Cosmological Constraint on the String Dilaton in Gauge-Mediated Supersymmetry Breaking Theories

Journal Article · Mon Dec 01 00:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.79.4525· OSTI ID:550577

Hashiba, J ^[1]; Kawasaki, M ^[2]; Yanagida, T ^[1]

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1. Department of Physics, The University of Tokyo, Tokyo 113 (Japan)
2. Institute for Cosmic Ray Research, The University of Tokyo, Tanashi 188 (Japan)

The dilaton field in string theories (if it exists) is expected to have a mass of the order of the gravitino mass m{sub 3/2} which is in a range of 10{sup {minus}2} keV{endash} 1 GeV in gauge-mediated supersymmetry breaking models. If this is the case, the cosmic energy density of coherent dilaton oscillation easily exceeds the critical density of the present Universe. We show that even if this problem is solved by a late-time entropy production (thermal inflation) a stringent constraint on the energy density of the dilaton oscillation is derived from experimental upper bounds on the cosmic x({gamma} )-ray backgrounds. This excludes an interesting mass region, 500 keV{approx_lt}m{sub 3/2}{approx_lt} 1 GeV , in gauge-mediated supersymmetry breaking models. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 550577
• Journal Information: Physical Review Letters, Vol. 79, Issue 23; Other Information: PBD: Dec 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
SUPERSYMMETRY
COSMOLOGICAL CONSTANT
SYMMETRY BREAKING
STRING MODELS
MASS
GRAVITONS
SPARTICLES
ENERGY DENSITY
OSCILLATIONS
UNIVERSE
INFLATION
ENTROPY