CMS ridge effect at LHC as a manifestation of bremstralung of gluons due to the quark-anti-quark string formation

Abstract

The recently reported effect of long-range near-side angular correlations at LHC occurs for large multiplicities of particles with 1 GeV < p T < 3 GeV. To understand the effect several possibilities have been discussed. In the letter we propose a simple qualitative mechanism which corresponds to gluon bremstralung of quarks moving with acceleration appropriate to the quark-anti-quark string. The smallness of azimuthal angle difference ∆φ along with large ∆η at large multiplicities in this interval of p T are natural in the mechanism. The mechanism predicts also bremstralung photons with mean values of p T ≈ 2.9 and 0.72 GeV.

Bose-Einstein interference in the passage of a jet in a dense medium

“…Many models have been proposed to explain the ridge phenomenon [31][32][33][34][35][36][37][38]. They include the collision of jets with medium partons [31-38, 60, 61], flows and hydrodynamics with initial state fluctuations [40,41,48,49,57,59,66], color-glass condensate [47-49, 53, 58], modeling pQCD [62][63][64][65], parton cascade [67], gluon bremsstrahlung in string formation [68], strongcoupling AdS/CFT [70], quantum entanglement [72], and BFKL evolution and beyond [74]. There are however two difficulties associated with these phenomenological models.…”

Momentum-kick model description of the ridge inΔφ-Δηcorrelations inppcollisions at 7 TeV

“…Although many theoretical models have been proposed to discuss the ridge phenomenon in AA collisions and pp collisions [49][50][51][52][53][54][55][58][59][60][61][62][63][64], the ridge phenomenon has not yet been fully understood. Most of the models deal only with some fragmented and qualitative parts of the experimental data.…”