Measurement of the $\Lambda_b$ cross section and the $_{\bar{\Lambda}_b}$ to $\Lambda_b$ ratio with $J/\Psi \Lambda$ decays in $pp$ collisions at $\sqrt{s}=7$ TeV

CMS collaboration (2191 authors)Hollar, JonathanNayak, ArunaAlmeida, NunoBargassa, PedrameDavid Tinoco Mendes, AndreFaccioli, PietroFerreira Parracho, Pedro GuilhermeGallinaro, MicheleSeixas, JoaoVarela, JoaoVischia, PietroLloret Iglesias, LaraMusella, PasqualeRodrigues Antunes, JoaoSilva, PedroPela, JoaoLeonardo, Nuno2019-02-032019-02-032013-07-16http://dx.doi.org/10.1016/j.physletb.2012.05.063http://hdl.handle.net/10400.26/26169The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.engMeasurement of the $\Lambda_b$ cross section and the $_{\bar{\Lambda}_b}$ to $\Lambda_b$ ratio with $J/\Psi \Lambda$ decays in $pp$ collisions at $\sqrt{s}=7$ TeVjournal article2019-02-03