Poster Presentations

Abstract:
The fate of the heavy-quark bound states, such as J/Psi, in the hot quark-gluon plasma has been discussed in various approaches. Taking an open quantum systems approach, we describe the dynamics of heavy quarkonium in terms of stochastic potential, which represents the fluctuation of potential due to the collisions with medium particles. The fate of the bound state can be viewed as a decoherence phenomenon and is found to be sensitive to the spatial correlation length of the stochastic potential.

Abstract:
We present the results of verifing focusing system for Time Of Propagation(TOP) counter. TOP counter is a kind of Ring Imaging Cherenkov counter(RICH) which detect internally reflected Cherenkov light. We used prototype of TOP counter which have focusing mirror, and so we could confirm a proof of focusing mechanism.We verified focusing mechanism using 120GeV/c pion beam at CERN.

Abstract:
We have shown that the B － L generation due to the decay of the thermally produced superheavy fields can explain the Baryon assymmetry in the universe if the superheavy fields are heavier than 1013－14 GeV. Note that although the superheavy fields have non-vanishing charges under the standard model gauge interactions, the thermally prduced baryon asymmetry is sizable. The B － L violating effective operators induced by integrating the superheavy fields have dimension 7, while the operator in the famous leptogenesis has dimension 5. Therefore, the constraints from the nucleon stability can be easily satisfied.

Abstract:
We report on the results from the XMM-Newton observation of Mrk 766. The X-ray light curves show the intense variation on timescales of hours to years. The variation in the low (0.7-1.5 keV) and high (3-12 keV) energy band seem to synchronize through out the observation. However, when the source entered in the lowest flux state, the variation amplitude in the high energy band was more prominent compared with that in the low energy band. This means that the spectrum in the dim state becomes harder than that in the normal flux state. From the detailed spectral analyses, thick and patchy materials surrounding the central supermassive black hole may play an important role in the observed spectral variation.

Abstract:
We argue that the whole or the part of the phase diagrams of QCD and QCD-like theories should be universal in the large-N_c limit through the orbifold equivalence. The whole phase diagrams, including the chiral phase transitions and the BEC-BCS crossover regions, are identical between SU(N_c) QCD at finite isospin chemical potential and SO(2N_c) and Sp(2N_c) gauge theories at finite baryon chemical potential. Outside the BEC-BCS crossover region in these theories, the phase diagrams are also identical to that of SU(N_c) QCD at finite baryon chemical potential. We also argue how large finite-N_c correction is expected. Our results strongly suggest that the chiral phase transition and the QCD critical point at finite baryon chemical potential can be studied using sign-free theories, such as QCD at finite isospin chemical potential, in lattice simulations.

Abstract:
We propose an approach for the calculation of the yukawa coupling through the scalar decay constant and the chiral condensate in the context of the extended technicolor. We also comment on the coupling of the techni-dilaton to the weak bosons.

Abstract:
We report recent results on the analysis with tau decays obtained by Belle experiment. We have searched for the lepton flavor violating tau decays using about 1000 fb^-1 data and obtained the sensitivity of O(10^-8) on the branching ratios. We also obtained the results on the tau hadronic decays.

Abstract:
The CP-violating angle gamma can be measured using only tree-level decays, and thus it provides an essential benchmark to search for new physics. In this presentation, we show latest results on several B->DK channels obtained from the Belle experiment as well as a global fit of the angle gamma.

Abstract:
The structure of sigma meson is studied by the $D_1^\prime \to D\pi^0\pi^0$ decay using the effective Lagrangian preserving the chiral symmetry and heavy quark symmetry. The sigma meson is included in our approach through the linear sigma model with two-quark and four-quark states. The sigma meson mass and $\sigma$-$\pi$-$\pi$ coupling are fit by using the $I=0$, $S$-wave $\pi$-$\pi$ scattering data. We plot the ratio $h = U_{a1}^{-1}/\cos\theta_\pi$ ($U_{a1}^{-1}$ and $\cos\theta_\pi$ are the two-quark component of sigma meson and pion, respectively) dependence of the $D_1^\prime \to D \pi^0\pi^0$ decay rate.

