A search for $B_s^0 \to \overline{D}^{0} f_{0}(980)$ decays is performed using $3.0\, {\rm fb}^{-1}$ of $pp$ collision data recorded by the LHCb experiment during 2011 and 2012. The $f_{0}(980)$ ...meson is reconstructed through its decay to the $\pi^{+}\pi^{-}$ final state in the mass window $900\, {\rm MeV}/c^{2} < m(\pi^{+}\pi^{-}) < 1080\, {\rm MeV}/c^{2}$. No significant signal is observed. The first upper limits on the branching fraction of $\mathcal{B}(B_s^0 \to \overline{D}^{0} f_{0}(980)) < 3.1\,(3.4) \times 10^{-6}$ are set at $90\,\%$ ($95\,\%$) confidence level.
Invariant mass distributions of B+pi- and B0pi+ combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fb-1 of pp collision ...data, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Precise measurements of the masses and widths of the B_1(5721)^(0,+) and B_2*(5747)^(0,+) states are reported. Clear enhancements, particularly prominent at high pion transverse momentum, are seen over background in the mass range 5850--6000 MeV in both B+pi- and B0pi+ combinations. The structures are consistent with the presence of four excited B mesons, labelled B_J(5840)^(0,+) and B_J(5960)^(0,+), whose masses and widths are obtained under different hypotheses for their quantum numbers.
(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.
A search is performed for the central exclusive production of pairs of charmonia produced in proton-proton collisions. Using data corresponding to an integrated luminosity of collected at ...centre-of-mass energies of 7 and 8 TeV, and pairs are observed, which have been produced in the absence of any other activity inside the LHCb acceptance that is sensitive to charged particles in the pseudorapidity ranges and . Searches are also performed for pairs of P-wave charmonia and limits are set on their production. The cross-sections for these processes, where the dimeson system has a rapidity between 2.0 and 4.5, are measured to be where the upper limits are set at the 90% confidence level. The measured and cross-sections are consistent with theoretical expectations.
The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 phi gamma has been measured using an integrated luminosity of 1.0 fb-1 of pp collision data collected by the LHCb ...experiment at a centre-of-mass energy of sqrt(s)=7 TeV. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.23 +/- 0.06(stat.) +/- 0.04(syst.) +/- 0.10(fs/fd), where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for BR(B0 -> K*0 gamma), the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.5 +/- 0.4) x 10^{-5}. The direct CP asymmetry in B0 -> K*0 gamma decays has also been measured with the same data and found to be A(CP)(B0 -> K*0 gamma) = (0.8 +/- 1.7(stat.) +/- 0.9(syst.))%. Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations.
The differential cross-section as a function of rapidity has been measured for the exclusive production of J ψ and ψ(2S) mesons in proton-proton collisions at TeV, using data collected by the LHCb ...experiment, corresponding to an integrated luminosity of 930 pb−1. The cross-sections times branching fractions to two muons having pseudorapidities between 2.0 and 4.5 are measured to be where the first uncertainty is statistical and the second is systematic. The measurements agree with next-to-leading order QCD predictions as well as with models that include saturation effects.
The results of searches for B0(s) -> J/{\psi} p pbar and B+ -> J/{\psi} p pbar {\pi}+ decays are reported. The analysis is based on a data sample, corresponding to an integrated luminosity of 1.0 ...fb^-1 of pp collisions, collected with the LHCb detector. An excess with 2.8 {\sigma} significance is seen for the decay B0s -> J/{\psi} p pbar and an upper limit on the branching fraction is set at the 90 % confidence level: B(B0s -> J/{\psi} p pbar) < 4.8 x 10^-6, which is the first such limit. No significant signals are seen for B0 -> J/{\psi} p pbar and B+ -> J/{\psi} p pbar {\pi}+ decays, for which the corresponding limits are set: B(B0 -> J/{\psi} p pbar) < 5.2 x 10^-7, which significantly improves the existing limit; and B(B+ -> J/{\psi} p pbar {\pi}+) < 5.0 x 10^-7, which is the first limit on this branching fraction.