The electromagnetic fields produced by non-central heavy ion collisions are extremely powerful and give rise to a plethora of fascinating subjects in strongly interacting matter. Their evolution is a significant and unresolved issues. Because the relaxation time of the hot QCD matter to the electromagnetic fields is comparable with the lifetime of external electromagnetic field, we question,...
In this talk, we present a study of direct photons in relativistic nuclear collisions, along with the production of hadrons, from RHIC Beam Energy Scan (BES) to LHC energies. Thermal photons are soft and penetrating probes of the strongly-coupled nuclear matter created in relativistic heavy-ion collisions. Their spectrum and momentum anisotropies remember the QGP’s chemistry evolution and its...
The Compressed Baryonic Matter (CBM), currently under construction at the Facility for Anti-proton and Ion Research (FAIR) accelerator complex in Darmstadt, Germany aims to explore the QCD phase diagram at high baryon densities. Till date, no dilepton data have been collected in heavy-ion collisions at beam energies between 2A and 40A GeV. CBM aims to perform pioneering measurements of lepton...
We present a comparison of observables related to photon-triggered jets for different collision energy systems, at LHC and RHIC energies, with the latest update of the JETSCAPE framework [1,2]. In heavy-ion collisions, multiple probes are used to study the properties of the Quark-Gluon Plasma (QGP). Photons can be produced at any stage of the heavy-ion collision. Since photons do not interact...
Because photons and dileptons are unlikely to interact after production within a quark-gluon plasma (QGP), they can probe the inner dynamics of this strongly interacting system. To leading order in the electromagnetic coupling and all orders in the strong coupling, the observable emission rates can be determined from the QCD vector channel spectral function. The resummed next-to-leading order...
Direct photons are a useful probe to study the properties of QGP and the dynamic evolution of the collision system as they do not interact with the medium strongly. Low transverse momentum direct photons are believed to originate primarily from thermal radiation, however, calculations of thermal photon emission fall short in describing the measured direct photon yield and the anisotropy at the...
The temperature and size of the quark-gluon plasma that is created in heavy-ion collisions are properties that are to be experimentally constrained. This can be done via direct photon Hanbury Brown and Twiss (HBT) measurements that are able to both quantify the excess of thermal photons as well as the size of the emitting source. In contrast to femtoscopic measurements of bulk particles, this...
We present a consistent photon production calculation from hadronic cross sections, including bremsstrahlung and 2-to-2 reactions, matching the usually employed thermal rates [1]. Using the hadronic transport approach SMASH as the afterburner for the hadronic stage at RHIC and LHC energies, we find a significant increase in the calculated momentum anisotropies of these photons due to...
The high-statistics search for high baryon-density matter at relatively low temperature comes to be possible by the recent experiments using heavy-ion collision (HIC), which may realize the color superconductivity (CSC): Such experiments include the beam-energy scan program at RHIC, and HADES and NA61/SHINE collaborations as well as those to be performed in future experimental facilities such...
An ultra-intense magnetic field is expected to be created in relativistic heavy-ion collisions with an intensity up to 10$^{15}$ T. These strong magnetic fields are predicted to produce various nonlinear QED behaviors and other interesting phenomena, such as the chiral magnetic effect and quark synchrotron radiation. However, such a magnetic field has not yet been detected experimentally. The...
We reconstruct effective spectral functions of the $\rho$-meson in different scenarios via lifetime analysis using the hadronic transport SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). The theoretical interest in the behavior of in-medium spectral functions lies in the expected restoration of chiral symmetry at high energy densities, which may be accessed experimentally by...
A recent analysis from the PHENIX collaboration on direct photon production yield in heavy ion collisions has shown a universal, within experimental uncertainties, multiplicity scaling, in which the photon $p_T$-spectra for transverse momenta up to 2 GeV/c are scaled with charged-hadron pseudorapidity density at midrapidity raised to the power $\alpha=1.25$. This low-$p_T$ scaling suggests...
A new complete method, based on the Wigner distributions of photons, how to calculate differential distributions of dileptons created via photon-photon fusion in semicentral ($b<2R_{AA}$) AA collisions is reviewed [1]. The formalism is used to calculate different distributions of invariant mass, dilepton transverse momentum and acoplanarity for different regions of centrality. The results of...
Dielectron production in high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV with ALICE
Dielectron production is a powerful tool to investigate the properties of the quark-gluon plasma created in relativistic heavy-ion collisions, as they carry information about the temperature of the medium and its space-time evolution without any distortion due to final-state interactions. Dielectron...
