A search for previously unobserved decays of beauty baryons to the final states K0 S p− and K0 SpK− is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions. The 0b ! K 0 p− decay is observed with a significance of 8.6 , with branching fraction B(0b ! K 0 p−) = (1.26 ± 0.19 ± 0.09 ± 0.34 ± 0.05) × 10−5 , where the uncertainties are statistical, systematic, from the ratio of fragmentation fractions f0 b /fd, and from the branching fraction of the B0 ! K0+− normalisation channel, respectively. A first measurement is made of the CP asymmetry, giving ACP (0b ! K 0 p−) = 0.22 ± 0.13 (stat) ± 0.03 (syst) . No significant signals are seen for 0b ! K0 SpK− decays, 0 b decays to both the K0 S p− and K0 SpK− final states, and the 0b ! D− s (! K0 SK−)p decay, and upper limits on their branching fractions are reported.
Searches for Λ0b and Ξ0b decays to K0Spπ− and K0SpK− final states with first observation of the Λ0b→K0Spπ− decay
ANDREOTTI, Mirco;CALABRESE, Roberto;FIORE, Marco;FIORINI, Massimiliano;LUPPI, Eleonora;PAPPALARDO, Luciano Libero;SAVRIE', Mauro;TELLARINI, Giulia;TOMASSETTI, Luca;
2014
Abstract
A search for previously unobserved decays of beauty baryons to the final states K0 S p− and K0 SpK− is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb−1 of pp collisions. The 0b ! K 0 p− decay is observed with a significance of 8.6 , with branching fraction B(0b ! K 0 p−) = (1.26 ± 0.19 ± 0.09 ± 0.34 ± 0.05) × 10−5 , where the uncertainties are statistical, systematic, from the ratio of fragmentation fractions f0 b /fd, and from the branching fraction of the B0 ! K0+− normalisation channel, respectively. A first measurement is made of the CP asymmetry, giving ACP (0b ! K 0 p−) = 0.22 ± 0.13 (stat) ± 0.03 (syst) . No significant signals are seen for 0b ! K0 SpK− decays, 0 b decays to both the K0 S p− and K0 SpK− final states, and the 0b ! D− s (! K0 SK−)p decay, and upper limits on their branching fractions are reported.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.