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hep-lat/9311054
Alpha_s from the Lattice Potential
We present an extensive study on the direct determination of the running coupling alpha_s from the static quark antiquark force at short distances, in quenched QCD. We find from our high statistics potential analysis that alpha_qq exhibits two-loop asymptotic behaviour for momenta as low as .5 GeV. As a result, we dete...
1993-11-29
2011-07-19
[ "hep-lat" ]
K. Schilling, G.S. Bali
hep-lat/9311055
The analysis of Polyakov loop and spin correlators in finite volumes
We derive an analytic expression for point to point correlation functions of the Polyakov loop based on the transfer matrix formalism. The contributions from the eigenvalues of the transfer matrix including and beyond the mass gap are investigated both for the $2d$ Ising model and in finite temperature $SU(2)$ gauge th...
1993-11-29
2009-10-22
[ "hep-lat" ]
J. Engels, V. K. Mitrjushkin and T. Neuhaus
hep-lat/9311051
High statistics calculations of quenched QCD spectrum using various quark sources
We present the results for the hadron spectrum calculated on 400 configurations using point source, wall source and 8-cubic sources, in quenched QCD with Wilson fermions at $\beta=6.0$ and $K=0.155$ on a $24^3 \times 54$ lattice. The results for the ground state masses obtained with three types of quark sources agree w...
1993-11-29
2009-10-22
[ "hep-lat" ]
QCDPAX collaboration: Y.Iwasaki, K.Kanaya, S.Sakai, T.Yoshie, T.Hoshino and T.Shirakawa
hep-lat/9311058
Status of the Higgs Mass Bound
The status of the triviality bound of the Higgs mass in the Minimal Standard Model is reviewed. It is emphasized that the bound is obtained, in the scalar sector, by limiting cutoff effects on physical processes. Results from several regularization schemes, including actions that allow a parameterization and tuning of ...
1993-11-29
2009-10-22
[ "hep-lat" ]
Urs M. Heller
hep-lat/9311052
Topological charge density around static color sources
We analyze the topological structure of quenched QCD in the presence of static color sources. Distributions of the topological charge density around static quarks and mesons are computed in both phases of QCD. We observe a suppression of topological fluctuations in the vicinity of external sources. In the confinement p...
1993-11-29
2008-11-26
[ "hep-lat" ]
Manfried Faber, Harald Markum, Stefan Olejnik and Wolfgang Sakuler
hep-lat/9311049
Finite-Size Effect of Hadron Masses with Kogut-Susskind Quarks
We present numerical results and their analyses of finite-size effects of hadron masses for both quenched and full QCD calculations. We show that they are much larger for full QCD due to dynamical sea quarks and the associated breaking of $Z(3)$ symmetry. We also argue that finite-size effects are non-negligible even f...
1993-11-29
2009-10-22
[ "hep-lat" ]
S. Aoki, T. Umemura, M. Fukugita, N. Ishizuka, H. Mino, M Okawa, and A. Ukawa
hep-lat/9311056
QCD correlation functions and instantons
QCD point-to-point correlation functions at distances .2-1 fm are very different for different channels, and they tell us a lot about inter-quark interactions. Recent studies based on experimental data, 'instanton liquid' approach and lattice measurements are reviewed. Agreement between all of them show that instanton-...
1993-11-29
2009-10-22
[ "hep-lat", "hep-ph" ]
E.Shuryak (Physics Department, State University of New York, Stony Brook NY, USA)
hep-lat/9311050
Sea Quark Effects on the Strong Coupling Constant
We present results showing that the strong coupling constant measured in two-flavor full QCD with dynamical Kogut-Susskind quarks at $\beta=5.7$ exhibit a 15\% increase due to sea quarks over that for quenched QCD at the scale $\mu\approx 7$GeV . (talk at lattice93)
1993-11-29
2009-10-22
[ "hep-lat" ]
T. Onogi, S. Aoki, M. Fukugita, S. Hashimoto, N. Ishizuka, H. Mino, M.Okawa, and A. Ukawa
hep-lat/9311059
Simple Matrix Elements with Dynamical Fermions
We report on studies of simple matrix elements from simulations with two flavors of sea quarks, both staggered and Wilson. We show the decay constants of vector and pseudoscalar mesons. The effects of sea quarks are small. These simulations are done at relatively large lattice spacing compared to most quenched studies.
1993-11-29
2015-06-25
[ "hep-lat" ]
The High Energy Monte Carlo Grand Challenge
hep-lat/9311048
Some Interesting Features of Noncompact QED_3
We study the phase diagram of non compact $QED_3$ using the $MFA$ method and present evidence for a continuous phase transition line at small $N_f$. We also analyze the chiral structure of the vacuum by means of the computation of the probability distribution function of the order parameter in the exact chiral limit.
1993-11-27
2009-10-22
[ "hep-lat" ]
V. Azcoiti, G. Di Carlo, A. Galante, A.F. Grillo, V. Laliena, X.Q. Luo and C.E. Piedrafita
hep-lat/9311045
Lattice Computation of a Magnetic Monopole Mass
A single magnetic monopole in pure SU(2) gauge theory is simulated on the lattice and its mass is computed in the full quantum theory. The results are relevant for our proposed realization of the dual superconductor hypothesis of confinement.
1993-11-26
2011-04-20
[ "hep-lat" ]
J. Smit and A.J. van der Sijs
hep-lat/9311046
Computing the Mass of a Magnetic Monopole in SU(2) Gauge Theory
A single magnetic monopole in pure SU(2) gauge theory is simulated on the lattice and its mass is computed in the full quantum theory. The results are relevant for our proposed realization of the dual superconductor hypothesis of confinement.
1993-11-26
2009-10-22
[ "hep-lat", "hep-th" ]
J. Smit and A.J. van der Sijs
hep-lat/9311041
Quantum chromodynamics with various number of flavors
The phase structure of QCD with various number of flavors is studied for Wilson quarks. For the case of $N_F=3$ we find that the finite temperature deconfining transition is of first order in the chiral limit on an $N_t=4$ lattice. Together with our previous results that the deconfining transition in the chiral limit i...
