Spontaneous CP Violation and Horizontal Symmetry in the MSSM: Toward Lepton Flavor Naturalness

Abstract

We study the contributions of supersymmetric models with a $U(1)$ horizontal symmetry and only spontaneous CP breaking to various lepton flavor observables, such as $\mu \to e\gamma$ and the electron electric dipole moment. We show that both a horizontal symmetry and a lack of explicit CP violation can alleviate the existing bounds from such observables. The undetermined $\mathcal{O}(1)$ coefficients in such mass matrix models muddle the interpretation of the bounds from various flavor observables. To overcome this, we define a new fine-tuning measure for different observables in such setups. This allows us to study how naturally the observed IR flavor observables can emerge from a given mass matrix model. We use our flavor-naturalness measure in study of our supersymmetric models and quantify the degree of fine tuning required by the bounds from various lepton flavor observables at each mass scale of sleptons, neutralinos, and charginos.

Minor changes to how random numbers are generated. Conclusions unchanged. Version published in JHEP. 31+18 Pages. 9 Figures. 6 Tables

References in corpus (19)

• The fate of hints: updated global analysis of three-flavor neutrino oscillations
• Symmetries and Strings in Field Theory and Gravity
• Precision Measurement of Time-Reversal Symmetry Violation with Laser-Cooled Polyatomic Molecules
• SUSY Breaking in Local String/F-Theory Models
• Electric Dipole Moments in the MSSM Reloaded
• Simply Unnatural Supersymmetry
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• A unique Z_4^R symmetry for the MSSM
• Improved constraints on neutrino mixing from the T2K experiment with $3.13\times 10^{21}$ protons on target
• Search for supersymmetry in final states with two oppositely charged same-flavor leptons and missing transverse momentum in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Sequestered de Sitter String Scenarios: Soft-terms
• Neutrino oscillations: the rise of the PMNS paradigm
• Methods for measuring the electron EDM using ultracold YbF molecules
• Oriented polar molecules in a solid inert-gas matrix: a proposed method for measuring the electric dipole moment of the electron
• Efficient sampling of constrained high-dimensional theoretical spaces with machine learning
• A submission to the 2020 update of the European Strategy for Particle Physics on behalf of the COMET, MEG, Mu2e and Mu3e collaborations
• SUSY FLAVOR v2.5: a computational tool for FCNC and CP-violating processes in the MSSM
• Searches for new sources of CP violation using molecules as quantum sensors
• Particle Physics Model Building with Reinforcement Learning

Cited by in corpus (1)

• Supersymmetric Alignment Models for $(g-2{)}_{\mu }$