English
Related papers

Related papers: Challenges for the Nelson-Barr Mechanism

200 papers

A recent work combined the popular left-right parity (LR) and Peccei-Quinn (PQ) symmetries to explain the alignment in quark masses. Since axions may not exist, we break PQ softly and discover a new solution to the strong CP problem.…

High Energy Physics - Phenomenology · Physics 2018-05-04 Ravi Kuchimanchi

We formulate general conditions under which the strong CP problem is solved by spontaneous CP violation. Quark-mass matrix elements are polynomials in the CP-breaking order parameters, engineered such that their determinant is a real…

High Energy Physics - Phenomenology · Physics 2024-08-16 Ferruccio Feruglio , Matteo Parriciatu , Alessandro Strumia , Arsenii Titov

We readdress the issue of strong CP violation both in the Standard Model and in the Minimal Left-Right Symmetric Model and try to clear the confusion that seems to still pervade the field. We argue that the smallness of strong CP violation,…

High Energy Physics - Phenomenology · Physics 2020-06-15 Goran Senjanovic , Vladimir Tello

We discuss a class of models in which CP is violated softly in a heavy sector adjoined to the standard model. Heavy-sector loops produce the observed CP violation in kaon physics, yielding a tiny and probably undetectable value for…

High Energy Physics - Phenomenology · Physics 2009-09-11 Howard Georgi , Sheldon L. Glashow

We present a cosmological solution to the electroweak hierarchy problem. After discussing general features of cosmological approaches to naturalness, we extend the Standard Model with two light scalars very weakly coupled to the Higgs and…

High Energy Physics - Phenomenology · Physics 2022-02-08 Raffaele Tito D'Agnolo , Daniele Teresi

I study the scalar representations of the electroweak group of the Standard Model, with a special emphasis on their chiral properties and on their behaviour by the discrete symmetries P and CP. A gauge theory for J=0 mesons naturally…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Machet

It is known that the Schwinger mechanism of vector-like QED theory is afflicted by a logarithmic singularity under background electromagnetic field due to a hypothetical massless charged fermion. We extend singularity analysis to a more…

High Energy Physics - Phenomenology · Physics 2022-09-07 M. Yoshimura

We reconsider the massless up quark solution of the strong CP problem. We show that an anomaly free horizontal symmetry can naturally lead to a massless up quark and to a corresponding accidental anomalous symmetry. Reviewing the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tom Banks , Yosef Nir , Nathan Seiberg

The main progress in the field of nucleon-nucleon (NN) potentials, which we have seen in recent years, is the construction of some very quantitative (high-quality/high-precision) NN potentials. These potentials will serve as excellent input…

Nuclear Theory · Physics 2007-05-23 R. Machleidt

We present a unified relaxion solution to the five major outstanding issues in particle physics: the hierarchy problem, dark matter, matter-antimatter asymmetry, neutrino masses and the strong CP problem. The only additional field content…

High Energy Physics - Phenomenology · Physics 2019-09-11 R. S. Gupta , J. Y. Reiness , M. Spannowsky

CP invariance is a very attractive solution to the strong CP problem in QCD. This solution requires the vanishing ${\rm arg}\,[{\rm det}\, M_d\, {\rm det} M_u]$, where the $M_d$ and $M_u$ are the mass matrices for the down- and up-type…

High Energy Physics - Phenomenology · Physics 2025-10-22 Morimitsu Tanimoto , Tsutomu T. Yanagida

In the framework of the left-right symmetric model the CP-parity violation has been studied in heavy Majorana neutrino decays $N\rightarrow e^{\mp} \mu^{\pm} n$. The numerical estimates of CP-asymmetry for different masses of neutrino and…

High Energy Physics - Phenomenology · Physics 2010-11-01 R. A. Alanakyan , H. M. Asatrian , A. N. Ioannisian , S. A. Chatrchyan

We point out the possibility of spontaneous and hard CP-violation in the scalar potential of R-parity broken supersymmetric Standard Model. The existence of spontaneous CP-violation depends crucially on the R-parity breaking terms in the…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. S. Joshipura , M. Nowakowski

The object of this thesis is the study of some open problems in the electroweak matter sector from an effective theory perspective. The topics studied include: General aspects of dynamical symmetry breaking models, studying what traces…

High Energy Physics - Phenomenology · Physics 2007-05-23 Julian Manzano

I briefly review solutions to the strong CP problem based on axions, parity invariance, CP-invariance, and present a new idea based on CP as part of a spontaneously broken flavour symmetry such as a U(1) or modular invariance.

High Energy Physics - Phenomenology · Physics 2025-01-29 Alessandro Strumia

We propose theories of a complete mirror world with parity (P) solving the strong CP problem. P exchanges the entire Standard Model (SM) with its mirror copy. We derive bounds on the two new mass scales that arise: $v'$ where parity and…

High Energy Physics - Phenomenology · Physics 2023-11-03 Quentin Bonnefoy , Lawrence Hall , Claudio Andrea Manzari , Christiane Scherb

I discuss vacuum alignment and CP violation in technicolor theories of electroweak and flavor symmetry breaking. I review the surprising appearance of rational phase solutions in the technifermion sector and propose a new solution of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Kenneth Lane

Global symmetries and symmetry breaking patterns of QCD with light quarks, in particular chiral symmetry, provide basic guidance not only for low-energy hadron physics but also for nuclear forces and the nuclear many-body problem. Recent…

Nuclear Theory · Physics 2019-04-17 Wolfram Weise

We find a solution to the Strong CP problem that may be testable at the LHC and future colliders. In this solution CP is broken by parity conserving terms, while parity breaking VEVs conserve CP. The quark mass matrix is Hermitian at the…

High Energy Physics - Phenomenology · Physics 2011-01-05 Ravi Kuchimanchi

Motivated by recent claims questioning the existence of strong CP violation, we present a pedagogical review of CP violation in Quantum Chromodynamics (QCD). Using fundamental properties of the QCD partition function, we analyze the…

High Energy Physics - Phenomenology · Physics 2026-01-09 Andreas Ringwald