Maki Takeuchi, Kobe University
The Mystery of the Standard Model and the Extra-Dimensional Model
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online: Zoom
The Standard Model achieved significant success with the discovery of the Higgs in 2012. However, there are still numerous unexplained phenomena. One of them is the number of generations problem, where quarks and leptons come in three copies with only differences in mass while having identical spin and charge. Is the existence of these three generations a mere coincidence, or is there a deeper reason behind it? The Standard Model cannot explain why there are three generations.On the other hand, the higher dimensional theory offers a possible explanation for the number of generations problem. In the higher dimensional theory, the number of generations is related to the geometry of the extra dimensions. In other words, the number of generations carries a physical meaning associated with the geometry of the extra dimensions. In this seminar, I will talk about the generation structure of the T^2/Z_N orbifold with magnetic flux.
Joe Sato, Yokohama National U
L_{\mu-\tau} symmetry and its unification with Standard gauge group
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online: Zoom In this talk I show many aspects of gauged L_{\mu-\tau} symmetry. The symmetry gauges {the muon number – the tau number} in the standard model so as to be anomaly free. First I will show how it is interesting for phenomenology. It includes IceCube Gap, Hubble tension etc. Then I show our phenomenological model for lepton mass and mixing with the symmetry. In this model the symmetry appears as the family symmetry. Finally I will
In this talk I show many aspects of gauged L_{\mu-\tau} symmetry. The symmetry gauges {the muon number – the tau number} in the standard model so as to be anomaly free. First I will show how it is interesting for phenomenology. It includes IceCube Gap, Hubble tension etc. Then I show our phenomenological model for lepton mass and mixing with the symmetry. In this model the symmetry appears as the family symmetry. Finally I will
present my trial to unify the symmetry with the Standard gauge group in terms of coset space family unification.
Kazumi Okuyama, Shinshu University
Hartle-Hawking wavefunction in double scaled SYK
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online: Zoom
We compute the transition amplitude between the chord number 0 and ￥ ell states in the double scaled SYK model and interpret it as a Hartle-Hawking wavefunction of the bulk gravitational theory. We observe that the so-called un-crossed matter correlators of double scaled SYK model are obtained by gluing the Hartle-Hawking wavefunctions with an appropriate weight.
Kotaro Murakami, Tokyo Institute of Technology
Investigation of baryon resonances from meson-baryon scatterings in lattice QCD
Hybrid On-site: Tokai 1st building (KEK Tokai campus), 2F, Room 227, Online : zoom
Studying hadron resonances in lattice QCD plays an important role in understanding exotic hadrons. We investigate baryon resonances from meson-baryon scatterings in the HAL QCD method, where we derive scattering amplitudes in lattice QCD via the interaction potentials. In this talk, I present the analysis of Δ and Ω baryons, both of which belong to the baryon decuplet. In our analysis, we use heavy quark masses so that Δ is a stable particle as well as Ω. If time permits, I also show our preliminary results of the study on Λ(1405) in flavor SU(3) limit.
Alexander Broll, Humboldt University of Berlin
Estimating the B Pi Excited States Contamination of B Meson Correlators with Heavy Meson Chiral Perturbation Theory
Online (Zoom)
CKM matrix elements are free parameters of the Standard Model which are determined by combining experimental and theoretical input. On the theory side, this requires the computation of hadronic matrix elements (ME) in lattice simulations. The lattice correlators can suffer from excited states contamination, i.e. additional contributions from multi-particle states with the same quantum numbers as the initial and/or final state of the matrix element. This can lead to an over- or underestimation of the ME and thus to a systematic error in the results of CKM matrix elements. In this talk, I present how Heavy Meson Chiral Perturbation Theory can be used to estimate the excited states contamination of B meson correlation functions relevant for flavour physics.