Abstract:
Broken-symmetry quantum Hall (QH) states with filling factors \nu= 0, ±1, ±2, ±3 in the lowest Landau level in bilayer graphene are analyzed by solving the gap equation. It is shown that in the phase plane of electric and magnetic fields, the critical line, which separates the spin and layer polarized phases at \nu = 0, extends to the \nu = ±1 QH states. The amplitudes of the gaps in the\nu = ±1, ±3, and \nu = ±2 QH states are significantly smaller than the amplitude of the \nu = 0 gap, due to the separate filling of the n = 0, 1 orbital Landau levels and the negative contribution of the Hartree term, respectively. The critical lines and energy gaps obtained from this work are in well agreement with experiments.

Abstract:
The LEM (Low Energy Module) experiment is a test experiment in the J-PARC facility to measure the energy spectrum of the on-axis neutrino beam. The detailed understanding of the neutrino beam flux is indispensable for the current and future neutrino oscillation experiments. Indeed neutrino flux measurement always includes some poor understanding components such as the cross-sections of neutrino interactions and hadron productions from the proton collision on the target. A new detector, LEM, has ben installed at the ND280 hall in the end of September, 2011. Only this detector can be measured the beam component of energy below 1 GeV and on-axis direction. Data taking will be performed when the J-PARC beam operation is restarted. We introduce the details of the LEM project and activities during the installation.

Abstract:
E6 unification is an interesting candidate for the model of grand unified theory because the assumption for the Yukawa hierarchies can be derived with a reasonable setup. In this study, we examine the relation between the structure of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and the direction of the vacuum expectation value (VEV) of the Higgs fields which break the E6 gauge group. We have shown that our model can lead to a favorable structure of CKM matrix by choosing the VEV of the adjoint Higgs not to break U(1)_{B-L} symmetry. this choice of the VEV plays an important role in solving the doublet-triplet splitting problem by the Dimopoulos-Wilczek mechanism.

Abstract:
We formulate the Schwinger-Dyson (SD) equation in a finite-size space-time with the periodic boundary condition. Finite-size and mass-deformation effects on the solution of the SD equation are studied in theories which have an (approximate) infrared fixed point (IRFP). We show that, in the case of theories which have an exact IRFP, low-energy physical quantities generated by such deformation effects behave consistently with the so called hyperscaling relation. We also show that how the scaling relation is violated in theories in which the IRFP is only approximate due to the dynamical chiral symmetry breaking.

Abstract:
We discuss string GUT scenario, realizing the standard model from string theory via SUSYGUT with adjoint Higgs fields. We especially construct E6 SUSYGUT models in heterotic string theory. We use diagonal embedding method to realize an adjoint Higgs field and utilize lattice engineering technique for the model building. In the framework of Z12 heterotic asymmetric orbifold construction, we obtain two more three-family E6 models with an adjoint Higgs field.

Abstract:
A sky region close to the supernova remnant SN1006 was observed twice with Suzaku on September 12, 2005, and on January 26, 2006. We found that the region was bright in a soft X-ray band during the first observation. Investigating the XIS spectra of the two observations, we found that the soft X-ray brightening can be explained by emission lines from ionized carbon, nitrogen, oxygen, iron, and so on. Emission lines due to the transitions from the M shell or higher to the K shell were included. These characteristics strongly suggest that the origin of the soft X-ray brightening is the charge exchange between solar wind ions and neutral atoms in the Earth atmosphere. We also found that a hard power-law component was required to explain the spectra of the first observation. Such hard component had been already discovered in a previous research, but the origin of the component was not clear. We found that the FI and BI sensors required different normalizations for the hard component. This indicates a non-X-ray origin of the hard component.

