Phenomenological Estimation of Parameters in minimal Supergravity Model

Abstract

Several parameters of the minimal supergravity model are estimated by the method of the renormalization group. In this model, five arbitrary parameters $(m_0, m_{1/2}, \tan{\beta}, A_0, {sig}(\mu))$ are contained. $\tan{\beta}$ is evaluated as 7.5 by the likelihood analysis of the gauge and Yukawa coupling constants. Further, the trilinear coupling constant $A_0$ is fixed by the equation of $B_0=(A_0-1)m_0$ at the GUT scale $M_X \simeq 2\times10^{16}$(GeV) and by the Higgs potential at the Z-boson mass scale $M_Z=$91(GeV). As the results, (1) allowed $m_0-m_{1/2}$ regions, (2) the sparticle mass spectra, and (3) the lightest supersymmetric particle mass are shown in this paper.