1993-11-26
2016-08-14
[ "hep-lat" ]
Y. Iwasaki, K. Kanaya, S. Sakai and T. Yoshi\'e
hep-lat/9311042
The Behavior of Vortex Loops in the 3-d XY Model
The behavior of vortex loops is studied in the 3-d XY model. It is found that the phase transtiton of the 3-d XY model is caused by percolating vortex loops.
1993-11-26
2009-10-22
[ "hep-lat" ]
Arjan Hulsebos
hep-lat/9311043
Quenched Heavy-Light Decay Constants
We present decay constants from a quenched simulation using both propagating quarks and the static theory at $\beta=6.2$ on $24^3\times48$. The results using propagating quarks are used to test scaling laws predicted by the heavy quark symmetry.
1993-11-26
2010-11-01
[ "hep-lat" ]
Hartmut Wittig, UKQCD Collaboration
hep-lat/9311044
New Method for Dynamical Fermions and Chiral-Symmetry Breaking
The reasons for the feasibility of the Microcanonical Fermionic Average ($MFA$) approach to lattice gauge theory with dynamical fermions are discussed. We then present a new exact algorithm, which is free from systematic errors and convergent even in the chiral limit.
1993-11-26
2009-10-22
[ "hep-lat" ]
V. Azcoiti, G. Di Carlo, A.F. Grillo, V. Laliena and X.Q. Luo
hep-lat/9311047
Scaling in Steiner Random Surfaces
It has been suggested that the modified Steiner action functional has desirable properties for a random surface action. In this paper we investigate the scaling of the string tension and massgap in a variant of this action on dynamically triangulated random surfaces and compare the results with the gaussian plus extrin...
1993-11-26
2009-10-22
[ "hep-lat" ]
C.F. Baillie, A. Irback, W. Janke and D.A. Johnston
hep-lat/9311040
Topological Features in a Two-Dimensional Higgs Model
Topological properties of the gauge field in a two-dimensional Higgs model are investigated. Results of exploratory numerical simulations are presented.
1993-11-25
2009-10-22
[ "hep-lat" ]
Istvan Montvay
hep-lat/9311039
A lattice calculation of the branching ratio for $\overline{B} \rightarrow K^* \gamma$
Preliminary results are presented on the calculation of the relevant form factor for the radiative decay $\overline{B} \rightarrow K^* \gamma$ We find that the form factor is weakly dependent on the spectator quark mass. We compare the results obtained for a full chiral extrapolation and where this independence is assu...
1993-11-24
2007-05-23
[ "hep-lat" ]
Hugh Shanahan, UKQCD Collaboration
hep-lat/9311037
Fermion number violation and a two-dimensional Higgs model
The investigation of topological properties of the gauge field in a two-dimensional Higgs model can help in understanding anomalous fermion number violation.
1993-11-24
2011-04-15
[ "hep-lat" ]
Istvan Montvay
hep-lat/9311038
A Lattice Study of Spin and Flavour Symmetry in Heavy Quark Physics
We present a first test of heavy quark spin-flavour symmetries in matrix elements for semi-leptonic decays \bar B to D l\bar\nu and \bar B to D^* l\bar\nu. We show that O(1/m_Q) corrections are small at masses around the charm for form factors protected by Luke's Theorem, but are of order 30-40 \% for h_V and h_V/h_{A_...
1993-11-24
2007-05-23
[ "hep-lat", "hep-ph" ]
Henning Hoeber
hep-lat/9311033
Running Coupling in SU(3) Yang-Mills Theory
We report about our ongoing computation of running coupling constants in asymptotically free theories using the recursive finite size scaling technique. The latest results for the SU(3) Yang-Mills theory are presented.
1993-11-23
2009-10-22
[ "hep-lat" ]
Ulli Wolff (CERN)
hep-lat/9311032
On the top of the energy barrier. Margarita Garcia Perez
We present results related to the search of SU(2) instantons on a geometry $[0,L]^3\times [0,T]$ obtained using over-improved cooling with fixed boundary conditions. We also introduce a criterion for finding a sphaleron at the top of the energy barrier of the instanton path.
1993-11-23
2008-11-26
[ "hep-lat", "hep-th" ]
Antonio Gonzalez-Arroyo, Jeroen Snippe and Pierre van Baal
hep-lat/9311034
The Improvement Program in Nonrelativistic Lattice QCD
Progress in the improvement program in nonrelativistic lattice QCD is outlined. The leading radiative corrections to the heavy-quark mass renormalization, energy shift, and two important kinetic coupling coefficients are presented. The reliability of tadpole-improved perturbation theory in determining the energy shift ...
1993-11-23
2010-11-01
[ "hep-lat" ]
Colin J. Morningstar
hep-lat/9311036
Critical Slowing Down of Cluster Algorithms for Ising Models Coupled to 2-d Gravity
We simulate single and multiple Ising models coupled to 2-d gravity using both the Swendsen-Wang and Wolff algorithms to update the spins. We study the integrated autocorrelation time and find that there is considerable critical slowing down, particularly in the magnetization. We argue that this is primarily due to the...
1993-11-23
2009-10-22
[ "hep-lat", "cond-mat" ]
M. Bowick, M. Falcioni, G. Harris and E. Marinari
hep-lat/9311035
Induced Chern-Simons term in lattice QCD at finite temperature
The general conditions for the Chern-Simons action to be induced as a nonuniversal contribution of fermionic determinant are formulated in the finite temperature lattice QCD. The dependence of the corresponding action coefficient on nonuniversal parameters (chemical potentials, vacuum features, etc. ) is explored. Spec...
1993-11-23
2009-10-22
[ "hep-lat" ]
O.A.Borisenko, V.K.Petrov, G.M.Zinovjev
hep-lat/9311031
Wavelets as a variational basis of the XY model
We use Daubechies' orthonormal compact wavelets as a variational basis for the $XY$ model in two and three dimensions. Assuming that the fluctuations of the wavelet coefficients are Gaussian and uncorrelated, minimization of the free energy yields the fluctuation strength of wavelet coefficients at different scales, fr...
