Abstract:
Study of the Nuclear Transparency Effect at 4.2 A GeV/c
The use of nuclear transparency effect of protons, + - and - - mesons in proton, and
deuteron induced interactions with carbon at 4.2 A GeV/c, to get information about
properties of nuclear matter is reported in this work. Half angle (θ 1/2 ) technique is used to
extract the nuclear transparency effect. The θ 1/2 divides the multiplicity of charged
particles produced in nucleon-nucleon collisions into two equal parts depending on their
polar angle in the lab. frame. Particles with angle smaller than (incone particles) and
greater than (outcone particles) θ 1/2 are considered separate. The average values of
multiplicity, momentum and transverse momentum of the protons + - and - - mesons are
analyzed as a function of a number of identified protons in an event. We observed
evidences in the data which could be considered as transparency effect. For quantitative
analysis, the results are compared with cascade model. The observed effects are
categorized into leading effect transparency and medium effect transparency. Analysis of
the results shows that the leading effect is the basis of the observed transparency in the
former case. The transparency in the latter case could be the reason of collective
interactions of grouped nucleons with the incident particles.
