Unquenched QCD simulation results

The recent progress on unquenched QCD simulations is critically reviewed. After some discussions on problems and subtleties in unquenched simulations, hadron spectra obtained from both quenched and unquenched simulations are compared among various gauge and quark actions. It is found that the Edinburgh plot does not agree in the continuum limit between Wilson and KS quark actions even in quenched QCD. Dynamical quark effects on hadron spectra, in particular, on meson masses are then presented for Wilson-type quark actions. Finally dynamical quark effects on other quantities such as the topological susceptibility and the flavor-singlet meson mass are discussed.Comment: Lattice 2000 (Plenary), LaTex(espcrc2.sty), 16 pages, 22 eps figure

Comparative Study of full QCD Hadron Spectrum and Static Quark Potential with Improved Actions

We investigate effects of action improvement on the light hadron spectrum and the static quark potential in two-flavor QCD for $a^{-1} \approx 1$ GeV and $m_{PS}/m_V = 0.7-0.9$. We compare a renormalization group improved action with the plaquette action for gluons, and the SW-clover action with the Wilson action for quarks. We find a significant improvement in the hadron spectrum by improving the quark action, while the gluon improvement is crucial for a rotationally invariant static potential. We also explore the region of light quark masses corresponding to $m_{PS}/m_V \geq 0.4$ on a 2.7 fm lattice using the improved gauge and quark action. A flattening of the potential is not observed up to 2 fm.Comment: LaTeX, 35 pages, 22 eps figures, uses revtex and eps

Late Miocene Soricidae (Mammalia) fauna from Tardosbánya (Western Hungary)

The Soricidae (Mamrnalia, Insectivora) elements of the rich and well preserved fossil vertebrate fauna from Tardosbánya limestone quarry (Western Hungary, Gerecse Mountains) are presented. Five species could have been identified from the material: Amblycoptus oligodon KORMOS 1926, Crusafontina konnosi (BACHMAYER& WILSON, 1970), Blarinella dubia (BACHMAYER and WILSON, 1970), Episoricuius gibberodon (PETÉNYI, 1864) and Paenelimnoecus repenningi (BACHMAYER & WILSON, 1970). The occurrence of Crusafantina, B. dubia and P. repenningi indicates that the age of the sarnple is Late Miocene. The morphometrical studies on C. konnosi, and the morphology and the low relative frequency of A. oligodon suggest that the fauna is correlative with the Turolian MN 12 Zone. The occurrence of A. oligodon, C. konnosi and E. gibberodon indicates well watered, forested environment

Light cone quantization and interactions of a new closed bosonic string inspired to D1 string

We quantize the bosonic part of the D1 string with closed boundary conditions on the light cone and we consider the U(1) worldsheet gauge field a dynamical variable. We compute also 3-Reggeon vertex by the overlapping technique. We find that the Fock space is the sum of sectors characterized by the momentum of the U(1) Wilson line and that these sectors do not interact among them. Each sector has exactly the same spectrum of the usual bosonic string when expressed in properly sector dependent rescaled variables. Rescaling is forced by factorization of the string amplitudes. We are also able to determine the relative string coupling constant of the different sectors. It follows a somewhat unexpected picture in which the effective action is always the same independently on the sector but string amplitudes are only the same when expressed in sector dependent rescaled variables.Comment: 17 pages, 2 figure

Elastic Differential Cross Sections for Space Radiation Applications

The eikonal, partial wave (PW) Lippmann-Schwinger, and three-dimensional Lippmann- Schwinger (LS3D) methods are compared for nuclear reactions that are relevant for space radiation applications. Numerical convergence of the eikonal method is readily achieved when exact formulas of the optical potential are used for light nuclei (A $\le$ 16), and the momentum-space representation of the optical potential is used for heavier nuclei. The PW solution method is known to be numerically unstable for systems that require a large number of partial waves, and, as a result, the LS3D method is employed. The effect of relativistic kinematics is studied with the PW and LS3D methods and is compared to eikonal results. It is recommended that the LS3D method be used for high energy nucleon-nucleus reactions and nucleus-nucleus reactions at all energies because of its rapid numerical convergence and stability

Darboux transformations for the KP hierarchy in the Segal-Wilson setting

In this paper it is shown that inclusions inside the Segal-Wilson Grassmannian give rise to Darboux transformations between the solutions of the $KP$-hierarchy corresponding to these planes. We present a closed form of the operators that procure the transformation and express them in the related geometric data. Further the associated transformation on the level of $\tau$-functions is given. \u

Effective lattice theories for Polyakov loops

We derive effective actions for SU(2) Polyakov loops using inverse Monte Carlo techniques. In a first approach, we determine the effective couplings by requiring that the effective ensemble reproduces the single-site distribution of the Polyakov loops. The latter is flat below the critical temperature implying that the (untraced) Polyakov loop is distributed uniformly over its target space, the SU(2) group manifold. This allows for an analytic determination of the Binder cumulant and the distribution of the mean-field, which turns out to be approximately Gaussian. In a second approach, we employ novel lattice Schwinger-Dyson equations which reflect the SU(2) x SU(2) invariance of the functional Haar measure. Expanding the effective action in terms of SU(2) group characters makes the numerics sufficiently stable so that we are able to extract a total number of 14 couplings. The resulting action is short-ranged and reproduces the Yang-Mills correlators very well.Comment: 27 pages, 8 figures, v2: method refined, chapter and references adde

Hadron spectroscopy and static quark potential in full QCD: A comparison of improved actions on the CP-PACS

We present first results from a full QCD calculation on the CP-PACS, comparing various actions at $a^{-1} \sim 1 GeV$ and $m_\pi/m_\rho \approx 0.7$--0.9. We use the plaquette and a renormalization group improved action for the gluons, and the Wilson and the SW-Clover action for quarks. We find that significant improvements in the hadron spectrum results from improving the quarks, while the gluon improvement is required for a rotationally invariant static potential. An ongoing effort towards exploring the chiral limit in full QCD is described.Comment: 6 pages, based on talks presented by R. Burkhalter and T. Kaneko at Lattice97, Edinburg

An analytic description of the vector constrained KP hierarchy

In this paper we give a geometric description in terms of the Grassmann manifold of Segal and Wilson, of the reduction of the KP hierarchy known as the vector $k$-constrained KP hierarchy. We also show in a geometric way that these hierarchies are equivalent to Krichever's general rational reductions of the KP hierarchy.Comment: 15 pages, Latex2

Holographic dual of the Eguchi-Kawai mechanism

archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2014-40, UUITP-03-14, QMUL-PH-14-08 slaccitation: %%CITATION = ARXIV:1404.0225;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2014-40, UUITP-03-14, QMUL-PH-14-08 slaccitation: %%CITATION = ARXIV:1404.0225;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2014-40, UUITP-03-14, QMUL-PH-14-08 slaccitation: %%CITATION = ARXIV:1404.0225;%%The work of K.Z. was supported by the ERC advanced grant No 341222, by the Marie Curie network GATIS of the European Union’s FP7 Programme under REA Grant Agreement No 317089, and by the Swedish Research Council (VR) grant 2013-4329. DY acknowledges NORDITA where this work was begun, during his time as a NORDITA fellow