Measurement of the cross section for e(+)e(-) -> Lambda(Lambda)over-bar and evidence of the decay psi(3770) -> Lambda(Lambda)over-bar

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Küçük Resim

Tarih

2021

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

AMER PHYSICAL SOC

Erişim Hakkı

info:eu-repo/semantics/openAccess

Özet

The Born cross section of the process e(+)e(-) ->Lambda(Lambda) over bar over line is measured at 33 center-of-mass energies between 3.51 and 4.60 GeV using data corresponding to the total integrated luminosity of 20.0 fb(-1) collected with the BESIII detector at the BEPCII collider. Describing the energy dependence of the cross section requires a contribution from the psi(3770) -> Lambda(Lambda) over bar decay, which is fitted with a significance of 4.6 - 4.9 sigma including the systematic uncertainty. The lower bound on its branching fraction is 2.4 x 10(-6) at the 90% confidence level (C.L.), at least an order of magnitude larger than expected from predictions using a scaling based on observed electronic widths. This result indicates the importance of effects from vector charmonium(like) states when interpreting data in terms of e.g., electromagnetic structure observables. The data do not allow for definite conclusions on the interplay with other vector charmonium(like) states, and we set 90% C.L. upper limits for the products of their electronic widths and the branching fractions.

Açıklama

Anahtar Kelimeler

Kaynak

PHYSICAL REVIEW D

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

104

Sayı

9

Künye

Ablikim, M., Achasov, M. N., Adlarson, P., Ahmed, S., Albrecht, M., Aliberti, R., ... & Kolcu, O. B. (2021). Measurement of the cross section for e+ e−→ Λ Λ¯ and evidence of the decay ψ (3770)→ Λ Λ¯. Physical Review D, 104(9), L091104.