Related papers: Solution of the strong CP problem
Hierarchical masses of quarks and leptons are addressed by imposing horizontal symmetries. In supersymmetric Standard Models, the same symmetries play a role in suppressing flavor violating processes induced by supersymmetric particles.…
Supersymmetric models with broken R-parity induced by lepton number violating terms provide a calculable framework for neutrino masses and mixings. Within models with bilinear R-parity breaking six new physical phases appear which are…
We examine certain extensions of the standard model in which $CP$ violation is spontaneous and the strong $CP$ problem is resolved. In these models, the $3 \times 3$ quark mixing matrix is neither real nor unitary. However, to a precision…
Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic ${m_u=0}$ solution to the strong CP problem. QCD is embedded…
We explore a dynamical mechanism to realize the emergence of a global $U(1)_{\rm PQ}$ symmetry and its spontaneous breaking at an intermediate scale for an axion solution to the strong CP problem. Such a dynamics is provided by a new…
We address the question whether it is possible in GUTs to obtain R-parity violation with a large ${\Delta L{/}\Delta B}$ hierarchy of strengths so that the proton is stable while phenomenologically interesting $L$-violation is present. We…
We investigate the potential for spontaneous CP violation in a Higgs Triplet Model extension, including a complex singlet scalar. We demonstrate that the scalar potential strictly forbids spontaneous CP violation across the entire parameter…
We study the phenomenology of a hypercharge-zero SU(2) triplet scalar whose existence is motivated by two-step electroweak symmetry-breaking. We consider both the possibility that the triplets are stable and contribute to the dark matter…
A U(2)^3 flavour symmetry acting on the first two generations of quarks partially explains the hierarchies of the yukawa couplings, and provides a natural embedding for Supersymmetry with heavier first two generations, where collider…
We introduce a mirror copy of the ordinary fermions and Higgs scalars for embedding the $SU(2)_L\times U(1)_Y$ electroweak gauge symmetry into an $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ left-right gauge symmetry. We then show the…
Supersymmetric models with a high supersymmetry breaking scale give, in general, large contributions to epsilon_K and/or to various electric dipole moments, even when contributions to CP conserving, flavor changing processes are…
The standard model (SM) has several issues related to the $CP$ violation which could give clues to search physics beyond the SM. They are a $CP$ phase in the CKM matrix, the strong $CP$ problem, $CP$ phases in the PMNS matrix and $CP$…
We develop a grand unified theory of matter and forces based on the gauge symmetry $SU(5)_L\times SU(5)_R$ with parity interchanging the two factor groups. Our main motivation for such a construction is to realize a minimal GUT embedding of…
We briefly review the question of spontaneous CP violation in some models of weak interactions. The next-to-minimal supersymmetric standard model, with two Higgs doublets and one gauge singlet, is one of the minimal extensions of the…
We solve the strong CP problem in a broad class of two Higgs doublet theories that will be probed at the Large Hadron Collider and at future colliders. These theories feature CP and Abelian flavor symmetries, both broken softly in the…
We present an extended version of the Conformal Standard Model (characterized by the absence of any new intermediate scales between the electroweak scale and the Planck scale) with an enlarged scalar sector coupling to right-chiral…
We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Z b_L bbar_L coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner…
The Nelson-Barr mechanism to solve the strong CP problem requires vector-like quarks (VLQs) to transmit the spontaneous CP breaking to the SM. We study the scenario where only these VLQs are within reach at the TeV scale while the…
The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made…
We construct a scalar dark matter model with $U(1)_{L_\mu-L_\tau}$ symmetry in which the dark matter interacts with the quark flavours, allowing lepton non-universal $b \to s \ell \bar{\ell}$ decays. The model can solve $b \to s \mu \mu$…