Estimate of the branching fraction {tau}{sup -}{yields}{eta}{pi}{sup -}{nu}{sub {tau}}, the a{sub 0}{sup -}(980), and nonstandard weak interactions

Journal Article · Fri Aug 01 00:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.033006· OSTI ID:21250596

Nussinov, S ^[1]; Soffer, A ^[1]

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1. Tel Aviv University, Tel Aviv, 69978 (Israel)

We consider the 'second-class current' decay {tau}{sup -}{yields}{pi}{sup -}{eta}{nu}{sub {tau}} from several points of view. We first focus on the decay rate as expected within standard weak interaction and QCD due to isospin violation. The decay contributions divide into P- and S-wave parts. The former can be reliably estimated using the {rho}{eta}{pi} coupling inferred from the rates and Dalitz-plot distributions of {eta}{yields}3{pi} decays. The somewhat larger S-wave part, which was previously computed using chiral perturbation theory, is estimated from a simple qq model. Both estimates of the S-wave part depend on whether the a{sub 0}(980) scalar particle is a qq or some other (4-quark) state. Finally, we discuss genuinely new, non-V-A scalar weak interactions. The {tau}{sup -}{yields}{pi}{sup -}{eta}{nu}{sub {tau}} decay provides information on this question, which nicely complements that from precision {beta} decay experiments. In summary, we discuss the possible implications of putative values of the branching fraction B({tau}{sup -}{yields}{pi}{sup -}{eta}{nu}{sub {tau}}). In the case of larger values, in particular, of the S-wave part, not only will detection of the decay be more likely and more reliable, its implications will be more far-reaching and interesting.

• OSTI ID: 21250596
• Journal Information: Physical Review. D, Particles Fields, Vol. 78, Issue 3; Other Information: DOI: 10.1103/PhysRevD.78.033006; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
A0-980 MESONS
BRANCHING RATIO
CHIRALITY
COUPLING
DALITZ PLOT
DETECTION
DISTRIBUTION
ISOSPIN
P WAVES
PARTICLE DECAY
PARTICLES
PERTURBATION THEORY
PIONS MINUS
QUANTUM CHROMODYNAMICS
QUARKS
S WAVES
SECOND-CLASS CURRENTS
TAU NEUTRINOS
TAU PARTICLES
WEAK INTERACTIONS