TY - JOUR

T1 - Observation of Λ ¯ p →K+π+π-π0 and Λ ¯ p →K+π+π-2π0

AU - BESIII Collaboration

AU - Ачасов, Михаил Николаевич

AU - Мучной, Николай Юрьевич

AU - Николаев, Иван Борисович

N1 - The BESIII Collaboration thanks the staff of BEPCII ([49]) 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. 2023YFA1606000, No. 2023YFA1606704; National Natural Science Foundation of China (NSFC) under Contracts No. 11635010, No. 11935015, No. 11935016, No. 11935018, No. 12025502, No. 12035009, No. 12035013, No. 12061131003, No. 12165022, No. 12192260, No. 12192261, No. 12192262, No. 12192263, No. 12192264, No. 12192265, No. 12221005, No. 12225509, No. 12235017, No. 12342502, No. 12342502, No. 12361141819; the China Postdoctoral Science Foundation under Grant No. 2024M753040; the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation under Grant No. GZC20241608; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; 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 Cosmology; Yunnan Fundamental Research Project under Contract No. 202301AT070162; 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 No. 2021.0174, No. 2021.0299, No. 2023.0315; 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 - 2026/4/29

Y1 - 2026/4/29

N2 - Using (10 087±44)×106  퐽/휓 events collected with the BESIII detector at a center-of-mass energy of √푠 =3.097  GeV, the antihyperon-nucleon annihilation processes ¯Λ⁢푝→퐾+⁢휋+⁢휋−+푘⁢휋0 (푘 =1, 2, 3) are studied at an incident ¯Λ momentum of approximately 1.074  GeV/푐. The reactions ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢휋0 and ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢2⁢휋0 are observed for the first time, with corresponding cross sections 휎¯Λ⁢푝→퐾+⁢휋+⁢휋−⁢휋0=8.5+1.2−1.1⁢(stat)±0.4⁢(syst)  mb and 휎¯Λ⁢푝→퐾+⁢휋+⁢휋−⁢2⁢휋0=7.9+1.9−1.7±0.4  mb. No significant signal is found for ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢3⁢휋0, and an upper limit of 7.2 mb is set at a 90% confidence level. Evidence for the 퐾*⁢(892)+ resonance is seen in the 퐾+⁢휋0 invariant mass spectrum 푀퐾+⁢휋0 for 푘 =1, and the corresponding cross section for ¯Λ⁢푝→퐾*⁢(892)+⁢휋+⁢휋− is measured to be 휎¯Λ⁢푝→퐾*⁢(892)+⁢휋+⁢휋−=12.5+3.8−3.4±1.2  mb. Owing to the limited statistics, possible interference effects are not considered. These findings offer crucial input to deepen our understanding of the antihyperon-nucleon interactions.

AB - Using (10 087±44)×106  퐽/휓 events collected with the BESIII detector at a center-of-mass energy of √푠 =3.097  GeV, the antihyperon-nucleon annihilation processes ¯Λ⁢푝→퐾+⁢휋+⁢휋−+푘⁢휋0 (푘 =1, 2, 3) are studied at an incident ¯Λ momentum of approximately 1.074  GeV/푐. The reactions ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢휋0 and ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢2⁢휋0 are observed for the first time, with corresponding cross sections 휎¯Λ⁢푝→퐾+⁢휋+⁢휋−⁢휋0=8.5+1.2−1.1⁢(stat)±0.4⁢(syst)  mb and 휎¯Λ⁢푝→퐾+⁢휋+⁢휋−⁢2⁢휋0=7.9+1.9−1.7±0.4  mb. No significant signal is found for ¯Λ⁢푝 →퐾+⁢휋+⁢휋−⁢3⁢휋0, and an upper limit of 7.2 mb is set at a 90% confidence level. Evidence for the 퐾*⁢(892)+ resonance is seen in the 퐾+⁢휋0 invariant mass spectrum 푀퐾+⁢휋0 for 푘 =1, and the corresponding cross section for ¯Λ⁢푝→퐾*⁢(892)+⁢휋+⁢휋− is measured to be 휎¯Λ⁢푝→퐾*⁢(892)+⁢휋+⁢휋−=12.5+3.8−3.4±1.2  mb. Owing to the limited statistics, possible interference effects are not considered. These findings offer crucial input to deepen our understanding of the antihyperon-nucleon interactions.

KW - Strong interaction

KW - Hyperons

KW - Mesons

KW - Protons

UR - https://www.scopus.com/pages/publications/105037911229

U2 - 10.1103/x17s-xsgn

DO - 10.1103/x17s-xsgn

M3 - Article

C2 - 42139464

VL - 136

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 17

M1 - 171904

ER -