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Measurement of Michel Parameters ($bareta$, $xikappa$) in the radiative leptonic decay of tau at Belle

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 نشر من قبل Nobuhiro Shimizu
 تاريخ النشر 2016
  مجال البحث
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We present the first measurement of the Michel parameters $bar{eta}$ and $xikappa$ in the radiative leptonic decay of the $tau$ lepton using 703 f$mathrm{b}^{-1}$ of data collected with the Belle detector at the KEKB $e^+e^-$ collider. The Michel parameters are measured by an unbinned maximum likelihood fit to the kinematic information of $e^+e^-rightarrowtau^+tau^-rightarrow (pi^+pi^0 bar{ u})(l^- ubar{ u}gamma)$ $(l=e$ or $mu)$. The preliminary values of the measured Michel parameters are $bar{eta} = -2.0 pm 1.5 pm 0.8$ and $xikappa = 0.6 pm 0.4 pm 0.2$, where the first error is statistical and the second is systematic.

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