# Effect of initial-state nucleon shadowing on the elliptic flow of thermal photons

## TL;DR

This paper investigates how nucleon shadowing influences the elliptic flow of thermal photons in heavy-ion collisions, revealing that shadowing enhances photon elliptic flow without significantly changing photon spectra.

## Contribution

It introduces the incorporation of nucleon shadowing effects into hydrodynamic models to study thermal photon elliptic flow in heavy-ion collisions, a novel approach.

## Key findings

- Photon spectra are largely unaffected by shadowing.
- Elliptic flow of thermal photons is significantly increased due to shadowing.
- Results align better with experimental data when shadowing is included.

## Abstract

Recently the effect of nucleon shadowing on the Monte-Carlo Glauber initial condition was studied and its role on the centrality dependence of elliptic flow ($v_2$) and fluctuations in initial eccentricity for different colliding nuclei were explored. It was found that the results with shadowing effects are closer to the QCD based dynamical model as well as to the experimental data. Inspired by this outcome, in this work we study the transverse momentum ($p_T$) spectra and elliptic flow of thermal photons for Au+Au collisions at RHIC and Pb+Pb collisions at LHC by incorporating the shadowing effects in deducing the initial energy density profile required to solve the relativistic hydrodynamical equations. We find that the thermal photon spectra remain almost unaltered, however, the elliptic flow of photon is found to be enhanced significantly due to shadowing effects.