First observation of universality of short range nucleon correlations in the production of strange mesons
Yu. T. Kiselev
National Research Center "Kurchatov institute" - KCFI, 117219 Moscow, Russia
Abstract
Nucleon-nucleon short range correlations (SRCs) in nuclei are
important part of the nuclear structure and have been a subject of
intensive studies in the last years. These objects represent temporary
fluctuations in average nuclear matter density that occur when two or
more nucleons separated by about 1 fermi (1 fm=10-13 cm). Inspired
by recent theoretical and experimental progress in understanding of SRC
we reanalyzed our data on the production of high momentum K+ and K-
mesons emitted from nuclear targets irradiated by a proton beam. One of
the basic properties of SRCs is the universality which means that they
are equally involved in the creation of different hadrons on different
nuclei, reflecting the properties of nuclear matter. So far, the property
of universality has been observed in electron-nuclear collisions for the
breakup of proton-neutron correlations, as well as in proton-nuclear
collisions for the production of cumulative pions with high momenta. Both
processes involve only light quarks. In this letter, we report the first
observation of SRC universality in kaon production on nuclei in the
kinematic region of large energy-momentum transfers thereby extending the
investigation of the SRC universality to the sector of strange quarks.