Measurements of the branching fractions of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi mathvariant="normal">Λ</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:mi>p</mml:mi><mml:mi>η</mml:mi></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>c</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:mi>p</mml:mi><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>decays at Belle
S. X. Li, C. P. Shen, I. Adachi, J. K. Ahn, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. K. Behera, J. V. Bennett, F. U. Bernlochner, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, J. P. Biswal, A. Bobrov, A. Bożek, T. E. Browder, M. Campajola, L. Cao, D. Červenkov, M.-C. Chang, A. Chen, B. G. Cheon, K. Chilikin, H. E. Cho, K. Cho, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Das, N. Dash, G. De Nardo, R. Dhamija, F. Di Capua, Z. Doležal, T. V. Dong, S. Eidelman, D. Epifanov, T. Ferber, D. Ferlewicz, B. G. Fulsom, R. Garg, V. Gaur, A. Garmash, A. Giri, P. Goldenzweig, B. Golob, O. Grzymkowska, K. Gudkova, C. Hadjivasiliou, O. Hartbrich, K. Hayasaka, H. Hayashii, M. T. Hedges, W.-S. Hou, C.-L. Hsu, T. Iijima, K. Inami, G. Inguglia, A. Ishikawa, R. Itoh, M. Iwasaki, M. Iwasaki, W. W. Jacobs, E. -J. Jang, S. Jia, Y. Jin, C. Joo, K. K. Joo, A. B. Kaliyar, K. Kang, G. Karyan, Yuji Katō, T. Kawasaki, H. Kichimi, B. H. Kim, C.H. Kim, D. Y. Kim, K.-H. Kim, S. H. Kim, Y.-K. Kim, K. Kinoshita, P. Kodyš, T Konno, A. Korobov, S. Korpar, E. Kovalenko, P. Križan, R. Kroeger, P. Krokovny, T. Kuhr, M. Kumar, K. Kumara, A. Kuzmin, Y. Kwon
Abstract
We report measurements of the branching fractions of singly Cabibbo-suppressed decays ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p\ensuremath{\eta}$ and ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{0}$ using the full Belle data sample corresponding to an integrated luminosity of $980.6\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. The data were collected by the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric energy collider. A clear ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}$ signal is seen in the invariant mass distribution of $p\ensuremath{\eta}$. The fitted number of signal events of the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p\ensuremath{\eta}$ process is $7734\ifmmode\pm\else\textpm\fi{}263$; from this, we measure the ratio of branching fractions $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p\ensuremath{\eta})/\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=\phantom{\rule{0ex}{0ex}}[2.258\ifmmode\pm\else\textpm\fi{}0.077(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.122(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, from which we infer the branching fraction $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p\ensuremath{\eta})=\phantom{\rule{0ex}{0ex}}[1.42\ifmmode\pm\else\textpm\fi{}0.05(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.11(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. In addition, no significant signal for ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{0}$ is found, so an upper limit on the branching fraction of $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{0})<8.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ at a 90% credibility level is set, more than 3 times better than the best current upper limit.