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hep-lat/9206025
Scaling analysis of the O(4)-symmetric $\Phi^4$-theory in the broken phase
We study the $O(4)$-symmetric $ \Phi^4 $-theory in the scaling region of the broken phase using the standard and a Symanzik improved action with infinite bare self-coupling $\lambda$. A high precision Monte Carlo simulation is performed by applying the reflection cluster algorithm. Employing the histogram method we ana...
1992-06-29
2009-10-22
[ "hep-lat", "hep-ph" ]
Meinulf G\"ockeler, Hans A. Kastrup, Thomas Neuhaus, Frank Zimmermann
hep-lat/9206024
The Four-Fermi Model in Three Dimensions at Non-Zero Density and Temperature
The Four Fermi model with discrete chiral symmetry is studied in three dimensions at non-zero chemical potential and temperature using the Hybrid Monte Carlo algorithm. The number of fermion flavors is chosen large $(N_f=12)$ to compare with analytic results. A first order chiral symmetry restoring transition is found ...
1992-06-29
2009-10-22
[ "hep-lat" ]
Simon Hands (CERN), Aleksandar Kocic (CERN) and John Kogut (Illinois)
hep-lat/9206023
Lattice QCD Spectroscopy with an Improved Wilson Fermion Action
We study the hadronic spectrum in quenched lattice QCD using an improved Wilson fermion action (Hamber-Wu(1983),Eguchi-Kawamoto(1984)) at $\beta= 5.7$ and $\beta =6.0$. We find a systematic reduction of the finite spacing effects compared to the results obtained by using the standard Wilson action.
1992-06-27
2009-10-22
[ "hep-lat" ]
M.-P. Lombardo, G.Parisi and A. Vladikas
hep-lat/9206022
Properties of Interfaces in the two and three dimensional Ising Model
To investigate order-order interfaces, we perform multimagnetical Monte Carlo simulations of the $2D$ and $3D$ Ising model. Following Binder we extract the interfacial free energy from the infinite volume limit of the magnetic probability density. Stringent tests of the numerical methods are performed by reproducing wi...
1992-06-25
2009-10-22
[ "hep-lat" ]
B.A.Berg, U.Hansmann (SCRI,FSU) and T.Neuhaus (Uni Bielefeld)
hep-lat/9206021
Numerical Study of c>1 Matter Coupled to Quantum Gravity
We present the results of a numerical simulation aimed at understanding the nature of the `c = 1 barrier' in two dimensional quantum gravity. We study multiple Ising models living on dynamical $\phi^3$ graphs and analyse the behaviour of moments of the graph loop distribution. We notice a universality at work as the av...
1992-06-24
2009-10-22
[ "hep-lat", "hep-th" ]
Simon M. Catterall, John B. Kogut, and Ray L. Renken
hep-lat/9206020
Low temperature expansion for the 3-d Ising Model
We compute the weak coupling expansion for the energy of the three dimensional Ising model through 48 excited bonds. We also compute the magnetization through 40 excited bonds. This was achieved via a recursive enumeration of states of fixed energy on a set of finite lattices. We use a linear combination of lattices wi...
1992-06-24
2009-10-22
[ "hep-lat" ]
Gyan Bhanot, Michael Creutz, and Jan Lacki
hep-lat/9206019
London relation and fluxoid quantization for monopole currents in U(1) lattice gauge theory
We explore the analogy between quark confinement and the Meissner effect in superconductors. We measure the response of color-magnetic "supercurrents" from Dirac magnetic monopoles to the presence of a static quark-antiquark pair in four dimensional U(1) lattice gauge theory. Our results indicate that in the confined p...
1992-06-23
2009-10-22
[ "hep-lat" ]
Vandana Singh, Richard W. Haymaker and Dana A. Browne
hep-lat/9206017
Tunneling and the Spectrum of the Potts Model
The three-dimensional, three-state Potts model is studied as a paradigm for high temperature quantum chromodynamics. In a high statistics numerical simulation using a Swendson-Wang algorithm, we study cubic lattices of dimension as large as $64^3$ and measure correlation functions on long lattices of dimension $20^2\ti...
