TY - JOUR

T1 - First measurement of Σ+n → ¢p and Σ+n → Σ0 p cross sections via Σ+-nucleus scattering at an electron-positron collider

AU - BESIII Collaboration

AU - Ачасов, Михаил Николаевич

AU - Мучной, Николай Юрьевич

AU - Николаев, Иван Борисович

N1 - The BESIII Collaboration thanks the staff of BEPCII 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 No. 2020YFA0406300, No. 2020YFA0406400, and No. 2023YFA1606000; National Natural Science Foundation of China (NSFC) under Contracts No. 12375071, No. 11635010, No. 11735014, No. 11935015, No. 11935016, No. 11935018, No. 12025502, No. 12035009, No. 12035013, No. 12061131003, No. 12192260, No. 12192261, No. 12192262, No. 12192263, No. 12192264, No. 12192265, No. 12221005, No. 12225509, No. 12235017, and No. 12361141819; Natural Science Foundation of Henan under Contract No. 242300421163; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contract No. U1832207; 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 Cosmology; 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; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand under Contract No. B50G670107; Polish National Science Centre under Contract No. 2019/35/O/ST2/02907; Swedish Research Council under Contract No. 2019.04595; The Swedish Foundation for International Cooperation in Research and Higher Education under Contract No. CH2018-7756; U. S. Department of Energy under Contract No. DE-FG02-05ER41374.

PY - 2026/3/23

Y1 - 2026/3/23

N2 - Using (1.0087 ± 0.0044) × 1010 J/ψ events collected with the BESIII detector at the BEPCII storage ring, the reactions +n → p and +n → 0 p are studied, where the + baryon is produced in the process J/ψ → +¯ − and the neutron is a component of the 9Be, 12C, and 197Au nuclei in the beam pipe. Clear signals of these two reactions are observed for the first time. Their cross sections are measured to be σ (+ + 9Be → + p + X ) = (45.2 ± 12.1stat ± 7.2sys) mb and σ (+ + 9Be → 0 + p + X ) = (29.8 ± 9.7stat ± 6.9sys) mb for a + average momentum of 0.992 GeV/c, within a range of ±0.015 GeV/c, where X represents the residual nucleus. This is the first study of +-nucleon scattering at an electron-positron collider. The measured results serve as a significant element in enhancing the comprehensive understanding of hyperon-nucleon interactions, and also constitute an important factor in resolving the “hyperon puzzle” of neutron stars.

AB - Using (1.0087 ± 0.0044) × 1010 J/ψ events collected with the BESIII detector at the BEPCII storage ring, the reactions +n → p and +n → 0 p are studied, where the + baryon is produced in the process J/ψ → +¯ − and the neutron is a component of the 9Be, 12C, and 197Au nuclei in the beam pipe. Clear signals of these two reactions are observed for the first time. Their cross sections are measured to be σ (+ + 9Be → + p + X ) = (45.2 ± 12.1stat ± 7.2sys) mb and σ (+ + 9Be → 0 + p + X ) = (29.8 ± 9.7stat ± 6.9sys) mb for a + average momentum of 0.992 GeV/c, within a range of ±0.015 GeV/c, where X represents the residual nucleus. This is the first study of +-nucleon scattering at an electron-positron collider. The measured results serve as a significant element in enhancing the comprehensive understanding of hyperon-nucleon interactions, and also constitute an important factor in resolving the “hyperon puzzle” of neutron stars.

KW - Meson & hyperon induced nuclear reactions

KW - Particle interactions

KW - Total cross sections

KW - Baryons

KW - Strange quark

KW - Lepton colliders

UR - https://www.scopus.com/pages/publications/105040166787

U2 - 10.1103/nzzh-4f6y

DO - 10.1103/nzzh-4f6y

M3 - Letter

VL - 113

JO - Physical Review C

JF - Physical Review C

SN - 2469-9985

IS - 3

M1 - L032201

ER -