Search for excited charmonium states ine+e−annihilation ats=10.6  GeV

Abstract

We suggest searching for excited charmonium states in e + e − annihilation via double charmonium production at √ s = 10.6 GeV with B factories, based on a more complete leading order calculation including both QCD and QED contributions for various processes. In particular, for the C=+ states, the χ c0 (nP ) (n=2,3) and η c (mS) (m=3,4) may have appreciable potentials to be observed;while for the C=-states, the η c h c production and especially the χ c1 h c production might provide opportunities for observing the h c with higher statistics in the future. A brief discussion for the X(3940) observed in the double charmonium production is included.

Observation of an alternative χc0(2P) candidate in e+e−

“…[43]; the angular distribution of this process was also found to be consistent with pure S-wave production. Note that while the production amplitudes for the X * (3860) and χ c0 (1P ) are in mutual agreement, they do not agree with the NRQCD prediction [35]. In addition, the X * (3860) mass and width agree with the χ c0 (2P ) parameters determined from an alternative fit to the Belle and BABAR γγ → DD data performed in Ref.…”

“…This nonresonant amplitude model is denoted hereinafter as the NRQCD model (although, for the actual NRQCD calculation of the e + e − → ψχ c cross section, the χ c mass is set to 2m c [35]). …”

“…[35]. The matrix element for the process e + e − → ψχ c is integrated over angle, and M DD is used instead of the χ c mass.…”

Pair double heavy diquark production in high energy proton–proton collisions

“…It depends significantly on the structure of the Feynman amplitude and has to be calculated independently. For example, it is well known that such corrections lead to a significantly increasing factor K = 1.6 ÷ 1.9 to the cross section of charmonium pair production in e + e − annihilation [9][10][11]62]. On the other hand, recently it was found that the NLO α s contribution to the cross section of J/ψ pair production in pp-collisions for the LHCb rapidity range amounts to a value of order 10 % [63].…”

“…The progress was initiated by experiments of the Belle and BaBar collaborations, which measured the cross sections of pair charmonium production in e + e − annihilation [2][3][4][5]. The importance of such reactions for the development of theoreta e-mail: a.p.martynenko@samsu.ru ical methods of their investigation was demonstrated in [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. An essential improvement in the theoretical description of the processes of quarkonium pair production was obtained with the assumption of a systematic account of relativistic and radiative corrections to nonrelativistic results.…”