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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 | 2023/02 |
| 形態種別 | その他 |
| 標題 | Study of the lineshape of $X(3872)$ using $B$ decays to $D^0\overline{D}{}^{*0}K$ |
| 執筆形態 | その他 |
| 著者・共著者 | Belle Collaboration,H. Hirata,T. Iijima,Y. Kato,K. Tanida,I. Adachi,J. K. Ahn,H. Aihara,S. Al Said,D. M. Asner,H. Atmacan,T. Aushev,R. Ayad,V. Babu,Sw. Banerjee,P. Behera,K. Belous,J. Bennett,M. Bessner,V. Bhardwaj,B. Bhuyan,T. Bilka,D. Biswas,A. Bobrov,D. Bodrov,J. Borah,A. Bozek,M. Bračko,P. Branchini,T. E. Browder,A. Budano,M. Campajola,D. Červenkov,M. -C. Chang,P. Chang,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,G. de Ma |
| 概要 | We present a study of the $X(3872)$ lineshape in the decay $B \to X(3872)K\to
D^0\overline{D}{}^{*0}K$ using a data sample of $772\times 10^6$ $B\overline{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The peak near the threshold in the $D^0\overline{D}{}^{*0}$ invariant mass spectrum is fitted using a relativistic Breit-Wigner lineshape. We determine the mass and width parameters to be $m = 3873.71 ^{+0.56}_{-0.50} ({\rm stat}) \pm0.13 ({\rm syst}) ~{\rm MeV}/c^2$ and $\Gamma_0 = 5.2 ^{+2.2}_{-1.5} ({\rm stat}) \pm 0.4 ({\rm syst})~{\rm MeV}$, respectively. The branching fraction is found to be ${\cal B} (B^+\to X(3872)K^+) \times {\cal{B } }(X(3872) \to D^0\overline{D}{}^{*0}) = (0.97 ^{+0.21}_{-0.18} ({\rm stat}) \pm 0.10 ({\rm syst})) \times 10^{-4}$. The signal from $B^0$ decays is observed for the first time with $5.2\sigma$ significance, and the ratio of branching fractions between charged and neutral $B$ decays is measured to be ${\cal B}(B^0\to X(3872)K^0)/{\cal B}(B^+ \to X(3872)K^+) = 1.34^{+0.47}_{-0.40} ({\rm stat}) ^{+0.10}_{-0.12} ({\rm syst})$. The peak is also studied using a Flatt\'{e} lineshape. We determine the lower limit on the $D\overline{D}{}^{*}$ coupling constant $g$ to be $0.075$ at 95% credibility in the parameter region where the ratio of $g$ to the mass difference from the $D^0\overline{D}{}^{*0}$ threshold is equal to $-15.11~{\rm GeV}^{-1}$, as measured by LHCb. |
| DOI | 10.1103/PhysRevD.107.112011 |
| PermalinkURL | http://arxiv.org/abs/2302.02127v2 |
| researchmap用URL | http://arxiv.org/pdf/2302.02127v2 |