We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88×106 Υ(4S)→BB̅ decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B0 or B̅ 0 from its decay products. The amplitude of the CP asymmetry, which in the standard model is proportional to sin⁡2β, is derived from the decay-time distributions in such events. We measure sin⁡2β=0.741±0.067(stat)±0.034(syst) and |λ|=0.948±0.051(stat)±0.030(syst). The magnitude of λ is consistent with unity, in agreement with the standard model expectation of no direct CP violation in these modes.

Measurement of the CP asymmetry amplitude sin 2beta with B0 mesons

CONTRI, ROBERTO;LO VETERE, MAURIZIO;MONGE, MARIA ROBERTA;PATRIGNANI, CLAUDIA;ROBUTTI, ENRICO;SANTRONI, ALBERTO;TOSI, SILVANO;
2002-01-01

Abstract

We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88×106 Υ(4S)→BB̅ decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B0 or B̅ 0 from its decay products. The amplitude of the CP asymmetry, which in the standard model is proportional to sin⁡2β, is derived from the decay-time distributions in such events. We measure sin⁡2β=0.741±0.067(stat)±0.034(syst) and |λ|=0.948±0.051(stat)±0.030(syst). The magnitude of λ is consistent with unity, in agreement with the standard model expectation of no direct CP violation in these modes.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/213240
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