Keiju Murata, Keio U
Electric Field Quench in AdS/CFT
Meeting room 1, Kenkyu honkan 1F
An electric field quench, a suddenly applied electric field, can induce nontrivial dynamics in confining systems which may lead to thermalization as well as a deconfinement transition. In order to analyze this nonequilibrium transitions, we use the AdS/CFT correspondence for N=2 supersymmetric QCD that has a confining meson sector. We find that the electric field quench causes the deconfinement transition even when the magnitude of the applied electric field is smaller than the critical value for the static case (which is the QCD Schwinger limit for quark-antiquark pair creation). The time dependence is crucial for this phenomenon, and the gravity dual explains it as the weakly turbulent instability of a D-brane in the bulk AdS spacetime. Interestingly, the d econfinement time takes only discrete values as a function of the magnitude of the electric field. We advocate that the new deconfinement phenomenon is analogous to the exciton Mott transition.
Kantaro Ohmori, The Univ. of Tokyo
Anomaly polynomial of general 6d SCFTs
Meeting room1, Kenkyu honkan 1F 6d N=(2,0) theories are the source of many beautiful stories on supersymmetric field theories whose dimensions are lower than six. We hope similar and richer stories hold for 6d N=(1,0) theories, although it should be much harder to investigate with fewer supersymmetries.
6d N=(2,0) theories are the source of many beautiful stories on supersymmetric field theories whose dimensions are lower than six. We hope similar and richer stories hold for 6d N=(1,0) theories, although it should be much harder to investigate with fewer supersymmetries.
As a first step, we want better understanding of 6d theories and some calculable quantities of those theories. We found that the anomaly polynomials of 6d N=(2,0) or N=(1,0) SCFTs can be determined on their tensor branch using a kind of anomaly maching mechanism similar to the Green-Schwarz mechanism. Each self-dual tensor fields associated to tensor branch scalars can have non-trivial Bianchi identities, which results in contribution to the anomaly additional to contribution from naive 1-loop calculation. Anomaly matching conditions uniquely determines such contributions, enabling us to calculate anomaly polynomials.
In this talk, I will review 6d N=(1,0) SCFTs which can be constructed with branes of the M-thoery, and then talk about anomaly polynomials. Especially, I will focus on the world volume theories of M5-branes on the ALE-singularities of general type.
Tomoaki Ishiyama, Center for Computational Sciences, University of Tsukuba
Dark Matter Structure Formation Simulations on K Supercomputer
Meeting room 1, Kenkyu honkan 1F
Smaller dark matter subhalos are more abundant in the Milky Way. The survivability of such subhalos in the Milky Way depends on their structure. This suggests that the structure of subhalos can determine the fine structure of the Milky Way halo. I report the results of high resolution cosmological simulations of very small scale structure formation peformed on K computer. I focus on the formation and evolution of dark matter halos near the free streaming scale, and their impact on the indirect dark matter detection experiments.
Guray Erkol, Ozyegin University
A look inside hadrons: What can we learn from theory?
Meeting room 1, Kenkyu honkan 1F
One theoretical challenge in hadron physics is to understand the hadron structure and interactions from QCD. I will summarize some recent results as obtained from QCD, with special emphasis on the spin and electromagnetic structure of light and heavy hadrons. I will give a comparison of various approaches.
George Knee, NTT Basic Research Laboratories
Is weak-value amplification useful for metrology?
Seminar room, Kenkyu honkan 3F
Weak value amplification is a technique combining both strong and weak quantum measurements which is gathering increased interest both theoretically and experimentally. The surprising effect arises when a weak measurement, where a quantum coherent measuring device is only weakly coupled to the system of interest, is followed by a strong measurement. Rarely, the measuring device can respond in an unusually energetic manner. I will discuss some approaches in statistical estimation theory, which may help to decide whether this effect can be exploited to increase the performance of quantum sensors.
Thorsten Feldmann, U Siegen
Light-cone distribution amplitude of the B-meson
Meeting room 3, Kenkyu honkan 1F
Light-cone distribution amplitudes (LCDAs) for B-mesons in heavy-quark effective theory (HQET) provide one of the essential non-perturbative inputs entering QCD factorization theorems for exclusive B-decays. In this talk, I show how to derive the eigenfunctions of the Lange-Neubert evolution equation which governs the behaviour of the B-meson LCDAs under a change of renormalization scale. The spectrum of the LCDA with respect to these eigenfunctions defines a “dual” function which renormalizes multiplicatively. In terms of these dual functions, renormalization-group improved factorization formulas take a very simple form. I also report on how to implement perturbative constraints from the operator product expansion in HQET within the new formalism.
Stefan Recksiegel, Technische Universitat Munchen
Using dimensional analysis as a measure of fine tuning
Meeting room 1, Kenkyu honkan 1F
When studying models of New Physics, usually many points in the parameter space of the model violate existing experimental constraints. We show that the fractal dimension of that part of parameter space that satisfies those constraints is a good measure of fine tuning. We introduce the concept of fractal dimensions, use a toy model to show that the fractal dimension measures fine tuning and then show examples from several models of New Physics.
Andrew Akeroyd, University of Southampton
Decay of charged Higgs bosons into charm and bottom quarks in multi-Higgs doublet models
Meeting room 1, Kenkyu honkan 1F
A scalar particle has been discovered at the Large Hadron Collider (LHC), but it is not yet known if this particle corresponds to the Higgs boson of the Standard Model or if it is the first of many Higgs bosons which are waiting to be discovered. Higgs bosons with electric charge (“charged Higgs bosons” or “charged scalars”) are predicted in many extensions of the Standard Model. Searches for such particles are being carried out at the LHC, in particular in the decays of the top quark, and these searches assume that two specific decay modes of the charged Higgs boson are dominant: In this talk I show that a third decay mode, into charm and bottom quarks, can be dominant in models with more than two Higgs isospin doublets. So far there has been no dedicated search for this decay to charm and bottom quarks at the LHC, but it could readily be performed as an extension of an ongoing search which assumes that the charged Higgs boson decays into a charm quark and a strange quark.
Francesco Knechtli, University of Wuppertal
Non-perturbative Gauge-Higgs Unification on the Lattice
Meeting room 1, Kenkyu honkan 1F Gauge-Higgs Unification models are theories where the Higgs field is identified with some of the extra-dimensional components of the gauge field.
Gauge-Higgs Unification models are theories where the Higgs field is identified with some of the extra-dimensional components of the gauge field.
One motivation for these models is that the extra-dimensional gauge symmetry protects the Higgs potential from divergences in the ultra-violet cut-off.
Perturbative studies indicate that fermions are necessary to trigger the Higgs mechanism. Given the non-renormalizability of gauge theories in dimensions higher than four, we study non-perturbatively the simplest model which is a five-dimensional SU(2) gauge theory on a orbifold.
The starting point is the formulation on an anisotropic Euclidean lattice.
Results using a semi-analytic mean-field expansion and Monte Carlo simulations show that the Higgs mechanism takes place without fermions and support an alternative view of the lattice orbifold as a five-dimensional bosonic superconductor.
Tsunehide Kuroki, Nagoya U
SUSY breaking by nonperturbative dynamics in a matrix model for 2D type IIA superstrings
Seminar room, Kenkyu honkan 3F
