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 $1GeV<p_T<3GeV$. 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 $\Delta \varphi$ along with large $\Delta \eta$ at large multiplicities in this interval of $p_T$ are natural in the mechanism. The mechanism predicts also bremstralung photons with mean values of $p_T\approx 2.9$ and $0.72GeV$.

Comments: 5 pages, 3 figures