新山　雅之
   所属   京都産業大学  理学部 物理科学科
   職種   教授
発行・発表の年月 2022/06
形態種別 その他
標題 Evidence of a new excited charmed baryon decaying to $Σ_{c}(2455)^{0,++} π^{\pm}$
執筆形態 その他
著者・共著者 Belle Collaboration,Y. B. Li,C. P. Shen,I. Adachi,H. Aihara,D. M. Asner,H. Atmacan,T. Aushev,R. Ayad,V. Babu,S. Bahinipati,P. Behera,K. Belous,J. Bennett,M. Bessner,V. Bhardwaj,B. Bhuyan,T. Bilka,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. Das,G. De Pietro,R. Dhamija,F. Di Capua,J. Dingfelder,Z. Doležal,T. V. Dong,D. Dos
概要 We present the study of $\bar{B}^{0} \to \Sigma_{c}(2455)^{0,++} \pi^{\pm}
\bar{p}$ decays based on $772\times 10^{6}$ $B\bar{B}$ events collected with
the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The
$\Sigma_{c}(2455)^{0,++} $ candidates are reconstructed via their decay to
$\Lambda_{c}^{+} \pi^{\mp}$ and $\Lambda_{c}^{+}$ decays to
$pK^{-}\pi^{+},~pK_{S}^{0},$ and $\Lambda\pi^{+}$ final states. The
corresponding branching fractions are measured to be ${\cal B}(\bar{B}^{0} \to
\Sigma_{c}(2455)^{0} \pi^{+} \bar{p}) = (1.09 \pm 0.06 \pm 0.07)\times10^{-4}$
and ${\cal B}(\bar{B}^{0} \to \Sigma_{c}(2455)^{++} \pi^{-} \bar{p}) = (1.84\pm
0.11 \pm 0.12)\times 10^{-4}$, which are consistent with the world average
values with improved precision. A new structure is found in the
$M_{\Sigma_{c}(2455)^{0,++}\pi^{\pm } }$ spectrum with a significance of
$4.2\sigma$ including systematic uncertainty. The structure is possibly an
excited $\Lambda_{c}^{+}$ and is tentatively named $\Lambda_{c}(2910)^{+}$. Its
mass and width are measured to be $(2913.8 \pm 5.6 \pm 3.8)$ MeV/$c^{2}$ and
$(51.8\pm20.0 \pm 18.8)$ MeV, respectively. The products of branching fractions
for the $\Lambda_{c}(2910)^{+}$ are measured to be ${\cal B}(\bar{B}^{0} \to
\Lambda_{c}(2910)^{+}\bar{p})\times{\cal B}(\Lambda_{c}(2910)^{+} \to
\Sigma_{c}(2455)^{0}\pi^{+}) = (9.5 \pm 3.6 \pm 1.6)\times 10^{-6}$ and ${\cal
B}(\bar{B}^{0} \to \Lambda_{c} (2910)^{+}\bar{p})\times {\cal
B}(\Lambda_{c}(2910)^{+} \to \Sigma_{c}(2455)^{++}\pi^{-}) = (1.24 \pm 0.35 \pm
0.10)\times 10^{-5}$. Here, the first and second uncertainties are statistical
and systematic, respectively.
DOI 10.1103/PhysRevLett.130.031901
PermalinkURL http://arxiv.org/abs/2206.08822v3
researchmap用URL http://arxiv.org/pdf/2206.08822v3