scholarly journals Radiative corrections for neutron decay and search for new physics

Author(s):  
V. Gudkov ◽  
K. Kubodera ◽  
F. Myhrer
1993 ◽  
Vol 08 (18) ◽  
pp. 1691-1700 ◽  
Author(s):  
GEORGE TRIANTAPHYLLOU

In view of the recent interest in the decays of mesons into a pair of light leptons, a computation of the QED radiative corrections to the decay of π0 into an electron-positron pair is presented here. The analysis is based on the soft-photon resummation method, which, unlike first-order perturbation theory, allows for very strict invariant-mass cuts on the final electrons. When combined with the theoretical estimates for the non-radiatively corrected decay rate, the results of the present paper could help to determine if new physics affect this decay.


1958 ◽  
Vol 112 (1) ◽  
pp. 267-270 ◽  
Author(s):  
S. M. Berman

1982 ◽  
Vol 209 (2) ◽  
pp. 372-388 ◽  
Author(s):  
Jean-Luc Cambier ◽  
Joel R. Primack ◽  
Marc Sher

2019 ◽  
Vol 219 ◽  
pp. 04007 ◽  
Author(s):  
Xiangzun Wang ◽  
Carmen Ziener ◽  
Hartmut Abele ◽  
Stefan Bodmaier ◽  
Dirk Dubbers ◽  
...  

The PERC (Proton and Electron Radiation Channel) facility is currently under construction at the research reactor FRM II, Garching. It will serve as an intense and clean source of electrons and protons from neutron beta decay for precision studies. It aims to contribute to the determination of the Cabibbo-Kobayashi-Maskawa quark-mixing element Vud from neutron decay data and to search for new physics via new effective couplings. PERC's central component is a 12 m long superconducting magnet system. It hosts an 8 m long decay region in a uniform field. An additional high-field region selects the phase space of electrons and protons which can reach the detectors and largely improves systematic uncertainties. We discuss the design of the magnet system and the resulting properties of the magnetic field.


2007 ◽  
Vol 22 (27) ◽  
pp. 4891-4899 ◽  
Author(s):  
N. F. BELL

The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment bounds are weaker than present experimental limits if μν is generated by new physics at ~ 1 TeV , and surpass current experimental sensitivity only for new physics scales > 10 – 100 TeV . The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Oleksandr Tomalak ◽  
Pedro Machado ◽  
Vishvas Pandey ◽  
Ryan Plestid

Abstract We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. 40Ar and 28Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light masses. These same loops, and those mediated by tau leptons, break the flavor universality because of mass-dependent electromagnetic radiative corrections. Nuclear physics uncertainties significantly cancel in flavor asymmetries resulting in subpercent relative errors. We find that for low neutrino energies, the cross section can be predicted with a relative precision that is competitive with neutrino-electron scattering. We highlight potentially useful applications of such a precise cross section prediction ranging from precision tests of the Standard Model, to searches for new physics and to the monitoring of nuclear reactors.


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