English
Related papers

Related papers: Enhanced EDMs from Small Instantons

200 papers

New sources of charge-parity (CP) violation beyond those described in the Standard Model (SM) are required to explain the observed matter--antimatter asymmetry of the Universe. The Standard Model Effective Field Theory (SMEFT) provides a…

High Energy Physics - Phenomenology · Physics 2026-04-27 Avalon Roberts , Patrick Dougan , Alexander Oh , Savanna Shaw

Contemporary attempts to explain the existence of ultra-high energy cosmic rays using plasma-based wakefield acceleration deliberately avoid non-Standard Model particle physics. However, such proposals exploit some of the most extreme…

High Energy Physics - Phenomenology · Physics 2016-08-29 D. A. Burton , A. Noble , T. J. Walton

It is shown that a two-Higgs doublet model with Vacuum CP Violation and Approximate Global $U(1)$ Family Symmetries (AGUFS) may provide one of the simplest and attractive models in understanding origin and mechanisms of CP violation at the…

High Energy Physics - Phenomenology · Physics 2008-02-03 Yue-Liang Wu

We demonstrate that electron electric dipole moment experiments with molecules in paramagnetic state are sensitive to $P,T$-violating nuclear forces and other $CP$-violating parameters in the hadronic sector. These experiments, in…

High Energy Physics - Phenomenology · Physics 2021-01-04 V. V. Flambaum , I. B. Samsonov , H. B. Tran Tan

New one- and two-loop contributions to the lepton's and nucleon's EDM, which are induced by an axion-like particle dark matter background, are examined. These contributions include effects from CP-violating ALP interactions with photons,…

High Energy Physics - Phenomenology · Physics 2025-09-17 Jason L. Evans , Nan Li , Junyuan Lyu

On general grounds based on quantum field theory the decay amplitude for $\Sigma^0 \to \Lambda \gamma$ consists of a parity conserving magnetic and a parity violating electric dipole transition moment. Because of the subsequent…

High Energy Physics - Phenomenology · Physics 2018-12-05 Shankar Sunil Nair , Elisabetta Perotti , Stefan Leupold

It is shown that the mechanism of spontaneous symmetry breaking provides not only a mechanism for giving mass to the bosons and the fermions, but also a mechanism for generating CP-phase of the bosons and the fermions. A two-Higgs doublet…

High Energy Physics - Phenomenology · Physics 2008-02-03 Yue-Liang Wu

Besides CP-preserving interactions, axions and axion-like particles may also have small CP-violating scalar Yukawa interactions with nucleons and electrons. Any such interaction will generate macroscopic monopole-dipole forces which can be…

High Energy Physics - Phenomenology · Physics 2021-01-04 Ciaran A. J. O'Hare , Edoardo Vitagliano

A nonvanishing value for the electric dipole moment (EDM) of the neutron is a prominent signature for CP violation. The EDM induced by the Kobayashi-Maskawa mechanism of the standard model (SM) has a small magnitude and its detection will…

High Energy Physics - Phenomenology · Physics 2007-05-23 Noriyuki Oshimo

The electric dipole moment (EDM) of elementary particles, arising from flavor-diagonal $CP$ violation, serves as a powerful probe for new physics beyond the Standard Model and holds the potential to provide novel insights in unraveling the…

High Energy Physics - Experiment · Physics 2023-12-29 Jinlin Fu , Hai-Bo Li , Jian-Peng Wang , Fu-Sheng Yu , Jianyu Zhang

Searches for intrinsic electric dipole moments (EDMs) of nucleons, atoms and molecules are precision flavor-diagonal probes of new $CP$-odd physics, as motivated by the need to explain the matter-antimatter asymmetry in the universe. We…

High Energy Physics - Phenomenology · Physics 2026-03-19 Maxim Pospelov , Adam Ritz

A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay…

High Energy Physics - Phenomenology · Physics 2016-08-29 Takeshi Kobayashi , Fuminobu Takahashi

A new possibility for solving the strong CP-problem is suggested,which assumes that apart of the ordinary world of observable particles described by standard model, there exits a mirror sector of particles and two sectors share the same…

High Energy Physics - Phenomenology · Physics 2009-10-31 Zurab Berezhiani , Leonida Gianfagna , Maurizio Giannotti

The CP parameters $\epsilon$ and $\epsilon'/\epsilon$ are calculated in the aspon model of spontaneous CP violation, a model which solves the strong CP problem. A new range for the scale of spontaneous breaking of CP is found. It is shown…

High Energy Physics - Phenomenology · Physics 2014-11-17 Paul H. Frampton , Masayasu Harada

In this talk I will show that the two-Higgs doublet model with vacuum CP violation and approximate global $U(1)$ family symmetries may provide one of the simplest and most attractive models for understanding the origin and mechanisms of CP…

High Energy Physics - Phenomenology · Physics 2009-10-28 Yue-Liang Wu

We analyze CP violation in supersymmetry with Effective Minimal Flavour Violation, as recently proposed in arXiv:1011.0730. Unlike the case of standard Minimal Flavour Violation, we show that all the phases allowed by the flavour symmetry…

High Energy Physics - Phenomenology · Physics 2011-05-13 Riccardo Barbieri , Paolo Lodone , David M. Straub

The absence of a neutron electric dipole moment (EDM) constrains the quantum chromodynamics (QCD) theta angle to be less than one part in ten billion, posing the Strong $CP$ problem. We revisit two classes of proposed solutions. First, we…

High Energy Physics - Phenomenology · Physics 2025-10-23 Joshua N. Benabou , Anson Hook , Claudio Andrea Manzari , Hitoshi Murayama , Benjamin R. Safdi

The impact of axion-like particles (ALPs) on the search of permanent electric dipole moments (EDMs) of molecules, atoms, nuclei and nucleons is systematically investigated. We classify first the full set of CP-violating Jarlskog invariants…

High Energy Physics - Phenomenology · Physics 2021-12-07 Luca Di Luzio , Ramona Gröber , Paride Paradisi

Experiments with paramagnetic ground or metastable excited states of molecules (ThO, HfF$^+$, YbF, YbOH, BaF, PbO, etc.) provide strong constraints on electron electric dipole moment (EDM) and coupling constant $C_{SP}$ of contact…

High Energy Physics - Phenomenology · Physics 2020-10-28 V. V. Flambaum , I. B. Samsonov , H. B. Tran Tan

We re-examine spontaneous CP violation at the tree level in the context of the next-to-minimal supersymmetric standard model (NMSSM) with two Higgs doublets and a gauge singlet field. We analyse the most general Higgs potential without a…

High Energy Physics - Phenomenology · Physics 2010-02-03 G. C. Branco , F. Krüger , J. C. Romão , A. M. Teixeira