Jr. Espinosa et al., ON THE ELECTROWEAK PHASE-TRANSITION IN THE MINIMAL SUPERSYMMETRIC STANDARD MODEL, Physics letters. Section B, 307(1-2), 1993, pp. 106-115
We study the finite-temperature effective potential of the Minimal Sup
ersymmetric Standard Model, in the limit of only one light Higgs boson
. Because of the large top Yukawa coupling, there can be significant d
ifferences with respect to the Standard Model case: for given values o
f the Higgs and top masses, little supersymmetry breaking in the stop
sector can make the phase transition more strongly first-order. After
including the full structure of the stop mass matrix, the most importa
nt experimental constraints and the leading plasma effects, we find th
at the present limits on Higgs and squark masses are still compatible
with the scenario of electroweak baryogenesis, in a small region of pa
rameter space corresponding to m(h) less than or similar too 70 GeV an
d m(b1)approximately less than or similar to 105 GeV.