First measurement of the absolute branching fraction of ? ?p?- ? ¯ ?
Yükleniyor...
Dosyalar
Tarih
2021
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
American Physical Society
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
The absolute branching fraction of ??p??¯?? is reported for the first time based on an e+e? annihilation sample of 10×109??J/? events collected with the BESIII detector at ?s=3.097??GeV. The branching fraction is determined to be B(??p??¯??)=[1.48±0.21(stat)±0.08(syst)]×10?4, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(??pe?¯?e), we obtain the ratio {[?(??p??¯??)]/[?(??pe?¯?e)]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of ??p??¯?? and ¯??¯p?+?? is also determined, and no evidence for CP violation is found.
Açıklama
Anahtar Kelimeler
Absolute, Branching, Measurement
Kaynak
Physical Review Letters
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
127
Sayı
12
Künye
Ablikim, M., Achasov, M. N., Adlarson, P., Ahmed, S., Albrecht, M., Aliberti, R., Amoroso, A., An, M. R., An, Q., Bai, X. H., Bai, Y., Bakina, O., Ferroli, R. B., Balossino, I., Ban, Y., Begzsuren, K., Berger, N., Bertani, M., Bettoni, D., … Collaboration, B. (2021). First Measurement of the Absolute Branching Fraction of $\Lambda \to p \mu^- \bar{\nu}_{\mu}$. https://doi.org/10.1103/PhysRevLett.127.121802
