Chinese Physics C > 1998, Vol. 22 > Issue(11): 961-968

Measurement of Michel Parameter in τ Decay

BES Collaborator

Institute of High Energy Physics, CAS, Beijing 100039

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Abstract：
We have analysed the e ⁺e ^－collision data collected with Beijing Spectrometer at the center-of-mass energy 4.03 GeV and selected e ⁺e ^－→τ ^±τ ⁺→e ^±X ⁺v's events, X ^±required as μ ^±、π ^±and ρ ^±. From fitting electron energy spectrum in τ→ev's decay, the measurement value of Michel parameter is given as ρ _τ→e=0.705, this result is in good agreement with the prediction of standrd Model.

References

[1]

Michel L. Proc. Phys. Soc, 1950,A63:514 [2] PDG. Review of Partical Propenies, Phys. Rev., 1996, D54:272 [3] Albrecht H et al. Phys. Lett., 1995, B341:441 [4] Derenzo et al.Phys. Rev., 1969,181:1854 [5] BES Coll. Nucl. Instr. Meth., 1994,A344:319[6] BES Coll. High Energy Phys. and Nuclear Phys. (in Chinese), 1997, 21: 193(BES合作组.高能物理与核物理,1997,21:193)[7] Ali A, Aydin Z Z. Nuovo Cimento, 1978, A43:270[8] Ye Suwei et al. High Energy Phys. and Nuclear Phys. (in Chirese), 1994, 18:577(叶树伟等.高能物理与核物理,1994,18:577)

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BES Collaborator. Measurement of Michel Parameter in τ Decay[J]. Chinese Physics C, 1998, 22(11): 961-968.

BES Collaborator. Measurement of Michel Parameter in τ Decay[J]. Chinese Physics C, 1998, 22(11): 961-968. shu

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Received: 1997-12-03
Revised: 1900-01-01

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沈阳化工大学材料科学与工程学院沈阳 110142

Measurement of Michel Parameter in τ Decay

BES Collaborator

Institute of High Energy Physics, CAS, Beijing 100039

Received Date:1997-12-03
Accepted Date:1900-01-01
Available Online:1998-11-05

Abstract:We have analysed the e⁺e^－collision data collected with Beijing Spectrometer at the center-of-mass energy 4.03 GeV and selected e⁺e^－→τ^±τ⁺→e^±X⁺v's events, X^±required as μ^±、π^±and ρ^±. From fitting electron energy spectrum in τ→ev's decay, the measurement value of Michel parameter is given as ρ_τ→e=0.705, this result is in good agreement with the prediction of standrd Model.