1992-06-22
2008-11-26
[ "hep-lat" ]
Jing-Dong Wang and Carleton DeTar
hep-lat/9206018
Spectroscopy, Scaling and Critical Indices in Strongly Coupled Quenched QED
The interplay of spectroscopy, scaling laws and critical indices is studied in strongly coupled quenched QED. Interpreted as a model of technicolor having strong interactions at short distances, we predict the techni-meson mass spectrum in a simplified model of a dynamically generated top quark mass $M_f$. Our results ...
1992-06-22
2009-10-22
[ "hep-lat", "hep-ph" ]
A.Kocic, J.B. Kogut, M.-P. Lombardo and K.C. Wang
hep-lat/9206016
Numerical study of Yang-Mills classical solutions on the twisted torus
We use the lattice cooling method to investigate the structure of some gauge fixed SU(2) Yang-Mills classical solutions of the euclidean equations of motion which are defined in the 3-torus with symmetric twisted boundary conditions.
1992-06-17
2009-10-22
[ "hep-lat" ]
M. Garcia Perez and A. Gonzalez-Arroyo
hep-lat/9206013
A Method for Simulating Chiral Fermions on the Lattice
A method for simulating chiral gauge theories on the lattice is proposed, involving zeromodes on a topological defect. Lattice doublers may be decoupled in a gauge invariant manner, and flavor anomalies can be directly observed on a finite lattice. (Requires harvmac)
1992-06-11
2011-07-19
[ "hep-lat", "hep-ph" ]
D.B. Kaplan
hep-lat/9206015
The XY Model Coupled to Two-Dimensional Quantum Gravity
We perform Monte Carlo simulations using the Wolff cluster algorithm of the XY model on both fixed and dynamical phi-cubed graphs (i.e. without and with coupling to two-dimensional quantum gravity). We compare the numerical results with the theoretical expectation that the phase transition remains of KT type when the X...
1992-06-11
2009-10-22
[ "hep-lat" ]
C.F. Baillie and D.A. Johnston
hep-lat/9206014
Chiral Fermions and Anomalies on a Finite Lattice
A recent proposal by Kaplan for a chiral gauge theory on the lattice is tested with background gauge fields. The spectrum of the finite lattice Hamiltonian is calculated and the existence of a chiral fermion is demonstrated. Lattice doublers are found to decouple. The flavor anomalies, which are in agreement with the c...
1992-06-10
2009-10-22
[ "hep-lat", "hep-ph" ]
Karl Jansen
hep-lat/9206012
An Effective Model for Crumpling in Two Dimensions?
We investigate the crumpling transition for a dynamically triangulated random surface embedded in two dimensions using an effective model in which the disordering effect of the $X$ variables on the correlations of the normals is replaced by a long-range ``antiferromagnetic'' term. We compare the results from a Monte Ca...
1992-06-08
2009-10-22
[ "hep-lat" ]
C.F. Baillie and D.A. Johnston
hep-lat/9206007
Virtual Bond Percolation for Ising Cluster Dynamics
The Fortuin-Kasteleyn mapping between the Ising model and the site-bond correlated percolation model is shown to be only one of an infinite class of exact mappings. These new cluster representations are a result of "renormalized" percolation rules correlated to entire blocks of spins. For example these rules allow for ...
1992-06-04
2009-10-22
[ "hep-lat" ]
R. Brower and P. Tamayo
hep-lat/9206009
Hopping Parameter Expansion for Heavy-Light Systems
We present a technique which permits the calculation of two-point functions of operators containing one heavy quark and an arbitrary number of light quarks as analytic functions of the heavy-quark mass. It is based on the standard Jacobi linear solver used for the calculation of quark propagators. Results for the heavy...
1992-06-04
2010-11-01
[ "hep-lat" ]
D.S. Henty and R.D. Kenway
hep-lat/9206010
Absence of Chiral Fermions in the Eichten--Preskill Model
The model proposed by Eichten and Preskill for obtaining theories with chiral fermions from the lattice is shown to undergo spontaneous symmetry breaking. In addition, the fermions appear to be Dirac-like everywhere in the phase diagram with no room for undoubled Weyl fermions. The phase diagram of a closely related Hi...
