Zeroing In On the Top Quark, LSP and Scalar Higgs Masses

Abstract

We estimate the top quark, lightest sparticle (LSP) and scalar higgs masses within a supersymmetric grand unified framework in which $\tan \beta \simeq m_t/m_b$ and the electroweak symmetry is radiatively broken. The requirement that the calculated $b$ quark mass lie close to its measured value, together with the cosmological constraint ${\Omega }_{LSP}\approx 1$, fixes the top quark mass to be $m_t(m_t)\approx 170\pm 15GeV$. The LSP (of bino purity $\stackrel{{}_{>}}{{}_{\sim }}98\%)$ has mass $\sim 200-350GeV$. In the scalar higgs sector the CP-odd scalar mass $m_A\stackrel{{}_{<}}{{}_{\sim }}220GeV$. With $m_A\stackrel{{}_{>}}{{}_{\sim }}{M}_Z$, as suggested by the decay $b\to s\gamma$, we find $M_Z\stackrel{{}_{<}}{{}_{\sim }}{m}_{h^0}(m_{H^0})\stackrel{{}_{<}}{{}_{\sim }}140(220)GeV$ and $120GeV\stackrel{{}_{<}}{{}_{\sim }}{m}_{H^{\pm }}\stackrel{{}_{<}}{{}_{\sim }}240GeV$.

Comments: 14 pages in plain LaTeX, BA-93-25, PRL-TH-93/6