Abstract:
A TOP counter is a ring imaging Cherenkov detector, which is used for particle identification in the Belle II experiment. It measures the time of propagation (TOP) of the Cherenkov photons in a quartz radiator with micro-channel-plate photomultiplier tubes (MCP-PMTs). We measured the quality of the quartz and MCP-PMT and assembled the first TOP counter, which are discussed in this poster.

Abstract:
We explore discovery signatures of techni-dilaton (TD) at LHC. It turns out that the TD signatures are quite different from those of the SM Higgs, dependently of models of walking technicolor. In sharp contrast to the SM Higgs case, particular for one-family model, TD has highly enhanced cross section about 0.10--1.0 fb at around the TD mass 600 GeV, which is large enough to be discovered during the first few year's run at LHC.

Abstract:
The LHCf experiment is one of the LHC forward experiments. The aim is to provide the energy and transverse momentum spectra of neutral particles (photons, neutral pions and neutrons) emitted in the forward regions of LHC collisions (pseudo-rapidity range of more than 8.4). The energy spectra of photons measured by LHCf durting sqrt(s)=7TeV p-p collisions has been published recently. We present the results and the analysis details.

Abstract:
The process such as $\pi^+ + n \rightarrow p +\mu^++ \mu^-$ may occur through the virtually exchanged neutrino and anti-neutrino.The neutrino exchanged between two vertices, one of them related to $\pi^+ \to \mu^+ \nu_\mu^\ast$ and the other is neutron absorption of the neutrino leading to $\nu_\mu^\ast +n \rightarrow p + \mu^-$ where $\nu_\mu^\ast$denotes the virtual neutrino exchanged between two the vertices. The two vertices are connected by neutrino Feynman propagator and it can be non-vanishing even when the space time distance of two vertices is spacelike $x^2 < 0$ and they reside outside the lightcone each other. One may interprete the result of recent OPERA's measurements of neutrino velocity as two world events (production of neutrino and ditection of neutrino) with space like distance apart rather than interpreting it as on-shell neutrino group velocity is faster than light velocity. The space like distance of two events is $x^2=((\frac{c}{v})^2-1) L^2$. Their result implies $r=\sqrt{-x^2}=\sqrt{5 \times10^{-5}} 730$(Km) $\sim 5 $ (Km). Relating the space like correlation lengthwith the compton wave length of neutrino, the mass of the exchanged neutrino is$m_\nu \simeq 4 \times 10^{-11}$(eV),which is much smaller than the neutrino mass squared difference measured by neutrino oscillation measurement.

Abstract:
Nucleon decay is important appearance of a beyond SM especially GUT. I consider a strength of nucleon decay interaction, a renormalization factor and so on in SUSY GUT models to calculate nucleon lifetime. From this, I find that difference of SUSY GUT models appear in ratio of main decay mode's decay width and some sub mode's decay width. So, detection of nucleon decay can restrict SUSY GUT models that are difficult to restrict by low energy experiment.

Abstract:
Gauge theories with the walking behavior near the infrared fixed point (IRFP) are candidates for the origin of the dynamical breaking of the electroweak symmetry. Since the non-perturbative investigation of QCD-like theories are very important for the construction of the walking technicolor model, we carry out the lattice QCD simulation with many flavors in KMI (Kobayashi-Maskawa Institute for the Origin of Particles and the Universe) at Nagoya university. In this poster, we report preliminary results of the simulation of the many flavor QCD with the highly improved staggered fermions (HISQ), Nf=4 and in particular Nf=8. We study the flavor dependence of the spectrum to make clear the walking behavior with the approximate IRFP.

Abstract:
In this work we explore the direct detection of dark matter which is degenerate in mass with new colored particles below TeV scale. The scenario with such a mass spectrum is difficult to be confirmed or excluded by the present analysis at the LHC experiments because the jets in the cascade decay of new particles produced in the proton-proton collision are too soft to be triggered in the event selection. It is shown that the scattering cross section of dark matter with nucleon may reach even the current bound of the direct detection experiments in such cases, and therefore these kinds of experiments may shed light on the degenerate scenario.

