Branching fraction and CP asymmetry of the decays B+ -> K-S(0)pi(+) and B+ -> (KSK+)-K-0

An analysis of B+→KS0π+ and B+→KS0K+ decays is performed with the LHCb experiment. The pp collision data used correspond to integrated luminosities of 1fb-1 and 2fb-1 collected at centre-of-mass energies of √s=7TeV and √s=8TeV, respectively. The ratio of branching fractions and the direct CP asymmetries are measured to be B(B+→KS0K+)/B(B+→KS0π+)=0.064±0.009 (stat.)±0.004(syst.), ACP(B+→KS0π+)=-0.022±0.025(stat.)±0.010 (syst.) and ACP(B+→KS0K+)=-0.21±0.14 (stat.)±0.01 (syst.). The data sample taken at √s=7 TeV is used to search for Bc+→KS0K+ decays and results in the upper limit (fc{dot operator}B(Bc+→KS0K+))/(fu{dot operator}B(B+→KS0π+))<5.8×10-2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a b- quark into a Bc+ or a B+ meson, respectively. © 2013 CERN

Study of the production of A(b)(0) and (B)over-bar(0) hadrons in pp collisions and first measurement of the A(b)(0)-> J/psi pK(-) branching fraction

The product of the A(b)(0) ((B) over bar (0)) differential production cross-section and the branching fraction of the decay A(b)(0)-> J/psi pK(-) ((B) over bar (0)-> J/psi p (K) over bar*(892)(0)) is measured as a function of the beauty hadron transverse momentum, p(T), and rapidity, y. The kinematic region of the measurements is p(T) <20 GeV/c and 2.0 < y < 4.5. The measurements use a data sample corresponding to an integrated luminosity of 3fb(-1) collected by the LHCb detector in pp collisions at centre-of-mass energies root s=7 TeV in 2011 and root s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio, f(Ab0)/f(d), the branching fraction of the decay A(b)(0)-> J/psi pK(-) is measured to be B(A(b)(0)-> J/psi pK(-))=(3.17 +/- 0.04 +/- 0.07 +/- 0.34(-0.28)(+0.45))x10(-4) where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay (B) over bar (0)-> J/psi p (K) over bar*(892)(0), and the fourth is due to the knowledge of f(Ab0)/f(d). The sum of the asymmetries in the production and decay between A(b)(0) and (A) over bar (0)(b) is also measured as a function of p(T) and y. The previously published branching fraction of A(b)(0)-> J/psi p pi(-), relative to that of A(b)(0)-> J/psi pK(-), is updated. The branching fractions of A(b)(0)-> P-c(+)(-> J/psi p)K- are determined