In this paper, we investigate the production of Majorana fermionic dark matter (DM) via Higgs portal, considering both freeze-in and freeze-out mechanisms during after post-inflationary reheating phase. We assume that Universe is reheated through decay inflaton into a pair massless fermions. Our analysis focuses on how non-standard evolution Hubble expansion rate thermal bath temperature influence DM production. Additionally, examine impact electroweak symmetry breaking (EWSB),...

The Georgi-Machacek model extends the standard Higgs sector by adding two isospin triplet scalar fields and imposing global SU(2)$_R$ symmetry on them. A feature of is that triplets can acquire a large vacuum expectation value without conflicting with current experimental bound $\rho$ parameter. We investigate electroweak phase transition in evaluating finite-temperature effective potential sector. be sufficiently strong parameter space when $O(10)$ GeV, opening possibility to realize...

We derive the most general sets of viable mass spectra exotic Higgs bosons in Georgi-Machacek model that are consistent with theoretical constraints vacuum stability and perturbative unitarity experimental electroweak precision observables, $$ Zb\overline{b} coupling boson signal strengths. Branching ratios various cascade decay channels doubly-charged 5 representation, singly-charged 3, singlet further computed. As one promising for discovering model, we study prospects detecting is...

The unidentified emission line at the energy of ~3.5 keV observed in X-rays from galaxy clusters may originate a process involving dark matter particle. On other hand, weakly interacting massive particle (WIMP) has been an attractive candidate, due to its well-understood thermal production mechanism and connection physics TeV scale. In this paper, we pursue possibility that 3.5 X-ray arises late time decay WIMP into another matter, both which have mass O(100) GeV whose splitting is about...

A bstract The Standard Model prediction for ϵ ′ / based on recent lattice QCD results exhibits a tension with the experimental data. We solve this through W R + gauge boson exchange in SU(2) L × U(1) B − model ‘charge symmetry’, whose theoretical motivation is to attribute chiral structure of spontaneous breaking group and charge symmetry. show that $$ {M_W}_{{}_R}&lt;58 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>M</mml:mi> <mml:mi>W</mml:mi> </mml:msub>...

We present a model that gives natural explanation to the charged lepton mass hierarchy and study contributions electron muon $g-2$. In model, we introduce lepton-flavor-dependent $U(1)_F$ symmetry three additional Higgs doublets with charges, realize each generation of leptons couples one doublets. The is softly broken by $+1$ smallness soft breaking naturally rise VEVs, which then accounts for hierarchy. Since couple different scalar particles, contributes $g-2$ differently. survey space...

We investigate the resonant leptogenesis scenario in minimally $U(1{)}_{B\ensuremath{-}L}$ extended standard model with minimal flavor violation. In our model, gauge symmetry is broken at TeV scale and singlet neutrinos gain Majorana masses of order TeV. addition, we introduce a on higher than The explicitly by neutrino Dirac Yukawa coupling, which induces splittings lower scales through renormalization group evolutions. call this setup mass are proportional to tiny hence they automatically...

We consider a light supersymmetric top-quark (top-squark) scenario, where top squark and neutralino are the lightest particles top-squark mass is close to sum of mass. In this quark coming from decay have almost equal velocity vectors, hence missing transverse momentum in pair production events at colliders suppressed, which makes search challenging, as degenerate scenario similar. paper, we propose novel analysis technique aimed discovering signal such an ``equal-velocity'' scenario. The...

Many extensions of the Standard Model include a new $U(1)$ gauge group that is broken spontaneously at scale much above TeV. If $U(1)$-breaking phase transition occurs nucleation temperature $O(100)--O(1000)\text{ }\text{ }\mathrm{TeV}$, it can generate stochastic gravitational waves in $O(10)--O(100)\text{ }\mathrm{Hz}$ range if ${\ensuremath{\beta}}_{\mathrm{n}}/{H}_{\mathrm{n}}=1000$, which be detected by ground-based detectors. Meanwhile, supersymmetry (SUSY) may play crucial role...

Abstract We study the gauge coupling unification (GCU) and proton decay in a nonsupersymmetric SU(5) grand unified theory (GUT) incorporating 45-representation Higgs field. Our analysis is based on assumption that Georgi–Jarlskog-type mass matrices for fermions are responsible explaining ratio of strange quark muon. examine conditions GCU, taking into account possibility certain components 45 field have masses much smaller than GUT scale. found to satisfy GCU conditions, at least two should...

Abstract We study the scenario of inflection point inflation where a flat direction minimal supersymmetric standard model (MSSM) is identified with inflaton. Specifically, we consider in full generality cases an MSSM lifted by higher-dimensional superpotential whose dimension $n=4,5,6,7,9$. confront scenarios various n Planck and BICEP data, thereby constrain soft supersymmetry breaking mass coefficient operator that lifts direction.

