Neutralino relic density including coannihilations

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.56.1879· OSTI ID:538646

Edsjoe, J ^[1]; Gondolo, P ^[2]

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1. Department of Theoretical Physics, Uppsala University, Box 803, SE-751 08 Uppsala (Sweden)
2. Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)

We evaluate the relic density of the lightest neutralino, the lightest supersymmetric particle, in the minimal supersymmetric extension of the standard model. For the first time, we include all coannihilation processes between neutralinos and charginos for any neutralino mass and composition. We use the most sophisticated routines for integrating the cross sections and the Boltzmann equation. We properly treat (sub)threshold and resonant annihilations. We also include one-loop corrections to neutralino masses. We find that coannihilation processes are important not only for light Higgsino-like neutralinos, as pointed out before, but also for heavy Higgsinos and for mixed and gauginolike neutralinos. Indeed, coannihilations should be included whenever {vert_bar}{mu}{vert_bar}{approx_lt}2{vert_bar}M{sub 1}{vert_bar}, independently of the neutralino composition. When {vert_bar}{mu}{vert_bar}{approximately}{vert_bar}M{sub 1}{vert_bar}, coannihilations can increase or decrease the relic density in and out of the cosmologically interesting region. We find that there is still a window of light Higgsino-like neutralinos that are viable dark matter candidates and that coannihilations shift the cosmological upper bound on the neutralino mass from 3 to 7 TeV. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 538646
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 4 Vol. 56; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANNIHILATION
BOLTZMANN EQUATION
CROSS SECTIONS
DENSITY
HIGGS BOSONS
MASS
NEUTRAL PARTICLES
NONLUMINOUS MATTER
SPARTICLES
STANDARD MODEL
SUPERSYMMETRY