First Observation of Universality of Short Range Nucleon Correlations in the Production of Strange Mesons

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 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 high energy–momentum transfers thereby extending the investigation of the SRC universality to the sector of strange quarks.