Poster Presentations

Upper limit on the amplitude of gravitational waves around 0.1Hz from the Global Positioning System
Aoyama, Shohei (Department of Physics and Astrophysics, Nagoya University)
In this presentation, we show upper bound on the amplitude of gravitational waves around 0.1 Hz from the global posioning system (GPS). GPS is composed of thirty one satellites with atomic clock and enables one not only to measure one's position precisely but also stabilize one's oscillator on the ground with high accuracy and stability successfully. When the amplitude of the continuous component of gravitational waves is large, gravitational waves prevent stabilizing one's oscillator on the ground by receiving the radio wave from satellites, because they modulate the frequency of electro-magnetic waves. From the fact that one can stabilize one's oscillator with accuracy $\Delta \nu\slash \nu \le 10^{-12}$ by receiving the radio wave for one to one hundred seconds, we set a constraint on the strain amplitude of continuous component of gravitational waves as $h_{\rm c}<4.8 \times 10^{-12}(1\slash f)$ for $10^{-2}<f<10^{0}$ Hz .
Board No. 11
Directional Dark Matter Search wih the Fine Grained Nuclear Emulsion
Asada, Takashi (Nagoya University)
The dark matter is one of the most serious problem of physics. There are many experiments to detect them all over the world. Some experiments found the signals which suggest the annual modulation of dark matter, but other experiments denied it, and evidence have not been concluded yet. Directional search plays important role to prove the existence of dark matter from other aspect. We are challenging it with fine grained nuclear emulsion. The emulsion is the only detector which can provide both directional search and large mass target.
Board No. 12
Higgs as a Top-Mode Pseudo
Fukano, Hidenori (KMI)
In the spirit of the top quark condensation, I would like to talk about a model which has a naturally light composite Higgs boson, "tHiggs", to be identified with the 126 GeV Higgs discovered at the LHC. The tHiggs emerges as a pseudo Nambu-Goldstone boson(NGB), "Top-Mode Pseudo", together with the exact NGBs (eaten by the W,Z boson) as well as another Top-Mode Pseudo (CP-odd composite scalar). Those 5 NGBs are dynamically produced simultaneously by a four-fermion dynamics.
Board No. 4
Properties of Bigravity Solutions in a Solvable Class
Katsuragawa, Taishi (Department of Physics, Nagoya University.)
We consider the properties of solutions in the bigravity theory for general model with a condition that two metric tensors are proportional to each other. We investigate the parameter region in which we can obtain non-trivial solutions. Also, we consider the entropy for black hole solutions and we discuss the difference between the obtained entropy and Bekenstein-Hawking entropy in general relativity.
Board No. 13
Renormalization Factors of Dimension-six Proton Decay Operators in the Supersymmetric Standard Models
Kobayashi, Daiki (Nagoya university)
The unified gauge coupling constant increases if there exist extra particles in the intermediate scale. We found that proton lifetime is significantly reduced in such cases. Moreover, the two-loop effects may be more significant in such cases. We evaluate the renormalization factors of the dimension-six effective operators for proton decay at two-loop level in the supersymmetric grand unified theories. These factors can be easily calculated using the effective K ̈ahler potential. Numerical values for the factors are presented in the minimal supersymmetric SU(5) grand unified model and that with extra vector-like multiplets.
Board No. 5
Decoupling can revive minimal supersymmetric SU(5)
Kuwahara, Takumi (Nagoya University)
We revisited proton decay via the color-triplet Higgs bosons in the minimal supersymmetric SU(5) grand unified model with High-scale supersymmetry breaking. Since this model has predicted too short lifetime of the proton if the supersymmetry is broken near the electroweak scale, it has been believed to be excluded. However, we have found that it is possible to evade the constraints on the proton lifetime if the supersymmetric particles have much heavier than the standard model particles. Since the proton lifetime lies in the region which may be reached in the future experiment, we may verify this scenario by the proton decay experiments.
Board No. 6
Study of the TOP counter performance with the 2 GeV/c positron beam at LEPS
Matsuoka, Kodai (Nagoya University)
The TOP (Time-Of-Propagation) counter is a novel ring-imaging Cherenkov detector developed for the particle identification in Belle II. A prototype of the TOP counter with almost the final design was tested with the 2 GeV/c positron beam at LEPS (Laser Electron Photon beamline at SPring-8). With this beam data, the optics of the TOP counter and the performance of the photodetector, MCP-PMT (Micro-Channel-Plate Photomultiplier Tube), were studied. This poster describes the results of the study.
Board No. 7
Dilaton Chiral Perturbation Theory - Determining Mass and Decay Constant of Technidilaton on the Lattice
Matsuzaki, Shinya (Nagoya University)
We propose a scale-invariant chiral perturbation theory of the pseudo-Nambu-Goldstone bosons of the chiral symmetry (pion) as well as the scale symmetry (dilaton) for the large N_f QCD. The chiral extrapolation of the lattice data on the dilaton mass vs pion mass plot then simultaneously determines the chiral-limit dilaton mass and decay constant in the walking technicolor. The chiral logarithmic corrections are explicitly given.
