1. A test of the Lorentz structure of semi-hadronic $\tau$ decays
- Author
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Thurn, H. and Kolanoski, H.
- Subjects
annihilation: electron positron ,electroproduction: tau ,electroproduction [Z0] ,axial-vector: coupling ,10 GeV ,annihilation [electron positron] ,coupling: scalar ,+Z0%22">electron positron --> Z0 ,axial-vector [coupling] ,Z0 [leptonic decay] ,electroproduction [tau] ,correlation [spin] ,differential cross section [angular dependence] ,electroproduction: Z0 ,Z0 [electroproduction] ,tau: pair production ,tau [pair production] ,semileptonic decay [tau] ,Monte Carlo [numerical calculations] ,vector: coupling ,+pi+pi0+antineutrino%2Ftau%22">tau --> pi pi0 antineutrino/tau ,tau [electroproduction] ,angular dependence [differential cross section] ,pair production [tau] ,numerical calculations: Monte Carlo ,correlation: spin ,Z0: electroproduction ,spin: correlation ,coupling [vector] ,scattering amplitude [decay] ,scattering amplitude: decay ,width [tau] ,pseudoscalar: coupling ,vector [coupling] ,electron positron: annihilation ,coupling [pseudoscalar] ,scalar: coupling ,+tau%2B+tau%22">electron positron --> tau+ tau ,pair production: tau ,tau [semileptonic decay] ,ddc:530 ,coupling [axial-vector] ,angular dependence: differential cross section ,tau: width ,transformation: Lorentz ,coupling: pseudoscalar ,electron positron [annihilation] ,decay [scattering amplitude] ,coupling: vector ,semileptonic decay: tau ,differential cross section: angular dependence ,leptonic decay [Z0] ,pseudoscalar [coupling] ,coupling: axial-vector ,scalar [coupling] ,coupling [scalar] ,interpretation of experiments: ARGUS ,tau: electroproduction ,leptonic decay: Z0 ,Z0: leptonic decay ,spin [correlation] ,decay: scattering amplitude ,ARGUS [interpretation of experiments] ,Lorentz [transformation] ,tau: semileptonic decay - Abstract
21 pp. (1993)., A method is proposed for the determination of the Lorentz structure of the electroweak interaction in semi-hadronic τ decays. Spin correlations in the process$e^+e^−→τ^+τ^−→\bar v τπ^+π^0vτπ^−π^0 e^+e^−→τ^+τ^−→\bar vτπ^+π^0vτπ^−π^0$ are exploited for a measurement of the normalized product, γAV = 2Re{gAgV*}/(|gV|2 + |gV|2), of the vector (gV) and axial vector (gA) coupling of the τ lepton. The contribution of scalar (gS) or pseudo-scalar (gP) couplings is also investigated. Since in the above process the direction of flight of the τ leptons can be reconstructed up to a twofold ambiguity a likelihood method using the whole kinematic information can be employed. The matrix element entering the likelihood function has been evaluated in terms of the momenta and angles of the observed pions. The sensitivity of the derived method in ane+e− energy region around 10 GeV has been investigated for the ARGUS experiment using Monte Carlo simulations.
- Published
- 1993
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