Radiative Corrections to the Fermi Part of Strangeness-Conserving<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>Decay

We analyse the sensitivity of all experimentally observable asymmetries and energy distributions for the neutron β − -decay with a polarized neutron and unpolarised decay proton and electron and the lifetime of the neutron to contributions of order 10 −4 of interactions beyond the Standard model (SM). Since the asymmetries and energy distributions are expressed in terms of the correlation coefficients of the neutron β − -decay, in order to obtain a theoretical background for the analysis of contributions beyond the SM we revise the calculation of the correlation coefficients within the SM. We take into account a complete set of contributions, induced to next-to-leading order in the large proton mass expansion by the "weak magnetism" and the proton recoil, and the radiative corrections of order (α/π), calculated to leading order in the large proton mass expansion. We confirm the results, obtained in literature. The contributions of interactions beyond the SM we analyse in the linear approximation with respect to the Herczeg phenomenological coupling constants, introduced at the hadronic level. Such an approximation is good enough for the analysis of contributions of order 10 −4 of interactions beyond the SM. We show that in such an approximation the correlation coefficients depend only on the axial coupling constant, which absorbs the contributions of the Herczeg left-left and left-right lepton-nucleon current-current interactions (vector and axial-vector interactions beyond the SM), and the Herczeg scalar and tensor coupling constants. In the lifetime of the neutron in addition to the axial coupling constant the contributions of the Herczeg left-left and left-right lepton-nucleon current-current interactions (vector and axial-vector interactions beyond the SM) are absorbed by the Cabibbo-Kobayashi-Maskawa (CKM) matrix element.

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“…Making a shift of variables q − p(x)y → q, a Wick rotation q 0 → iq 4 [104] and integrating over y we arrive at the expression [18,19] …”

Section: A Finite-photon Mass Regularizationmentioning

confidence: 99%

Neutronβ−decay as a laboratory for testing the standard model

2013

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“…The accuracy of these data is poorer than found by the direct measurement of the W boson mass m W and of the ratio m W /m Z by the collaborations UA2 in CERN [33] and CDF at Tevatron [34]. According to PDG [35], the fitted quantity is m W = 80.22 (26), which corresponds to s 2 W = 0.2264 (25). Note that according to the most recent data [36], the measurement accuracy is even higher for m W : m W = 80.26 (16)GeV .…”

Section: Deep Inelastic Neutrino Scattering By Nucleonsmentioning

confidence: 98%

“…At D = 4 the integrals in (A.24) contain a pole term 25) where γ = 0.577... is the Euler constant. Choice of constant terms in (A.25) is a matter of convention.…”

Section: Regularization Of Feynman Integralsmentioning

confidence: 99%

Electroweak radiative corrections in Z-boson decays

et al. 1996

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Contents. Introduction.New theories, new symmetries, new particles, new phenomena. W and Z boson 'factories'. What's the point of studying loop corrections?.2. Brief history of electroweak radiative corrections.Muon and neutron decays. Main relations of electroweak theory.Traditional parametrization of corrections to the µ-decay and the running α.Deep inelastic neutrino scattering by nucleons.Other processes involving neutral currents.3. On optimal parametrization of the theory and the choice of the Born approximation.Traditional choice of the main parameters.Optimal choice of the main parameters. Z boson decays. Amplitudes and widths.Asymmetries.The Born approximation for hadronless observables.4. One-loop corrections to hadronless observables. Four types of Feynman diagrams. Asymptotic limit at m 2 t ≫ m 2 Z . The functions V m (t, h), V A (t, h) and V R (t, h). The corrections δV i (t, h). Accidental (?) compensation and the mass of the t-quark. How to calculate V i ? 'Five steps'. Hadronic decays of the Z boson.The leading quarks and hadrons. Decays to pairs of light quarks. Decays to a pair b b. 6. Comparison of theoretical results with experimental data. LEPTOP code. General fit. 7. Conclusions. Achievements. Problems. Prospects.

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“…An important result of the CA formulation is that, if very small contributions of O(αE/M ) are neglected, where E is the charged lepton energy and M a hadronic mass, the photonic corrections to β-decay involving the hadronic vector current are not affected by the strong interactions [10,11]. In particular, one expects that the photonic corrections to pion β-decay involving the hadronic vector current are essentially the same when evaluated in the CA formulation or using more elementary calculations based directly on the pion fields (PF).…”

mentioning

confidence: 99%

“…An alternative, more general and powerful Current Algebra (CA) approach, that takes into account the effect of the strong interactions, was subsequently developed to study the photonic corrections to β-decay in the local V-A theory [9,10] and the corre- * Electronic address: passera@pd.infn.it † Electronic address: philip@physics.auth.gr ‡ Electronic address: alberto.sirlin@nyu.edu sponding electroweak corrections in the SM [11]. It is essentially based on the Ward identities associated with the time-time and time-space components of the CA of weak and electromagnetic currents, which are expressed in terms of the quark fields.…”

mentioning

confidence: 99%

Observations on the radiative corrections to pionβdecay

Passera

Philippides²,

Sirlin

2011

Phys. Rev. D

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We find that, in the local V-A theory, the radiative corrections to pion β-decay involving the weak vector current, when evaluated in the current algebra (CA) formulation in which quarks are the fundamental underlying fields, show a small difference with the more elementary calculations based directly on the pion fields. We show that this difference arises from a specific short-distance effect that depends on the algebra satisfied by the weak and electromagnetic currents. On the other hand, we present a simple theoretical argument that concludes that this difference does not occur when the CA formulation is compared with the chiral perturbation theory (χPT) approach. Comparisons with previous studies, and with a more recent calculation based on χPT, are included. We also briefly review the important differences between the results in the local V-A theory and the Standard Model.

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Radiative Corrections to the Fermi Part of Strangeness-ConservingβDecay

Cited by 99 publications

References 36 publications

Neutronβ−decay as a laboratory for testing the standard model

Neutronβ−decay as a laboratory for testing the standard model

Electroweak radiative corrections in Z-boson decays

Observations on the radiative corrections to pionβdecay

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