1992-06-04
2009-10-22
[ "hep-lat" ]
Maarten Golterman, Don Petcher and Elena Rivas
hep-lat/9206011
More about orbitally excited hadrons from lattice QCD
This is a second paper describing the calculation of spectroscopy for orbitally excited states from lattice simulations of Quantum Chromodynamics. New features include higher statistics for P-wave systems and first results for the spectroscopy of D-wave mesons and baryons, for relatively heavy quark masses. We paramete...
1992-06-04
2009-10-22
[ "hep-lat" ]
T. A. DeGrand and M. W. Hecht
hep-lat/9206008
Fermion-Higgs model with Reduced Staggered Fermions
We introduce a lattice fermion-Higgs model with one component `reduced staggered' fermions. In order to use the fermion field as efficiently as possible we couple the two {\em staggered} flavors to the O(4) Higgs field leading to a model with only one SU(2) doublet in the scaling region. The number of fermions is doubl...
1992-06-03
2009-10-22
[ "hep-lat" ]
Wolfgang Bock, Jan Smit and Jeroen C. Vink
hep-lat/9206004
Resonance Scattering Phase Shifts in a 2-d Lattice Model
We study a simple 2-d model representing two fields with different mass and a 3-point coupling term. The phase shift in the resonating 2-particle channel is determined from the energy spectrum obtained in Monte Carlo simulations on finite lattices. Masses and wave function renormalization constants of the fields as wel...
1992-06-03
2009-10-22
[ "hep-lat" ]
C.R. Gattringer and C.B. Lang
hep-lat/9206003
Finite size effects and scaling in lattice CP(N-1)
We present model predictions for the spectrum of $CP^{N-1}$ in a periodic box and use them to interpret the strong finite size effects observed in lattice simulations at medium values of $N$. The asymptotic scaling behaviour of alternative lattice actions is discussed along with some aspects of multigrid algorithm effi...
1992-06-03
2008-11-26
[ "hep-lat" ]
A.C. Irving and C. Michael
hep-lat/9206005
Massless Decoupled Doublers: Chiral Yukawa Models and Chiral Gauge Theories
We present a new method for regularizing chiral theories on the lattice. The arbitrariness in the regularization is used in order to decouple massless replica fermions. A continuum limit with only one fermion is obtained in perturbation theory and a Golterman-Petcher like symmetry related to the decoupling of the repli...
1992-06-03
2009-10-22
[ "hep-lat" ]
J.L. Alonso, Ph. Boucaud, J.L. Cortes, F. Lesmes, E. Rivas
hep-lat/9206006
Gauge Fixing on the Lattice without Ambiguity
A new gauge fixing condition is discussed, which is (lattice) rotation invariant, has the `smoothness' properties of the Landau gauge but can be efficiently computed and is unambiguous for almost all lattice gauge field configurations.
1992-06-03
2011-07-19
[ "hep-lat" ]
Jeroen C. Vink and Uwe-Jens Wiese
hep-lat/9206001
Lattice QCD with 8 Light Quark Flavors
QCD with eight flavors is studied on $16^3\times N_t$ lattices with $N_t=4$, 6, 8, 16 and 32, a dynamical quark mass $ma=0.015$ and lattice coupling $\beta=6/g^2$ between 4.5 and 5.0. For $N_t=16$ and 32, hadron masses and screening lengths are computed for a variety of valence quark masses. The previously observed, st...
1992-06-02
2016-08-31
[ "hep-lat" ]
Frank R. Brown, Hong Chen, Norman H. Christ, Zhihua Dong, Robert D. Mawhinney, Wendy Schaffer, and Alessandro Vaccarino
hep-lat/9206002
Exact Solution of Induced Lattice Gauge Theory at Large $N$
We find the exact solution of a recently proposed model of the lattice gauge theory induced by heavy scalar field in adjoint representation at $ N= \infty $ for arbitrary dimension $D$. The nonlinear integral equation for the gauge invariant density of eigenvalues of the vacuum average of the scalar field is derived. I...
