1999/01/19 by G. C. Cho, K. Hagiwara, Cho, G. C. +6
Computer Science · Physics and Astronomy · #Black Holes and Theoretical Physics #Computational Physics and Python Applications #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9901351
Contribution of the Precision Electroweak Subgroup of the SUGRA Working Group for the Physics at Run II -- Supersymmetry/Higgs Workshop, November 19-21, 1998. 6 pages
arxiv created 1999/01/19 · openalex publication_date 1999/01/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We place constraints on the parameter space of the minimal supergravity (SUGRA) inspired supersymmetric (SUSY) extension of the standard model (SM), i.e. the mSUGRA model, by studying the loop-level contributions of supersymmetric particles to electroweak precision observables. In general the Higgs and superpartner particles of SUSY models contribute to electroweak observables through universal propagator corrections as well as process-specific vertex and box diagrams. However, because the mass of the lightest chargino is contrained to be greater than 91 GeV, we find that the process-dependent contributions to four-fermion amplitudes are negligibly small. Hence, the full analysis may be reduced to an analysis of the propagator corrections, and in some regions of parameter space the constraints from the (b ---> s gamma) process are quite important. The propagator corrections are dominated by the contributions of the scalar fermions, and we summarize the results in the Peskin-Takeuchi S-T plane and the contributions to the W-boson mass. We then present the results in the mSUGRA m0 -- m1/2 plane and find that our analysis of the propagator corrections provides constraints in the small-m0 -- small-m1/2 region, precisely the region of interest for collider phenomenology. In some regions of parameter space, especially for mu < 0 and large tan(beta), the constrained region is enlarged considerably by including the process (b ---> s gamma).