scholarly journals A composite Higgs with a heavy composite axion

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Tony Gherghetta ◽  
Minh D. Nguyen
Keyword(s):  
Cp Violation ◽  
Gauge Group ◽  
Scalar Fields ◽  
Higgs Model ◽  
Global Symmetry ◽  
Color Group ◽  
High Scale ◽  
Axion Mass ◽  
Composite Higgs ◽  
The Standard Model

Abstract We consider the strong dynamics associated with a composite Higgs model that simultaneously produces dynamical axions and solves the strong CP problem. The strong dynamics arises from a new Sp or SU(4) hypercolor gauge group containing QCD colored hyperfermions that confines at a high scale. The hypercolor global symmetry is weakly gauged by the Standard Model electroweak gauge group and an enlarged color group, SU(N + 3) × SU(N)′. When hyperfermion condensates form, they not only lead to an SU(5)/SO(5) composite Higgs model but also spontaneously break the enlarged color group to SU(3)c× SU(N)D. At lower energies, the SU(N)D group confines, producing two dynamical axions that eliminates all CP violation. Furthermore, small instantons from the SU(N)′ group can enhance the axion mass, giving rise to TeV scale axion masses that can be detected at collider experiments. Our model provides a way to unify the composite Higgs with dynamical axions, without introducing new elementary scalar fields, while also extending the range of axion masses that addresses the strong CP problem.

scholarly journals Models of hypercolor based on symplectic gauge group with three heavy vectorlike hyperquarks

2019 ◽  
Vol 28 (13) ◽  
pp. 1941002 ◽  
Author(s):  
Nikolay Volchanskiy ◽  
Vladimir Kuksa ◽  
Vitaly Beylin
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Symmetry Group ◽  
Gauge Group ◽  
Global Symmetry ◽  
Composite Higgs ◽  
Global Symmetry Group ◽  
The Standard Model ◽  
Dynamical Breaking ◽  
Partially Composite

We study possibilities to extend the Standard Model (SM) by three flavors of vectorlike heavy quarks in pseudoreal representation of symplectic hypercolor gauge group. This extension of SM predicts a rich spectra of heavy composite hypermesons and hyperbaryons (all of them carry integer spins) including 14 pseudo-Nambu–Goldstone states emerging in dynamical breaking of the global symmetry group of the H-quarks, [Formula: see text], to its Sp(6) subgroup. The properties of the lightest states depend strongly on the choice of heavy-quark hypercharges. Our focus is placed on the variants of the model with partially composite Higgs boson, i.e. the experimentally observed boson comprised the elementary SM Higgs and a mixture of H-hadrons.

scholarly journals Higgs compositeness in Sp(2N) gauge theories – Determining the low-energy constants with lattice calculations

2018 ◽  
Vol 175 ◽  
pp. 08011 ◽  
Author(s):  
Ed Bennett ◽  
Deog Ki Hong ◽  
Jong-Wan Lee ◽  
C.-J. David Lin ◽  
Biagio Lucini ◽  
...  
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Effective Field ◽  
Higgs Model ◽  
Low Energy ◽  
Dirac Fermion ◽  
Global Symmetry ◽  
Composite Higgs ◽  
Lattice Calculations ◽  
Energy Constants

As a first step towards a quantitative understanding of the SU(4)/Sp(4) composite Higgs model through lattice calculations, we discuss the low energy effective field theory resulting from the SU(4) → Sp(4) global symmetry breaking pattern. We then consider an Sp(4) gauge theory with two Dirac fermion flavours in the fundamental representation on a lattice, which provides a concrete example of the microscopic realisation of the SU(4)/Sp(4) composite Higgs model. For this system, we outline a programme of numerical simulations aiming at the determination of the low-energy constants of the effective field theory and we test the method on the quenched theory. We also report early results from dynamical simulations, focussing on the phase structure of the lattice theory and a calculation of the lowest-lying meson spectrum at coarse lattice spacing.

SYMMETRY RESTORATION IN THE SUPERSTRING THEORY

2002 ◽  
Vol 11 (03) ◽  
pp. 311-319 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Gauge Symmetry ◽  
Gauge Group ◽  
Low Temperatures ◽  
Scalar Potential ◽  
Potential Drop ◽  
Scalar Fields ◽  
Superstring Theory ◽  
The Standard Model ◽  
The Right ◽  
Standard Model Gauge Group