1993-11-22
2009-10-22
[ "hep-lat" ]
C. Best and A. Schaefer
hep-lat/9311030
The First Order Signal in Pure U(1) Gauge Theory May be Fake
We study the deconfinement phase transition of compact $U(1)$ pure lattice gauge theory with the Wilson action on {\em closed topology} lattices. In contrast to studies of compact QED on {\em hypercubic lattices with periodic boundary conditions}, we find no metastability signal at the phase transition on the lattices ...
1993-11-22
2009-10-22
[ "hep-lat" ]
C.B. Lang and T. Neuhaus
hep-lat/9311029
Scaling and Density of Lee-Yang Zeroes in the Four Dimensional Ising Model
The scaling behaviour of the edge of the Lee--Yang zeroes in the four dimensional Ising model is analyzed. This model is believed to belong to the same universality class as the $\phi^4_4$ model which plays a central role in relativistic quantum field theory. While in the thermodynamic limit the scaling of the Yang--Le...
1993-11-20
2011-07-19
[ "hep-lat" ]
R. Kenna and C.B. Lang
hep-lat/9311025
Fast K System Generators of Pseudorandom Numbers
We suggest fast algorithm for the matrix generator of pseudorandom numbers based on Kolmogorov-Anosov K systems which has been proposed earlier. This algorithm reduces $N^{2}$ operation of the matrix generator to $NlnN$ and essentially reduces the generation time. It also clarifies the algebraic structure of this type ...
1993-11-19
2022-04-06
[ "hep-lat" ]
N.Z.Akopov, E.M.Madounts, A.B.Nersesian, G.K.Savvidy and W.Greiner
hep-lat/9311026
Self-Avoiding Gonihedric Srting and Spin Systems
We classify different theories of self-intersecting random surfaces assigning special weights to intersections. When self-intersection coupling constant $\kappa$ tends to zero, then the surface can freely inetrsect and it is completely self-avoiding when $\kappa$ tends to infinity. Equivalent spin systems for this gene...
1993-11-19
2009-10-22
[ "hep-lat" ]
G.K.Savvidy and K.G.Savvidy
hep-lat/9311023
On the Meissner effect in SU(2) lattice gauge theory
We investigate the dual superconductor model of color confinement in SU(2) lattice gauge theory. We find that the transverse distribution of the longitudinal chromoelectric field between static quarks displays the dual Meissner effect. We also give evidence that the problem of color confinement could be approached in t...
1993-11-19
2009-10-22
[ "hep-lat", "hep-th" ]
P. Cea and L. Cosmai
hep-lat/9311024
Exploring the Dynamics of Three-Dimensional Lattice Gauge Theories by External Fields
We investigate the dynamics of three-dimensional lattice gauge theories by means of an external Abelian magnetic field. For the SU(2) lattice gauge theory we find evidence of the unstable modes.
1993-11-19
2009-10-22
[ "hep-lat", "hep-th" ]
P. Cea and L. Cosmai
hep-lat/9311027
Effects of spatial size, lattice doubling and source operator on the hadron spectrum with dynamical staggered quarks
We have extended our previous study of the lattice QCD spectrum with 2 flavors of staggered dynamical quarks at $6/g^2=5.6$ and $am_q=0.025$ and 0.01 to larger lattices, with better statistics and with additional sources for the propagators. The additional sources allowed us to estimate the $\Delta$ mass and to measure...
1993-11-19
2009-10-22
[ "hep-lat" ]
Khalil M. Bitar, R. Edwards, Steven Gottlieb, U. M. Heller, A. D. Kennedy, J. B. Kogut, A. Krasnitz, W. Liu, Michael C. Ogilvie, R. L. Renken, D. K. Sinclair, R. L. Sugar, D. Toussaint, K. C. Wang
hep-lat/9311028
On the Phase Structure of the Schwinger Model with Wilson Fermions
We study the phase structure of the massive one flavour lattice Schwinger model on the basis of the finite size scaling behaviour of the partition function zeroes. At $\beta = 0$ we observe and discuss a possible discrepancy with results obtained by a different method.
1993-11-19
2009-10-22
[ "hep-lat" ]
H. Gausterer and C.B. Lang
hep-lat/9311020
The pi-N Sigma term - an evaluation using staggered fermions
A lattice calculation of the pi-N sigma term is described using dynamical staggered fermions. Preliminary results give a sea term comparable in magnitude to the valence term.
1993-11-18
2009-10-22
[ "hep-lat" ]
R.Altmeyer, M.Goeckeler, R.Horsley, E.Laermann and G.Schierholz
hep-lat/9311022
Results from a study of the Nambu--Jona-Lasinio model on the lattice
The main results of our analysis of the two flavor Nambu--Jona-Lasinio model with $SU(2) \times SU(2)$ chiral symmetry on the four--dimensional hypercubic lattice with naive and Wilson fermions are presented. Large $N$ techniques and numerical simulations are used to study various properties of the model. The scalar an...
1993-11-18
2009-10-22
[ "hep-lat" ]
K.M. Bitar and P. Vranas
hep-lat/9311019
Super-Instantons and the Reliability of Perturbation Theory in Non-Abelian Models
In dimension $D\leq 2$ the low temperature behavior of systems enjoying a continuous symmetry is dominated by super-instantons: classical configurations of arbitrarily low energy. Perturbation theory in the background of a super-instanton produces thermodynamic answers for the invariant Green's functions that differ fr...
1993-11-18
2009-10-22
[ "hep-lat", "cond-mat" ]
A. Patrascioiu and E.Seiler
hep-lat/9311021
Multigrid Monte Carlo in the Sine Gordon model
We pose two questions about the dynamical critical behavior of multigrid Monte Carlo: Will a multigrid Monte Carlo simulation of the two dimensional Sine Gordon model exhibit critical slowing down, as expected by a theoretical analysis of Metropolis acceptance rates? Can we reduce critical slowing down caused by decrea...