Abstract:
We study the SU(3) gauge theory with twelve flavors of the fundamental fermion. From the perturbative analysis, this theory is expected to be near the edge of the conformal window. The values of the critical exponents such as anomalous dimension are crucial to the walking technicolor scenario. We utilize the HISQ type action to reduce the discretization error and show our preliminary results on the bound state masses and decay constants at several lattice spacings. The finite volume scaling analysis in the conformal hypothesis is performed, from which we discuss anomalous dimension.

Abstract:
A measurement of the production cross section of the top quark pair in the proton-proton collisions at a center-of-mass energy of 7TeV is reported. The analysis is performed in the dilepton event topology, using 0.7/fb collisions recorded by the ATLAS detector. The cross section has been measured to be 177pb with 10% precision as the first precise evaluation at the LHC. The result is in good agreement with the Standard Model prediction.

Abstract:
We report new results concerning HESS J1614-518, which exhibits two regions with intense γ-ray emission. The south and center regions of HESS J1614-518 were observed with Suzaku in 2008, while the north region with the 1st brightest peak was observed in 2006. No X-ray counterpart is found at the 2nd brightest peak; the upper limit of the X-ray flux is estimated as 1.6 × 10^{-13} erg cm^{-2} s^{-1} in the 2-10 keV band. A previously-known soft X-ray source, Suzaku J1614-5152, is detected at the center of HESS J1614-518. Analyzing the XMM-Newton archival data, we reveal that Suzaku J1614-5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0-515225, could be described by a power-law model with the photon index Γ = 5.2^{+0.6}_{-0.5} or a blackbody model with the temperature kT = 0.38^{+0.04}_{-0.04} keV. In the blackbody model, the estimated column density N_{H} = 1.1^{+0.3}_{-0.2} × 10^{22} cm^{-2} is almost the same as that of the hard extended X-ray emission in Suzaku J1614-5141, spatially coincident with the 1st peak position. In this case, XMMU J161406.0-515225 may be physically related to Suzaku J1614-5141 and HESS J1614-518.

Abstract:
We perform the first search for lepton-number-violating B+ → D－l+l′+ decays, where l and l′ stand for e or μ, using 772×106 BB ? pairs accumulated at the Υ(4S) resonance with the Belle detector at the KEKB e+e－ collider. No evidence for these decays has been found. Assuming uniform three-body phase space distributions for the D－l+l′+ decays, we set the following upper limits on the branching fractions at 90% confidence level: B(B+ → D－e+e+) < 2.6×10－6, B(B+ → D－e+μ+) < 1.8 × 10－6 and B(B+ → D－μ+μ+) < 1.0 × 10－6.

Abstract:
We review recent results on charmonium-like exotic states from the Belle experiment. The two-photon process gamma gamma -> phi jpsi is measured to search for Y(4140). No signal for the Y(4140)->phi jpsi is observed. But a narrow peak with a significance of 3.2 sigma deviations including systematic uncertainty is observed at 4350.6 MeV/c^2 that we named X(4350). We also search for charmonium-like states, including X(3872), Y(4140), X(3915) and X(4350), in Y(1S) and Y(2S) radiative decays. No significant signal of any charmonium-like state is observed. The processes gamma gamma -> omega phi, phi phi and omega omega are also measured to search for the possible exotic states in low mass region. There are clear resonant structures in all the decay modes.

Abstract:
The dual Meissner effect is a promising mechanism for quark confinement. We have presented a new lattice formulation of Yang-Mills theory to draw conclusions in the gauge independent manner, and demonstrated by measuring the string tension　from the Wilson loop average that, in SU(3) Yang-Mills theory, a restricted non-Abelian variable and the extracted non-Abelian magnetic monopoles play the dominant role in confinement of fundamental　quarks (dominance in the string tension), in marked contrast to the Abelian projection. In this poster, we focus on the dual Meissner effect in SU(3) Yang-Mills theory, which is examined by measuring the distribution　of chromoelectric field strength created by a static quark-antiquark pair. Then, we discuss whether or not the non-Abelian dual superconductivity claimed by us is indeed a mechanism of quark confinement in SU(3) Yang-Mills theory.

