THE MIGDAL JUMP IN THE NUCLEON MOMENTUM DISTRIBUTION IN NUCLEAR-MATTER IS DETERMINED BY THE SPIN-ISOSPIN RESPONSE FUNCTION

The renormalization factor Z of the single-particle Green's function i n nuclear matter, equal to the jump in the nucleon momentum distributi on (''Migdal jump''), is expressed in terms of the nuclear response fu nction, using approximations that are realistic for nuclear physics. I t is shown that the spin-isospin channel makes the dominant contributi on to Z. (C) 1998 American Institute of Physics. [S0021-3640(98)00119- 4].