1993-11-18
2009-10-22
[ "hep-lat" ]
Martin Grabenstein and Bernhard Mikeska
hep-lat/9311018
Fluctuation Induced First Order Phase Transitions
We study a $U(N)\times U(N)$ symmetric scalar field model in four and three dimensions. First, using our data in four dimensions in the weak coupling region, we demonstrate explicitly that the observed first order phase transition is induced by quantum fluctuations. Next, based on the renormalization group and our new ...
1993-11-17
2009-10-22
[ "hep-lat", "hep-ph" ]
Yue Shen
hep-lat/9311016
Fixed Point Actions for Lattice Fermions
The fixed point actions for Wilson and staggered lattice fermions are determined by iterating renormalization group transformations. In both cases a line of fixed points is found. Some points have very local fixed point actions. They can be used to construct perfect lattice actions for asymptotically free fermionic the...
1993-11-16
2009-10-22
[ "hep-lat" ]
W. Bietenholz and U.-J. Wiese
hep-lat/9311017
An Exact Local Hybrid Monte Carlo Algorithm for Gauge Theories
We introduce a new Monte Carlo method for pure gauge theories. It is not intended for use with dynamical fermions. It belongs to the class of Local Hybrid Monte Carlo (LHMC) algorithms, which make use of the locality of the action by updating individual sites or links by following a classical mechanics trajectory in fi...
1993-11-16
2009-10-22
[ "hep-lat" ]
A. D. Kennedy and K. M. Bitar
hep-lat/9311014
Recent developments in chiral gauge theories: Approach of infinitely many fermi fields
I present the recent developments in a specific sub-field of chiral gauge theories on the lattice. This sub-field pertains to the use of infinitely many fermi fields to describe a single chiral field. In this approach, both anomalous and anomaly free theories can be discussed in equal footing. It produces the correct a...
1993-11-15
2009-10-22
[ "hep-lat" ]
Rajamani Narayanan
hep-lat/9311013
The ``Spin'' Structure of the Nucleon - a lattice investigation
We will discuss here an indirect lattice evaluation of the baryon axial singlet current matrix element. This quantity may be related to the fraction of nucleon spin carried by the quarks. The appropriate structure function has recently been measured (EMC experiment). As in this experiment, we find that the quarks do no...
1993-11-15
2011-04-15
[ "hep-lat" ]
R.Altmeyer, M.Goeckeler, R.Horsley, E.Laermann and G.Schierholz
hep-lat/9311015
Chiral determinant on the lattice -- Anomalies and Instantons
An expression for the lattice effective action induced by chiral fermions in any even dimensions in terms of an overlap of two states is shown to have promising properties in two and four dimensions: The correct abelian anomaly is reproduced and gauge field configurations with non-zero topological charge are completely...
1993-11-15
2009-10-22
[ "hep-lat" ]
R. Narayanan and H. Neuberger
hep-lat/9311012
The pi-N Sigma term - a lattice investigation
A lattice calculation of the pi-N sigma term is described using dynamical staggered fermions. Preliminary results give a sea term comparable in magnitude to the valence term.
1993-11-13
2007-05-23
[ "hep-lat" ]
R.Altmeyer, M.Goeckeler, R.Horsley, E.Laermann and G.Schierholz
hep-lat/9311011
Random Walks in Noninteger Dimension
One can define a random walk on a hypercubic lattice in a space of integer dimension $D$. For such a process formulas can be derived that express the probability of certain events, such as the chance of returning to the origin after a given number of time steps. These formulas are physically meaningful for integer valu...
1993-11-10
2009-10-22
[ "hep-lat" ]
Carl M. Bender, Stefan Boettcher, Lawrence R. Mead
hep-lat/9311010
$B \to K^* + \gamma$ and $B_s \to \phi + \gamma$ on the Lattice
A lattice calculation of the form factors that determine the ``hadronization ratios'', such as $R_{K^*}$ and $R_{\phi}$, where $R_{K^*} \equiv [\Gamma ($B \to K^* \gamma$)/\Gamma(b \to s \gamma)]$, is presented in the quenched approximation. Lattice data shows strong evidence for the scaling law suggested by heavy quar...
1993-11-07
2009-10-22
[ "hep-lat", "hep-ph" ]
C. Bernard, P. Hsieh, and A. Soni
hep-lat/9311009
The Running Coupling From Lattice QCD
A recent lattice calculation of the QCD running coupling is presented. The coupling is extracted from the force between two static quarks in the framework of the valence quark approximation. A value of the Lambda-parameter for zero quark flavours is determined: Lambda_msbar=0.630(38)\sqrt{\sigma} =293(18)^{+25}_{-63} M...
1993-11-05
2009-09-25
[ "hep-lat" ]
Gunnar S. Bali
hep-lat/9311007
A New Approach to the Problem of Dynamical Quarks in Numerical Simulations of Lattice QCD
Lattice QCD with an even number of degenerate quark flavours is shown to be a limit of a local bosonic field theory. The action of the bosonic theory is real and bounded from below so that standard simulation algorithms can be expected to apply. The feasibility of such calculations is discussed, but no practical tests ...
1993-11-04
2009-10-22
[ "hep-lat" ]
Martin Luescher
hep-lat/9311005
The SU(2) $\times$ SU(2) chiral spin model in terms of SO(3) and Z$_2$ variables: vortices and disorder
We rewrite the two-dimensional SU(2)$\times$ SU(2) chiral spin model in terms of SO(3) and {\bf Z}$_2$ degrees of freedom. The transformation, which is motivated by a similar representation of the corresponding lattice gauge theory in higher dimensions, exhibits the presence of dynamical SO(3) vortices and associated s...
1993-11-04
2009-10-22
[ "hep-lat", "cond-mat", "hep-th" ]
Tam\'as G. Kova\'acs and E.T. Tomboulis
hep-lat/9311006
Radial Excited States for Heavy Quark Systems in NRQCD
Following the Non-Relativistic QCD approach we use a gauge invariant smearing method with factorization to measure the excitation energies for a heavy $Q\bar{Q}$ system on a $24^3\times 48$ lattice at $\beta=6.2$. The results come from averaging over an ensemble of 60 QCD configurations. In order to enhance the signal ...
