English

Measurement of CP violation observables and parameters for the decays $B^{\pm}\to D K^{*\pm}$

High Energy Physics - Experiment 2010-04-12 v1

Abstract

We study the decay BDKB^-\to DK^{*-} using a sample of 379×106\times 10^6 Υ(4S)BBˉ\Upsilon(4S)\to B\bar{B} events collected with the BABAR detector at the PEP-II BB-factory. We perform a "GLW" analysis where the DD meson decays into either a CP-even (CP+CP+) eigenstate (K+KK^+K^-, π+π\pi^+\pi^-), CP-odd (CPCP-) eigenstate (KS0π0K^0_S\pi^0, KS0ϕK^0_S\phi, KS0ωK^0_S\omega) or a non-CP state (Kπ+K^-\pi^+). We also analyze DD meson decays into K+πK^+\pi^- from a Cabibbo-favored Dˉ0\bar{D}^0 decay or doubly suppressed D0D^0 decay ("ADS" analysis). We measure observables that are sensitive to the CKM angle γ\gamma: the partial-rate charge asymmetries ACP±{\cal A}_{CP\pm}, the ratios RCP±{\cal R}_{CP\pm} of the B-decay branching fractions in CP±CP\pm and non-CP decay, the ratio RADS{\cal R}_{ADS} of the charge-averaged branching fractions, and the charge asymmetry AADS{\cal A}_{ADS} of the ADS decays: ACP+=0.09±0.13±0.06{\cal A}_{CP+}= 0.09\pm0.13 \pm 0.06, ACP=0.23±0.21±0.07{\cal A}_{CP-}=-0.23\pm 0.21\pm 0.07, RCP+=2.17±0.35±0.09{\cal R}_{CP+} =2.17 \pm 0.35 \pm 0.09,RCP=1.03±0.27±0.13{\cal R}_{CP-} =1.03\pm 0.27\pm 0.13, RADS=0.066±0.031±0.010{\cal R}_{ADS}=0.066\pm0.031\pm0.010, and AADS=0.34±0.43±0.16{\cal A}_{ADS}=-0.34\pm0.43\pm 0.16, where the first uncertainty is statistical and the second is systematic. Combining all the measurements and using a frequentist approach yields the magnitude of the ratio between the Cabibbo-suppressed and favored amplitudes, rBr_B = 0.31 with a one (two) sigma confidence level interval of [0.24, 0.38] ([0.17, 0.43]). The value rB=0r_B=0 is excluded at the 3.3 sigma level. A similar analysis excludes values of γ\gamma in the intervals [0,7],[55,111][0, 7]^{\circ}, [55, 111]^{\circ}, and [175,180][175, 180]^{\circ} ([85, 99]^{\circ}) at the one (two) sigma confidence level.

Keywords

Cite

@article{arxiv.0909.3981,
  title  = {Measurement of CP violation observables and parameters for the decays $B^{\pm}\to D K^{*\pm}$},
  author = {The BaBar Collaboration and B. Aubert},
  journal= {arXiv preprint arXiv:0909.3981},
  year   = {2010}
}

Comments

15 pages, 13 figures (.eps), to be submitted to PRD