Propagation of Supersymmetric Charged Slepton at High Energies Shufang Su • U. of Arizona M.H. Reno, I. Sarcevic and S. Su hep-ph/0503030

Motivation Neutrino telescopes have great potential - Neutrino telescopes have great potential to probe new physics beyond SM  earth  ~ Gravitino LSP Stau NLSP   earth Msl=250 GeV Mwino=250 GeV Albuquerque, Chacko and Burdman (2003)  N  l ~ q  Larger production rate smaller production rate  = 2.197£ 10-6 sec c=659 meter Larger effective detector volumn S. Su stau propagation

stau energy loss - Discovery potential for neutrino telescope depends on the stau lifetime and range Crucial to determine the energy loss of the high energy stau as it traverse the earth S. Su stau propagation

Average energy loss of a particle traversing distance X stau energy loss - Average energy loss of a particle traversing distance X ionization energy loss Constant: =2 £ 10-3 cm2/g radiative energy loss m,  , more later … energy When  E ¿ , i.e. E ¿ 4 £ 105 GeV £ (msl/150 GeV) Stau range determined by ionization energy loss  or lifetime c  c = E / () S. Su stau propagation

radiative energy loss:  - photonuclear bremsstrahlung pair production S. Su stau propagation

radiative energy loss:  - Stau / 1/m Stau: mass dependence muon / 1/m2 S. Su stau propagation

stau range: X(E, E0)  E À   E ¿  m=250 GeV lifetime m=250 GeV - m=250 GeV lifetime m=250 GeV m=150 GeV E0=106 GeV lifetime m=250 GeV  E À  m=150 GeV m=150 GeV  E ¿  E0=103 GeV S. Su stau propagation

Comparison ? Xus / XABC In Albuquerque, Chacko and Burdman (2003) - In Albuquerque, Chacko and Burdman (2003) Rescale from :  = 0.8 £ 10-6 cm2/g  stau=9.5 £ 10-9 (150 GeV/mstau) cm2/g No energy dependence Xus / XABC ? Improve the potential of neutrino telescopes for detecting metastable stau S. Su stau propagation

Conclusion Stau radiative energy loss  is dominated by - Stau radiative energy loss  is dominated by photo-nuclear and pair production Photonuclear and pair: / 1/m Bremsstrahlung: / 1/m2 Low energy ( E ¿ ), stau range is determined by ionization energy loss or stau lifetime, X / E High energy ( E À ), stau range is determined by radiative energy loss, X / log (E) Previous estimation (scale stau) underestimate stau range by about a factor of two S. Su stau propagation