The first observation of the decays Lambda(b)(0) -> chi(c1)pK(-) , Lambda(0)(b) -> chi(c2)pK(-) is reported using a data sample corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment in pp collisions at center-of-mass energies of 7 , 8 TeV The following ratios of branching fractions are measured: B(Lambda(0)(b) -> chi(c1)pK(-))/B(Lambda(0)(b) -> J/psi pK(-)) = 0.242 +/- 0.014 +/- 0.013 +/- 0.009, B(Lambda(0)(b) -> chi(c2)pK(-))/B(Lambda(0)(b) -> J/psi pK(-)) = 0.248 +/- 0.020 +/- 0.014 +/- 0.009, B(Lambda(0)(b) -> chi(c2)pK(-))/B(Lambda(0)(b) -> chi(c1)pK(-)) = 1.02 +/- 0.010 +/- 0.02 +/- 0.05, where the first uncertainty is statistical the second systematic , the third due to the uncertainty on the branching fractions of the x(c1) -> J/psi gamma, chi(c2) -> J/psi gamma decays. Using both decay modes the mass of the Ab baryon is also measured to be m(Lambda b0) = 5619.44 +/- 0.28 +/- 0.26 MeV/c(2) where the first, second uncertainties are statistical, systematic respectively.

Observation of the Decays Alpha(0)(b) -> chi(c1)pK(-) and Alpha(0)(b) ->chi(c2)pK(-)

Bursche A.;Chen S.;Dettori F.;Lai A.;Manca G.;Oldeman R.;Saitta B.;
2017-01-01

Abstract

The first observation of the decays Lambda(b)(0) -> chi(c1)pK(-) , Lambda(0)(b) -> chi(c2)pK(-) is reported using a data sample corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment in pp collisions at center-of-mass energies of 7 , 8 TeV The following ratios of branching fractions are measured: B(Lambda(0)(b) -> chi(c1)pK(-))/B(Lambda(0)(b) -> J/psi pK(-)) = 0.242 +/- 0.014 +/- 0.013 +/- 0.009, B(Lambda(0)(b) -> chi(c2)pK(-))/B(Lambda(0)(b) -> J/psi pK(-)) = 0.248 +/- 0.020 +/- 0.014 +/- 0.009, B(Lambda(0)(b) -> chi(c2)pK(-))/B(Lambda(0)(b) -> chi(c1)pK(-)) = 1.02 +/- 0.010 +/- 0.02 +/- 0.05, where the first uncertainty is statistical the second systematic , the third due to the uncertainty on the branching fractions of the x(c1) -> J/psi gamma, chi(c2) -> J/psi gamma decays. Using both decay modes the mass of the Ab baryon is also measured to be m(Lambda b0) = 5619.44 +/- 0.28 +/- 0.26 MeV/c(2) where the first, second uncertainties are statistical, systematic respectively.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/239489
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