Journal article

First Observation of Λπ and Λπ- Signals near the K ¯ N (I=1) Mass Threshold in Λc → Λπ π π- Decay

Y Ma, J Yelton, K Tanida, I Adachi, JK Ahn, H Aihara, S Al Said, DM Asner, H Atmacan, T Aushev, R Ayad, V Babu, S Bahinipati, S Banerjee, P Behera, K Belous, J Bennett, M Bessner, B Bhuyan, T Bilka Show all

Physical Review Letters | Published : 2023

Abstract

Using the data sample of 980 fb-1 collected with the Belle detector operating at the KEKB asymmetric-energy e+e- collider, we present the results of an investigation of the Λπ+ and Λπ- invariant mass distributions looking for substructure in the decay Λc+→Λπ+π+π-. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ+ (Λπ-) combination a mass of 1434.3±0.6(stat)±0.9(syst) MeV/c2 [1438.5±0.9(stat)±2.5(syst) MeV/c2], an intrinsic width of 11.5±2.8(stat)±5.3(syst) MeV/c2 [33.0±7.5(stat)±23.6(syst) MeV/c2] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K̄N threshold, we also investigate the possibility of a K̄N ..

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University of Melbourne Researchers

Grants

Awarded by National Science Foundation


Funding Acknowledgements

This work, based on data collected using the Belle detector, which was operated until June 2010, was supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan, the Japan Society for the Promotion of Science (JSPS) , and the Tau-Lepton Physics Research Center of Nagoya University; the Australian Research Council including Grants No. DP210101900, No. DP210102831, No. DE220100462, No. LE210100098, No. LE230100085; Austrian Federal Ministry of Education, Science and Research (FWF) and FWF Austrian Science Fund No. P 31361-N36; the National Natural Science Foundation of China under Contracts No. 11675166, No. 11705209; No. 11975076; No. 12135005; No. 12175041; No. 12161141008; Key Research Program of Frontier Sciences, Chinese Academy of Sciences (CAS) , Grant No. QYZDJ-SSW-SLH011; Project ZR2022JQ02 supported by ShandongProvincial Natural Science Foundation; the Ministry of Education, Youth and Sports of the Czech Republic under Contract No. LTT17020; the Czech Science Foundation Grant No. 22-18469S; Horizon 2020 ERC Advanced Grant No. 884719 and ERC Starting Grant No. 947006 ?InterLeptons? (European Union) ; the Carl Zeiss Foundation, the Deutsche Forschungsgemeinschaft, the Excellence Cluster Universe, and the VolkswagenStiftung; the Department of Atomic Energy (Project Identification No. RTI 4002) and the Department of Science and Technology of India; the Istituto Nazionale di Fisica Nucleare of Italy; National Research Foundation (NRF) of Korea Grants No. 2016R1D1A1B02012900, No. 2018R1A2B3003643, No. 2018R1A6A1A06024970, No. RS202200197659, No. 2019R1I1A3A01058933, No. 2021R1A6A1A03043957, No. 2021R1F1A1060423, No. 2021R1F1A1064008, No. 2022R1A2C1003993; Radiation Science Research Institute, Foreign Large-size Research Facility Application Supporting project, the Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIAD; the Polish Ministry of Science and Higher Education and the National Science Center; the Ministry of Science and Higher Education of the Russian Federation, Agreement 14.W03.31.0026, and the HSE University Basic Research Program, Moscow; University of Tabuk research Grants No. S-1440-0321, No. S-0256-1438, and No. S-0280-1439 (Saudi Arabia) ; the Slovenian Research Agency Grants No. J1-9124 and No. P1-0135; Ikerbasque, Basque Foundation for Science, Spain; the Swiss National Science Foundation; the Ministry of Education and the Ministry of Science and Technology of Taiwan; and the United States Department of Energy and the National Science Foundation. These acknowledgements are not to be interpreted as an endorsement of any statement made by any of our institutes, funding agencies, govern-ments, or their representatives. We thank the KEKB group for the excellent operation of the accelerator; the KEKcryogenics group for the efficient operation of the solenoid; and the KEK computer group and the Pacific Northwest National Laboratory (PNNL) Environmental Molecular Sciences Laboratory (EMSL) computing group for strong computing support; and the National Institute of Informatics, and Science Information NETwork 6 (SINET6) for valuable network support.