Nobuhito Maru, Osaka City University
Predictions of Higgs mass and Weinberg angle in 6D gauge-Higgs unification
Meeting Room 1, Kenkyu Honkan 1F We address a question whether there exists a model of gauge-Higgs unification in 6-dimensional space-time, which successfully predicts the Weinberg angle and the mass ratios between Higgs boson and weak gauge bosons.
We address a question whether there exists a model of gauge-Higgs unification in 6-dimensional space-time, which successfully predicts the Weinberg angle and the mass ratios between Higgs boson and weak gauge bosons.
First, we give a general argument on the condition to get a realistic prediction of the Weinberg angle, and find that triplet and sextet representations of the minimal SU(3) gauge group lead to the realistic prediction.
We notice that in the models with one Higgs doublet, the predicted Higgs mass is always twice the W-boson mass at the leading order.
However, in models with two Higgs doublets, Higgs mass can be smaller than twice the W-boson mass.
Nilakash Sorokhaibam, TIFR
2D Critical Quench, Thermalization and Non-Universality
Meeting room 3, Kenkyu honkan 1F
I will talk about about my last two papers. We studied the long time behaviour of local observables following a quantum quench in 1+1 dimensional conformal field theories possessing additional conserved charges besides the energy. We showed exponential approach to equilibrium of finite sub-interval characterized by a temperature and chemical potentials defined in terms of the quenched state. We compute the exact wavefunction that results from a quantum quench to a vanishing mass, in a large class of examples The resulting wavefunction is of a generalized Calabrese-Cardy form i.e., conformal boundary state deformed by an infinite number of charges. Special squeezed states with small chemical potentials show equilibration to a Generalized Gibbs Ensemble(GGE). By contrast, with general pre-quench states, including the ground state, the chemical potentials are not small; exact correlators in these cases, although equilibrating at long times, do not generically have a simple thermal or GGE form even at large distances. The main lesson is that in 2D critical quench, long time and large distance physics can be sensitive to perturbations by high dimension operators,contrasting general Wilsonian lore.
Bum-Hoon Lee, CQUeST, Sogang U., Korea
Fubini Instantons in curved spacetime
Meeting Room 3, Kenkyu Honkan 1F
TBA
Masato Nozawa, University of Milan
Supersymmetry of (Euclidean) Plebanski-Demianski solution
Meeting Room 3, Kenkyu Honkan 1F,
The Plebanski-Demianski (PD) solution has played a central role in the development of black-hole physics in general relativity since it describes the most general Petrov D metric in Einstein-Maxwell-Lambda system. Recently, Houri and Yasui have found a new king of nondegenerate rank-2 Killing-Yano (KY) tensor in the self-dual Euclidean PD metric. I will discuss in detail how this makes consistent with the theorem by Houri-Oota-Yasui, according to which the local metric admitting a non-degenerate rank 2 KY tensor must fall into the Carter family. It turns out that this is closely related to the fact that the self-dual PD solution preserves half of supersymmetry, whereas the non-self-dual solution admits only one quarter of supersymmetry. I will also explore the underlying mathematical structure of Euclidean PD solution, such as conformal ambi-Kahler structure and new type of Einstein-Weyl space.
Kei Yagyu, University of Southampton
Synergy between direct and indirect searches of non-minimal Higgs sectors
Meeting Room 3, Kenkyu Honkan 1F I would like to review on recent my phenomenological research of non-minimal Higgs sectors especially focusing on two Higgs doublet models.
I would like to review on recent my phenomenological research of non-minimal Higgs sectors especially focusing on two Higgs doublet models.
First, I discuss the direct search for extra Higgs bosons at collider experiments.
Next, I talk about the indirect search which focuses on deviations in the coupling constants of the discovered Higgs boson.
Finally, I discuss the synergy between the direct and indirect searches.
