Cherenkov gluons (predictions and proposals)

TL;DR

This paper discusses the theoretical prediction of Cherenkov gluons, their potential experimental signatures like ring-like events and two-bump structures, and how they can reveal properties of the hadronic medium and parton densities.

Contribution

It introduces the concept of Cherenkov gluons in high-energy collisions and proposes their role in observed phenomena, offering a new way to probe the partonic structure of matter.

Findings

Ring-like events and two-bump structures observed at RHIC support Cherenkov gluon predictions.

Properties of the hadronic medium can be inferred from Cherenkov gluon signatures.

High-energy Cherenkov gluons at LHC could enable scanning the parton density in the (x, Q^2)-plane.

Abstract

The coherent hadron production analogous to Cherenkov radiation of photons gives rise to the ring-like events. Being projected on the ring diameter they produce the two-bump structure recently observed for the away-side jets at RHIC. The position of the peaks and their height determine such properties of the hadronic medium as its nuclear refractive index, the parton density, the free path length and the energy loss of Cherenkov gluons. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson observed in experiment. Beside comparatively low energy gluons observed at RHIC, there could be high energy gluons at LHC, related to the high energy region of positive real part of the forward scattering amplitude and possessing different characteristics. This would allow to scan (x, Q^2)-plane determining the parton densities in its various regions.