Quark distributions in nuclear matter and the EMC effect Original Research Article

Quark light cone momentum distributions in nuclear matter and the structure function of a bound nucleon are investigated in the framework of the Nambu–Jona-Lasinio model. This framework describes the nucleon as a relativistic quark–diquark state, and the nuclear matter equation of state by using the mean field approximation. The scalar and vector mean fields in the nuclear medium couple to the quarks in the nucleon and their effect on the spin independent nuclear structure function is investigated in detail. Special emphasis is placed on the important effect of the vector mean field and on a formulation which guarantees the validity of the number and momentum sum rules from the outset.