scholarly journals Neutron Oscillations and the Parity Doubling Theorem

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2202
Author(s):  
Kazuo Fujikawa ◽  
Anca Tureanu

We review several aspects of parity and CP violation in the framework of neutron-antineutron oscillations. We focus on the parity doubling theorem, which provides a criterion for neutron oscillation in the general theory with ΔB=2 baryon number-violating interactions. We prove by explicit calculations that the violation of the conventional parity symmetry with P2=1 is the necessary condition for neutron oscillations to happen. While the CP violation is not manifest in the oscillation, it is nevertheless intrinsic to the system, and it is transferred, by the mixing matrix, to the neutron interactions and potentially observable as a contribution to the electric dipole moment.

1997 ◽  
Vol 12 (40) ◽  
pp. 3131-3137 ◽  
Author(s):  
M. Frank

We study the contribution of the doubly charged higgsino to the electric dipole moment of the electron in a left–right extension of the standard supersymmetric model. The CP violation comes from the trilinear scalar interaction terms in the selectron mixing matrix. We find that this contribution can be quite large, of the same order of magnitude as the electric dipole moment of the electron in the MSSM, and reachable by future experiments.


2006 ◽  
Vol 21 (03) ◽  
pp. 243-264 ◽  
Author(s):  
MÜGE BOZ

We study the explicit CP violation of the Higgs sector in the next-to-minimal supersymmetric model with a gauge singlet Higgs field. Our numerical predictions show that electric dipole moment of electron lies around the present experimental upper limits. The mass of the lightest Higgs boson is quite sensitive to the CP violating phases in the theory. It is observed that as the vacuum expectation value of the singlet gets higher values, CP violation increases.


2018 ◽  
Vol 175 ◽  
pp. 01014 ◽  
Author(s):  
Boram Yoon ◽  
Tanmoy Bhattacharya ◽  
Rajan Gupta

For the neutron to have an electric dipole moment (EDM), the theory of nature must have T, or equivalently CP, violation. Neutron EDM is a very good probe of novel CP violation in beyond the standard model physics. To leverage the connection between measured neutron EDM and novel mechanism of CP violation, one requires the calculation of matrix elements for CP violating operators, for which lattice QCD provides a first principle method. In this paper, we review the status of recent lattice QCD calculations of the contributions of the QCD Θ-term, the quark EDM term, and the quark chromo-EDM term to the neutron EDM.


1969 ◽  
Vol 47 (6) ◽  
pp. 693-695 ◽  
Author(s):  
Radha Gourishankar ◽  
A. N. Kamal

A model of CP violation due to the existence of a neutral intermediate weak vector boson is studied. It is found that all leptonic and semileptonic decays are CP conserving; however nonleptonic decays are all CP violating to order [Formula: see text]. The CP-violating decays also preserve the [Formula: see text]. An estimate of the electric dipole moment of the nucleon based on such a model gives μe ≈ 10−29 e cm. The electric dipole moment of the electron is zero.


2007 ◽  
Vol 85 (6) ◽  
pp. 597-606
Author(s):  
A Ritz

We dicuss the utility of precision probes for flavour-diagonal CP-violation, namely, searches for electric dipole moments of nucleons, atoms, and molecules, in looking for new physics thresholds that manifest themselves primarily through higher dimensional operators. After reviewing the status of the electric dipole moment (EDM) constraints, we consider first the sensitivity to a generic class of dimension-five operators generated at a supersymmetric threshold, through their contribution to CP- and flavour-violating observables. Such thresholds can be probed by EDMs up to a scale of order 108 GeV depending on the flavour structure. We then turn to consider the possibility that electroweak baryogenesis is made feasible by the introduction of dimension-six operators at a TeV-scale threshold. The EDM costraints on dimension-six couplings of the Higgs to the fermions currently still allow a reasonable window in parameter space for these models, but the next generation of experiments should provide a conclusive test. PACS Nos.: 11.30.Er, 12.60.Fr, 12.60.Jv


2002 ◽  
Vol 17 (23) ◽  
pp. 1489-1497 ◽  
Author(s):  
C. Q. GENG ◽  
J. N. NG ◽  
T. H. WU

We study the CP violating effects in the decay of η → π+π- γ. We show that to have CP violation in the decay, one has to consider both linear and circular photon polarizations. In the standard model, the polarizations are vanishingly small. However, model independently, i.e. using only experimental constraint imposed by the limit on Br (η → π+ π-), it can be up to O(10%). We also explore various possible operators and we find that the tensor type operator, possibly arising from a nonzero CP violating electric dipole moment of the strange quark, can induce a sizable linear photon polarization.


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