A search for previously unobserved decays of beauty baryons to the final states K(s)(0)p pi(-) and K(s)(0)pK(-) is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions. The Lambda(0)(b) -> (K) over bar0 p pi(-) decay is observed with a significance of 8.6 sigma, with branching fraction B(Lambda(0)(b) -> (K) over bar0 p pi(-)) = (1.26 +/- 0.19 +/- 0.09 +/- 0.34 +/- 0.05) x 10(-5,) where the uncertainties are statistical, systematic, from the ratio fragmentation fractions f Lambda(0)(b)/fd, and from the branching fraction of the B-0 -> K-0 pi(+)pi(-) normalisation channel, respectively. A first measurement is made of the CP asymmetry, giving A(CP)(Lambda(0)(b) -> (K) over bar0 p pi(-)) = 0.22 +/- 0.13 (stat) +/- 0.03 (syst). No significant signals are seen for Lambda(0)(b) -> K(s)(0)pK(-) decays, Xi(0)(b) decays to both the K(s)(0)p pi(-) and K(s)(0)pK(-) final states, and the Lambda(0)(b) -> D-s(-)(-> (KsK-)-K-0)p decay, and upper limits on their branching fractions are reported.
Archilli, F., Carboni, G., Santovetti, E., The LHCb, C. (2014). Searches for and decays to and final states with first observation of the decay. JOURNAL OF HIGH ENERGY PHYSICS(4) [10.1007/JHEP04(2014)087].
Searches for and decays to and final states with first observation of the decay
Archilli, FMembro del Collaboration Group
;Carboni, GMembro del Collaboration Group
;Santovetti, EMembro del Collaboration Group
;
2014-01-01
Abstract
A search for previously unobserved decays of beauty baryons to the final states K(s)(0)p pi(-) and K(s)(0)pK(-) is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions. The Lambda(0)(b) -> (K) over bar0 p pi(-) decay is observed with a significance of 8.6 sigma, with branching fraction B(Lambda(0)(b) -> (K) over bar0 p pi(-)) = (1.26 +/- 0.19 +/- 0.09 +/- 0.34 +/- 0.05) x 10(-5,) where the uncertainties are statistical, systematic, from the ratio fragmentation fractions f Lambda(0)(b)/fd, and from the branching fraction of the B-0 -> K-0 pi(+)pi(-) normalisation channel, respectively. A first measurement is made of the CP asymmetry, giving A(CP)(Lambda(0)(b) -> (K) over bar0 p pi(-)) = 0.22 +/- 0.13 (stat) +/- 0.03 (syst). No significant signals are seen for Lambda(0)(b) -> K(s)(0)pK(-) decays, Xi(0)(b) decays to both the K(s)(0)p pi(-) and K(s)(0)pK(-) final states, and the Lambda(0)(b) -> D-s(-)(-> (KsK-)-K-0)p decay, and upper limits on their branching fractions are reported.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.