Understanding the cross section ofe+e−→ηJ/ψprocess via nonrelativistic QCD

Abstract

Motivated by the large cross section of e + e − → ηJ/ψ process measured by the BESIII and Belle Collaborations recently, we evaluate this process at O(α 4 s ) accuracy in the framework of nonrelativistic QCD. We find that the cross section at the center-of-mass energy √ s = 4.009 GeV is 34.6pb, which is consistent with the BESIII data. The comparison with the Belle data in the region from 4.0 GeV to 5.3 GeV is also presented. Concerning the η and η ′ mixing and the potential gluonium component of η ′ , we also estimate the rate of e + e − → η ′ J/ψ process, which can be checked within the updated Belle data.

Radiative hc/b decays to η or η′Zhu1, Dai2 2016Phys. Rev. D171200View full textAdd to dashboardCite

“…The Gegenbauer momenta are adopted as a q,s 2 (1GeV ) = 0.44 ± 0.22 [26]. For η , we have a g 2 (1GeV ) = 0.1 and sin 2 φ G = 0.26 [21]. The decay constant of η c is about 498 MeV [23].…”

“…This kind of production mechanism is blind to quark charges, so the amplitude is identical to the production of |qq and |ss . Two gluons transitions to η and η are also investigated in electroproduction e + e − → J/ψ + η(η ) [21].…”

Observation ofe+e−→η′J/ψAblikim1, Ачасов2, Ahmed3 et al. 2016Phys. Rev. D25190View full textAdd to dashboardCite

“…Treating η and η ′ with the Light-Cone approach and J/ψ with non-relativistic QCD, and together with the contribution of the resonance decays, the authors of Ref. [13] can reproduce the measured e + e − → ηJ/ψ line shape and predict the production cross section of the analogous process e + e − → η ′ J/ψ at c.m. energies √ s from 4.3 to 5.3 GeV.…”

“…To check the theoretical predictions [13] and to search for potential η ′ J/ψ transitions from charmonium and charmonium-like states, we measure the process e + e − → η ′ J/ψ with the data taken at BESIII. The CLEO-c experiment searched for this process with data at c.m.…”

Exclusive decay of the upsilon intohc, theX(3940)andX(Zhu1 2015Phys. Rev. D130110View full textAdd to dashboardCite

“…So the LDMEs for the X(3940) and X(4160) can be obtained correspondingly. For the LDMEs of ψ(nS), we can obtain the value from the measured electric widths [4,40,41], i.e.…”