PaperPanorama

HEP Lattice·hep-lat

Tue·Aug 27, 2002

11 papers—8 primary·3 cross-listed·reconstructed*

All11Primary8Cross-lists3
  1. 01*

    Lattice supersymmetry

    David B. Kaplan🇺🇸

    A method is proposed for latticizing a class of supersymmetric gauge theories, including N=4 super Yang-Mills. The technique is inspired by recent work on ``deconstruction''. Part of the target theory's supersymmetry is realized exactly on the lattice, reducing or eliminating the need for fine tuning. (Talk based on the paper "Supersymmetry on a Spatial Lattice", hep-lat/0206019, by D.B.K., Emmanuel Katz and Mithat Unsal).

    hep-latNucl.Phys.B Proc.Suppl.(2003)·7 citations
  2. 02*

    Static quark potential and string tension for compact U(1) in (2+1) dimensions

    Mushtaq Loan🇦🇺 · Michael Brunner🇦🇺 · Chris Hamer🇦🇺

    Compact U(1) lattice gauge theory in (2+1) dimensions is studied on anisotropic lattices using Standard Path Integral Monte Carlo techniques. We extract the static quark potential and the string tension from 1.0 <= Dtau <= 0.333 simulations at 1.0 <= beta <= 3.0. Estimating the actual value of the renormalization constant, (c = 44), we observe the evidence of scaling in the string tension for 1.4142 <= beta <= 2.5; with the asymptotic behaviour in the large-beta limit given by K sqrt(beta) = e^(-2.494 beta +2.29). Extrapolations are made to the extreme anisotropic or "Hamiltonian" limit, and comparisons are made with previous estimates obtained by various other methods in the Hamiltonian formulation.

    hep-lat1 citation
  3. 03*

    Lanczos Methods for UV-Suppressed Fermions

    Artan Borici🇬🇧

    In this talk I indroduce lattice fermions with suppressed cutoff modes. Then I present Lanczos based methods for stochastic evaluation of the fermion determinant.

    hep-latNucl.Phys.B Proc.Suppl.(2003)·3 citations
  4. 04*

    Gauge Problem of Monopole Dynamics in SU(2) Lattice Gauge Theory

    Shoichi Ito🇯🇵 · Shun-ichi Kitahara🇯🇵 · Tae Woong Park🇯🇵 · Tsuneo Suzuki🇯🇵

    Gauge problem of monopole dynamics is studied in SU(2) lattice gauge theory. We study first abelian and monopole contributions to the static potential in four smooth gauges, i.e., Laplacian Abelian (LA), Maximally Abelian Wilson Loop (MAWL) and L-type gauges in comparison with Maximally Abelian (MA) gauge. They all reproduce the string tension in good agreement with the SU(2) string tension. MA gauge is not the only choice of the good gauge which is suitable for the color confinement mechanism. Using an inverse Monte-Carlo method and the blockspin transformation, we determine effective monopole actions and the renormalization group (RG) flows of its coupling constants in various abelian projection schemes. Every RG flow looks to converge to a unique curve which suggests gauge independence in the infrared region.

    hep-latPRD(2003)·3 citations
  6. 06*

    M_pi^2 versus m_q: comparing CP-PACS and UKQCD data to Chiral Perturbation Theory

    Stephan Dürr🇩🇪

    I present a selection of CP-PACS and UKQCD data for the pseudo-Goldstone masses in QCD with doubly degenerate quarks. At least the more chiral points should be consistent with Chiral Perturbation Theory for the latter to be useful in an extrapolation to physical masses. I find consistency with the chiral prediction but no striking evidence for chiral logs. Nonetheless, the consistency guarantees that the original estimate, by Gasser and Leutwyler, of the QCD low-energy scale was not entirely wrong.

    hep-lathep-phEPJC(2003)·32 citations
  7. 07*

    Universality and RG-improved gauge actions

    Silvia Necco🇩🇪

    The reference energy scale r_0 is evaluated for RG-improved Iwasaki and DBW2 gauge actions (N_f = 0), at values of the deconfinement coupling beta_c corresponding to N_t = 3,4,6,8. The universality of r_0 T_c between Iwasa ki and Wilson action is confirmed; the scaling behaviour and the influence of th e violation of positivity in the extraction of effective masses are investigated.

    hep-latNucl.Phys.B Proc.Suppl.(2003)·5 citations
  9. 09*

    Scale setting for alpha_s beyond leading order

    K. Hornbostel🇺🇸 · G.P. Lepage🇺🇸 · C. Morningstar🇺🇸

    We present a general procedure for incorporating higher-order information into the scale-setting prescription of Brodsky, Lepage and Mackenzie. In particular, we show how to apply this prescription when the leading coefficient or coefficients in a series in the strong coupling alpha_s are anomalously small and the original prescription can give an unphysical scale. We give a general method for computing an optimum scale numerically, within dimensional regularization, and in cases when the coefficients of a series are known. We apply it to the heavy quark mass and energy renormalization in lattice NRQCD, and to a variety of known series. Among the latter, we find significant corrections to the scales for the ratio of e+e- to hadrons over muons, the ratio of the quark pole to MSbar mass, the semi-leptonic B-meson decay width, and the top decay width. Scales for the latter two decay widths, expressed in terms of MSbar masses, increase by factors of five and thirteen, respectively, substantially reducing the size of radiative corrections.

    ↳ hep-phhep-latPRD(2003)·51 citations
  10. 10*

    Symmetry Breaking and False Vacuum Decay after Hybrid Inflation

    Juan Garcia-Bellido🇪🇸 · Margarita Garcia Perez🇨🇭 · Antonio Gonzalez-Arroyo🇪🇸

    We discuss the onset of symmetry breaking from the false vacuum in generic scenarios in which the mass squared of the symmetry breaking (Higgs) field depends linearly with time, as it occurs, via the evolution of the inflaton, in models of hybrid inflation. We show that the Higgs fluctuations evolve from quantum to classical during the initial stages. This justifies the subsequent use of real-time lattice simulations to describe the fully non-perturbative and non-linear process of symmetry breaking. The early distribution of the Higgs field is that of a smooth classical gaussian random field, and consists of lumps whose shape and distribution is well understood analytically. The lumps grow with time and develop into ``bubbles'' which eventually collide among themselves, thus populating the high momentum modes, in their way towards thermalization at the true vacuum. With the help of some approximations we are able to provide a quasi-analytic understanding of this process.

    ↳ hep-phhep-lathep-thPRD(2003)·168 citations
  11. 11*

    Complex singularities of the critical potential in the large-N limit

    Y. Meurice🇺🇸

    We show with two numerical examples that the conventional expansion in powers of the field for the critical potential of 3-dimensional O(N) models in the large-N limit, does not converge for values of phi^2 larger than some critical value. This can be explained by the existence of conjugated branch points in the complex phi^2 plane. Pade approximants [L+3/L] for the critical potential apparently converge at large phi^2. This allows high-precision calculation of the fixed point in a more suitable set of coordinates. We argue that the singularities are generic and not an artifact of the large-N limit. We show that ignoring these singularities may lead to inaccurate approximations.

    ↳ hep-thcond-mat.stat-mechhep-latmath-ph+1PRD(2003)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.