Abstract We study the $\gamma$-ray signal emitted from dark matter (DM) pair annihilation in Higgs portal Majorana fermion DM model. In model, a $\chi$ couples with Standard Model (SM) field $H$ through higher-dimensional term $-{\cal L}\supset H^\dagger H \bar{\chi }\chi /\Lambda$, where $\Lambda$ is cutoff scale [1]. The of above produces boson and longitudinal modes $W,Z$ gauge bosons. Milky Way dwarf spheroidal satellite galaxies (dSphs) are used as most promising targets to search for...

We present a novel extension of the Standard Model which fulfills multiple-point principle without contradicting Higgs particle mass measurement. In model, scalar potential has two minima where field vacuum expectation values 246 GeV and Planck $\simeq 2.44\times 10^{18}$ GeV, latter is realized by considering classically scale invariant setup requiring that quartic coupling its beta function vanish at scale. The mixture an elementary composite scalars in new strongly-coupled gauge theory,...

A bstract Since the standard model contribution is virtually absent, any observation of direct CP violation in Cabibbo-favored charmed meson decays would be evidence new physics. In this paper, we conduct a quantitative study on D 0 → K − π + , s ηπ and η ′ SU(2) L ×SU(2) R ×U(1) B gauge extension model. model, arises mainly from interference between decay amplitude coming SM left-left current operators that right-right induced by W boson exchange. Interestingly, strong phase two amplitudes...

We propose a simple extension of the minimal universal extra dimension model by introducing small curvature. The is formulated as anti--de Sitter curvature limit five-dimensional standard (SM) in Randall-Sundrum background geometry. While lightest Kaluza-Klein (KK) particle can be thermal relic dark matter usual model, KK parity explicitly broken presence and decays into SM fermions with long lifetime. Couplings fermion pairs bulk are controlled masses. By tuning masses quarks, we suppress...

We investigate the scenario where standard model is extended with classical scale invariance, which broken by chiral symmetry breaking and confinement in a new strongly coupled gauge theory that resembles QCD. The Higgs field emerges as result of mixing scalar meson strong dynamics massless elementary field. mass decay constant meson, are generated dynamically theory, give rise to term, automatically possessing correct negative sign bosonic seesaw mechanism. Using analogy QCD, we evaluate...

We study the discovery potential for mixing of heavy isospin-singlet neutrinos in extensions Tokai-to-Kamioka (T2K) experiment, Tokai-to-Hyper-Kamiokande (T2HK), Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector $$\simeq 1000$$ km baseline length and $$1^\circ $$ off-axis angle, plan adding small at Oki Islands to T2HK. further pursue possibility measuring neutrino mass hierarchy standard CP-violating phase $$\delta _{CP}$$ presence by fitting data oscillation parameters only....

A bstract We study colored Higgsino-mediated proton decay (dimension-five decay) in a model based on the flipped SU(5) GUT. In model, GUT-breaking 10 , $$ \overline{\mathbf{10}} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mn>10</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> fields have GUT-scale mass term and gain VEVs through higher-dimensional operators, which induces an effective between color triplets 5 \overline{\mathbf{5}} <mml:mn>5</mml:mn> Higgs...

A bstract The SUSY SO(10) GUT is in severe tension with the experimental bounds on proton partial lifetimes because decay mediated by colored Higgsinos (dimension-five decay) too rapid. In this paper, we pursue possibility that a texture of Yukawa coupling matrices renormalizable model suppresses dimension-five decay. We focus general which contains 10 + 126 $$ \overline{\textbf{126}} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mn>126</mml:mn>...

It has been pointed out that the mixing of an eV-scale sterile neutrino with active flavors can lead to a loss sensitivity ${\ensuremath{\theta}}_{23}$ octant (sign ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{23}\ensuremath{-}1/2$) in long baseline experiments, because main oscillation probability ${P}_{0}=4{\mathrm{sin}}^{2}{\ensuremath{\theta}}_{23}{\mathrm{sin}}^{2}{\ensuremath{\theta}}_{13}{\mathrm{sin}}^{2}{\mathrm{\ensuremath{\Delta}}}_{31}$ be degenerate sum interferences solar...

We consider a model based on the supersymmetric QCD theory with ${N}_{c}=2$ and ${N}_{f}=3$. The is strongly coupled at infrared scale ${\ensuremath{\Lambda}}_{H}$. Its low-energy effective below ${\ensuremath{\Lambda}}_{H}$ described by standard Higgs sector that contains four isospin doublets, two neutral singlets charged singlets. If multi-TeV to 10 TeV, coupling constants for F terms of these composite fields are relatively large electroweak scale. Nevertheless, model-like boson...