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$mu - e$ Conversion With Four Generations

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 نشر من قبل Xiao-Gang He
 تاريخ النشر 2011
  مجال البحث
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We study $mu - e$ conversion with sequential four generations. A large mass for the fourth generation neutrino can enhance the conversion rate by orders of magnitude. We compare constraints obtained from $mu - e$ conversion using experimental bounds on various nuclei with those from $mu to e gamma$ and $mu to ebar e e$. We find that the current bound from $mu - e$ conversion with Au puts the most stringent constraint in this model. The relevant flavor changing parameter $lambda_{mu e} = V^*_{mu 4}V_{e4}^{}$ is constrained to be less than $1.6times 10^{-5}$ for the fourth generation neutrino mass larger than 100 GeV. Implications for future $mu -e$ conversion, $mu to egamma$ and $mu to ebar e e$ experiments are discussed.

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