Speaker
Description
Recent measurements of the triple J/psi production performed by the CMS collaboration suggest non-negligible contribution from a triple parton scattering (TPS). The CMS results can be seen as a first experimental observation of a TPS process. Unfortunately, due to the absence of experimental fits, triple parton distribution functions (tPDFs), needed for the theoretical computation of TPS cross sections, remain unknown. Therefore, in phenomenological studies of the TPS phenomenon one still has to rely on certain model-dependent assumptions about the shape of tPDFs and their relation to standard single parton distribution functions.
In this talk I will discuss how one can extend the sum rules, previously proposed by Gaunt and Stirling for the double parton distribution functions, to the case of tPDFs and how one can use PYTHIA8 code to construct tPDFs which will approximately obey such sum rules. Additionally, I will demonstrate how one can proof the sum rules for ''bare'' tPDFs using the light-cone formalism.
