Conveners
Particle physics beyond the Standard Model: TR6
- Davide Vadacchino (University of Plymouth)
Particle physics beyond the Standard Model: TR6
- Herodotos Herodotou (University of Cyprus)
Particle physics beyond the Standard Model: TR6
- Georg Bergner (University of Jena)
Particle physics beyond the Standard Model: TR6
- Roman Zwicky (Edinburgh University)
We present a first-principle lattice QCD calculation of the axial ฮณZ box correction, which is necessary to be taken into account to determine the weak charge in low energy parity violating ep scattering. We calculate the electron energy dependence of axial ฮณZ box up to 155MeV, which perfectly matches the beam energy range of the upcoming PVES experiment at Mainz E < 155MeV . Combining the...
We study the pseudoscalar flavour-singlet mesons of $Sp(4)$ gauge theory with two distinct fermion representations. The model contains two fundamental and three anti-symmetric Dirac fermion. It is a minimal realization of a composite Higgs scenario with partial top compositeness. We determine both the masses and the mixing angles of the states associated with the global U(1) symmetries, one...
In this study, we determine the fine-tuning of parameters in $\mathcal{N} = 1$ Supersymmetric QCD, discretized on a Euclidean lattice. Our focus is on the renormalization of Yukawa (gluino-quark-squark interactions) and quartic (four-squark interactions) couplings. Given that SUSY is broken on the lattice, non-supersymmetric counterterms must be added to the discretized Lagrangian, with...
I will first discuss model-independent properties of dilaton effective theory. Using soft theorems a constraint on the operator generating a potential dilaton mass will be derived. As the operator is relevant this indicates that the dilaton can only acquire a mass through explicit symmetry breaking. The results will derived alternatively from the Lagrangian and linked to the improvement...
We critically discuss the algorithmic process of estimating spectral densities using the Hansen-Lupo-Tantalo method. A novel approach at finite volume is deployed to extract the spectrum of lattice gauge theories. As a case study, our discussion focuses on symplectic gauge theories with matter field consisting of a mixed fermion representation---fundamental and two-index antisymmetric one. We...
In quantum field theories, spectral densities are directly related to relevant physical observables. In Lattice QCD, their non-perturbative extraction from first principles requires the Inverse Laplace transform of Euclidean-time correlation functions, a notorious ill-posed problem. In this talk we present a new strategy to perform this inversion both in the continuum and on the lattice, also...
First order phase transitions in the early universe have rich phenomenological implications, such as the production of potentially detectable background gravitational waves. Density of states methods, and in particular the linear logarithmic relaxation method, can be used to resolve issues related to the meta-stable dynamics around the critical point and allow for the accurate determination of...
We report our preliminary results for the mass spectrum of the Sp(4) gauge theory coupled to two Dirac fermions transforming in the fundamental representation and three transforming in the antisymmetric representation, which serves as an ultra-violet completion of the strongly interacting gauge sector in a composite Higgs model. We mainly focus on the mass of the top partners in the context of...
The custodial Two-Higgs-Doublet-Model with SU(2) gauge fields is studied on the
lattice. This model has the same global symmetry structure as the Standard
Model but the additional Higgs field enlarges the scalar spectrum and opens the
possibility for the occurrence of non-SM spontaneous symmetry breaking. Both
the spectrum and the running of the gauge coupling of the custodial 2HDM...
In this talk I compare perturbative and lattice results for the Abelian-Higgs model in three dimensions. In particular, I show that new lattice results agree remarkably well with three-loop perturbative predictions. I also present the second-order end point for the theory and discuss lattice vs perturbation theory for related models.
We present a bottom-up holographic model that contains the dual description of a strongly coupled field theory. The spontaneous breaking of an approximate global symmetry in the theory produces the SO(5)/SO(4) coset relevant to minimal composite-Higgs models.
Some boundary-localised terms are introduced in the dual gravity for consistency and production of the desired properties of the...
We take a dilaton EFT that has been successfully used to analyze lattice data for confining gauge theories near the conformal window boundary, and show that it can form a viable description of composite dark matter. The EFT contains a dilaton that is slightly heavier than a multiplet of stable pNGBs, and naturally implements the forbidden dark matter mechanism for relic density generation. Our...
The first-order confinement transition of a strongly coupled composite dark matter theory can provide a possible source of gravitational waves in the early universe. In this talk, on behalf of the Lattice Strong Dynamics (LSD) Collaboration, we present our recent investigation on the finite temperature confinement transition of the 1-flavor SU(4) dark gauge theory named Hyper Stealth Dark...
$SU(2)$ with two fundamental flavours is a minimal model for the Composite Higgs sector proposed to tackle the hierarchy and naturalness problems associated with the Standard Model Higgs boson. We present an update on lattice results for the spectrum of $SU(2)$ with two fundamental flavours with the exponential clover Wilson fermion action. This includes the final non-perturbative tuning of...
The SU(2) gauge group with two fundamental flavors is a candidate for a composite Higgs extension of the Standard Model. Central to Higgs phenomenology is a non-perturbative determination of observables of the theory, such as the decay constant of the pseudo-Nambu-Goldstone Bosons. We present preliminary results for the continuum limit of the pseudoscalar decay constant using a mixed-action...
I will describe new strongly coupled phases of staggered fermions in which all states can be given mass without breaking any exact lattice symmetries.
Numerical results for Higgs-Yukawa and gauge theories will be shown.
A necessary condition for the existence of such phases is the cancellation
of a certain exact lattice 't Hooft anomaly. I will show that the minimal
anomaly free theory has...
Lattice models with 2 sets of staggered fermions, corresponding to 8 Dirac flavors at the perturbative fixed point, are free of all 't Hooft anomalies. They can support symmetric mass generation phase (SMG) where mass generation occurs without symmetry breaking.
The SU(3) gauge model has an SMG phase in the strong coupling that appears to be separated from the weak coupling phase by a...
Tantalizing signs for a novel phase with symmetric mass generation have been reported for the SU(3) gauge system with $N_f=8$ fundamental fermions (represented by two sets of staggered fields) at very large renormalized coupling ($g^2_{GF} \gtrsim 25$). To scrutinize these findings, we are generating a set of large volume zero temperature ensembles using nHYP improved staggered fermions with...
Analytical investigations and lattice simulations have previously suggested that the spectrum of observable particles in "BSM-like" theories may differ from that expected naively from perturbation theory. We consider a GUT-like toy theory, which already showed such qualitative discrepancies in exploratory lattice simulations, and perform a detailed quantitative investigation of its physical...