1992-06-02
2009-10-22
[ "hep-lat", "hep-th" ]
A.A. Migdal
hep-lat/9205030
Renormalization group and triviality in noncompact lattice QED with light fermions
In the framework of noncompact lattice QED with light fermions, we derive the functional dependence of the average energy per plaquette on the bare parameters using block-spin Renormalization Group arguments and assuming that the renormalized coupling vanishes. Our numerical results for this quantity in $8^4$ and $10^4...
1992-06-01
2015-06-25
[ "hep-lat" ]
V. Azcoiti, G. Di Carlo and A.F. Grillo
hep-lat/9205029
Three Dimensional Quantum Gravity Coupled to Ising Matter
We establish the phase diagram of three--dimensional quantum gravity coupled to Ising matter. We find that in the negative curvature phase of the quantum gravity there is no disordered phase for ferromagnetic Ising matter because the coordination number of the sites diverges. In the positive curvature phase of the quan...
1992-06-01
2009-10-22
[ "hep-lat", "hep-th" ]
R.L. Renken, S.M. Catterall, and J.B. Kogut
hep-lat/9205028
Numerical Investigation of the Interface Tension in the three-dimensional Ising Model
The interface tension in the three-dimensional Ising model in the low temperature phase is investigated by means of the Monte Carlo method. Together with other physically relevant quantities it is obtained from a calculation of time-slice correlation functions in a cylindrical geometry. The results at three different v...
1992-05-29
2010-12-23
[ "hep-lat" ]
Sabine Klessinger and Gernot Muenster
hep-lat/9205027
High-Temperature series for the $RP^{n-1}$ lattice spin model (generalized Maier-Saupe model of nematic liquid crystals) in two space dimensions and with general spin dimensionality n
High temperature series expansions of the spin-spin correlation functions of the RP^{n-1} spin model on the square lattice are computed through order beta^{8} for general spin dimensionality n. Tables are reported for the expansion coefficients of the energy per site, the susceptibility and the second correlation momen...
1992-05-27
2009-10-22
[ "hep-lat", "cond-mat" ]
P. Butera and M. Comi
hep-lat/9205026
Central Charge of the Parallelogram Lattice Strong Coupling Schwinger Model
We put forth a Fierzed hopping expansion for strong coupling Wilson fermions. As an application, we show that the strong coupling Schwinger model on parallelogram lattices with nonbacktracking Wilson fermions span, as a function of the lattice skewness angle, the $\Delta = -1$ critical line of $6$-vertex models. This F...
1992-05-27
2009-10-22
[ "hep-lat", "cond-mat", "hep-th" ]
Ken Yee
hep-lat/9205025
Regularizations, Anomalies and Fermion Number Non-Conservation in Chiral Gauge Theories
We study how fermion number conservation fails in fermion number preserving regularization schemes. We show that the fermion number have to be carried by the gauge field configurations with non-zero winding number in this scheme and this fermion number is not conserved in the presence of instantons. We also consider ot...
1992-05-27
2015-06-25
[ "hep-lat", "hep-th" ]
Sinya Aoki
hep-lat/9205024
Grand Canonical Partition Function of a 2-dimensional Hubbard Model
We present a new technique for a numerical analysis of the phase structure of the 2D Hubbard model as a function of the hole chemical potential. The grand canonical partition function for the model is obtained via Monte Carlo simulations. The dependence of the hole occupation number on the chemical potential and the te...
1992-05-26
2009-10-22
[ "hep-lat" ]
I.M. Barbour and E.G. Klepfish
hep-lat/9205022
Parity breaking at high temperature and density
We investigate the question of parity breaking in three-dimensional Euclidean SU(2) gauge-Higgs theory by Monte Carlo simulations. We observe no sign of spontaneous parity breaking in the behaviour of both local and non-local gauge invariant operators. However, the presence of parity odd terms in the action can induce ...
1992-05-26
2009-10-22
[ "hep-lat" ]
J. Ambj{\o}rn, K. Farakos and M. E. Shaposhnikov
hep-lat/9205023
Mirror fermions in chiral gauge theories
Mirror fermions appear naturally in lattice formulations of the standard model. The phenomenological limits on their existence and discovery limits at future colliders are discussed. After an introduction of lattice actions for chiral Yukawa-models, a recent numerical simulation is presented. In particular, the emergin...
