2002/08/05 by Jun Tabei, Tabei, Jun, Hiroshi Hotta +1 · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0208039
5 pages, 2 figures in the ReVTex4 format
arxiv created 2002/09/18 · arxiv updated 2009/11/30
Constraints on the common trilinear coupling constant A0 are obtained in the minimal supergravity model. A0 is usually given at GUT scale MX by-hand, and has been regarded as one of the five arbitrary parameters in this model. However, B(MZ) as the common bilinear coupling constant B at the electroweak scale MZ ≃ 91(GeV) is fixed by the shape of the Higgs potential. With the renormalization group equations, this B(MZ) is evolved to B0 at MX where a well-known relation exists between the evolved B0 and A0 as B0 = (A0-1) m0. Therefore, A0 is fixed as a function of the other arbitrary parameters. In other words, the number of arbitrary parameters are reduced by this method. Additionally, large tanβ > 40 is forbidden by the conditions at MZ.