Takuya Kanazawa, RIKEN
Some remarks on topology in QCD at high temperature
Meeting Room 3, Kenkyu Honkan 1F
QCD topology relevant to anomaly at high temperature has been elusive in the past, but the situation is changing due to rapid progress in lattice simulation techniques. In this regard, it is important to understand the finite-volume effects on topology correctly. I will present a simple analytical argument to grasp physics in a finite volume at high temperature. In addition the role of (non-)analyticity in the QCD Dirac spectra will be discussed.
Dai-suke Takahashi, OIST
Classically conformal U(1)' extended standard model and Higgs vacuum stability
Seminar Room, Kenkyu Honkan 3F
We consider the minimal U(1)’ extension of the standard model (SM) with conformal invariance at the classical level, where in addition to the SM particle contents, three generations of right-handed neutrinos and a U(1)’ Higgs field are introduced. In the presence of the three right-handed neutrinos, which are responsible for the seesaw mechanism, this model is free from all the gauge and gravitational anomalies. The U(1)’ gauge symmetry is radiatively broken via the Coleman-Weinberg mechanism, by which the U(1)’ gauge boson (Z’ boson) mass as well as the Majorana mass for the right-handed neutrinos are generated. The radiative U(1)’ symmetry breaking also induces a negative mass squared for the SM Higgs doublet to trigger the electroweak symmetry breaking. In this context, we investigate a possibility to solve the SM Higgs vacuum instability problem. The model includes only three free parameters (U(1)’ charge of the SM Higgs doublet, U(1)’ gauge coupling and Z’ boson mass), for which we perform parameter scan, and identify a parameter region resolving the SM Higgs vacuum instability. We also examine naturalness of the model. The heavy states associated with the U(1)’ symmetry breaking contribute to the SM Higgs self-energy. We find an upper bound on Z’ boson mass, mZ’ \lesssim 6 TeV, in order to avoid a fine-tuning severer than 10% level. The Z’ boson in this mass range can be discovered at the LHC Run-2 in the near future.
Nobuchika Okada, University of Alabama
Running Non-Minimal Inflation with Stabilized Inflaton Potential
Meeting Room 1, Kenkyu Honkan 1F In the context of the Higgs model involving gauge and Yukawa interactions with
In the context of the Higgs model involving gauge and Yukawa interactions with
the spontaneous gauge symmetry breaking, we consider $\lambda \phi^4$ inflation
with non-minimal gravitational coupling, where the Higgs field is identified as inflaton.
Since the inflaton quartic coupling is very small, once quantum corrections through the
gauge and Yukawa interactions are taken into account, the inflaton effective potential
most likely becomes unstable. In order to avoid this problem, we need to impose stability
conditions on the effective inflaton potential, which lead to not only non-trivial relations
among the particle mass spectrum of the model, but also correlations between the
inflationary predictions and the mass spectrum. For concrete discussion, we investigate
the minimal B−L extension of the Standard Model with identification of the B−L Higgs
field as inflaton. The stability conditions for the inflaton effective potential fix the mass
ratio among the B−L gauge boson, the right-handed neutrinos and the inflaton. This
mass ratio also correlates with the inflationary predictions. In other words, if the B−L
gauge boson and the right-handed neutrinos are discovered in future, their observed
mass ratio provides constraints on the inflationary predictions.
Takahiro Nishinaka, Yukawa Inst.
On the superconformal Index of Argues-Douglas theories
Meeting room 1, Kenkyu honkan 1F
Argyres-Douglas (AD) theories are 4d N=2 superconformal field theories without useful Lagrangian descriptions. Therefore their superconformal indices cannot be evaluated by supersymmetric localization. In this talk, I will discuss our conjectural expression for the superconformal index of AD theories given in terms of 2d q-deformed Yang-Mills theory. Our conjecture is based on the S^1 x S^3 version of the AGT relation, and is perfectly consistent with the Higgs branch chiral rings, 2d chiral algebras, RG-flows, and the 3d reduction of AD theories.
Makoto Takamoto, The University of Tokyo
Thermal Synchrotron Radiation By Double Tearing Mode Reconnection - Application to the Crab Gamma-Ray Flares
Meeting room 1, Kenkyu honkan 1F
