# Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

Abstract : The Lambda(b) differential production cross section and the cross-section ratio for anti-Lambda(b)/Lambda(b) production are measured as functions of transverse momentum pt(Lambda(b)) and rapidity 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 1.02 +/- 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.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00694341
Contributor : Dominique Girod <>
Submitted on : Friday, May 4, 2012 - 10:04:24 AM
Last modification on : Thursday, June 17, 2021 - 3:19:01 PM

### Citation

S. Chatrchyan, M. Besancon, S. Choudhury, M. Dejardin, D. Denegri, et al.. Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV. Physics Letters B, Elsevier, 2012, 714, pp.136-157. ⟨10.1016/j.physletb.2012.05.063⟩. ⟨in2p3-00694341⟩

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