Eur. Phys. J. A (2020) 56: 53
https://doi.org/10.1140/epja/s10050-020-00060-9

Regular Article –Theoretical Physics

Centrality dependence of photon yield and elliptic flow from gluon fusion and splitting induced by magnetic fields in relativistic heavy-ion collisions

¹ Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, 04510, CdMx, Mexico
² Department of Physics, Centre for Theoretical and Mathematical Physics, University of Cape Town, Rondebosch, 7700, South Africa
³ Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Sinaloa, Avenida de las Américas y Boulevard Universitarios, Ciudad Universitaria, CP 80000, Culiacán, Sinaloa, México
⁴ Facultad de Ciencias-CUICBAS, Universidad de Colima, Bernal Díaz del Castillo No. 340, Col. Villas San Sebastián, 28045, Colima, Mexico

^* e-mail: jorgecastanoy@gmail.com

Received: 13 August 2019
Accepted: 19 December 2019
Published online: 12 February 2020

Abstract

We compute the photon yield and elliptic flow coefficient in relativistic heavy-ion collisions from gluon fusion and splitting processes induced by a magnetic field for different centralities. The calculation accounts for the intense magnetic field and the high gluon occupation number at early times. The photon production induced by these process represents an excess contribution over calculations without magnetic field effects. We compare this excess to the difference between PHENIX data and recent hydrodynamic calculations for the photon transverse momentum distribution and elliptic flow coefficient . The time evolution of the field strength and reaction volume is computed using UrQMD. We show that with reasonable values for the saturation scale, the calculation helps to better describe the experimental results obtained at RHIC energies for the lowest part of the transverse photon momentum at different centralities.