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Thermal Photon Radiation in High Multiplicity p+Pb Collisions at the Large Hadron Collider
Chun Shen1, Jean-François Paquet1, Gabriel S Denicol1,2
1Department of Physics, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8, Canada.
Physical Review Letters
|March 5, 2016
Summary
Scientists calculated thermal photon radiation from small collision systems, finding it can signal a hot quark-gluon plasma. This enhances the low momentum photon spectrum, validating hydrodynamic behavior in these systems.
Area of Science:
- Nuclear Physics
- High-Energy Physics
- Quantum Chromodynamics
Background:
- Collective behavior of hadronic particles observed in proton-lead and deuteron-gold collisions.
- Small collision systems can achieve temperatures comparable to nucleus-nucleus collisions.
Purpose of the Study:
- To present the first hydrodynamic calculation of thermal photon radiation from small collision systems.
- To investigate thermal photon enhancement as a signature of quark-gluon plasma in small systems.
Main Methods:
- Hydrodynamic framework calculations.
- Analysis of thermal photon radiation spectrum.
Main Results:
- Thermal photons can significantly enhance the low transverse momentum direct photon spectrum (factor of 2-3) in central proton-lead collisions.
- Calculated temperatures in small systems comparable to central nucleus-nucleus collisions.
Conclusions:
- Thermal photon enhancement serves as a signature for the existence of a hot quark-gluon plasma in small collision systems.
- Hydrodynamic calculations validate the existence of such plasma and its behavior in small systems.
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