QCD axion from a spontaneously broken B \u2212 L gauge symmetry

Gongjun Choi,Tsutomu T. Yanagida,Motoo Suzuki

doi:10.1007/jhep07(2020)048

Abstract

In this paper, we show that the Peccei-Quinn (PQ) symmetry with a good quality can be realized in a simple B −L extension of the minimal supersymmetric standard model. The PQ symmetry is a remnant of the B − L gauge symmetry at the renormalizable level. Besides, the sufficient quality of the PQ symmetry is preserved by a non anomalous discrete gauged R-symmetry and a small gravitino mass m3/2 ≪ 100 GeV. A viable mass range is {m}_{3/2}=mathcal{O}(1) eV which allows a high reheating temperature and many baryogenesis scenarios typified by the thermal leptogenesis without any astrophysical and cosmological problems. Such a light gravitino may be tested in the future 21cm line observations.

Highlights

A gravitino mass range of m3/2 < O(1) eV is consistent with a high reheating temperature, allowing many baryogenesis scenarios typified by the thermal leptogenesis [16] without suffering from neither astrophysical nor cosmological problems [17,18,19]
In this paper, we show that the Peccei-Quinn (PQ) symmetry with a good quality can be realized in a simple B −L extension of the minimal supersymmetric standard model
We argue that an origin of an accidental PQ symmetry with good quality can be provided by a simple extension of the minimal supersymmetric standard model (MSSM) with B − L gauge symmetry

Summary

The B-L gauge symmetry in a SUSY standard model

We discuss a B − L extension of the minimal supersymmetric standard model (MSSM). In the SM, the B − L symmetry is realized as an accidental global symmetry Gauging this symmetry requires additional B − L charged fields from the gauge anomaly cancellation. The majorana masses of the right handed neutrinos are provided when one introduces the SM gauge singlet chiral superfields, Φ(−10), Φ (10) ,. Where X is a SM and B − L gauge singlet chiral superfield, v denotes a parameter with a mass dimension, and we are assuming the existence of the R-symmetry. We consider the charge assignments where the mass terms of 5 and 5 ̄ with B − L charges opposite in sign are forbidden by the B − L gauge symmetry. To give the other 5 and 5 ̄ masses, we introduce additional SM gauge singlet chiral superfields with B − L charges ±15,. The gravitational anomaly is model dependent. we do not specify the field contents from those anomaly cancellations

An emergent global Peccei-Quinn symmetry from the B-L gauge symmetry

Axion and global PQ

Domain wall problem

Conclusions

A Generating constant term in the superpotential and μ-term