1993-11-04
2011-04-20
[ "hep-lat" ]
S.M. Catterall, F.R. Devlin, I.T. Drummond, R.R. Horgan
hep-lat/9311008
Geometric Measurement of Topological Susceptibility on Large Lattices
The topological susceptibility of the quenched QCD vacuum is measured on large lattices for three $\beta$ values from $6.0$ to $6.4$. Charges possibly induced by $O(a)$ dislocations are identified and shown to have little effect on the measured susceptibility. As $\beta$ increases, fewer such questionable charges are f...
1993-11-04
2009-10-22
[ "hep-lat" ]
Jeffrey Grandy and Rajan Gupta
hep-lat/9311003
Compact U(1)xU(1) Model with Minimal Interspecies Interaction
We introduce a minimally interacting pure gauge compact U(1)xU(1) model consistent with abelian projection symmetries. This paradigm, whose interactions are entirely due to compactness, illustrates how compactness can contribute to interspecies interactions. Furthermore, it has a much richer phase structure(including a...
1993-11-03
2009-10-22
[ "hep-lat" ]
Ken Yee
hep-lat/9311004
$B \to K^* \gamma$: Penguins on the Lattice
We calculate the leading-order matrix element for the decay $B \to K^* \gamma$ in the quenched approximation of lattice QCD on a $24^3 \times 48$ lattice at $\beta=6.2$, using an O(a)-improved fermion action. Extrapolating the quark masses to their physical values we obtain an on-shell form factor of $T_1(q^2=0)=0.15+1...
1993-11-03
2015-06-25
[ "hep-lat", "hep-ph" ]
UKQCD Collaboration
hep-lat/9311002
Full QCD on APE100 Machines
We present the first tests and results from a study of QCD with two flavours of dynamical Wilson fermions using the Hybrid Monte Carlo Algorithm (HMCA) on APE100 machines.
1993-11-02
2015-06-25
[ "hep-lat" ]
S. Antonelli, M. Bellacci, A. Donini and R. Sarno
hep-lat/9311001
The crossover from first to second-order finite size scaling: A numerical study Christian Borgs
We consider a particular case of the two dimensional Blume-Emery-Griffiths model to study the finite-size scaling for a field driven first-order phase transition with two coexisting phases not related by a symmetry. For low temperatures we verify the asymptotic (large volume) predictions of the rigorous theory of Bor...
1993-11-01
2009-09-25
[ "hep-lat" ]
Stefan Kappler and Paul Rakow
hep-lat/9310030
C-Periodicity and the Physical Mass in the 3-State Potts Model
The standard infinite-volume definition of connected correlation function and particle mass in the 3-state Potts model can be implemented in Monte Carlo simulations by using C-periodic spatial boundary conditions. This avoids both the breaking of translation invariance (cold wall b.c.) and the phase-dependent and thus ...
1993-10-29
2009-10-22
[ "hep-lat" ]
R.V.Gavai (ICTP, Trieste, Italy, and Tata Institute of Fundamental Research, Bombay 400 005, India) and L.Polley (FB Physik, Oldenburg University, 26111 Oldenburg, Germany)
hep-lat/9310029
Towards Multigrid Methods for Propagators of Staggered Fermions with Improved Averaging and Interpolation Operators
A Dirac choice for the averaging kernel $C$ is implemented numerically. This improved kernel will be needed in gauge covariant multigrid computations for propagators of staggered fermions. Results for $C$ and the variational coarse grid operator will be given in 2-$d$ $SU(2)$ gauge fields. C++ is advocated for future a...
1993-10-28
2016-08-31
[ "hep-lat" ]
Thomas Kalkreuter
hep-lat/9310027
A Study of the Nambu--Jona-Lasinio Model on the Lattice
We present our full analysis of the two flavor Nambu--Jona-Lasinio model with $SU(2) \times SU(2)$ chiral symmetry on the four--dimensional hypercubic lattice with naive and Wilson fermions. We find that this model is an excellent toy field theory to investigate issues related to lattice QCD. We use the large $N$ appro...
1993-10-26
2009-10-22
[ "hep-lat", "hep-ph" ]
K.M. Bitar and P.M. Vranas
hep-lat/9310028
Capillary Wave Approach to Order-Order Fluid Interfaces in the 3D Three-State Potts Model
The physics of fluid interfaces between domains of different magnetization in the ordered phase of the 3D three-state Potts model is studied by means of a Monte Carlo simulation. It is shown that finite--size effects in the interface free energy are well described by the capillary wave model at two loop order, supporti...
1993-10-26
2009-10-22
[ "hep-lat", "cond-mat", "hep-th" ]
Paolo Provero and Stefano Vinti
hep-lat/9310025
Ising Model Universality for Two-Dimensional Lattices
We use the single-cluster Monte Carlo update algorithm to simulate the Ising model on two-dimensional Poissonian random lattices of Delaunay type with up to 80\,000 sites. By applying reweighting techniques and finite-size scaling analyses to time-series data near criticality, we obtain unambiguous support that the cri...
1993-10-25
2009-10-22
[ "hep-lat" ]
W. Janke, M. Katoot, and R. Villanova
hep-lat/9310024
Interface Tensions and Perfect Wetting in the Two-Dimensional Seven-State Potts Model
We present a numerical determination of the order-disorder interface tension, \sod, for the two-dimensional seven-state Potts model. We find $\sod=0.0114\pm0.0012$, in good agreement with expectations based on the conjecture of perfect wetting. We take into account systematic effects on the technique of our choice: the...
1993-10-25
2009-10-22
[ "hep-lat" ]
B.Grossmann and Sourendu Gupta
hep-lat/9310026
Fitting Correlated Data
We discuss fitting correlated data - with the example of hadron mass spectroscopy in mind. The main conclusion is that the method of minimising correlated $\chi^2$ is unreliable if the data sample is too small.
