Chiral Nelson--Barr Models: Quality and Cosmology

Abstract

It was recently shown that domain walls from the spontaneous breaking of CP symmetry are exactly stable, and must be inflated away to recover a viable cosmology. We investigate the phenomenological implications of this result in Nelson--Barr solutions of the strong CP problem. Combined with the upper bound on the scale of spontaneous CP breaking necessary to suppress contributions from dangerous, nonrenormalizable operators to $\bar{\theta }$, this puts an upper bound on the scale of inflation and the reheating temperature after inflation. Minimal Nelson--Barr models are therefore in tension with thermal leptogenesis, models of large-field inflation, or potential future observations of signals from topological remnants of an unrelated, subsequent phase transition. We study how extending Nelson--Barr models with a new, continuous chiral gauge symmetry can ameliorate this tension by forbidding the dangerous dimension-five operators. In particular, we show that gauging a linear combination of baryon number and hypercharge allows for an economic, anomaly-free extension of the minimal Nelson--Barr model, and discuss the phenomenological implications.

23 pages + appendices, 2 figures. v3: matches published version

References in corpus (18)

• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Symmetries and Strings in Field Theory and Gravity
• Gravitational-wave sensitivity curves
• Measurement of the permanent electric dipole moment of the neutron
• An Improved Measurement of Neutrino Oscillation Parameters by the NOvA Experiment
• Electric Dipole Moments in the MSSM Reloaded
• Improved constraints on neutrino mixing from the T2K experiment with $3.13\times 10^{21}$ protons on target
• Generalized Symmetry Breaking Scales and Weak Gravity Conjectures
• Wash-In Leptogenesis
• P not PQ
• The CKM Phase and $\bar{\theta }$ in Nelson-Barr Models
• Higgs Parity, Strong CP, and Dark Matter
• Super-Soft CP Violation
• A Natural Model of Spontaneous CP Violation
• Solving the strong CP problem with non-conventional CP
• High quality Nelson-Barr solution to the strong CP problem with $\theta =\pi$
• Baryon Asymmetric Universe from Spontaneous CP Violation

Cited by in corpus (13)

• Fractionally Charged Particles at the Energy Frontier: The SM Gauge Group and One-Form Global Symmetry
• Nelson-Barr ultralight dark matter
• Non-Invertible Peccei-Quinn Symmetry, Natural 2HDM Alignment, and the Visible Axion
• Revisiting the Minimal Nelson-Barr Model
• Explicit parametrization of more than one vector-like quark of Nelson-Barr type
• Leptogenesis in automatic Nelson-Barr models
• Dark-sector seeded solution to the strong CP problem
• Strong CP from a Hidden Chiral Condensate
• Leptonic CP violation from the seesaw
• Spontaneous CP violation, sterile neutrino dark matter, and leptogenesis
• Exploring the Landscape of Spontaneous CP Violation in Supersymmetric Theories
• Effective description of Nelson-Barr models and the theta parameter
• Nelson-Barr Models with Vector-Like Quark Doublets