Double charmonium production at B factories within light cone formalism

Abstract

This paper is devoted to the study of the processes e + e − → J/Ψηc, J/Ψη ′ c , ψ ′ ηc, ψ ′ η ′ c within light cone formalism. It is shown that if one disregards the contribution of higher fock states, the twist-3 distribution amplitudes needed in the calculation can be unambiguously determined from the twist-2 distribution amplitudes and equations of motion. Using models of the twist-2 distribution amplitudes the cross sections of the processes under study have been calculated. The results of the calculation are in agreement with Belle and BaBar experiments. It is also shown that relativistic and radiative corrections to the cross sections play crucial role in the achievement of the agreement between the theory and experiments. The comparison of the results of this paper with the results obtained in other papers has been carried out. In particular, it is shown that the results of papers where relativistic and radiative corrections were calculated within NRQCD are overestimated by a factor of ∼ 1.5.

The leading twist light-cone distribution amplitudes for the S-wave and P-wave quarkonia and their applications in single quarkonium exclusive productions

“…Many phenomenological applications along this line have been made for exclusive hard production of charmonium [7][8][9][10][11][12][13], exclusive charmonium production in B meson decays [14][15][16][17], etc. All of these applications require the understanding of the LCDAs for quarkonia.…”

“…Due to the discrete C, P, and T symmetries, one can check that, when ω → 0, we have 13) and corresponding integrals of the rest LCDAs do not vanish. Thus, we set the normalization conditions for the LCDAs as following…”

α s v 2 corrections to η c and χ cJ production recoiled with a photon at e + e − colliders

“…For the J PC of photon is same with J/ψ, studies have focused on the production of quarkonium with even charge conjugation recoiled with a hard photon in the e + e − annihilation. The LO contribution for heavy quarkonium with even charge conjugation recoiled with a hard photon in the e + e − annihilation at the B factories and BESIII is a pure QED process [67,68]. The NLO radiative corrections have been computed and analyzed [69][70][71][72][73].…”

Associated Charmonium-Bottomonium Production in a Single Boson e+e− Annihilation

“…It is worth noting here the intrigue related to the observation of J/ψ η c pair in the e + e − annihilation: the theoretical predictions [1] underestimated the real yield measured at BELLE and BaBar [2,3] by the order of magnitude. This stimulated numerous studies [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21], as a result of which a fair agreement with the data has been achieved. The previous year gave researchers a new sensation: the LHCb Collaboration observed the structure in the J/ψ J/ψ spectrum at large statistics [22].…”

“…Another problem that is outside the scope of this study is the relativistic effects caused by the use of relativistic or relativized wave functions. It is known that accounting for such effects can crucially change the predictions, especially for the charmonium-pair production in the e + e − annihilation, where accounting for the relativistic effects decreases the virtuality of the intermediate gluon, and therefore essentially increases the cross section value (see for example [9][10][11][12][13][14][15][16][17][18][19][20][21]). Another example of the influence of the relativistic effects on the paired quarkonium production could be found in [29][30][31][32].…”