Journal Article

Observations of the singly Cabibbo-suppressed decays$$ {\\Xi}_c^{+}\\to p{K}_S^0 $$ ,$$ {\\Xi}_c^{+}\\to \\Lambda {\\pi}^{+} $$ , and$$ {\\Xi}_c^{+}\\to {\\Sigma}^0{\\pi}^{+} $$at Belle and Belle II

Madaan, C., Althubiti, N., Borah, J., de Sangro, R., Di Canto, A., Hayashii, H., Mantovano, M., Chirapatpimol, K., Gaur, V., Meleshko, D., Onuki, Y., Kinoshita, K., Watanabe, M., Lin, J., Kawasaki, T., Domínguez Jiménez, I., Mancinelli, G., Chilikin, K., Praz, C., Di Capua, F., Gaudino, G., Hoppe, R., Bertholet, E., Mirra, M., Itoh, R., Unno, Y., Natkaniec, Z., Yuan, C. Z., Gruberová, Z., Jaffe, D. E., Xu, X. P., De Pietro, G., Bozek, A., Soffer, A., Dugic, K., Fillinger, T., Marcello, S., Nakamura, I., Bianchi, F., Schwanda, C., Cui, J. X., Patra, S., Jang, E.-J., Kumara, K., Nazaryan, G., Ghevondyan, G., Nishida, S., Graziani, E., Moneta, S., Ricalde Herrmann, D., De Nardo, G., Jacobs, W. W., Podobnik, T., Gobbo, B., Junkerkalefeld, H., Destefanis, M., Kovalenko, E., Križan, P., Asner, D. M., Massaccesi, L., Alhakami, M., Lyu, C., Dingfelder, J., Park, H., Hohmann, M., Horak, P., Higuchi, T., Martinov, T., Roehrken, M., Casarosa, G., Hernández Villanueva, M., Aversano, M., Giordano, R., Kojima, K., Cecchi, C., Tamponi, U., Ueda, I., Peruzzi, I., Pakhlova, G., Senyo, K., Ripp-Baudot, I., Sobotzik, M., Dey, S., Dujany, G., Campagna, Q., Svidras, H., Camp

2025

Overview

Using data samples of 983.0 fb − 1 and 427.9 fb − 1 accumulated with the Belle and Belle II detectors operating at the KEKB and SuperKEKB asymmetric-energy e + e − colliders, singly Cabibbo-suppressed decays$$ {\\Xi}_c^{+}\\to p{K}_S^0 $$Ξ c + → p K S 0 ,$$ {\\Xi}_c^{+}\\to \\Lambda {\\pi}^{+} $$Ξ c + → Λ π + , and$$ {\\Xi}_c^{+}\\to {\\Sigma}^0{\\pi}^{+} $$Ξ c + → Σ 0 π + are observed for the first time. The ratios of branching fractions of$$ {\\Xi}_c^{+}\\to p{K}_S^0 $$Ξ c + → p K S 0 ,$$ {\\Xi}_c^{+}\\to \\Lambda {\\pi}^{+} $$Ξ c + → Λ π + , and$$ {\\Xi}_c^{+}\\to {\\Sigma}^0{\\pi}^{+} $$Ξ c + → Σ 0 π + relative to that of$$ {\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+} $$Ξ c + → Ξ − π + π + are measured to be$$ {\\displaystyle \\begin{array}{c}\\frac{\\mathcal{B}\\left({\\Xi}_c^{+}\\to p{K}_S^0\\right)}{\\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+}\\right)}=\\left(2.47\\pm 0.16\\pm 0.07\\right)\\%,\\\ {}\\frac{\\mathcal{B}\\left({\\Xi}_c^{+}\\to \\Lambda {\\pi}^{+}\\right)}{\\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+}\\right)}=\\left(1.56\\pm 0.14\\pm 0.09\\right)\\%,\\\ {}\\frac{\\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Sigma}^0{\\pi}^{+}\\right)}{\\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+}\\right)}=\\left(4.13\\pm 0.26\\pm 0.22\\right)\\%.\\end{array}} $$B Ξ c + → p K S 0 B Ξ c + → Ξ − π + π + = 2.47 ± 0.16 ± 0.07 % , B Ξ c + → Λ π + B Ξ c + → Ξ − π + π + = 1.56 ± 0.14 ± 0.09 % , B Ξ c + → Σ 0 π + B Ξ c + → Ξ − π + π + = 4.13 ± 0.26 ± 0.22 % . Multiplying these values by the branching fraction of the normalization channel,$$ \\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+}\\right)=\\left(2.9\\pm 1.3\\right)\\% $$B Ξ c + → Ξ − π + π + = 2.9 ± 1.3 % , the absolute branching fractions are determined to be$$ {\\displaystyle \\begin{array}{c}\\mathcal{B}\\left({\\Xi}_c^{+}\\to p{K}_S^0\\right)=\\left(7.16\\pm 0.46\\pm 0.20\\pm 3.21\\right)\\times {10}^{-4},\\\ {}\\mathcal{B}\\left({\\Xi}_c^{+}\\to \\Lambda {\\pi}^{+}\\right)=\\left(4.52\\pm 0.41\\pm 0.26\\pm 2.03\\right)\\times {10}^{-4},\\\ {}\\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Sigma}^0{\\pi}^{+}\\right)=\\left(1.20\\pm 0.08\\pm 0.07\\pm 0.54\\right)\\times {10}^{-3}.\\end{array}} $$B Ξ c + → p K S 0 = 7.16 ± 0.46 ± 0.20 ± 3.21 × 10 − 4 , B Ξ c + → Λ π + = 4.52 ± 0.41 ± 0.26 ± 2.03 × 10 − 4 , B Ξ c + → Σ 0 π + = 1.20 ± 0.08 ± 0.07 ± 0.54 × 10 − 3 . The first and second uncertainties above are statistical and systematic, respectively, while the third ones arise from the uncertainty in$$ \\mathcal{B}\\left({\\Xi}_c^{+}\\to {\\Xi}^{-}{\\pi}^{+}{\\pi}^{+}\\right) $$B Ξ c + → Ξ − π + π + .