Board No. 1
String Tension in Walking and Conformal Regime
Miura, Kohtaroh (KMI, Nagoya University)
Novel (quasi) conformal dynamics associated with the infra-red fixed point (IRFP) in 8 or 12 flavor QCD has received much attention both theoretically and phenomenologically. We investigate the string tension in those theories by using the lattice Monte Carlo simulations. Utilizing the gauge configurations generated by LatKMI collaboration with the use of the HISQ fermion action and the tree-level Symanzik gauge action, we perform the Wilson loop measurements and evaluate the square root of the string tension. as a function of a bare fermion mass (ma). In 8 flavor QCD, both hyper-scaling and linear ansatz work and lead to the similar x^2/d.o.f., and the latter gives a finite intersection in the vanishing $ma$. A possible interpretation is that the 8 flavor QCD shows the chiral symmetry breaking but feels a remnant of the IRFP dynamics. In 12 flavor QCD, the hyper-scaling fit works more than the linear fit. The string tension versus the pion mass shows an approximate linear scaling with a zero intersection in the 12 flavor (but not in the 8 flavor). The result indicates that the IRFP dynamics dominates the 12 flavor QCD.
Board No. 2
Hard X-ray Telescopes onboard ASTRO-H
Mori, Hideyuki (KMI, Nagoya University)
We develop two Hard X-ray Telescopes (HXT) onboard ASTRO-H, the 6th Japanese X-ray satellite to be launched in 2015. The HXT, together with Hard X-ray Imager, enables us to collect X-rays up to 80keV for imaging spectroscopy. We completed the fabrication of two HXTs in July 2013. Moreover, the ground calibration of the HXTs has been done at the synchrotron radiation facility, SPring-8. The HXT angular resolution was found to be 1.9 arcmin (Half Power Diameter) at 30keV. In addition, the effective areas of 170cm^2 at 30keV and 82 cm^2 at 50keV, which satisfy the requirement, were obtained. In this presentation, we also report the detailed X-ray performance of the HXT.
Board No. 14
Nucleon decay via dimension 6 operators in anomalous $U(1)_A$ SUSY GUT models and $E_6 \times SU(2)_F$ SUSY GUT models
Muramatsu, Yu (Nagoya University)
We calculate nucleon decay via dimension 6 operators for various decay modes in the anomalous $U(1)_A$ GUT scenarios, in which the unification scale $\Lambda_u$ becomes smaller than the usual SUSY GUT scale $\Lambda_G = 2 \times 10^{16}$ GeV in general. Since the predicted lifetime $\tau(p \rightarrow \pi^0 + e^c)$ falls around the experimental lower bound, the discovery of the nucleon decay in near future can be expected. The two ratios $R_1 = \frac{\Gamma_{n \rightarrow \pi^0 + \nu^c}}{\Gamma_{p \rightarrow \pi^0 + e^c}}$ and $R_2 = \frac{\Gamma_{p \rightarrow K^0 + \mu^c}}{\Gamma_{p \rightarrow \pi^0 + e^c}}$ are important in identifying grand unification group We make a scatter plot of $R_1$ and $R_2$. As a result, we show that three anomalous $U(1)_A$ SUSY GUT models, with $SU(5)$, $SO(10)$ and $E_6$ grand unification group can be identified by measuring the two ratios. In these calculation we consider uncertainties of the unitary matrices that make Yukawa matrices diagonal. In addition, we calculate the nucleon decay in anomalous $U(1)_A$ $E_6 \times SU(2)_F$ SUSY GUT model. In this model, $SU(2)_F$ symmetry restrict Yukawa structure at GUT scale. As a result the unitary matrices that make Yukawa matrices diagonal are restricted. Our calculation shows that in many model points $R_1$ and $R_2$ become smaler than these in $E_6$ model which does not have flavor symmetry. And scatter plot region becomes smaller than that in $E_6$ model which does not have flavor symmetry because of restricted Yukawa structure.
Board No. 8
Sum rules among Higgs gauge couplings in the electroweak chiral Lagrangian.
Nagai, Ryo (Nagoya Univarsity)
In the framework of the electroweak chiral Lagrangian, we derive sum rules for the Higgs gauge couplings by requiring following two conditions.The first is the cancellation of bad high energy behavior in the longitudinal electroweak gauge boson scattering amplitudes.The second is the finiteness of the oblique correction parameters, S,T and U. Using the sum rules, we evaluate upper mass bounds on the neutral, singly-charged and doubly-charged scalar bosons as a function of the deviation of the SM-like Higgs gauge coupling.
Board No. 9
Pion condensation at finite isospin chemical potential in a holographic QCD model
Nishihara, Hiroki (Nagoya University)
We study the pion condensation at finite isospin chemical potential using a holographic QCD model. By solving the equations of motion for the pion fields together with those for the iso-singlet scalar and iso-triplet vector meson fields, we show that the phase transition from the normal phase to the pion condensation phase is second order, and that the critical value of the isospin chemical potential is equal to the pion mass, consistently with the result given by Son and Stephanov (SS) using the chiral effective Lagrangian. For higher chemical potential, we find a deviation from SS, which can be understood as a higher order effects in the chiral effective Lagrangian.
