Charmed meson formation in proton-proton collisions

Abstract

At present there exists a large volume of experimental data [1-4] which indicates that in hadron-hadron (in particular, proton-proton) collisions charmed hadrons are formed. In [5, 6] it was noted that to interpret such data, in addition to conventional quantum chromodynamic (QCD) mechanisms of gluon--gluon merger and quark--antiq~ark annihilation into a pair of c and ~ quarks, one must consider diffraction formation of charmed hadrons. The essence of this mechanism is that as a result of QCD evolution, within the sea structure of the nucleon there is formed a hard component of charmed quarks, which interact by gluon exchange with light quarks or gluons from the incident hadrons. This leads to a significant increase in charmed hadron output forward and increase in their generation section. To determine the quark--gluon interaction constants a S the authors of [5, 6] commenced from a parameter value characterizing the position of the infrared bands, A = 500 MeV. But at the present we know = (160~_ao) MeV [7], which agrees with A = i00 MeV the mean value of this parameter to be A ~o predicted theoretically by QCD summing rules [8]. In view of the fact that the charmed had2 ron generation section in QCD mechanisms, which we will denote by ocQCD, depends on aS, recalculation of a S from A = 500 MeV to A = i00 MeV leads to a decrease in acQCDbya factorof 4-6 times as compared to that obtained in [5, 6].