English
Related papers

Related papers: Solving the strong CP problem by a $\bar{\theta}$-…

200 papers

It has been known since decades that imposing a symmetry group G on the scalar sector of multi-Higgs-doublet models has consequences for CP-violation. In all examples of two- and three-Higgs-doublet models equipped with symmetries, one…

High Energy Physics - Phenomenology · Physics 2016-02-17 G. C. Branco , I. P. Ivanov

An extension of the Standard Model with three right-handed neutrinos and a simple invisible axion model can account for all experimentally confirmed signals of new physics (neutrino oscillations, dark matter and baryon asymmetry) in…

High Energy Physics - Phenomenology · Physics 2019-02-06 Alberto Salvio

We present results of an investigation to study CP violation in the Higgs sector in $t\bar t$ production at a $\gamma\gamma$-collider, via the process $ \gamgam \ra \phi \ra t \bar t$ where the $\phi$ is a scalar with indeterminate CP…

High Energy Physics - Phenomenology · Physics 2007-05-23 Rohini M. Godbole

One possible solution to the strong CP problem is that CP is an exact symmetry, spontaneously broken at some scale. Some years ago, Nelson and Barr suggested a mechanism for obtaining $\theta=0$ at tree level in this framework, and showed…

High Energy Physics - Phenomenology · Physics 2010-11-01 M. Dine , A. Kagan , R. G. Leigh

We demonstrate a new type of cancellation of contributions to the electron and neutron electric dipole moments (EDMs) that occurs in three Higgs doublet models (3HDMs) when CP violation appears in the charged Higgs sector. The cancellation…

High Energy Physics - Phenomenology · Physics 2021-08-18 Heather E. Logan , Stefano Moretti , Diana Rojas-Ciofalo , Muyuan Song

In this work we study a mirror model with inverse seesaw neutrino masses in which symmetry breaking scales are fixed from bounds in the neutrino sector. The Higgs sector of the model has two doublets and neutral singlets. The mirror model…

High Energy Physics - Phenomenology · Physics 2011-12-12 M. M. Candido , Y. A. Coutinho , P. C. Malta , J. A. Martins Simões , A. J. Ramalho

We characterize models where electroweak symmetry breaking is driven by two light Higgs doublets arising as pseudo-Nambu-Goldstone bosons of new dynamics above the weak scale. They represent the simplest natural two Higgs doublet…

High Energy Physics - Phenomenology · Physics 2015-05-28 Jan Mrazek , Alex Pomarol , Riccardo Rattazzi , Michele Redi , Javi Serra , Andrea Wulzer

Parity and CP symmetries are broken in the world around us. Nonetheless, parity (or CP) may be a gauge symmetry which is higgsed in our universe. This is assumed in many scenarios for physics beyond the Standard Model, including the classic…

High Energy Physics - Theory · Physics 2022-12-05 Jacob McNamara , Matthew Reece

The most general Higgs potential of the two-Higgs-doublet model (2HDM) contains three squared-mass parameters and seven quartic self-coupling parameters. Among these, one squared-mass parameter and three quartic coupling parameters are…

High Energy Physics - Phenomenology · Physics 2009-11-11 John F. Gunion , Howard E. Haber

We present a new mechanism for solving the strong CP problem using a Z2 discrete symmetry and an anomalous U(1) symmetry. A Z2 symmetry is used so that two gauge groups have the same theta angle. An anomalous U(1) symmetry makes the…

High Energy Physics - Phenomenology · Physics 2015-04-16 Anson Hook

Twin Higgs models are the prime illustration of neutral naturalness, where the new particles of the twin sector, gauge singlets of the Standard Model (SM), ameliorate the little hierarchy problem. In this work, we analyse phenomenological…

High Energy Physics - Phenomenology · Physics 2018-04-04 Aqeel Ahmed

Given the lack of empirical evidence of weakly interacting dark matter, it is reasonable to look to other candidates such as a confining dark sector with a similar number of particles as the standard model. Twin Higgs mirror matter is one…

The effects of the CP violating $\theta$ term in the QCD Lagrangian upon low energy hadronic phenomenology are reconsidered. Strong CP violating interactions among Goldstone bosons and octet baryons are incorporated into an effective chiral…

High Energy Physics - Phenomenology · Physics 2010-11-01 Peter Cho

We consider the simplest realization of leptogenesis with one heavy Majorana neutrino species much lighter than the other ones. In this scenario, when the temperature of the early universe is smaller than the lightest Majorana neutrino…

High Energy Physics - Phenomenology · Physics 2016-10-12 Simone Biondini , Nora Brambilla , Antonio Vairo

We study a CP-violating triple product correlation that occurs in the decay of a neutral Higgs boson into t\bar{t} pairs when the Higgs boson does not have a definite CP nature. We consider the H -> t \bar{t} decay channel as well as the…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Valencia , Yili Wang

We discuss and compare the charge-parity (CP) asymmetry in the charged Higgs boson decays H -> \bar{u}_i d_j for the second and third generation quarks in the minimal supersymmetric standard model. As part of the analysis, we derive some…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mariana Frank , Ismail Turan

The differential branching ratio, forward-backward asymmetry, CP asymmetry and lepton polarization for a B-meson to decay to strange hadronic final states and a $\tau^+\tau^-$ pair in a CP softly broken two Higgs doublet model are computed.…

High Energy Physics - Phenomenology · Physics 2014-11-17 Chao-Shang Huang , Shou Hua Zhu

Nonstandard CP violation in the Higgs sector can play an essential role in electroweak baryogenesis. We calculate the full two-loop matching conditions of the standard model, with Higgs Yukawa couplings to light quarks modified to include…

High Energy Physics - Phenomenology · Physics 2019-02-20 Joachim Brod , Dimitrios Skodras

We demonstrate that a certain class of low scale supersymmetric ``Nelson-Barr'' type models can solve the strong and supersymmetric CP problems while at the same time generating sufficient weak CP violation in the $K^{0}-\bar{K}^{0}$…

High Energy Physics - Phenomenology · Physics 2009-10-31 Otto C. W. Kong , Brian D. Wright

We generalize the basis of CP-even chiral effective operators describing a dynamical Higgs sector, to the case in which the Higgs-like particle is light. Gauge and gauge-Higgs operators are considered up to mass dimension five. This…

High Energy Physics - Phenomenology · Physics 2015-06-12 R. Alonso , M. B. Gavela , L. Merlo , S. Rigolin , J. Yepes