b{r_arrow}s{gamma} constraints on the minimal supergravity model with large tan{beta}
- Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)
- Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
- Saint Leo College, St. Leo, Florida 33574 (United States)
- Department of Physics and Astronomy, University of Hawaii, Honolulu, Hawaii 96822 (United States)
In the minimal supergravity model (MSUGRA), as the parameter tan{beta} increases, the charged Higgs boson and light bottom squark masses decrease, which can potentially increase contributions from tH{sup {plus_minus}}, {tilde g}{tilde b}{sub j} and {tilde Z}{sub i}{tilde b}{sub j} loops in the decay b{r_arrow}s{gamma}. We update a previous QCD improved b{r_arrow}s{gamma} decay calculation to include in addition the effects of gluino and neutralino loops. We find that, in the MSUGRA model, loops involving charginos also increase, and dominate over tW, tH{sup {plus_minus}}, {tilde g}{tilde q} and {tilde Z}{sub i}{tilde q} contributions for tan{beta}{approx_gt}5{minus}10. We find for large values of tan{beta}{approximately}35 that most of the parameter space of the MSUGRA model for {mu}{lt}0 is ruled out due to too large a value of branching ratio B(b{r_arrow}s{gamma}). For {mu}{gt}0 and large tan{beta}, most of parameter space is allowed, although the regions with the least fine-tuning (low m{sub 0} and m{sub 1/2}) are ruled out due to too {ital low} a value of B(b{r_arrow}s{gamma}). We compare the constraints from b{r_arrow}s{gamma} to constraints from the neutralino relic density, and to expectations for sparticle discovery at CERN LEP2 and the Fermilab Tevatron p{bar p} colliders. Finally, we show that non-universal GUT scale soft breaking squark mass terms can enhance gluino loop contributions to b{r_arrow}s{gamma} decay rate even if these are diagonal. {copyright} {ital 1998} {ital The American Physical Society}
- OSTI ID:
- 656285
- Journal Information:
- Physical Review, D, Vol. 58, Issue 1; Other Information: PBD: Jul 1998
- Country of Publication:
- United States
- Language:
- English
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