The Σ→Λ+e+v decay as a test of the conserved vector current hypothesis

Alles, W.

doi:10.1007/bf02780378

“…Semileptonic hyperon decays have traditionally been analyzed in the rest frame of the decaying parent hyperon using fully covariant methods based on either four-component Dirac spinor methods [1,2,3,4,5,6,7] or on two-component Pauli spinor methods [8,9,10]. The latter method is particularly well suited for an implementation of a zero- [8] or a near zero-recoil [9,10] approximation. In the present paper we employ helicity methods to analyze semileptonic hyperon decays.…”

Section: Introductionmentioning

confidence: 99%

Helicity analysis of semileptonic hyperon decays including lepton-mass effects

Kadeer

¹

,

Körner

²

,

Moosbrugger

³

2008

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Using the helicity method we derive complete formulas for the joint angular decay distributions occurring in semileptonic hyperon decays including lepton mass and polarization effects. Compared to the traditional covariant calculation the helicity method allows one to organize the calculation of the angular decay distributions in a very compact and efficient way. In the helicity method the angular analysis is of cascade type, i.e. each decay in the decay chain is analyzed in the respective rest system of that particle. Such an approach is ideally suited as input for a Monte Carlo event generation program. As a specific example we take the decay Ξ 0 → Σ + + l − +ν l (l − = e − , µ − ) followed by the nonleptonic decay Σ + → p + π 0 for which we show a few examples of decay distributions which are generated from a Monte Carlo program based on the formulas presented in this paper. All the results of this paper are also applicable to the semileptonic and nonleptonic decays of ground state charm and bottom baryons, and to the decays of the top quark.

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“…Early analyses of hyperon β decay with the final-state polarization observed were restricted to the zero-recoil approximation [2] or were limited in scope [3]. More recent detailed treatments exist [4,5], but the resulting expressions are quite opaque, and, as a result, the physical content is hidden.…”

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confidence: 99%

“…As can be seen in Ref. [2], the zero-recoil (δ = 0) expression for S e (S ν ) is the same as that for the neutrino (electron) asymmetry for a polarized initial baryon [5].…”

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confidence: 99%

Effective Hamiltonian approach to hyperon beta decay with final-state baryon polarization

Bright

¹

,

Winston

²

,

Swallow

³

et al. 1999

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“…Early analyses of hyperon β decay with the final-state polarization observed were restricted to the zero-recoil approximation [2] or were limited in scope [3]. More recent detailed treatments exist [4,5], but the resulting expressions are quite opaque, and, as a result, the physical content is hidden.…”

mentioning

confidence: 99%

“…[2], the zero-recoil (δ = 0) expression for S e (S ν ) is the same as that for the neutrino (electron) asymmetry for a polarized initial baryon [5]. One of us (SB) acknowledges receipt of a U. S. Department of Education GANN Fellowship.…”

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confidence: 99%