Initial state angular asymmetries in high energy p+A collisions: Spontaneous breaking of rotational symmetry by a color electric field and C-odd fluctuations

Abstract

We present a simple model for generating initial-state azimuthal asymmetries in pA collisions from dipole scattering on an anisotropic dense target. Parity even angular harmonics arise from the C-even real part of the dipole S-matrix which spontaneously breaks rotational symmetry in two dimensions due to a condensate for the color electric field. This leads to an angular correlation with the direction of E. Parity odd harmonics are generated by the C-odd imaginary part (odderon) due to coupling to coherent target fluctuations which again break rotational invariance. We perform a first qualitative extraction of the amplitude and cutoff of C-odd fluctuations in the dense target.

Entanglement entropy and entropy production in the color glass condensate framework

“…Note that although the diagram in Fig. 1b has a disconnected topology, it does in fact contribute to the correlated production in the large N c limit if the target averages do not factorize [33,36]. In the language of the Reggeon field theory, this contribution is due to correlated production from two Pomerons, while the diagrams in Fig 1a are due to correlated production from the B-reggeon [37].…”

Azimuthal asymmetries and the emergence of “collectivity” from multi-particle correlations in high-energy pA collisions

“…In the soft, long wavelength regime, c 2 {4} is negative when hydrodynamic flow dominates over "non-flow" correlations [17]. In this paper we perform a first computation of all connected and disconnected contributions to the cumulants in the short distance regime using a model that allows for anisotropic "domains" of the color-electric fields E of the target [10,18] …”

Rapidity dependence of the average transverse momentum in hadronic collisions

“…As the ridge effect, the azimuthal asymmetries observed in pPb collisions at the LHC energies by the ALICE [12], ATLAS [13,33] and CMS [11,17] collaborations are also open to different theoretical explanations. While in the hydro approaches those anisotropies emerge as a final state feature due to the hydrodynamic flow [20,21,34] in the CGC approach they are described as a initial state anisotropies which are present at the earliest stages of the collision [35]. In Ref.…”