TY - JOUR
T1 - New constraints on "INO" masses from cosmology (I). Supersymmetric "inos"
AU - Krauss, Lawrence M.
N1 - Funding Information:
The present baryon to entropy ratio in the universe provides a handle on possible non-adiabatic reheating in the early universe. If this ratio differed significantly during primordial nucleosynthesis from the value today, too much deuterium would have been produced \[1\]i ndicating a relatively adiabatic expansion since that time. Similarly if we are to believe in primordial baryosynthesis in the early universe such as predicted in GUT models \[2\],w e cannot accommodate drastic reheating since that era. While the first constraint is on much firmer footing than the last, such considerations of reheating can in general allow us to constrain the out of equilibrium decays of elementary particles which may be abundant in the early universe. In this note we utilize such considerations to refine the mass limits on two fundamental particles associated with supersymmetric theories: the gravitino and photino. We find that the gravitino and photino constraints are not independent. The original constraint that gravitino reheating must not affect nucleosynthesis must be supplanted to take into account that photinos are produced in the reheating process resulting from gravitino decay. If photinos are absolutely stable then the number produced in gravitino decay * Research supported in part by the National Science Foundation under contract nos. PHY77-22864 and PHY82-15249, and by NSERC. 1J unior Fellow, Harvard Society of Fellows.
PY - 1983/11/7
Y1 - 1983/11/7
N2 - In this first paper we derive new constraints on gravitino and photino masses in big bang cosmology. First, in the context of induced supersymmetry breaking we calculate explicitly the gravitino decay rate into gauginos, and find that in the absence of significant dilution the gravitino mass must be ≥5 × 104 GeV in order not to affect nucleosynthesis. We also find in this case that constraints in the lightest R-odd particle, the photino, differ significantly from earlier bounds based on analogy with stable heavy neutrino bounds in the standard model, due to out of equilibrium gravitino decay. In order to avoid both these constraints the gravitino distribution must be severely suppressed. If this is due to inflation, it must occur at a scale ≲1010-1011 GeV.
AB - In this first paper we derive new constraints on gravitino and photino masses in big bang cosmology. First, in the context of induced supersymmetry breaking we calculate explicitly the gravitino decay rate into gauginos, and find that in the absence of significant dilution the gravitino mass must be ≥5 × 104 GeV in order not to affect nucleosynthesis. We also find in this case that constraints in the lightest R-odd particle, the photino, differ significantly from earlier bounds based on analogy with stable heavy neutrino bounds in the standard model, due to out of equilibrium gravitino decay. In order to avoid both these constraints the gravitino distribution must be severely suppressed. If this is due to inflation, it must occur at a scale ≲1010-1011 GeV.
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U2 - 10.1016/0550-3213(83)90574-6
DO - 10.1016/0550-3213(83)90574-6
M3 - Article
AN - SCOPUS:0001645436
SN - 0550-3213
VL - 227
SP - 556
EP - 569
JO - Nuclear Physics, Section B
JF - Nuclear Physics, Section B
IS - 3
ER -