We present a summary of recent results on CP violation and mixing in the charm quark sector based on a high statistics sample collected by photoproduction experiment FOCUS (E831 at Fermilab). We have measured the difference in lifetimes for the D0 decays: D0 --> K-pi+ and D0 --> K-K+ . This translates into a measurement of the y_cp mixing parameter in the D0/D0bar system, under the assumptions that K+K- is an equal mixture of CP odd and CP even eigenstates, and CP violation is negligible in the neutral charm meson system. We verified the latter assumption by searching for a CP violating asymmetry in the Cabibbo suppressed decay modes D+ --> K-K+pi+ , D0 --> K-K+ and D0 --> pi-pi+ . We show preliminary results on a measurement of the branching ratio Gamma(D*+ --> pi+(K+pi-))/Gamma(D*+ --> pi+(K-pi+)).
New FOCUS results on charm mixing and CP violation
ARENA, VINCENZO;BOCA, GIANLUIGI;LIGUORI, GIUSEPPE;RATTI, SERGIO PEPPINO;RICCARDI, CRISTINA;TORRE, PAOLA;VITULO, PAOLO;
2000-01-01
Abstract
We present a summary of recent results on CP violation and mixing in the charm quark sector based on a high statistics sample collected by photoproduction experiment FOCUS (E831 at Fermilab). We have measured the difference in lifetimes for the D0 decays: D0 --> K-pi+ and D0 --> K-K+ . This translates into a measurement of the y_cp mixing parameter in the D0/D0bar system, under the assumptions that K+K- is an equal mixture of CP odd and CP even eigenstates, and CP violation is negligible in the neutral charm meson system. We verified the latter assumption by searching for a CP violating asymmetry in the Cabibbo suppressed decay modes D+ --> K-K+pi+ , D0 --> K-K+ and D0 --> pi-pi+ . We show preliminary results on a measurement of the branching ratio Gamma(D*+ --> pi+(K+pi-))/Gamma(D*+ --> pi+(K-pi+)).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
