TY - JOUR

T1 - Measurement of the singly Cabibbo-suppressed decay Λc+→pη′ with deep learning

AU - BESIII Collaboration

AU - Ачасов, Михаил Николаевич

AU - Мучной, Николай Юрьевич

AU - Николаев, Иван Борисович

N1 - The BESIII Collaboration thanks the staff of BEPCII (https://cstr.cn/31109.02.BEPC) and the IHEP computing center for their strong support. This work is supported in part by National Key R&D Program of China under Contracts Nos. 2023YFA1606000, 2023YFA1606704; National Natural Science Foundation of China (NSFC) under Contracts Nos. 11635010, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; CAS Project for Young Scientists in Basic Research No. YSBR-117; the Strategic Priority Research Program of Chinese Academy of Sciences under Contract No. XDA0480600; CAS under Contract No. YSBR-101; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmol-ogy; ERC under Contract No. 758462; German Research Foundation DFG under Contract No. FOR5327; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation under Contracts Nos. 2021.0174, 2021.0299; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Research Foundation of Korea under Contract No. NRF-2022R1A2C1092335; National Science and Technology fund of Mongolia; Polish National Science Centre under Contract No. 2024/53/B/ST2/00975; STFC (United Kingdom); Swedish Research Council under Contract No. 2019.04595; U.S. Department of Energy under Contract No. DE-FG02-05ER41374.

PY - 2026/7/28

Y1 - 2026/7/28

N2 - Using 4.5 fb−1 of e +e − collision data collected with the BESIII detector at center-of-mass energies from 4.600 to 4.699 GeV, we report a measurement of the singly Cabibbo-suppressed decay Λ + c → pη′ with the single-tag method. To effectively distinguish the signal from the large backgrounds, we exploit a deep-learning classifier built on a Transformer-based neural network. Extensive validation and uncertainty quantification are carried out. The Λ + c → pη′ signal is observed with a statistical significance of 3.1σ. The ratio of branching fractions of B(Λ+ c → pη′ )/B(Λ+ c → pω) = 0.55 ± 0.22 ± 0.05 is obtained, where the first uncertainty is statistical and the second systematic.

AB - Using 4.5 fb−1 of e +e − collision data collected with the BESIII detector at center-of-mass energies from 4.600 to 4.699 GeV, we report a measurement of the singly Cabibbo-suppressed decay Λ + c → pη′ with the single-tag method. To effectively distinguish the signal from the large backgrounds, we exploit a deep-learning classifier built on a Transformer-based neural network. Extensive validation and uncertainty quantification are carried out. The Λ + c → pη′ signal is observed with a statistical significance of 3.1σ. The ratio of branching fractions of B(Λ+ c → pη′ )/B(Λ+ c → pω) = 0.55 ± 0.22 ± 0.05 is obtained, where the first uncertainty is statistical and the second systematic.

KW - Branching fraction

KW - Charm Physics

KW - e +-e − Experiments

UR - https://www.scopus.com/pages/publications/105048036364

U2 - 10.1007/JHEP07(2026)265

DO - 10.1007/JHEP07(2026)265

M3 - Article

VL - 2026

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1029-8479

IS - 7

M1 - 265

ER -