Study of Λc+ → Λμ+νμ and test of lepton flavor universality with Λc+ → Λℓ+νℓ decays

Date Issued
01-08-2023
Author(s)
Ablikim, M.
Achasov, M. N.
Adlarson, P.
Ai, X. C.
Aliberti, R.
Amoroso, A.
An, M. R.
An, Q.
Bai, Y.
Bakina, O.
Balossino, I.
Ban, Y.
Bao, H. R.
Batozskaya, V.
Begzsuren, K.
Berger, N.
Berlowski, M.
Bertani, M.
Bettoni, D.
Bianchi, F.
Bianco, E.
Bortone, A.
Boyko, I.
Briere, R. A.
Brueggemann, A.
Cai, H.
Cai, X.
Calcaterra, A.
Cao, G. F.
Cao, N.
Cetin, S. A.
Chang, J. F.
Chang, T. T.
Chang, W. L.
Che, G. R.
Chelkov, G.
Chen, C.
Chen, Chao
Chen, G.
Chen, H. S.
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.
Choi, S. K.
Chu, X.
Cibinetto, G.
Coen, S. C.
Cossio, F.
Cui, J. J.
Dai, H. L.
Dai, J. P.
Dbeyssi, A.
De Boer, R. E.
Dedovich, D.
Deng, Z. Y.
Denig, A.
Denysenko, I.
Destefanis, M.
De Mori, F.
Ding, B.
Ding, X. X.
Ding, Y.
Ding, Y.
Dong, J.
Dong, L. Y.
Dong, M. Y.
Dong, X.
Du, M. C.
Du, S. X.
Duan, Z. H.
Egorov, P.
Fan, Y. H.
Fang, J.
Fang, S. S.
Fang, W. X.
Fang, Y.
Fang, Y. Q.
Farinelli, R.
Fava, L.
Feldbauer, F.
Felici, G.
Feng, C. Q.
Feng, J. H.
Fischer, K.
Fritsch, M.
Fu, C. D.
Fu, J. L.
Fu, Y. W.
Gao, H.
Gao, Y. N.
Gao, Yang
Garbolino, S.
Garzia, I.
DOI
Abstract
The study of the Cabibbo-favored semileptonic decay Λc+→Λμ+νμ is reported using 4.5 fb-1 of e+e- annihilation data collected at center-of-mass energies ranging from 4.600 to 4.699 GeV. The branching fraction of the decay is measured to be B(Λc+→Λμ+νμ)=(3.48±0.14stat±0.10syst)%, 3 times more precise than the prior world average result. Tests of lepton flavor universality using Λc+→Λℓ+νℓ (ℓ=e, μ) decays are reported for the first time, based on measurements of the differential decay rates and the forward-backward asymmetries in separate four-momentum transfer regions. The results are compatible with Standard Model predictions. Furthermore, we improve the determination of the form-factor parameters in Λc+→Λℓ+νℓ decays, which provide stringent tests and calibration for lattice quantum chromodynamics calculations.
Volume
108