Search for collective phenomena in hadron interactions

Abstract

Experimental studies of collective phenomena are carried out on U-70 accelerator in Protvino. These phenomena can be discovered since the high parton density can form in the high multiplicity region. The collective behavior of secondary particles can manifest in the BoseEinstein condensation of pions, Vavilov-Cherenkov gluon radiation, excess of soft photon yield and other unique phenomena. The revealed peaks in the angular distribution are interpreted as the gluon radiation. The search for Bose-Einstein condensation is continued. The gluon dominance model has shown a good agreement with the multiplicity distribution at high multiplicity and confirmed the guark-gluon medium formation.

Alternative way of describing hadronic processes within the parton model

“…This set of equations is solved analytically in the quark and gluon dominance approximation D q D a , a = q and G g G a , a = g. This approximation can be improved for the accuracy level, which is required, by using the iteration procedure. This assumption is known as the gluon dominance which is used in the description of multiplicity of π mesons in the hadron collisions [10][11][12].…”

“…It was a success of the numerous applications of the DGLAP set of equations, working with two densities q, G of quarks and gluons in a proton. However, the problems associated with processes with large multiplicity [10][11][12] require some generalization of traditional approach introducing the correlation functions [13]. This paper is organized in the following manner.…”

A new conception in describing the Drell-Yan type processes

“…At this stage we need to notice that the cross section of sub-process in (19) depends on angle θ between the direction of momentum of produced t-quark and the beam in the system of center-ofmass of initial proton-proton beams, while the expression ( 16) depends on the scattering angle θ in the center-of-mass reference frame of sub-process. Since these angles correspond to each other with the relation (11), i.e. :…”

“…Problems associated with processes with large multiplicity [10][11][12], however require some generalization of traditional approach, introducing the correlation functions [13].…”

“…One of successful phenomenological model-based on the dominant role of gluon distribution G g in describing the processes with high hadron multiplicities [10][11][12].…”