Related papers: Probing the Light Pseudoscalar Window
We examine the light quark masses in a standard--like superstring model in the four dimensional free fermionic formulation. We find that the supersymmetry constraints in the observable and hidden sectors eliminate all large contributions to…
Recent results from several direct detection experiments have imposed severe constraints on the multi-GeV mass window for various dark matter (DM) models. However, many of these experiments are not sensitive to MeV scale DM as the…
Many existing or proposed intensity-frontier search experiments look for decay signatures of light long-lived particles (LLPs), highly displaced from the interaction point, in a distant detector that is well-shielded from SM background.…
We study a limit of the nearly-Peccei-Quinn-symmetric Next-to-Minimal Supersymmetric Standard Model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally co-exist three light singlet-like particles: a…
We investigate the phenomenological viability of a very light bottom squark, with a mass less than half of the Z boson mass. The decays of the Z and Higgs bosons to light sbottom pairs are, in a fairly model independent manner, strongly…
In this paper we consider very weakly interacting and ultra light scalar and pseudoscalar dark matter candidates. We show that quantum gravity has important implications for such models and that the masses of the singlet scalar and…
The minimal dark matter model is given a supersymmetric extension. A super SU(2)L quintuplet is introduced with its fermionic neutral component still being the dark matter, the dark matter particle mass is about 19.7 GeV. Mass splitting…
In a variety of supersymmetric extensions of the Standard Model, the scalar partners of the quarks and leptons are predicted to be very heavy and beyond the reach of next-generation colliders. For instance, the realization of electroweak…
Future searches for new physics beyond the Standard Model are without doubt in need of a diverse approach and experiments with complementary sensitivities to different types of classes of models. One of the directions that should be…
We revisit the Simple Extension of the Standard Model (SESM), which can account for various tentative new physics anomalies and dark matter. The B physics anomalies, muon anomalous magnetic moment, and dark matter can be explained already…
We study the electroweak baryogenesis in a fermionic dark matter scenario with a (pseudo)scalar being the mediator in the Higgs portal. It is discussed that the electroweak phase transition turns to be first-order after taking into account…
The THDMa is a new physics model that extends the scalar sector of the Standard Model by an additional doublet as well as a pseudoscalar singlet and allows for mixing between all possible scalar states. In the gauge-eigenbasis, the…
In a broad class of consistent models, MeV to few-GeV dark matter interacts with ordinary matter through weakly coupled GeV-scale mediators. We show that a suitable meter-scale (or smaller) detector situated downstream of an electron…
Extensions of the Standard Model that include vector-like quarks commonly also include additional particles that may mediate new production or decay modes. Using as example the minimal linear $\sigma$ model, that reduces to the minimal…
We explore the whole parameter space of the singlet fermionic cold dark matter model with respect to constraints on, first, the relic density and second, gamma-ray lines up to 10 TeV. We investigate 44000 random sample models which…
We review here the physics of purely leptonic decays of pi-, K-, D+, Ds+, and B- pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak interaction based CKM matrix element of the constituent quarks…
We construct a weakly-coupled renormalizable model to explain the $750\mbox{GeV}$ diphoton excess. The $750\mbox{GeV}$ resonance (denoted as $X(750)$) is interpreted as a pseudoscalar coming from a complex singlet. The model also naturally…
We show that left-right symmetric models can easily accommodate stable TeV-scale dark matter particles without the need for an ad-hoc stabilizing symmetry. The stability of a newly introduced multiplet arises either accidentally as in the…
The Minimal Supersymmetric Standard Model has a candidate dark matter particle in its spectrum and may be able to generate the baryon asymmetry of the Universe (BAU) at the electroweak phase transition. In the Constrained MSSM, we find the…
We consider a minimal Dark Matter model with just two additional states, a Dark Matter Majorana fermion and a colored or electroweakly charged scalar, without introducing any symmetry to stabilize the DM state. We identify the parameter…