1993-10-25
2008-11-26
[ "hep-lat" ]
C. Michael
hep-lat/9310023
The nature of the thermal phase transition with Wilson quarks
We describe a series of simulations of high temperature QCD with two flavors of Wilson quarks aimed at clarifying the nature of the high temperature phase found in current simulations. Most of our work is with four time slices, although we include some runs with six and eight time slices for comparison. In addition to ...
1993-10-21
2009-09-25
[ "hep-lat" ]
Claude Bernard, Thomas A. DeGrand, Carleton DeTar, Steven Gottlieb, A. Hasenfratz, Leo Karkkainen, R. L. Sugar and D. Toussaint
hep-lat/9310022
A New Way to Set the Energy Scale in Lattice Gauge Theories and its Application to the Static Force and $\alpha_s$ in SU(2) Yang--Mills Theory
We introduce a hadronic scale $R_0$ through the force $F(r)$ between static quarks at intermediate distances $r$. The definition $F(R_0)R_0^2=1.65$ amounts to $R_0 \simeq 0.5$~fm in phenomenological potential models. Since $R_0$ is well defined and can be calculated accurately in a Monte Carlo simulation, it is an idea...
1993-10-21
2010-02-18
[ "hep-lat" ]
R. Sommer
hep-lat/9310020
Critical Behaviour of the 3d Gross-Neveu and Higgs-Yukawa Models
We measure the critical exponents of the three dimensional Gross-Neveu model with two four-component fermions. The exponents are inferred from the scaling behaviour of observables on different lattice sizes. We also calculate the exponents, through a second order epsilon-expansion around 4d, for the three dimensional H...
1993-10-19
2009-09-25
[ "hep-lat" ]
L. Karkkainen, R. Lacaze, P. Lacock, and B.Petersson
hep-lat/9310019
The running coupling from lattice gauge theory:
I discuss some calculations of the running coupling in SU($N$) gauge theories from lattice simulations, centering on the work of the UKQCD collaboration. This talk is introductory in nature; full details have been published elsewhere.
1993-10-19
2007-05-23
[ "hep-lat" ]
P.W. Stephenson
hep-lat/9310018
Quark Mass Renormalization on the Lattice with Staggered Fermions
The QCD light quark mass renormalized at a 1 GeV scale in the $ \overline{MS} $ scheme is obtained from the numerical results of the lattice QCD simulation with staggered fermions. The primary emphasis is given to the connection between the lattice and continuum parameters. The results are compared with those from the ...
1993-10-18
2009-10-22
[ "hep-lat", "hep-ph" ]
Weonjong Lee
hep-lat/9310021
An Algorithm for Dynamic Load Balancing of Synchronous Monte Carlo Simulations on Multiprocessor Systems
We describe an algorithm for dynamic load balancing of geometrically parallelized synchronous Monte Carlo simulations of physical models. This algorithm is designed for a (heterogeneous) multiprocessor system of the MIMD type with distributed memory. The algorithm is based on a dynamic partitioning of the domain of the...
1993-10-18
2009-10-22
[ "hep-lat" ]
P. Altevogt, A. Linke
hep-lat/9310016
Monte Carlo Simulation of 2-D Quantum Gravity as Open Dynamically Triangulate Random Surfaces
We describe a Monte Carlo procedure for the simulation of dynamically triangulate random surfaces with a boundary (topology of a disk). The algorithm keeps the total number of triangles fixed, while the length of the boundary is allowed to fluctuate. The algorithm works in the presence of matter fields. We here present...
1993-10-15
2009-10-22
[ "hep-lat" ]
E. Adi, M. Hasenbusch, M. Marcu, E. Pazy, K. Pinn, and S. Solomon
hep-lat/9310017
Discretized Laplacians on an Interval and their Renormalization Group
The Laplace operator admits infinite self-adjoint extensions when considered on a segment of the real line. They have different domains of essential self-adjointness characterized by a suitable set of boundary conditions on the wave functions. In this paper we show how to recover these extensions by studying the contin...
1993-10-15
2015-06-25
[ "hep-lat", "hep-th" ]
G. Bimonte, E .Ercolessi and P. Teotonio-Sobrinho
hep-lat/9310015
A Cluster Method for the Ashkin--Teller Model
A cluster Monte Carlo algorithm for the Ashkin-Teller (AT) model is constructed according to the guidelines of a general scheme for such algorithms. Its dynamical behaviour is tested for the square lattice AT model. We perform simulations on the line of critical points along which the exponents vary continuously, and f...
1993-10-14
2009-09-25
[ "hep-lat", "cond-mat" ]
S. Wiseman, E. Domany
hep-lat/9310014
The Physical Phase of Dimensionally Reduced Gauge Theories
We investigate the relationship between the high temperature deconfined phase of the SU(2) gauge theory to the phases of the corresponding three dimensional adjoint Higgs model. For various temperatures we simulate the effective theory in a neighbourhood of the physical states, that is of those values of the coupling c...
1993-10-12
2009-09-25
[ "hep-lat" ]
L. Karkkainen, P. Lacock, D.E. Miller, B. Petersson and T. Reisz
hep-lat/9310013
Comparison of Monte Carlo Results for the 3D Ising Interface Tension and Interface Energy with (Extrapolated) Series Expansions
We compare Monte Carlo results for the interface tension and interface energy of the 3-dimensional Ising model with Pad\'e and inhomogeneous differential approximants of the low temperature series that was recently extended by Arisue to $17^{\rm th}$ order in $u=\exp(-4\beta)$. The series is expected to suffer from the...
1993-10-11
2009-10-22
[ "hep-lat", "cond-mat" ]
M. Hasenbusch and K. Pinn
hep-lat/9310010
Monopole Condensation and Confinement in SU(2) QCD (1)
An effective monopole action is derived from vacuum configurations after abelian projection in the maximally abelian gauge in $SU(2)$ QCD. Entropy dominance over energy of monopole loops is seen on the renormalized lattice with the spacing $b>b_c\simeq 5.2\times10^{-3} \Lambda_L^{-1}$ when the physical volume of the sy...