Abstract:
Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench, via calculations of two-point functions, Wilson loops and entanglement entropy in d=2,3,4. In the saddlepoint approximation these probes are computed in AdS space in terms of invariant geometric objects - geodesics, minimal surfaces and minimal volumes. Our calculations for two-dimensional field theories are analytical. In our strongly coupled setting, all probes in all dimensions share certain universal features in their thermalization: (1) a slight delay in the onset of thermalization, (2) an apparent non-analyticity at the endpoint of thermalization, (3) top-down thermalization where the UV thermalizes first. For homogeneous initial conditions the entanglement entropy thermalizes slowest, and sets a timescale for equilibration that saturates a causality bound over the range of scales studied. The growth rate of entanglement entropy density is nearly volume-independent for small volumes, but slows for larger volumes.

Abstract:
We study linear perturbations around the static and spherically symmetric spacetime for the gravitational theories whose Lagrangian depends on Ricci scalar and the parity violating Chern-Simons term. By an explicit construction, we show that Hamiltonian for the perturbation variables is not bounded from below in general, suggesting that such a background spacetime is unstable against perturbations. This gives a strong limit on a phenomenological gravitational model which violates parity. We also provide a necessary and sufficient condition for the theory to belong to a special class in which no such instability occurs. For such theories, the number of propagating modes for $\ell \ge 2$ is three, one from the odd and the other two from the even. Unlike in the case of $f(R)$ theories, those modes are coupled each other, which can be used as a distinctive feature to test the parity violating theories from observations. All the modes propagate at the speed of light. No-ghost condition and no-tachyon condition are the same as those in $f(R)$ theories. For the dipole perturbations, the odd and the even modes completely decouple. The odd mode gives a slowly-rotating BH solution whose metric is linearized in its angular momentum. We provide an integral expression of such a solution. On the other hand, the even mode propagates at the speed of light. For the monopole perturbation, in addition to a mode which just shifts the mass of the background BH, there is also one even mode that propagates at the speed of light.

Abstract:
We investigate the impact of recent direct supersymmetry (SUSY) searches on a non-universal sfermion mass scenario focusing on naturalness. One of the advantages of this scenario is that the non-universality between third generation and first two generation sfermion masses can relax the tension between naturalness and constraints from flavour and CP violating observables. In the parameter region, where various phenomenological constraints are satisfied, the constraints to this scenario from ATLAS 165pb-1 "0-lepton" search and 35pb-1 "b-jet" search are much weaker than those to the constrained minimal SUSY standard model, because of differences in the main SUSY production processes and the main decay chains. Naturalness can be easily achieved in this scenario in accord with the current direct SUSY searches. An additional dedicated analysis may be needed to discover/exclude this scenario.

Abstract:
We study the Kaluza-Klein(KK) graviton decay caused by three KK gravitons interaction in the Randall-Sundrum model. By a property of the KK gravitons' polarization tensor we expected large partial decay widths for these processes. After computations, However, we get small partial decay widths compared with the decay to the Standard Model particles.

Abstract:
It is well known that the SU(3) gauge theory with the fundamental 16-flavor fermion is governed by a non-trivial infrared fixed point in the 2-loop perturbation theory, while the theory has not been well investigated by non-perturbative lattice simulations. We investigate properties of 16-flavor QCD by lattice simulation with highly improved action setup(HISQ/tree) at two lattice spacings. We present preliminary results for the mass of the lightest pseudoscalar meson, and its decay constant at non-zero fermion mass. We discuss the finite-mass and finite-volume scaling of the quantities, the mass anomalous dimension extracted from the scaling, and comparison of the anomalous dimension with the perturbation theory.