English
Related papers

Related papers: Challenges for the Nelson-Barr Mechanism

200 papers

Assuming the seesaw and leptogenesis mechanisms, I give some general remarks on possible connection or disconnection between CP violation in heavy Majorana neutrino decays and that in neutrino oscillations. A simple but predictive ansatz is…

High Energy Physics - Phenomenology · Physics 2009-11-07 Zhi-zhong Xing

I discuss strategies for probing CP properties in the top quark system at $e^-e^+$ and hadron Colliders. The magnitudes of CP violation effects predicted by various models are reviewed. I also discuss the potential of various current and…

High Energy Physics - Phenomenology · Physics 2010-11-01 C. -P. Yuan

We construct the most general effective Lagrangian of the matter sector of the Standard Model, including mixing and CP violating terms. The Lagrangian contains the effective operators that give the leading contribution in theories where the…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Espriu , J. Manzano

We propose simple scoto-seesaw models to account for dark matter and neutrino masses with spontaneous CP violation. This is achieved with a single horizontal $\mathcal{Z}_8$ discrete symmetry, broken to a residual $\mathcal{Z}_2$ subgroup…

High Energy Physics - Phenomenology · Physics 2021-05-12 D. M. Barreiros , F. R. Joaquim , R. Srivastava , J. W. F. Valle

We provide an introduction to the power-counting issue in baryon chiral perturbation theory and discuss some recent developments in the manifestly Lorentz-invariant formulation of the one-nucleon sector. As explicit applications we consider…

High Energy Physics - Phenomenology · Physics 2014-11-20 Stefan Scherer

The strong CP problem can be solved in Parity symmetric theories with electroweak gauge group containing $SU(2)_L \times SU(2)_R$ broken by the minimal Higgs content. Neutrino masses may be explained by adding the same number of gauge…

High Energy Physics - Phenomenology · Physics 2023-11-20 Lawrence J. Hall , Keisuke Harigaya , Yogev Shpilman

I rebuild a conventional two-Higgs doublet model by relaxing the spontaneous CP violation and considering approximate global U(1) family symmetries. So that the domain-wall problem does not explicitly arise at the weak scale, but CP…

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

Setting aside anthropic arguments, there is no reason for CP symmetry to be obeyed within the theory of quantum chromodynamics. However, no such violation of CP symmetry has ever been observed in a strongly interacting experiment. This is…

High Energy Physics - Phenomenology · Physics 2021-08-11 Drew Backhouse

We review the main achievements of the research programme for the study of nuclear forces in the framework of chiral symmetry and discuss some problems which are still open.

Nuclear Theory · Physics 2007-05-23 R. Higa , M. R. Robilotta , C. A. da Rocha

CP non-invariance is strongly limited by present experiments, while extra sources of CP-violation are needed for a successful baryogenesis. Motivated by those observations we consider a model which predicts spontaneous violation of CP at…

High Energy Physics - Phenomenology · Physics 2018-09-26 Bohdan Grzadkowski , Da Huang

We explore the breaking of Lorentz and CPT invariance in strong interactions at low energy in the framework of chiral perturbation theory. Starting from the set of Lorentz-violating operators of mass-dimension five with quark and gluon…

High Energy Physics - Phenomenology · Physics 2016-08-17 J. P. Noordmans , J. de Vries , R. G. E. Timmermans

We show that a very simple solution to the strong CP problem naturally leads to Dirac neutrinos. Small effective neutrino masses emerge from a type I Dirac seesaw mechanism. Neutrino mass limits probe the axion parameters in regions…

High Energy Physics - Phenomenology · Physics 2020-08-26 Eduardo Peinado , Mario Reig , Rahul Srivastava , Jose W. F. Valle

We present a comprehensive overview of chirality and its optical manifestation in plasmonic nanosystems and nanostructures. We discuss top-down fabricated structures that range from solid metallic nanostructures to groupings of metallic…

Despite its tremendous success, the Standard Model of particle physics does not explain why the weak interaction breaks chiral symmetry. Various unified theories got us closer to an answer, but too often the explanation consists of labeling…

High Energy Physics - Theory · Physics 2020-05-19 Ovidiu Cristinel Stoica

Structural causal models are the basic modelling unit in Pearl's causal theory; in principle they allow us to solve counterfactuals, which are at the top rung of the ladder of causation. But they often contain latent variables that limit…

Artificial Intelligence · Computer Science 2021-11-23 Marco Zaffalon , Alessandro Antonucci , Rafael Cabañas

The observed light neutrinos may be related to the existence of new heavy neutrinos in the spectrum of the SM. If a pair of heavy neutrinos has nearly degenerate masses, then CP violation from the interference between tree-level and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Simon Bray , Jae Sik Lee , Apostolos Pilaftsis

Using a left-right symmetric model with Spontaneous CP Violation and the hypothesis of a weakly first order electroweak phase transition we derive a relation between the produced baryon asymmetry and the observed parameter $\varepsilon$,…

High Energy Physics - Phenomenology · Physics 2010-11-01 L. Reina , M. Tytgat

We parameterize the non-universal couplings of t-t-Z and t-b-W in the electroweak chiral lagrangian approach, and examine the constraints on these parameters from the LEP data. We also study how the SLC, Tevatron, LHC and NLC can improve…

High Energy Physics - Phenomenology · Physics 2009-10-28 Douglas O. Carlson , Ehab Malkawi , C. --P. Yuan

We report on recent nonperturbative techniques that combine the information of chiral Lagrangians (with and without resonances) with unitarity in coupled channels and other requirements of the S-matrix theory of the strong interactions. As…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Oller , E. Oset , A. Ramos

The basic ideas and methods of chiral perturbation theory are briefly reviewed. I discuss the recent attempts to build an effective Lagrangian in the resonance region and summarize the known large-N_C constraints on the low-energy chiral…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Pich