The grand unified gauge group G 6≡ SU (3) C × SU (3) L × SU (3) R , which results from compactification of the heterotic superstring onto a three-generation Calabi–Yau space as a maximal subgroup of E 6, contains two superfields, whose scalar components are the conjugates neutrino [Formula: see text] and the neutral Higgs N, which are singlets of the standard-model gauge group G 4≡ SU (3) C × SU (2) L × U (1) Y , and which therefore break G 6to G 4 when they acquire non-vanishing vacuum expectative values. Here, we show how this process can be implemented in two steps when the scalar potential V(ϕi) is chosen along a non-D-flat direction, using the "superconducting" model due to Mohapatra and Senjanović, in which one of two scalar fields remains in the asymmetric state up to a temperature T0~ 1017 GeV , above which the kinetic energy exceeds the potential drop, forcing restoration of the symmetry below the compactification scale T c ≈ 1017 GeV . This implies that [Formula: see text] initially, but at low temperatures T ≪ M w , we find that [Formula: see text], thus avoiding the problems associated with large intermediate scales M I ≳ 109 GeV while keeping the Higgs mixing term ~ NH1H2 at the right level. A discrete gauge symmetry can prevent the proton from decaying too rapidly.

scholarly journals Simple model for large CP violation in charm decays, B-physics anomalies, muon g − 2 and dark matter

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Tianjun Li ◽  
Ying Li ◽  
Bin Zhu
Keyword(s):  
Dark Matter ◽  
Cp Violation ◽  
B Physics ◽  
Scalar Fields ◽  
Electroweak Symmetry Breaking ◽  
Dark Matter Candidate ◽  
Minimal Extension ◽  
Electroweak Symmetry ◽  
Charm Decays ◽  
The Standard Model

Abstract We present a minimal extension of the Standard Model that can simultaneously account for the anomalies in semi-leptonic B meson decays and the muon g − 2, give large CP violation in charm decays (up to the value recently measured by LHCb), and provide thermal-relic dark matter, while evading all constraints set by other flavour observables, LHC searches, and dark matter experiments. This is achieved by introducing only four new fields: a vectorlike quark, a vectorlike lepton, and two scalar fields (a singlet and a doublet) that mix due to the electroweak symmetry breaking and provide the dark matter candidate. The singlet-doublet mixing induces chirally-enhanced dipole transitions, which are crucial for the explanation of the muon g − 2 discrepancy and the large charm CP violation, and allows to achieve the observed dark matter density in wide regions of the parameter space.

scholarly journals Nonperturbative effects in the Standard Model with gauged 1-form symmetry

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Mohamed M. Anber ◽  
Erich Poppitz
Keyword(s):  
Standard Model ◽  
Nonperturbative Effects ◽  
Gauge Group ◽  
Topological Charge ◽  
Lepton Number ◽  
Global Symmetry ◽  
Weak Scale ◽  
Instanton Contribution ◽  
The Standard Model ◽  
Lepton Number Violating

Abstract We study the Standard Model with gauged $$ {\mathrm{\mathbb{Z}}}_{N=2,3,6}^{(1)} $$ ℤ N = 2 , 3 , 6 1 subgroups of its $$ {\mathrm{\mathbb{Z}}}_6^{(1)} $$ ℤ 6 1 1-form global symmetry, making the gauge group $$ \frac{\mathrm{SU}(3)\times \mathrm{SU}(2)\times \mathrm{U}(1)}{{\mathrm{\mathbb{Z}}}_N} $$ SU 3 × SU 2 × U 1 ℤ N . We show that, on a finite $$ {\mathbbm{T}}^3 $$ T 3 , there are self-dual instantons of fractional topological charge. They mediate baryon- and lepton-number violating processes. We compare their amplitudes to the ones due to the usual BPST-instantons. We find that the small hypercharge coupling suppresses the fractional-instanton contribution, unless the torus size is taken sub-Planckian, or extra matter is added above the weak scale. We also discuss these results in light of the cosmological bounds on the torus size.

scholarly journals New AdS4 vacua in dyonic ISO(7) gauged supergravity

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Nikolay Bobev ◽  
Thomas Fischbacher ◽  
Fridrik Freyr Gautason ◽  
Krzysztof Pilch
Keyword(s):  
Scalar Fields ◽  
Global Symmetry ◽  
Supergravity Theory

Abstract We identify 219 AdS4 solutions in four-dimensional dyonically gauged ISO(7) $$ \mathcal{N} $$ N = 8 supergravity and present some of their properties. One of the new solutions preserves $$ \mathcal{N} $$ N = 1 supersymmetry and provides a rare explicit example of an AdS4 vacuum dual to a 3d SCFT with no continuous global symmetry. There are also two new non-supersymmetric solutions for which all 70 scalar fields in the supergravity theory have masses above the BF bound. All of these AdS4 solutions can be uplifted to massive type IIA supergravity. Motivated by this we present the low lying operator spectra of the dual 3d CFTs for all known supersymmetric AdS4 solutions in the theory and organize them into superconformal multiplets.

scholarly journals Exothermic dark mesons in light of electron recoil excess at XENON1T

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Soo-Min Choi ◽  
Hyun Min Lee ◽  
Bin Zhu
Keyword(s):  
Dark Matter ◽  
Inelastic Scattering ◽  
Small Mass ◽  
Density Current ◽  
Flavor Symmetry ◽  
Color Group ◽  
Dark Sector ◽  
The Standard Model ◽  
Electron Recoil ◽  
Relic Density

