6533b852fe1ef96bd12ab55b

RESEARCH PRODUCT

τ→πππντ decays and the a1(1260) off-shell width revisited

D. Gómez DummAntonio PichPablo RoigJorge Portolés

subject

Quantum chromodynamicsPhysicsNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsBranching fractionSpectrum (functional analysis)Observable1/N expansion01 natural sciencesResonance (particle physics)Hadronization0103 physical sciencesPi010306 general physics

description

Abstract The τ → π π π ν τ decay is driven by the hadronization of the axial-vector current. Within the resonance chiral theory, and considering the large- N C expansion, this process has been studied in Ref. [1] (D. Gomez Dumm, A. Pich, J. Portoles, 2004). In the light of later developments we revise here this previous work by including a new off-shell width for the lightest a1 resonance that provides a good description of the τ → π π π ν τ spectrum and branching ratio. We also consider the role of the ρ ( 1450 ) resonance in these observables. Thus we bring in an overall description of the τ → π π π ν τ process in excellent agreement with our present experimental knowledge.

https://doi.org/10.1016/j.physletb.2010.01.059