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Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
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Photon production rate from Transverse-Longitudinal (T-L) mesonic correlator on the lattice.

Aug 12, 2022, 3:30 PM
CP1-HSZ/Ground-0.011 - HS1 (CP1-HSZ)

CP1-HSZ/Ground-0.011 - HS1


Oral Presentation QCD at Non-zero Temperature Non-zero Temperature


Dibyendu Bala (Bielefeld University)


Thermal photons from the QGP provide important information about the interaction among the plasma constituents. The photon production rate from a thermally equilibrated plasma is proportional to the transverse spectral function $\rho_T(k_0=|\vec k |,\vec k )$. One can calculate the photon production rate also from the difference between $\rho_T$(transverse) and $\rho_L$(longitudinal) correlator as $\rho_L$ vanishes on the photon point. The UV part of $\rho_T-\rho_L$ is suppressed, and therefore the corresponding Euclidean correlator receives most of its contribution from the IR part of $\rho_T-\rho_L$. We calculate the continuum extrapolated T-L correlator using Clover Improved Wilson fermion on the quenched lattices at temperatures 1.1 $T_c$ and 1.5$T_c$. We also calculate the same correlator on $N_f=2+1$ flavor HISQ configurations with $m_l = m_s/5$ at temperature $\sim 1.15T_c$ and $\sim 1.3T_c$. We have used two ansätze of the spectral function, which are 1) Polynomial ansatz of the spectral function connected to the UV perturbative region and 2) Hydro-inspired spectral function. We have also used the Backus-Gilbert method to estimate the spectral function. We will compare the photon production rate estimated from all these different methods.

Primary author

Dibyendu Bala (Bielefeld University)


Olaf Kaczmarek (University of Bielefeld) Hai-Tao Shu (Regensburg University) Sajid Ali (Bielefeld University) Luis Altenkort Anthony Francis Greg Jackson (INT, University of Washington) Tristan Ueding (Bielefeld University)

Presentation materials