Radiative decay of polarized {tau}-leptons, {tau}{sup -}{yields} V{sub {tau}} + {Pi}{sup -} + {gamma}

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · Annals of Physics (New York)

DOI:https://doi.org/10.1006/aphy.1995.1069· OSTI ID:113771

Pak, N K; Rekalo, M P; Yilmaz, T ^[1]

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1. Middle East Technical Univ., Ankara (Turkey)

Using the standard form of the matrix element, which contains the so-called structural part as well as Inner Bremsstrahlung (IB) contribution, we calculate the structure functions for {tau}{sup -}{yields}{sub tau} + {pi}{sup -} + {gamma} in terms of the vector and axial form factors of the transition W{yields}{pi} + {gamma}. We work out Dalitz plot for all three possible exclusive asymmetries and show that they are all non-zero. We discuss the consequences of the radiative zero in the IB amplitude. We show that inclusive asymmetries in {tau}{sup -}{yields}v{sub tau} + {pi}{sup -} + {gamma} can be calculated analytically without knowledge of any concrete parametrization of the form factors v(t) and a(t). The t-dependence of v(t) and a(t) is computed in the framework of the vector dominance model using the conservation of vector current hypothesis for the v(0) and the existing experimental data for the ratio {gamma}=a(0)/v(0) from {pi}{sup -}{yields}e{sup -} + {bar v}{sub e} + {gamma} decay. We demonstrate the sensitivity of exclusive and inclusive asymmetries to the sign of the vector form factor. The predicted polarization effects are large in magnitude. 25 refs., 10 figs., 1 tab.

• OSTI ID: 113771
• Journal Information: Annals of Physics (New York), Journal Name: Annals of Physics (New York) Journal Issue: 2 Vol. 241; ISSN APNYA6; ISSN 0003-4916
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BREMSSTRAHLUNG
MATRIX ELEMENTS
POLARIZATION
RADIATIVE DECAY
STRUCTURE FUNCTIONS
TAU PARTICLES