1993-10-09
2009-10-22
[ "hep-lat", "hep-ph" ]
Hiroshi Shiba and Tsuneo Suzuki
hep-lat/9310012
Momentum Lattice Simulation on a Small Lattice Using Stochastic Quantization
We have studied the scalar $\phi^4$-model in the symmetric phase and the non--compact $U(1)$ gauge theory on a momentum lattice using the Langevin equation for generating configurations. In the $\phi^4$-model we have analyzed the renormalized mass and in the $U(1)$-model we have analyzed the Wilson loop operator. We us...
1993-10-09
2015-06-25
[ "hep-lat" ]
H. Kr\"oger, S. Lantagne and K.J.M. Moriarty
hep-lat/9310011
Monopole Condensation and Confinement in SU(2) QCD (2)
Monopole and photon contributions to Wilson loops are calculated using Monte-Carlo simulations of SU(2) QCD in the maximally abelian gauge. The string tensions of SU(2) QCD are well reproduced by extended monopole contributions alone.
1993-10-09
2008-02-03
[ "hep-lat", "hep-ph" ]
Hiroshi Shiba and Tsuneo Suzuki
hep-lat/9310009
Meson Decay Constants from the Valence Approximation to Lattice QCD
We evaluate $f_{\pi}/ m_{\rho}$, $f_K/ m_{\rho}$, $1/f_{\rho}$, and $ m_{\phi}/(f_{\phi} m_{\rho})$, extrapolated to physical quark mass, zero lattice spacing and infinite volume, for lattice QCD with Wilson quarks in the valence (quenched) approximation. The predicted ratios differ from experiment by amounts ranging f...
1993-10-07
2009-10-22
[ "hep-lat" ]
F. Butler, H. Chen, J. Sexton, A. Vaccarino, and D. Weingarten
hep-lat/9310008
The Nambu--Jona-Lasinio Model of QCD on the Lattice
In an effort to investigate some of the low energy properties of QCD, in particular those related to chiral symmetry breaking, as well as to obtain insights on the behavior of an interacting theory of fermions on the lattice, the two flavor Nambu--Jona-Lasinio model with $SU(2) \times SU(2)$ chiral symmetry is studied ...
1993-10-07
2011-07-19
[ "hep-lat", "hep-ph" ]
K.M. Bitar and P.M. Vranas
hep-lat/9310007
Semileptonic form factors of heavy-light mesons from lattice QCD
The form factors for the semileptonic decays of heavy-light pseudoscalar mesons of the type $D \to Ke\nu$ are studied in quenched lattice QCD at $\beta=6.0$ using Wilson fermions. We explore new numerical techniques for improving the signal and study $O(a)$ corrections using three different lattice transcriptions of th...
1993-10-07
2007-05-23
[ "hep-lat" ]
Rajan Gupta, Tanmoy Bhattacharya and David Daniel
hep-lat/9310006
Anomalies and chiral defect fermions
Chiral defect fermions in the background of an external, $2n$ dimensional gauge field are considered. Assuming first a finite extra dimension, we calculate the axial anomaly in a vector-like, gauge invariant model for arbitrary $n$, and the consistent anomaly in a gauge {\it variant} model with a chiral spectrum. For t...
1993-10-06
2009-10-22
[ "hep-lat", "hep-th" ]
Yigal Shamir
hep-lat/9310005
Zooming-in on the SU(2) fundamental domain
For SU(2) gauge theories on the three-sphere we analyse the Gribov horizon and the boundary of the fundamental domain in the 18 dimensional subspace that contains the tunnelling path and the sphaleron and on which the energy functional is degenerate to second order in the fields. We prove that parts of this boundary co...
1993-10-05
2009-10-22
[ "hep-lat", "hep-th" ]
Pierre van Baal and Bas van den Heuvel
hep-lat/9310004
Perturbative Corrections for Staggered Four-Fermion Operators
We present results for one-loop matching coefficients between continuum four-fermion operators, defined in the Naive Dimensional Regularization scheme, and staggered fermion operators of various types. We calculate diagrams involving gluon exchange between quark lines, and ``penguin'' diagrams containing quark loops. F...
1993-10-05
2011-07-19
[ "hep-lat" ]
Stephen Sharpe and Apoorva Patel
hep-lat/9310003
2D O(3) + 2D QG
It has been suggested that the peak in the specific heat observed numerically for random surface actions with extrinsic curvature on dynamical lattices might be the result of a low mass bound state in an asymptotically free theory, rather than the signal for a real phase transition. The $O(3)$ model on a fixed lattice ...
1993-10-04
2008-11-26
[ "hep-lat" ]
C.F. Baillie and D.A. Johnston
hep-lat/9310002
Almost Gauge Invariant Lattice Actions for Chiral Gauge Theories, using Laplacian Gauge Fixing
It is described how to obtain an almost gauge invariant lattice action $S$ for chiral gauge theories, or other models in which a straightforward discretization leads to a lattice action $S^\pr$ in which gauge invariance is broken. The lattice action is `almost' gauge invariant, because a local gauge transformation leav...
1993-10-01
2009-10-22
[ "hep-lat" ]
Jeroen C. Vink
hep-lat/9310001
Instantons and Surface Tension at a First-Order Transition
We study the dynamics of the first order phase transition in the two dimensional 15-state Potts model, both at and off equilibrium. We find that phase changes take place through nucleation in both cases, and finite volume effects are described well through an instanton computation. Thus a dynamical measurement of the s...
1993-10-01
2009-10-22
[ "hep-lat", "cond-mat", "hep-ph" ]
Sourendu Gupta
hep-lat/9309021
A Consumer's Guide to Lattice QCD Results
I present an overview of recent lattice QCD results on hadron spectroscopy and matrix elements. Case studies include light quark spectroscopy, the determination of $\alpha_s$ from heavy quark spectroscopy, the D-meson decay constant, a calculation of the Isgur-Wise function, and some examples of the (lack of) effect of...