1992-05-26
2009-10-22
[ "hep-lat" ]
Istvan Montvay
hep-lat/9205021
3d quantum gravity coupled to matter
We investigate the phase structure of three-dimensional quantum gravity coupled to an Ising spin system by means of numerical simulations. The quantum gravity part is modelled by the summation over random simplicial manifolds, and the Ising spins are located in the center of the tetrahedra, which constitute the buildin...
1992-05-26
2009-10-22
[ "hep-lat", "hep-th" ]
J. Ambjorn, Z. Burda, J. Jurkiewicz, C.F. Kristjansen
hep-lat/9205020
Quenched Chiral Logarithms
I develop a diagrammatic method for calculating chiral logarithms in the quenched approximation. While not rigorous, the method is based on physically reasonable assumptions, which can be tested by numerical simulations. The main results are that, at leading order in the chiral expansion, (a) there are no chiral logari...
1992-05-25
2009-10-22
[ "hep-lat", "hep-ph" ]
Stephen Sharpe
hep-lat/9205019
Critical mass in nonzero temperature QCD with staggered fermions
The behaviour of the chiral condensate in QCD is investigated by means of a study of the distribution of the zeros of the partition function in the complex quark mass plane. Simulations are performed at fixed temperature on three different spatial volumes at $\beta=5.04$ and at $\beta=4.9$ and $\beta=5.2$ on a $4^4$ la...
1992-05-23
2009-10-22
[ "hep-lat" ]
I.M. Barbour, A. J. Bell and E.G. Klepfish
hep-lat/9205018
Simulated Tempering: A New Monte Carlo Scheme
We propose a new global optimization method ({\em Simulated Tempering}) for simulating effectively a system with a rough free energy landscape (i.e. many coexisting states) at finite non-zero temperature. This method is related to simulated annealing, but here the temperature becomes a dynamic variable, and the system ...
1992-05-22
2010-12-17
[ "hep-lat", "cond-mat", "hep-ph", "hep-th" ]
Enzo Marinari and Giorgio Parisi
hep-lat/9205017
The Quantized $O(1,2)/O(2)\times Z_2$ Sigma Model Has No Continuum Limit in Four Dimensions. II. Lattice Simulation
A lattice formulation of the $O(1,2)/O(2)\times Z_2$ sigma model is developed, based on the continuum theory presented in the preceding paper. Special attention is given to choosing a lattice action (the ``geodesic'' action) that is appropriate for fields having noncompact curved configuration spaces. A consistent cont...
1992-05-22
2009-10-09
[ "hep-lat" ]
Jorge de Lyra, Bryce DeWitt, See Kit Foong, Timothy Gallivan, Rob Harrington, Arie Kapulkin, Eric Myers and Joeseph Polchinski
hep-lat/9205015
Chiral Limit of Nucleon Lattice Electromagnetic Form Factors
We calculate electric and magnetic form factors of protons and neutrons in quenched Monte Carlo lattice QCD on a $16^3\times 24$ lattice at $\beta = 6.0$ using Wilson fermions. We employ a method which characterizes one of the nucleon fields as a fixed zero-momentum secondary source. Extrapolating the overall data set ...
1992-05-21
2008-11-26
[ "hep-lat" ]
Walter Wilcox, Terrence Draper and Keh-Fei Liu
hep-lat/9205014
The Quantized $O(1,2)/O(2)\times Z_2$ Sigma Model Has No Continuum Limit in Four Dimensions. I. Theoretical Framework
The nonlinear sigma model for which the field takes its values in the coset space $O(1,2)/O(2)\times Z_2$ is similar to quantum gravity in being perturbatively nonrenormalizable and having a noncompact curved configuration space. It is therefore a good model for testing nonperturbative methods that may be useful in qua...
1992-05-21
2009-10-09
[ "hep-lat", "hep-th" ]
Jorge de Lyra, Bryce DeWitt, See Kit Foong, Timothy Gallivan, Rob Harrington, Arie Kapulkin, Eric Myers and Joseph Polchinski
hep-lat/9205016
Quenched Hadrons using Wilson and O(a)-Improved Fermion Actions at beta=6.2
We present the first study of the light hadron spectrum and decay constants for quenched QCD using an O(a)-improved nearest-neighbour Wilson fermion action at \beta=6.2. We compare the results with those obtained using the standard Wilson fermion action, on the same set of 18 gauge field configurations of a 24^3 times ...
