arXiv subjects
Publications and source records attributed to H. Sahoo.
We present the result of a search for charge asymmetry in B^+ -> J/psi K^+ decays. The CP-violating charge asymmetry is measured to be A_CP(B^+ -> J/psi K^+) = [-0.76 +/- 0.50 (stat) +/- 0.22 (syst)]%.
We report a measurement of $CP$ violating asymmetries in $B^0(\overline{B}^0) \to K^+ K^- K^0_S$ decays with a time-dependent Dalitz approach. This analysis is based on a data sample of $657\times 10^6$ $B\overline{B}$ pairs accumulated at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. As the result of an unbinned maximum likelihood fit to the selected candidates, the mixing-induced and direct $CP$ violation parameters, $ϕ^{\rm eff}_1$ and ${\cal A}_{CP}$ are obtained for $B^0 \to ϕ(1020) K^0_S$, $B^0 \to f_0(980) K^0_S$ and other $B^0 \to K^+ K^- K^0_S$ decays. We find four solutions that describe the data. There are \{eqnarray*} ϕ_1^{\rm eff}(B^0\to ϕ(1020) K^0_S) & = & (32.2 \pm 9.0 \pm 2.6 \pm 1.4)^{\circ}; ϕ_1^{\rm eff}(B^0\to ϕ(1020) K^0_S) & = & (26.2 \pm 8.8 \pm 2.7 \pm 1.2)^{\circ};\\ ϕ_1^{\rm eff}(B^0\to ϕ(1020) K^0_S) & = & (27.3 \pm 8.6 \pm 2.8 \pm 1.3)^{\circ}\; {\rm and}\\ ϕ_1^{\rm eff}(B^0\to ϕ(1020) K^0_S) & = & (24.3 \pm 8.0 \pm 2.9 \pm 5.2)^{\circ}.{eqnarray*}\ The values for the $CP$ violating phase in $B^0\to ϕ(1020) K^0_S$ are similar but other properties of the Dalitz plot are quite different for the four solutions. These four solutions have consistent $ϕ^{\rm eff}_1$ values for all three $B$ meson decay channels and none of them deviates significantly from the values measured in $B \to (c\bar{c}) K^0$ decays with the currently available statistics. In addition, we find no significant direct $CP$ violation.
We present the result of a search for charge asymmetry in B^+ -> J/psi K^+ decays. The CP-violating charge asymmetry is measured to be A_CP(B^+ -> J/psi K^+) = [-0.76 +/- 0.50 (stat) +/- 0.22 (syst)]%.
In this proceeding, we discuss recent results on exclusive radiative B meson decays from the Belle Collaboration. These decays are sensitive to right-handed currents from New Physics. In particular, we measure time-dependent CP violation parameters in B^0->K_Sπ^0γand B^0->K_Sρ^0γdecays, using high-statistics data samples collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. With the present statistics, these measurements are consistent with the standard model predictions. We also search for the radiative decay B^0->\phiK^0γand report the first observation with a significance of 5.4 σ, including systematic uncertainties.
We report improved measurements of time-dependent CP violation parameters for B^0(\bar{B}^0) -> psi(2S) K_S. This analysis is based on a data sample of 657x10^6 BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. We fully reconstruct one neutral B meson in the psi(2S) K_S CP-eigenstate decay channel, and the flavor of the accompanying B meson is identified to be either B^0 or \bar{B}^0 from its decay products. CP violation parameters are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays: S (psi(2S) K_S) = +0.72 +/- 0.09(stat) +/- 0.03(syst), A (psi(2S) K_S) = +0.04 +/- 0.07(stat) +/- 0.05(syst). These results are in agreement with results from measurements of B^0 -> J/psi K^0.