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On the possibility of a very light A^0 at low \tanβ

A. G. Akeroyd·S. Baek·Gi-Chol Cho·K. Hagiwara
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Abstract

The searches at LEP II for the processes e^+e^-\to h^0Z and e^+e^-\to h^0A^0 in the Minimal Supersymmetric Standard Model (MSSM) fail to exclude regions of the m_h,m_A plane where \tanβ<1, thus allowing a very light A^0 (m_A< 20 GeV). Such a parameter choice would predict a light H^\pm with m_{H^\pm}< m_W. Although the potentially large branching ratio for H^\pm \to A^0 W^* would ensure that H^\pm also escaped detection in direct searches at LEP II and the Tevatron Run I, we show that this elusive parameter space is overwhelmingly disfavoured by electroweak precision measurements.

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A. G. Akeroyd, S. Baek, Gi-Chol Cho, K. Hagiwara. 2002-07-03. On the possibility of a very light A^0 at low \tanβ. https://doi.org/10.1103/physrevd.66.037702

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