1992-05-21
2011-02-19
[ "hep-lat" ]
The UKQCD Collaboration: C.R. Allton, H. Duong, C.T. Sachrajda, R.M. Baxter, S.P. Booth, K.C. Bowler, S. Collins, D.S. Henty, R.D. Kenway, C. McNeile, B.J. Pendleton, D.G. Richards, J.N. Simone, A.D. Simpson, B.E. Wilkes, A. Hulsebos, A.C. Irving, A. McKerrell, C. Michael, M. Prisznyak, P.W. Stephenson, G. Mart...
hep-lat/9205013
Effective Field Theories
Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low ultraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight fro...
1992-05-19
2015-06-25
[ "hep-lat", "hep-th" ]
G.Mack, T.Kalkreuter, G.Palma, and M.Speh
hep-lat/9205011
Tunneling and Energy Splitting in Ising Models
The energy splitting $E_{0a}$ in two and four dimensional Ising models is measured in a cylindrical geometry on finite lattices. By comparing to exact results in the two dimensional Ising model we demonstrate that $E_{0a}$ can be extracted very reliably from Monte Carlo calculations in practice. In four dimensions we c...
1992-05-18
2009-10-22
[ "hep-lat" ]
Karl Jansen and Yue Shen
hep-lat/9205012
Reflection positive formulation of chiral gauge theories on a lattice
Gauge invariant chiral theories satisfying the reflection positivity is constructed on a lattice. This requires the introduction of "half gauge fields" defined some time ago by Brydges, Fr\"{o}hlich, and Seiler \cite{BFS}. A two-dimensional model is considered in some detail.
1992-05-18
2009-10-22
[ "hep-lat" ]
Sergei V. Zenkin
hep-lat/9205010
The Running Coupling from Lattice Gauge Theory
From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of $R$-values and hence estimate the scale $\Lambda_{\msbar} $. Detailed results are presented for $SU(2)$ pure gauge theory to illustrate the method.
1992-05-14
2008-11-26
[ "hep-lat" ]
Chris Michael (University of Liverpool, Liverpool, UK)
hep-lat/9205009
Ising Model Coupled to Three-Dimensional Quantum Gravity
We have performed Monte Carlo simulations of the Ising model coupled to three-dimensional quantum gravity based on a summation over dynamical triangulations. These were done both in the microcanonical ensemble, with the number of points in the triangulation and the number of Ising spins fixed, and in the grand canoncal...
1992-05-09
2009-10-22
[ "hep-lat" ]
C.F. Baillie
hep-lat/9205008
Dynamics of Langevin Simulation
This chapter [of a supplement to Prog. Theo. Phys.] reviews numerical simulations of quantum field theories based on stochastic quantization and the Langevin equation. The topics discussed include renormalization of finite step-size algorithms, Fourier acceleration, and the relation of the Langevin equation to hybrid s...
1992-05-08
2008-11-26
[ "hep-lat" ]
A.S. Kronfeld
hep-lat/9205006
Rigorous QCD Predictions for Decays of P-Wave Quarkonia
Rigorous QCD predictions for decay rates of the P-wave states of heavy quarkonia are presented. They are based on a new factorization theorem which is valid to leading order in the heavy quark velocity and to all orders in the running coupling constant of QCD. The decay rates for all four P states into light hadronic o...
1992-05-07
2010-11-01
[ "hep-lat", "hep-ph" ]
Geoffrey T. Bodwin, Eric Braaten, G. Peter Lepage
hep-lat/9205007
Improved Nonrelativistic QCD for Heavy Quark Physics
We construct an improved version of nonrelativistic QCD for use in lattice simulations of heavy quark physics, with the goal of reducing systematic errors from all sources to below 10\%. We develop power counting rules to assess the importance of the various operators in the action and compute all leading order correct...
