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新山 雅之 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 発行・発表の年月 | 2021/06 |
| 形態種別 | その他 |
| 標題 | Measurement of branching fractions and search for $CP$ violation in $D^{0}\toπ^{+}π^{-}η$, $D^{0}\to K^{+}K^{-}η$, and $D^{0}\toφη$ at Belle |
| 執筆形態 | その他 |
| 著者・共著者 | Belle Collaboration,L. K. Li,A. J. Schwartz,K. Kinoshita,I. Adachi,H. Aihara,S. Al Said,D. M. Asner,H. Atmacan,V. Aulchenko,T. Aushev,R. Ayad,V. Babu,S. Bahinipati,P. Behera,J. Bennett,M. Bessner,T. Bilka,J. Biswal,A. Bobrov,G. Bonvicini,A. Bozek,M. Bra\v,P. Branchini,T. E. Browder,A. Budano,M. Campajola,D. \v,M. -C. Chang,P. Chang,V. Chekelian,A. Chen,Y. Q. Chen,B. G. Cheon,K. Chilikin,H. E. Cho,K. Cho,S. -J. Cho,S. -K. Choi,Y. Choi,S. Choudhury,D. Cinabro,S. Cunliffe,S. Das,N. Dash,G. De Nardo |
| 概要 | We measure the branching fractions and $CP$ asymmetries for the singly
Cabibbo-suppressed decays $D^{0}\to\pi^{+}\pi^{-}\eta$, $D^{0}\to K^{+}K^{-}\eta$, and $D^{0}\to\phi\eta$, using 980 fb$^{-1}$ of data from the Belle experiment at the KEKB $e^+e^-$ collider. We obtain \begin{eqnarray} \mathcal{B}(D^{0}\to\pi^{+}\pi^{-}\eta) & = & [1.22\pm 0.02\,({\rm stat})\pm 0.02\,({\rm syst})\pm 0.03\,(\mathcal{B}_{\rm ref})]\times 10^{-3}\,, \nonumber \\ \mathcal{B}(D^{0}\to K^{+}K^{-}\eta) & = & [1.80\,^{+0.07}_{-0.06}\,({\rm stat})\pm 0.04\,({\rm syst})\pm 0.05\,(\mathcal{B}_{\rm ref})]\times 10^{-4}\,, \nonumber \\ \mathcal{B}(D^{0}\to\phi\eta) & = & [1.84\pm 0.09\,({\rm stat})\pm 0.06\,({\rm syst})\pm 0.05\,(\mathcal{B}_{\rm ref})]\times 10^{-4}\,, \nonumber \end{eqnarray} where the third uncertainty ($\mathcal{B}_{\rm ref}$) is from the uncertainty in the branching fraction of the reference mode $D^{0}\to K^{-}\pi^{+}\eta$. The color-suppressed decay $D^{0}\to\phi\eta$ is observed for the first time, with very high significance. The results for the $CP$ asymmetries are \begin{eqnarray} A_{CP}(D^{0}\to\pi^{+}\pi^{-}\eta) & = & [0.9\pm 1.2\,({\rm stat})\pm 0.5\,({\rm syst})]\%\,, \nonumber \\ A_{CP}(D^{0}\to K^{+}K^{-}\eta) & = & [-1.4\pm 3.3\,({\rm stat})\pm 1.1\,({\rm syst})]\%\,, \nonumber \\ A_{CP}(D^{0}\to\phi\eta)&= & [-1.9\pm 4.4\,({\rm stat})\pm 0.6\,({\rm syst})]\%\,. \nonumber \end{eqnarray} The results for $D^{0}\to\pi^{+}\pi^{-}\eta$ are a significant improvement over previous results. The branching fraction and $A_{CP}$ results for $D^{0}\to K^{+}K^{-}\eta$, and the $A_{CP}$ result for $D^{0}\to\phi\eta$, are the first such measurements. No evidence for $CP$ violation is found in any of these decays. |
| DOI | 10.1007/JHEP09(2021)075 |
| PermalinkURL | http://arxiv.org/abs/2106.04286v2 |
| researchmap用URL | http://arxiv.org/pdf/2106.04286v2 |