O(αsv2)correction toe+e−

Abstract

We investigate the Oð s v 2 Þ correction to the e þ e À ! J=c þ c process in the nonrelativistic QCD (NRQCD) factorization approach. Within some reasonable choices of the relative order-v 2 NRQCD matrix elements, we find that including this new ingredient of correction only mildly enhances the existing NRQCD predictions. We have also deduced the asymptotic expressions for the Oð s v 2 Þ short-distance coefficients, and reconfirm the early speculation that at next-to-leading order in s , the double logarithm of type ln 2 ðs=m 2 c Þ appearing in various NRQCD short-distance coefficients is always associated with the helicity-suppressed channels.

O(αs) corrections to e+Dong1, Feng2, Jia3 2018Phys. Rev. DSelf Cite7190View full textAdd to dashboardCite

“…1. The calculation is quite similar to our preceding works on double charmonium exclusive production, i.e., e þ e − → J=ψ þ χ c0;1;2 [24] and the e þ e − → J=ψ þ η c [21], so here we will only present a very brief description.…”

“…The original lowest-order (LO) NRQCD predictions to this process [10,11] is about 1 order of magnitude smaller than the measurement [1]. This alarming discrepancy has triggered a great amount of theoretical investigations in both NRQCD and light-cone approaches [12][13][14][15][16][17][18][19][20][21][22]. One crucial element in alleviating the discrepancy between the NRQCD prediction and the data is the substantial and positive next-to-leading-order (NLO) perturbative corrections [16,17].…”

Relativistic corrections toϒexclusive decay into doubleS-wave charmonia

“…For γ * → η c J/ψ, the amplitude with the photon energy the same as that at B factories has been evaluated accurate up to O(α s v 2 ) corrections in [39,40]. In our process, since the virtual photon is produced through Υ annihilation, it is reasonable for us to take the invariant mass of γ * to be the mass of Υ.…”

“…Our result for γ * → η c J/ψ with the same energy as B factories agrees with Refs. [39,40], where the subprocess γ * → η c J/ψ has been deeply investigated in [39,40]. For details, we refer the authors to Refs.…”

“…For details, we refer the authors to Refs. [39,40]. In the following section, we will present the numerical predictions.…”