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B -> X_s gamma in supersymmetry: large contributions beyond the leading order

G. Degrassi·P. Gambino·G. F. Giudice
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Abstract

We discuss possible large contributions to B -> X_s gamma, which can occur at the next-to-leading order in supersymmetric models. They can originate from terms enhanced by tan(beta) factors, when the ratio between the two Higgs vacuum expectation values is large, or by logarithm of M_{susy}/M_W, when the supersymmetric particles are considerably heavier than the W boson. We give compact formulae which include all potentially large higher-order contributions. We find that tan(beta) terms at the next-to-leading order do not only appear from the Hall-Rattazzi-Sarid effect (the modified relation between the bottom mass and Yukawa coupling), but also from an analogous effect in the top-quark Yukawa coupling. Finally, we show how next-to-leading order corrections, in the large tan(beta) region, can significantly reduce the limit on the charged-Higgs mass, even if supersymmetric particles are very heavy.

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G. Degrassi, P. Gambino, G. F. Giudice. 2000-11-18. B -> X_s gamma in supersymmetry: large contributions beyond the leading order. https://doi.org/10.1088/1126-6708%2F2000%2F12%2F009

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