2014/10/19 by Blok, B., Strikman, M.
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.1410.5064
We derive expressions for the differential distributions and the total cross section of double- parton interaction in direct photon interaction with proton and nuclei. We demonstrate that in this case the cross section is more directly related to the nucleon generalized parton distribution than in the case of double parton interactions in the proton - proton collisions. We focus on the production of two dijets each containing charm (anticharm) quarks and carrying x1,x2>0.2 fractions of the photon momentum. Numerical results are presented for the case of γp collisions at LHeC, HERA and in the ultraperipheral AA and pA collisions at the LHC. We find that the events of this kind would be abundantly produced at the LHeC. For √(s)=1.3 TeV the expected rate is 2⋅ 108 events for the luminosity 1034 cm-2s-1, the running time of 106 s and the transverse cutoff of pt>5 GeV. This would make it feasible to use these processes for the model independent determination of two parton GPDs in nucleon and in nuclei. For HERA the total accumulated number of the events is also high, but efficiency of the detection of charm seems too low to study the process. We also find that a significant number of such double parton interactions should be produced in p - Pb and Pb- Pb collisions at the LHC: ∼ 6⋅ 104 for Pb-Pb, and ∼ 7 ⋅ 103 for p-Pb collisions for the same transverse momentum cutoff.