Masamichi Miyaji, Nagoya University
Fluctuations in the Entropy of Hawking Radiation
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online: Zoom
Recent study revealed that the inclusion of Euclidean wormhole into the gravitational path integral renders the entropy of Hawking radiation consistent with unitarity, deriving the Page curve of the Hawking radiation. On the other hand, since the gravitational path integral with Euclidean wormhole computes quantities of ensemble average of theories, it is possible that the entropy of Hawking radiation of each gravity theory fluctuate wildly around the ensemble average. In this talk we show that such fluctuation is as small as the dimension of the system, ensuring the answer from the ensemble average is typical. We use the gravitational path integral to compute the fluctuations of the Hawking radiation entropy around the Page curve, in a two-dimensional model introduced by Penington \emph{et al}. Before the Page time, we find that $\delta S = e^{-S}/\sqrt{2}$, where $S$ is the black hole entropy. This result agrees with the Haar-averaged entropy fluctuations of a bipartite system, which we also compute at leading order. After the Page time, we find that $\delta S = \sqrt{2}e^{-S}/\pi$. This is not symmetric under exchange of subsystem sizes and so does not agree with the Haar average for a subsystem of fixed Hilbert space dimension. We show that the discrepancy can be attributed to an additive $\sqrt{2}/\pi$ fluctuation in the number of black hole states in a given energy band. As a by- product, our result gives a refinement on the known upper bound on the subsystem entropy fluctuation in Haar random pure state.
Owe Philipsen, Frankfurt University
[QCD theory Seminar] Surprises on the way toward the QCD phase diagram
Online (Zoom)
A strong fermion sign problem prohibits direct lattice simulations of QCD at finite baryon density, so that knowledge of the phase diagram is limited to small chemical potentials. On the other hand, the phase diagram is severely constrained by information on the chiral limit. I discuss recent lattice results at vanishing density, which show the chiral phase transition for Nf=2-7 degenerate chiral quarks to be of second order, contrary to the expectations based on the seminal paper by Pisarski and Wilczek from 1984. Together with growing information on fluctuations, this implies phenomenologically relevant bounds on a possible critical endpoint. In another development at zero density, a dynamically emergent chiral spin symmetry was discovered in correlator multiplet stuctures in a temperature window above the chiral crossover. I discuss two additional variables, screening masses and the pion spectral functions, which also show this window and suggest its effective degrees of freedom to be hadron-like, rather than partonic.
Yui Hayashi, YITP
[QCD theory Seminar] Higgs-confinement continuity in light of particle-vortex statistics
Online (Zoom) Certain gauge theories with superfluidity, such as dense QCD, exhibit nontrivial Aharonov-Bohm (AB) phases around vortices, or anyonic particle-vortex statistics, in the Higgs regime. There has been a debate on whether this nontrivial AB phase implies a Higgs-confinement transition even with fundamental matters. In this seminar, we address this question in favor of Higgs-confinement continuity. By performing explicit calculations in relevant lattice models, we demonstrate how the AB phase realizes the continuity between the confining and Higgs regimes. In particular, this result supports the possibility of the quark-hadron continuity scenario.
Certain gauge theories with superfluidity, such as dense QCD, exhibit nontrivial Aharonov-Bohm (AB) phases around vortices, or anyonic particle-vortex statistics, in the Higgs regime. There has been a debate on whether this nontrivial AB phase implies a Higgs-confinement transition even with fundamental matters. In this seminar, we address this question in favor of Higgs-confinement continuity. By performing explicit calculations in relevant lattice models, we demonstrate how the AB phase realizes the continuity between the confining and Higgs regimes. In particular, this result supports the possibility of the quark-hadron continuity scenario.
This talk is based on arXiv:2303.02129 [hep-th].
Toshiki Kurita, IPMU
Constraints on anisotropic primordial non-Gaussianity from intrinsic alignments of SDSS-III BOSS galaxies
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online:(Zoom)
The current standard cosmological model, LambdaCDM model, predicts that the present-day cosmic large-scale structure (LSS) has formed as a result of a gravitational amplification of seed primordial fluctuations that were generated in the early universe such as inflationary scenario. The standard method to analyze LSS is based on the three-dimensional distribution of galaxies, inferred from their positions on the sky and redshifts. Here we show that “shapes” of galaxies, inferred from light (star) distribution in each galaxy, similarly originate from the primordial fluctuations in LSS formation — this phenomenon is called intrinsic alignments (IAs) of galaxy shapes. In this talk I will describe what the IA effect is, and show the actual measurement results from the SDSS-III BOSS datasets and the constraints on the anisotropic (quadrupolar) local primordial non-Gaussianity.
Yoshiki Kanazawa, University of Tokyo
Solution to Axion Quality Problem by Non-Minimal Gravitational Coupling
Hybrid On-site: Seminar room, Kenkyu honkan 3F Online: Zoom
