Observation of the singly Cabibbo-suppressed decay Λ c + → p π 0
Year: 2025
Type: article
Abstract: Utilizing 4.5 fb − 1 of e + e − annihilation data collected with the BESIII detector at the BEPCII collider at center-of-mass energies between 4.600 and 4.699 GeV, the first observation of the singly Cabibbo-suppressed decay Λ c + → p π 0 is presented, with a statistical significance of 5.4 σ . The ratio of the branching fractions of Λ c + → p π 0 and Λ c + → p η is measured as B ( Λ c + → p π 0 ) / B ( Λ c + → p η ) = ( 0.120 ± 0.02 6 stat ± 0.00 7 syst ) . This result resolves the longstanding discrepancy between earlier experimental searches, providing both a decisive conclusion and valuable input for QCD-inspired theoretical models. A sophisticated deep learning approach using a Transformer-based architecture is employed to distinguish the signal from the prevalent hadronic backgrounds, complemented by thorough validation and systematic uncertainty quantification.
Authors: M. Ablikim, M. N. Achasov, P. Adlarson, O. Afedulidis, X. C. Ai, R. Aliberti, A. Amoroso, Q. An, Y. Bai, O. Bakina, I. Balossino, Y. Ban, H.-R. Bao, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, J. F. Chang, G. R. Che, G. Chelkov, C. Chen, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. L. Chen, S. M. Chen, T. Chen, X. R. Chen, X. T. Chen, Y. B. Chen, Y. Q. Chen, Z. J. Chen, Z. Y. Chen, S. K. Choi, G. Cibinetto, F. Cossio, J. J. Cui, H. L. Dai, J. P. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, B. Ding, X. X. Ding, Y. Ding, Y. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, Y. H. Fan, J. Fang, J. Fang, S. S. Fang, W. X. Fang, Y. Fang, Y. Q. 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Institutions: Institute of High Energy Physics, Siberian Branch of the Russian Academy of Sciences, Budker Institute of Nuclear Physics, Uppsala University, Ruhr University Bochum, Zhengzhou University, Johannes Gutenberg University Mainz, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, University of Turin, University of Science and Technology of China, Southeast University, Joint Institute for Nuclear Research, Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Peking University, Chinese Academy of Sciences, University of Chinese Academy of Sciences, National Centre for Nuclear Research, Institute of Physics and Technology, Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Carnegie Mellon University, University of Münster, Wuhan University, Istinye University, Nankai University, China University of Geosciences, Soochow University, Henan University, North China Electric Power University, Nanjing University, Tsinghua University, Institute of Modern Physics, Jilin University, Hunan University, Chung-Ang University, Shandong University, Yunnan University, Helmholtz Institute Mainz, University of South China, University of Jinan, Liaoning University, Sun Yat-sen University, Università degli Studi del Piemonte Orientale “Amedeo Avogadro”, Nanjing Normal University, University of Ferrara, Henan Normal University, University of Manchester, University of Oxford, GSI Helmholtz Centre for Heavy Ion Research, Guangxi University, Shandong Normal University, Fudan University, Indiana University Bloomington, Indiana University, University of Hawaiʻi at Mānoa, University of Hawaii System, Suranaree University of Technology, South China Normal University, University of the Punjab, Liaoning Normal University, Hangzhou Normal University, Huangshan University, University of Tarapacá, University of Groningen, Indian Institute of Technology Madras, Justus-Liebig-Universität Gießen, Qufu Normal University, Renmin University of China, Lanzhou University, Hebei University, Sichuan University, Guangxi Normal University, Shanxi University, Central China Normal University, Henan University of Science and Technology, Henan University of Technology, Central South University, Zhejiang University, COMSATS University Islamabad, COMSATS University Islamabad, Lahore Campus, University of Perugia, Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Hunan Normal University, China Center of Advanced Science and Technology, Shanghai Jiao Tong University, Near East University, Beihang University, Inner Mongolia University, Yantai University, University of Bristol, Shanxi Normal University, University of Science and Technology Liaoning
Language: Latvian
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funders: U.S. Department of Energy, Strong, Istituto Nazionale di Fisica Nucleare Sezione di Padova, National Research Foundation, Deutsche Forschungsgemeinschaft, National Natural Science Foundation of China, Chinese Academy of Sciences, National Research Foundation of Korea, Renmin University of China, Narodowe Centrum Nauki, Vetenskapsrådet, Istituto Nazionale di Fisica Nucleare, Kalkinma Bakanliği, CAS Center for Excellence in Particle Physics, Shanghai Key Laboratory for Particle Physics and Cosmology, Guangxi Overseas High‐level Talent “Hundred People Program”, Horizon 2020 Framework Programme, Institute of High Energy Physics, National Key Research and Development Program of China, Fundamental Research Funds for the Central Universities, Key Research Program of Frontier Science, Chinese Academy of Sciences, HORIZON EUROPE Marie Sklodowska-Curie Actions
Awards: G1103821969, G1612394202, G1652990914, BESIII上正反超子对关联产生及其衰变的实验研究, G222768804, G2505060883, G2685115803, G2777307501, G2986027706, G305196018, G3234280719, G333704919, G3427629783, BESIII上胶球的寻找和轻介子谱的研究, G3534486373, G3790219004, G3800312211, G3829643926, G4460942179, G4799279977, G4883783264, BESIII实验类粲偶素的寻找和研究, UNDERSTANDING QCD IN THE LIGHT MESON SECTOR (WITH EMPHASIS ON MAPPING GLUONIC EXCITATIONS)..., Hochpräzisionsmessung des PionFormfaktors bei BESIII eine Verbesserung der hadronischen VakuumpolarisationsKorrektur zu (g2) des Myons, G6040273958, G6119985531, 北京谱仪III上Ds衰变的实验研究, G6371861488, 北京正负电子对撞机BESIII实验上粲重子Λc研究, G6746531785, G6768398141, G6789096068, G6845169765, G6927153966, G7356081053, 北京谱仪III上奇异介子和奇异夸克偶素的实验研究, G783835211, G8146335776, G8158558910, G8396383697, G8644667100, UNDERSTANDING QCD IN THE LIGHT MESON SECTOR (WITH EXPHASIS ON MAPPING GLUONIC EXCITATIONS) USING PION AND PHOTON PROBES, G8776819963, G8963843519, G904559116, G945438540, G965723986, G983105509
OpenAlex ID: W4408442546