Abstract We consider a novel mechanism to realize exothermic dark matter with dark mesons in the limit of approximate flavor symmetry in a dark QCD. We introduce a local dark U(1)′ symmetry to communicate between dark mesons and the Standard Model via Z′ portal by partially gauging the dark flavor symmetry with flavor-dependent charges for cancelling chiral anomalies in the dark sector. After the dark local U(1)′ is broken spontaneously by the VEV of a dark Higgs, there appear small mass splittings between dark quarks, consequently, leading to small split masses for dark mesons, required to explain the electron recoil excess in XENON1T by the inelastic scattering between dark mesons and electron. We propose a concrete benchmark model for split dark mesons based on SU(3)L× SU(3)R/SU(3)V flavor symmetry and SU(Nc) color group and show that there exists a parameter space making a better fit to the XENON1T data with two correlated peaks from exothermic processes and satisfying the correct relic density, current experimental and theoretical constraints.

scholarly journals Electroweak baryogenesis and gravitational waves in a composite Higgs model with high dimensional fermion representations

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Ke-Pan Xie ◽  
Ligong Bian ◽  
Yongcheng Wu
Keyword(s):  
Form Factors ◽  
Higgs Doublet ◽  
Higgs Model ◽  
High Dimensional ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Composite Higgs ◽  
Future Space ◽  
The Universe ◽  
Scalar Sector

Abstract We study electroweak baryogenesis in the SO(6)/SO(5) composite Higgs model with the third generation quarks being embedded in the 20′ representation of SO(6). The scalar sector contains one Higgs doublet and one real singlet, and their potential is given by the Coleman-Weinberg potential evaluated from the form factors of the lightest vector and fermion resonances. We show that the resonance masses at $$ \mathcal{O}\left(1\sim 10\kern0.5em \mathrm{TeV}\right) $$ O 1 ∼ 10 TeV can generate a potential that triggers the strong first-order electroweak phase transition (SFOEWPT). The CP violating phase arising from the dimension-6 operator in the top sector is sufficient to yield the observed baryon asymmetry of the universe. The SFOEWPT parameter space is detectable at the future space-based detectors.

scholarly journals Effective Scalar Potential in Asymptotically Safe Quantum Gravity

Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 45
Author(s):  
Christof Wetterich
Keyword(s):  
Quantum Gravity ◽  
Top Quark ◽  
Particle Physics ◽  
Scalar Potential ◽  
Scalar Fields ◽  
The Standard Model ◽  
Scaling Potential ◽  
Realistic Description ◽  
The Masses ◽  
Dynamical Dark Energy

We compute the effective potential for scalar fields in asymptotically safe quantum gravity. A scaling potential and other scaling functions generalize the fixed point values of renormalizable couplings. The scaling potential takes a non-polynomial form, approaching typically a constant for large values of scalar fields. Spontaneous symmetry breaking may be induced by non-vanishing gauge couplings. We strengthen the arguments for a prediction of the ratio between the masses of the top quark and the Higgs boson. Higgs inflation in the standard model is unlikely to be compatible with asymptotic safety. Scaling solutions with vanishing relevant parameters can be sufficient for a realistic description of particle physics and cosmology, leading to an asymptotically vanishing “cosmological constant” or dynamical dark energy.

scholarly journals A more natural composite Higgs model

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Hsin-Chia Cheng ◽  
Yi Chung
Keyword(s):  
Standard Model ◽  
Higgs Model ◽  
Quadratic Term ◽  
Beyond The Standard Model ◽  
Higgs Potential ◽  
Little Higgs ◽  
Composite Higgs ◽  
Partial Compositeness ◽  
Quartic Term ◽  
Natural Composite

Abstract Composite Higgs models provide an attractive solution to the hierarchy problem. However, many realistic models suffer from tuning problems in the Higgs potential. There are often large contributions from the UV dynamics of the composite resonances to the Higgs potential, and tuning between the quadratic term and the quartic term is required to separate the electroweak breaking scale and the compositeness scale. We consider a composite Higgs model based on the SU(6)/Sp(6) coset, where an enhanced symmetry on the fermion resonances can minimize the Higgs quadratic term. Moreover, a Higgs quartic term from the collective symmetry breaking of the little Higgs mechanism can be realized by the partial compositeness couplings between elementary Standard Model fermions and the composite operators, without introducing new elementary fields beyond the Standard Model and the composite sector. The model contains two Higgs doublets, as well as several additional pseudo-Nambu-Goldstone bosons. To avoid tuning, the extra Higgs bosons are expected to be relatively light and may be probed in the future LHC runs. The deviations of the Higgs couplings and the weak gauge boson couplings also provide important tests as they are expected to be close to the current limits in this model.

Sign in / Sign up

Export Citation Format

Share Document