We describe a measurement of the direct CP asymmetry between inclusive b-->sgamma and (b) over bar -->(s) over bar gamma decays. This asymmetry is expected to be less than 0.01 in the standard model, but could be enhanced up to about 0.10 by new physics contributions. We use a sample of 89x10(6) B (B) over bar pairs recorded with the BABAR detector at SLAC PEP-II, from which we reconstruct a set of 12 exclusive b-->sgamma final states containing one charged or neutral kaon and one to three pions. We measure an asymmetry of A(CP)(b-->sgamma)=0.025+/-0.050(stat)+/-0.015(syst), corresponding to an allowed range of -0.06sgamma)<+0.11 at 90% confidence level.
A measurement of the direct CP asymmetry between inclusive b→sγ decays was performed. It was observed that this asymmetry was expected to be less than 0.01 in the standard model but could be enhanced up to 0.10. The different components of the signal and background events was also identified that was described by a crystal ball function. Monte Carlo simulations were also applied to the four contributions to the beam energy substituted mass distribution of events.
Measurement of the direct CP asymmetry in b -> s gamma decays RID C-5223-2009 RID C-5719-2008 RID D-1055-2009
LUSIANI, Alberto;
2004
Abstract
A measurement of the direct CP asymmetry between inclusive b→sγ decays was performed. It was observed that this asymmetry was expected to be less than 0.01 in the standard model but could be enhanced up to 0.10. The different components of the signal and background events was also identified that was described by a crystal ball function. Monte Carlo simulations were also applied to the four contributions to the beam energy substituted mass distribution of events.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