Board No. 19
Radion in Randall-Sundrum model at the LHC and photon collider
Ohno, Yoshiko (Ochanomizu Univ.)
A warped extra dimension model proposed by Randall and Sundrum (RS) is one of the attractive candidates to solve the gauge hierarchy problem in the Standard Model. In a simplest version of the RS model, there are only two extra particles beyond the Standard Model - a spin-2 graviton (and its Kaluza-Klein (KK) excitations) and a radion which is a spin-0 and electrically neutral particle. In the poster presentation, firstly we show the results of our study on the production and decay of the radion at the LHC. Secondly, we also discuss a possibility of discovering the radion at a photon collider, which has been considered as an option of e^+ e^- liner collider, focusing on characteristic features of radion interactions with photon or gluon.
Board No. 10
GRAINE project: gamma-ray observation with balloon-borne emulsion telescope
Rokujo, Hiroki (Nagoya university)
Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE) is a balloon-borne experiment project for precise observation of cosmic gamma-rays. A next generation detector "emulsion telescope" for GRAINE consists of large area (~10m^2) nuclear emulsion plates, which is a three-dimensional charged particle tracking device with the submicron spatial resolution, and has the higher angular resolution and the linear polarization sensitivity for 10 MeV - 100 GeV gamma-rays. As the first step in GRAINE, a technical flight was performed by employing a small-scale telescope (125 cm^2 aperture) and the feasibility of each component of the detector was demonstrated. A next balloon flight in Australia is planned in 2014, and is aimed at detecting and imaging the Vela pulsar, which is the brightest source in the high energy gamma-ray sky. overview and situation of GRAINE are presented.
Board No. 15
Parity violation in the CMB bispectrum by a rolling pseudoscalar
Saga, Shohei (Nagoya university, cosmology group (C-lab.))
We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a concrete computation based on full-sky formalism, it is shown that resultant CMB bispectra have nonzero signals in both parity-even (l1 + l2 + l3 = even) and parity-odd (l1 + l2 + l3 = odd) spaces. And furthermore, we estimate the detectability of the tensor non-Gaussianity for cases with the auto- and cross-bispectra between the temperature and E-mode anisotropies, and with the B-mode auto-bispectrum alone. We finally summarize the expected 1-sigma errors of a model parameter determined by a coupling constant and a rolling condition of the pseudoscalar field.
Board No. 16
The unification of inflation and the late-time acceleration
Saitou, Rio (Nagoya university)
By using the formulation of the reconstruction, we construct models of non-canonical single scalar field, k-essence, which unify the inflation and the late-time acceleration of the universe.
Board No. 17
Constraining isocurvature perturbations with the 21cm emission from minihaloes
Takeuchi, Yoshitaka (Nagoya University)
We investigate the effects of isocurvature perturbations on the 21cm radiation from minihaloes (MHs) at high redshifts and examine constraints on the isocurvature amplitude and power spectrum using the next generation of radio telescopes such as the Square-Kilometer Array. We find that there is a realistic prospect of observing the isocurvature imprints in the 21cm emission from MHs, but only if the isocurvature spectral index is close to 3 (i.e. the spectrum is blue). When the isocurvature frac- tion increases beyond ∼ 10% of the adiabatic component, we observe an unexpected decline in the 21cm fluctuations from small-mass MHs, which can be explained by the incorporation small MHs into larger haloes. We perform a detailed Fisher-matrix analysis, and conclude that the combination of future CMB and 21cm experiments (such as CMBPol and the Fast-Fourier-Transform Telescope) is ideal in constraining the isocurvature parameters, but will stop short of distinguishing between CDM and baryon types of isocurvature perturbations, unless the isocurvature fraction is large and the spectrum is blue.
Board No. 18
Analysis of structure of the sigma meson from lattice QCD
Wakayama, Masayuki (Nagoya University)
Our purpose is to obtain insights of structure of the sigma meson from the first principle calculation, lattice QCD. At present we do not reach a conclusive understanding of nature of the sigma meson. Currently it is considered as a usual two-quark state, four-quark states such as a tetraquark and mesonic molecules or superposition of them. Besides, the mixing with glueballs is one of important and interesting ingredients for structure of the sigma meson. Furthermore, a disconnected diagram of the sigma meson plays an important role in the structure of the sigma meson. However, to evaluate the disconnected part of the propagator is not an easy task in lattice QCD calculation. To compute the disconnected part of the propagator, we use the Z2 noise method and the time dilution for estimating the all-to-all quark propagators. Here, we focus on four-quark states in the sigma meson. From investigation of two-quark and four-quark states with the inclusion of disconnected diagrams, we will discuss the mixing ratio between the two-quark states and four-quark states.
Board No. 3