Электронный каталог

Статья

Ablikim, M.
Test of CP Symmetry in Hyperon to Neutron Decays / M.Ablikim, O.Bakina, I.Boyko, G.Chelkov, D.Dedovich, I.Denysenko, P.Egorov, A.Guskov, Y.Nefedov, S.Pogodin, A.Sarantsev, A.Zhemchugov, [a.o.] // Physical Review Letters [Electronic resource]. – 2023. – Vol.131, No.19. – P.191802. – URL: https://doi.org/10.1103/PhysRevLett.131.191802. – Bibliogr.:38.

The quantum entangled J/ψ→Σ+¯Σ− pairs from (1.0087±0.0044)×1010  J/ψ events taken by the BESIII detector are used to study the nonleptonic two-body weak decays Σ+→nπ+ and ¯Σ−→¯nπ−. The CP-odd weak decay parameters of the decays Σ+→nπ+ (α+) and ¯Σ−→¯nπ− (¯α−) are determined to be 0.0481±0.0031stat±0.0019syst and −0.0565±0.0047stat±0.0022syst, respectively. The decay parameter ¯α− is measured for the first time, and the accuracy of α+ is improved by a factor of 4 compared to the previous results. The simultaneously determined decay parameters allow the first precision CP symmetry test for any hyperon decay with a neutron in the final state with the measurement of ACP=(α++¯α−)/(α+−¯α−)=−0.080±0.052stat±0.028syst. Assuming CP conservation, the average decay parameter is determined as ⟨α+⟩=(α+−¯α−)/2=−0.0506±0.0026stat±0.0019syst, while the ratios α+/α0 and ¯α−/¯α0 are −0.0490±0.0032stat±0.0021syst and −0.0571±0.0053stat±0.0032syst, where α0 and ¯α0 are the decay parameters of the decays Σ+→pπ0 and ¯Σ−→¯pπ0, respectively.



ОИЯИ = ОИЯИ (JINR)2023
Спец.(статьи,препринты) = С 346.5в - Свойства гиперонов: масса, спин, четность, виды и времена распадов