Improved Measurement of Cp Asymmetry in the Neutral B Meson System
نویسنده
چکیده
We present an improved measurement of the standard model CP violation parameter sin 2φ1 (also known as sin 2β) based on a sample of 45×10 BB pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy ee collider. One neutral B meson is reconstructed in the J/ψK S, ψ(2S)K 0 S , χc1K 0 S , ηcK 0 S , J/ψK , or J/ψK L CP -eigenstate decay channel and the flavor of accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain sin 2φ1 = 0.82± 0.12(stat) ± 0.05(syst). The result is preliminary.
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تاریخ انتشار 2002