Abstract: The charmless three- body decay modes B +/- -> K +/-pi(-)pi(-), B-+/- -> K-+/- (KK-)-K-+/-, B-+/- pi(-) K-K- and B-+/-pi(-)pi(-) are reconstructed using data, corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb detector. The inclusive CP asymmetries of these modes are measured to be [GRAPHICS] where the first uncertainty is statistical, the second systematic, and the third is due to the CP asymmetry of the B +/- J Psi K-+/- reference mode. The distributions of these asymmetries are also studied as functions of position in the Dalitz plot and suggest contributions from rescattering and resonance interference processes.

Abstract: We report on measurements of the mass and lifetime of the Xi(-)(b) baryon using about 1800 Xi(-)(b) decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment. The decays are reconstructed in the Xi(-)(b) -> Xi(0)(c)pi(-), Xi(0)(c) -> pK(-)K(-)pi(+) channel and the mass and lifetime are measured using the Lambda(0)(b) -> Lambda(+)(c)pi(-) mode as a reference. We measure M(Xi(-)(b)) – M(Lambda(0)(b)) = 178.36 +/- 0.46 +/- 0.16 MeV/c(2), (tau Xi(-)(b)/tau Lambda(0)(b)) = 1.089 +/- 0.026 +/- 0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Xi(-)(b) mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.

Abstract: The inclusive top quark pair (t (t) over tilde) production cross-section sigma(t (t) over bar) has been measured in proton-proton collisions at root s = 7 TeV and root s = 8 TeV with the ATLAS experiment at the LHC, using t (t) over bar events with an opposite-charge e μpair in the final state. The measurement was performed with the 2011 7 TeV dataset corresponding to an integrated luminosity of 4.6 fb(-1) and the 2012 8 TeV dataset of 20.3 fb(-1). The numbers of events with exactly one and exactly two b-tagged jets were counted and used to simultaneously determine sigma(t (t) over bar) and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section was measured to be: sigma(t (t) over bar) = 182.9 +/- 3.1 +/- 4.2 +/- 3.6 +/- 3.3 pb (root s = 7 TeV) and sigma(t (t) over bar) = 242.4 +/- 1.7 +/- 5.5 +/- 7.5 +/- 4.2 pb (root s = 8 TeV), where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, knowledge of the integrated luminosity and of the LHC beam energy. The results are consistent with recent theoretical QCD calculations at next-to-next-to-leading order. Fiducial measurements corresponding to the experimental acceptance of the leptons are also reported, together with the ratio of cross-sections measured at the two centre-of-mass energies. The inclusive cross-section results were used to determine the top quark pole mass via the dependence of the theoretically predicted cross-section on m(t)(pole) giving a result of m(t)(pole) = 172.9(-2.6)(+2.5) GeV. By looking for an excess of t (t) over bar production with respect to the QCD prediction, the results were also used to place limits on the pair-production of supersymmetric top squarks (t) over tilde (1) with masses close to the top quarkmass, decaying via (t) over tilde (1) -> t (chi) over tilde (0)(1) 1 to predominantly right-handed top quarks and a light neutralino (chi) over tilde (0)(1) 1, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 177 GeV are excluded at the 95% confidence level.