Discriminating Electroweak-ino Parameter Ordering at the LHC and Its   Impact on LFV Studies
  Current limit on the dark matter relic abundance may suggest that $|\mu|$ should be smaller than prediction in the minimal supergravity scenario (mSUGRA) for moderate $m_0$ and $m_{1/2}$. The electroweak-ino parameter $M_1, M_2$ and $|\mu|$ are then much closer to each other. This can be realized naturally in the non-universal Higgs mass model (NUHM). Since the heaviest neutralino ($\tilde\chi^0_4$) and chargino ($\tilde\chi^\pm_2$) have significant gaugino components, they may appear frequently in the left-handed squark decay and then be detectable at the LHC. In such a case, we showed that the hierarchy of $M_1, M_2$ and $|\mu|$ can be determined. In the light slepton mass scenario with non-vanishing lepton-flavor violation (LFV) in the right-handed sector, NUHM with small $|\mu|$ corresponds to region of parameter space where strong cancellation among leading contributions to $Br(\mu\to e\gamma)$ can occur. We showed that determination of electroweak-ino hierarchy plays a crucial role in resolving cancellation point of $Br(\mu\to e\gamma)$ and determination of LFV parameters. We also discussed test of the universality of the slepton masses at the LHC and the implications to SUSY flavor models. 
Junji Hisano, Mihoko M. Nojiri, Warintorn Sreethawong