Measuring initial temperature through photon to dilepton ratio in heavy   ion collision
  Theoretical calculation of transverse momentum($p_T$) distribution of thermal photons and dileptons originating from ultra-relativistic heavy ion collisions suffer from several uncertainties since the evaluation of these spectra needs various inputs which are not yet known unambiguously. In the present work the ratio of the $p_T$ spectra of thermal photons to lepton pairs has been evaluated and it is shown that the ratio is insensitive to some of these parameters. 
Jajati K. Nayak, Jan-e Alam, Sourav Sarkar and Bikash Sinha