Averaged Number of the Lightest Supersymmetric Particles in Decay of Superheavy Particle with Long Lifetime

TL;DR

This paper calculates the average number of lightest supersymmetric particles produced in superheavy particle decay, revealing implications for dark matter abundance and constraints on non-thermal LSP production scenarios.

Contribution

It introduces a generalized DGLAP equation approach to estimate LSP production in superheavy particle decay, extending the mass limits for dark matter origin.

Findings

Average LSP number can reach O(100) for high virtuality decays.

Superheavy particle mass limit increases from 10^12 GeV to 10^14 GeV.

Decay of inflaton can produce observed dark matter if reheating temperature is around 1 GeV.

Abstract

We calculate the averaged number \nu of the lightest supersymmetric particles (LSPs) in a shower from the decay of superheavy particle X by generalized DGLAP equations. If the primary decayed particles have color charges and the virtuality is around 10^13-10^14 GeV, the averaged number of the LSPs can become O(100). As the result, the upper limit of the mass of the superheavy particle, whose decay can produce the observed abundance of the dark matter, can increase from 10^12 GeV to 10^14 GeV. Since the typical scale of the inflaton mass of the chaotic inflation is around 10^13 GeV, the decay of the inflaton can produce the observed dark matter abundance if the reheating temperature is of order 1 GeV. Even for the standard model particles with virtuality Q\sim 10-100 TeV, the averaged number of the LSPs becomes O(0.1) for gluon, and O(0.01) for Higgs, which strongly constrains the scenario of non-thermal LSP production from the decay of moduli with 10-100 TeV mass.