Dark matter annihilation and jet quenching phenomena in the early universe

TL;DR

This paper explores how dark matter annihilation in the early universe produces jet quenching phenomena similar to heavy-ion collisions, affecting the energy transfer to cosmic matter.

Contribution

It introduces a novel analogy between dark matter annihilation effects and jet quenching observed in high-energy nuclear experiments.

Findings

Quark and gluon jets are rapidly damped in the primordial plasma.

Charged hadron and lepton jets are strongly damped until recombination.

Energy transfer impacts the thermal history of the early universe.

Abstract

Dark-matter particles like neutralinos should decouple from the hot cosmic plasma at temperatures of about 40 GeV. Later they can annihilate each other into standard-model particles, which are injected into the dense primordial plasma and quickly loose energy. This process is similar to jet quenching in ultrarelativistic heavy-ion collisions, actively studied in RHIC and LHC experiments. Using empirical information from heavy-ion experiments I show that the cosmological (anti)quark and gluon jets are damped very quickly until the plasma remains in the deconfined phase. The charged hadron and lepton jets are strongly damped until the recombination of electrons and protons. The consequences of energy transfer by the annihilation products to the cosmic matter are discussed.