Monday, January 30, 2012

1201.5305 (Zhaofeng Kang et al.)

On the Naturalness of the (N)MSSM    [PDF]

Zhaofeng Kang, Jinmian Li, Tianjun Li
We evaluate the naturalness of m_Z(m_h) in the (N)MSSM using the bottom-up
method. For high mediation scale the tuning of m_Z is dominated by the gluino,
and LHC gives \Delta_Z<2.5% even for light stops. But m_h near 125 GeV, if
natural, strongly favors the NMSSM. Then an anatomy of the NMSSM effect lifting
m_h is presented and find:
(1) Large \lambda with push or pull (but not decoupling) effect on m_h due to
H/S mixing, the former shows significant 2\gamma excess readily whereas the
latter is not. We point out the push scenario incurs extra acute tuning owing
to vacuum stability and large \lambda-RGE effect.
(2) Small \lambda with push effect can also lift m_h, although not so
effective (generically worse naturalness) neither shows significant diphoton
excess. (3) The LSP is strongly excluded by the XENON100, even survives still
disfavored by naturalness. However, if the mediation scale is sufficiently low,
the naturalness can be improved about one order.
View original: http://arxiv.org/abs/1201.5305

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