### Abstract

A convenient form of kinetic equation is derived for pair annihilation of heavy stable particles relevant to the dark matter problem in cosmology. The kinetic equation thus derived extends the on-shell Boltzmann equation in a most straightforward way, including the off-shell effect. A detailed balance equation for the equilibrium abundance is further analyzed. Perturbative analysis of this equation supports a previous result for the equilibrium abundance using the thermal field theory, and gives the temperature power dependence of equilibrium value at low temperatures. Estimate of the relic abundance is possible using this new equilibrium abundance in the sudden freeze-out approximation.

Original language | English |
---|---|

Article number | 123509 |

Pages (from-to) | 1-9 |

Number of pages | 9 |

Journal | Physical Review D |

Volume | 61 |

Issue number | 12 |

Publication status | Published - Jun 15 2000 |

Externally published | Yes |

### Fingerprint

### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Nuclear and High Energy Physics
- Mathematical Physics
- Physics and Astronomy (miscellaneous)

### Cite this

*Physical Review D*,

*61*(12), 1-9. [123509].

**New kinetic equation for pair-annihilating particles : Generalization of the Boltzmann equation.** / Matsumoto, Sh; Yoshimura, Motohiko.

Research output: Contribution to journal › Article

*Physical Review D*, vol. 61, no. 12, 123509, pp. 1-9.

}

TY - JOUR

T1 - New kinetic equation for pair-annihilating particles

T2 - Generalization of the Boltzmann equation

AU - Matsumoto, Sh

AU - Yoshimura, Motohiko

PY - 2000/6/15

Y1 - 2000/6/15

N2 - A convenient form of kinetic equation is derived for pair annihilation of heavy stable particles relevant to the dark matter problem in cosmology. The kinetic equation thus derived extends the on-shell Boltzmann equation in a most straightforward way, including the off-shell effect. A detailed balance equation for the equilibrium abundance is further analyzed. Perturbative analysis of this equation supports a previous result for the equilibrium abundance using the thermal field theory, and gives the temperature power dependence of equilibrium value at low temperatures. Estimate of the relic abundance is possible using this new equilibrium abundance in the sudden freeze-out approximation.

AB - A convenient form of kinetic equation is derived for pair annihilation of heavy stable particles relevant to the dark matter problem in cosmology. The kinetic equation thus derived extends the on-shell Boltzmann equation in a most straightforward way, including the off-shell effect. A detailed balance equation for the equilibrium abundance is further analyzed. Perturbative analysis of this equation supports a previous result for the equilibrium abundance using the thermal field theory, and gives the temperature power dependence of equilibrium value at low temperatures. Estimate of the relic abundance is possible using this new equilibrium abundance in the sudden freeze-out approximation.

UR - http://www.scopus.com/inward/record.url?scp=17144365489&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=17144365489&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:17144365489

VL - 61

SP - 1

EP - 9

JO - Physical review D: Particles and fields

JF - Physical review D: Particles and fields

SN - 0556-2821

IS - 12

M1 - 123509

ER -