1993-09-30
2007-05-23
[ "hep-lat" ]
T. DeGrand
hep-lat/9309022
Scaling of Pseudo-Critical Couplings in Two-Flavour QCD
We study the scaling behaviour of the pseudo-critical couplings for the chiral phase transition in two-flavour QCD. We show that all existing results from lattice simulations on lattices with temporal extent $N_\tau = 4$, 6 and 8 can be mapped onto a universal scaling curve. The relevant combination of critical exponen...
1993-09-30
2009-10-22
[ "hep-lat" ]
Frithjof Karsch
hep-lat/9309019
Renormalization Group Study of the soliton mass on the (lambda Phi^4)_{1+1} lattice model
We compute, on the $(\lambda \Phi^4)_{1+1}$ model on the lattice, the soliton mass by means of two very different numerical methods. First, we make use of a ``creation operator'' formalism, measuring the decay of a certain correlation function. On the other hand we measure the shift of the vacuum energy between the sym...
1993-09-28
2009-10-22
[ "hep-lat" ]
J. C. Ciria, A. Tarancon
hep-lat/9309020
A Portable High-Quality Random Number Generator for Lattice Field Theory Simulations
The theory underlying a proposed random number generator for numerical simulations in elementary particle physics and statistical mechanics is discussed. The generator is based on an algorithm introduced by Marsaglia and Zaman, with an important added feature leading to demonstrably good statistical properties. It can ...
1993-09-28
2009-10-22
[ "hep-lat" ]
Martin Luescher
hep-lat/9309018
Anomalous fermion number violation and numerical simulations
After discussing the problem of lattice regularization of chiral gauge theories, a simple model for anomalous fermion number violation is formulated which can be numerically studied with present day technique. Exploratory results of numerical simulations of a two-dimensional U(1) Higgs model are presented.
1993-09-27
2007-05-23
[ "hep-lat" ]
Istvan Montvay
hep-lat/9309017
Baryon Density Correlations in High Temperature Hadronic Matter
As part of an ongoing effort to characterize the high temperature phase of QCD, in a numerical simulation using the staggered fermion scheme, we measure the quark baryon density in the vicinity of a fixed test quark at high temperature and compare it with similar measurements at low temperature and at the crossover tem...
1993-09-26
2008-11-26
[ "hep-lat" ]
Claude Bernard, Thomas A. DeGrand, Carleton DeTar, Steven Gottlieb, Alex Krasnitz, Robert L. Sugar, and Douglas Toussaint
hep-lat/9309016
Lattice Gauge Theory -- Present Status
Lattice gauge theory is our primary tool for the study of non-perturbative phenomena in hadronic physics. In addition to giving quantitative information on confinement, the approach is yielding first principles calculations of hadronic spectra and matrix elements. After years of confusion, there has been significant re...
1993-09-24
2008-11-26
[ "hep-lat" ]
Michael Creutz
hep-lat/9309015
Investigation of the Domain Wall Fermion Approach to Chiral Gauge Theories on the Lattice
We investigate a recent proposal to construct chiral gauge theories on the lattice using domain wall fermions. We restrict ourselves to the finite volume case, in which two domain walls are present, with modes of opposite chirality on each of them. We couple the chiral fermions on only one of the domain walls to a gaug...
1993-09-23
2009-10-22
[ "hep-lat" ]
Maarten F.L. Golterman, Karl Jansen, Donald N. Petcher and Jeroen C. Vink
hep-lat/9309014
Perturbative analysis for Kaplan's lattice chiral fermions
Perturbation theory for lattice fermions with domain wall mass terms is developed and is applied to investigate the chiral Schwinger model formulated on the lattice by Kaplan's method. We calculate the effective action for gauge fields to one loop, and find that it contains a longitudinal component even for anomaly-fre...
1993-09-22
2009-10-22
[ "hep-lat", "hep-th" ]
S. Aoki and H. Hirose
hep-lat/9309013
Weyl Neutrinos on a Lattice: An Explicit Construction
Introducing a new and universally applicable discretizing technique, I construct a class of local and unitary lattice theories of Weyl neutrinos; this solves a longstanding and allegedly unsolvable problem in quantum field theory. En route, I also prove a general ``go'' theorem that all Lagrangian-density based continu...
1993-09-18
2016-08-31
[ "hep-lat", "cond-mat", "hep-th" ]
Anil K. Trivedi
hep-lat/9309012
The Nielsen-Ninomiya ``No-Go'' Theorem is False
The Nielsen-Ninomiya no-go theorem asserts that chiral Weyl~(``neutrino'') fields cannot exist on lattices. However, the actual mathematical arguments advanced in the theorem fail to make that case. The theorem leaves the problem of lattice neutrinos completely open; it identifies no obstacle which would prevent us fro...
1993-09-18
2008-02-03
[ "hep-lat", "cond-mat", "hep-th" ]
Anil K. Trivedi
hep-lat/9309011
Hadron Spectrum and Matrix Elements in QCD with Dynamical Wilson Fermions at 6/g^2=5.3
We present results of a lattice simulation of quantum chromodynamics with two degenerate flavors of dynamic Wilson fermions at $6/g^2=5.3$ at each of two dynamical fermion hopping parameters, $\kappa=0.1670$ and 0.1675, corresponding to pion masses in lattice units of about 0.45 and 0.31. The simulations include three ...
1993-09-17
2009-10-22
[ "hep-lat" ]
K. M. Bitar, et. al. (High Energy Monte Carlo Grand Challenge)
hep-lat/9309010
Phase diagrams of a Higgs-Yukawa system with chirally invariant lattice fermion actions
We study the phase structure of a $Z_2$ lattice Higgs-Yukawa system with different forms of chirally invariant lattice fermion actions: naive, two types of non-local actions, and a mirror fermion action. The calculations are performed in the variational mean field approximation with contribution of fermionic determinan...
1993-09-17
2009-09-25
[ "hep-lat" ]
Sergei V. Zenkin