Double Heavy Quarkonia Production at Hadron Collider
West Building, School of Physics, PKU
Double prompt heavy quarkonia production are studied in the non-relativistic QCD (NRQCD)factorization framework by including both color-singlet and color-octet contribution at QCD leading order. Two different approaches of dealing with the initial partons are investigated in details. Moreover, at QCD next-to leading order the NRQCD factorization is found to breakdown and an improved factorization formalism is introduced.