Measurements of Born cross sections for e+e- ? ?c+ ? ¯ c (2595)-+ c. c. and e+e- ? ?c+ ? ¯ c (2625)-+ c. c. at s =4918.0 and 4950.9 MeV
Küçük Resim Yok
Tarih
2024
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
American Physical Society
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Using e+e- collision data collected with the BESIII detector operating at the BEPCII collider, the Born cross sections of e+e-??c+?¯c(2595)-+c.c. and e+e-??c+?¯c(2625)-+c.c. are measured for the first time at center-of-mass energies of s=4918.0 and 4950.9 MeV. Nonzero cross sections are observed very close to the production threshold. The measured Born cross sections of e+e-??c+?¯c(2625)-+c.c. are about 2-3 times greater than those of e+e-??c+?¯c(2595)-+c.c., providing the similar behavior as semileptonic decays of ?b0, but different behavior from that in the hadronic decays of ?b0. The Born cross sections are 15.6±3.1±0.9 pb and 29.4±3.7±2.7 pb for e+e-??c+?¯c(2595)-+c.c., and are 43.4±4.0±4.1 pb and 76.8±6.5±4.2 pb for e+e-??c+?¯c(2625)-+c.c. at s=4918.0 and 4950.9 MeV, respectively. Based on the polar angle distributions of the ?¯c(2625)- and ?c(2625)+, the form-factor ratios |GE|2+3|GM|2/|GC| are determined for e+e-??c+?¯c(2625)-+c.c. for the first time, which are 5.95±4.07±0.15 and 0.94±0.32±0.02 at s=4918.0 and 4950.9 MeV, respectively. All of these first uncertainties are statistical and second systematic. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Açıklama
Anahtar Kelimeler
Kaynak
Physical Review D
WoS Q Değeri
Scopus Q Değeri
Q1
Cilt
109
Sayı
7
