TY - JOUR
T1 - Gravitino dark matter without R-parity
AU - Takayama, Fumihiro
AU - Yamaguchi, Masahiro
N1 - Funding Information:
This work was supported in part by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports, and Culture of Japan, on Priority Area 707 “Supersymmetry and Unified Theory of Elementary Particles”, and by the Grants-in-Aid No. 11640246 and No. 12047201.
PY - 2000/7/20
Y1 - 2000/7/20
N2 - Cosmological issues are examined when the gravitino is the lightest superparticle (LSP) and R-parity is broken. Decays of the next lightest superparticles occur rapidly via R-parity violating interaction, and thus they do not upset the big-bang nucleosynthesis, unlike the R-parity conserving case. The gravitino LSP becomes unstable, but its lifetime is typically much longer than the age of the Universe. It turns out that observations of the diffuse photon background coming from radiative decays of the gravitino do not severely constrain the gravitino abundance, and thus a gravitino weighing less than around 1 GeV can be the dark matter of the Universe when bilinear R-parity violation generates a neutrino mass which accounts for the atmospheric neutrino anomaly. (C) 2000 Elsevier Science B.V.
AB - Cosmological issues are examined when the gravitino is the lightest superparticle (LSP) and R-parity is broken. Decays of the next lightest superparticles occur rapidly via R-parity violating interaction, and thus they do not upset the big-bang nucleosynthesis, unlike the R-parity conserving case. The gravitino LSP becomes unstable, but its lifetime is typically much longer than the age of the Universe. It turns out that observations of the diffuse photon background coming from radiative decays of the gravitino do not severely constrain the gravitino abundance, and thus a gravitino weighing less than around 1 GeV can be the dark matter of the Universe when bilinear R-parity violation generates a neutrino mass which accounts for the atmospheric neutrino anomaly. (C) 2000 Elsevier Science B.V.
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U2 - 10.1016/S0370-2693(00)00726-7
DO - 10.1016/S0370-2693(00)00726-7
M3 - Article
AN - SCOPUS:0001235847
SN - 0370-2693
VL - 485
SP - 388
EP - 392
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
IS - 4
ER -