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is ...where the first uncertainty is statistical and the second is systematic.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The polarisation of prompt ... mesons is measured by performing an angular analysis of ... decays using proton-proton ...collision data, corresponding to an integrated luminosity of 1.0..., collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum ... and rapidity ... in the kinematic region ... and ..., and is compared to theoretical models. No significant polarisation is observed.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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