1992-05-07
2010-11-01
[ "hep-lat" ]
G. P. Lepage, L. Magnea, C. Nakhleh, U. Magnea, K. Hornbostel
hep-lat/9205005
Wolff-Type Embedding Algorithms for General Nonlinear $\sigma$-Models
We study a class of Monte Carlo algorithms for the nonlinear $\sigma$-model, based on a Wolff-type embedding of Ising spins into the target manifold $M$. We argue heuristically that, at least for an asymptotically free model, such an algorithm can have dynamic critical exponent $z \ll 2$ only if the embedding is based ...
1992-05-04
2009-10-22
[ "hep-lat" ]
Sergio Caracciolo, Robert G. Edwards, Andrea Pelissetto, Alan D. Sokal
hep-lat/9205004
Spontaneous symmetry breaking on the lattice generated by Yukawa interaction
We study by numerical simulation a lattice Yukawa model with naive fermions at intermediate values of the Yukawa coupling $y$ when the nearest neighbour coupling $\kp$ of the scalar field $\Phi$ is very weakly ferromagnetic ($\kp \approx 0$) or even antiferromagnetic ($\kappa < 0$) and the nonvanishing value of $\vev$ ...
1992-05-03
2009-10-22
[ "hep-lat" ]
Wolfgang Bock, Asit K. De, Christoph Frick, Jiri Jers\'ak and Thomas Trappenberg
hep-lat/9205002
Chiral Invariance and Species Doublers in Generic Fermion Models on the Lattice
Discussions are made on the structures of chirally invariant lattice actions without any restriction of hermiticity. With the help of the Ward-Takahashi identity a general conclusion can be derived that there must be species doublers in any chirally invariant model provided that the model is chosen as well-regularized,...
1992-05-01
2015-06-25
[ "hep-lat" ]
Koichi Funakubo and Taro Kashiwa
hep-lat/9205003
Non--perturbative bounds on the Higgs mass in the minimal standard model
This is a slightly extended version of the talk delivered at the Topical Workshop ``Non perturbative aspects of chiral gauge theories'', Accademia Nazionale dei Lincei, Roma, 9-11 March, 1992. Abstract: The Higgs mass in the minimal standard model is bounded by triviality and vacuum stability in the range 50--100 $GeV$...
1992-05-01
2009-10-22
[ "hep-lat" ]
Herbert Neuberger
hep-lat/9205001
Scaling topological charge in the CP^3 spin model
The CP^3 spin model is simulated at large correlation lengths in two dimensions. An overrelaxation algorithm is employed which yields reduced critical slowing down with dynamical exponents z around unity. We compare our results with recent multigrid data on the massgap m and the spin susceptibility and confirm the abse...
1992-05-01
2009-10-22
[ "hep-lat" ]
Ulli Wolff (CERN)
hep-lat/9204016
Acceptance Rates in Multigrid Monte Carlo
An approximation formula is derived for acceptance rates of nonlocal Metropolis updates in simulations of lattice field theories. The predictions of the formula agree quite well with Monte Carlo simulations of 2-dimensional Sine Gordon, XY and phi**4 models. The results are consistent with the following rule: For a cri...
1992-04-30
2009-12-30
[ "hep-lat" ]
M.Grabenstein and K.Pinn
hep-lat/9204017
Decoupling a Fermion Whose Mass Comes from a Yukawa Coupling: Nonperturbative Considerations
Perturbative analyses seem to suggest that fermions whose mass comes solely from a Yukawa coupling to a scalar field can be made arbitrarily heavy, while the scalar remains light. The effects of the fermion can be summarized by a local effective Lagrangian for the light degrees of freedom. Using weak coupling and large...
1992-04-29
2011-04-20
[ "hep-lat", "hep-ph" ]
T. Banks, A. Dabholkar
hep-lat/9204015
Blockspin Cluster Algorithms for Quantum Spin Systems
Cluster algorithms are developed for simulating quantum spin systems like the one- and two-dimensional Heisenberg ferro- and anti-ferromagnets. The corresponding two- and three-dimensional classical spin models with four-spin couplings are maped to blockspin models with two-blockspin interactions. Clusters of blockspin...
1992-04-28
2019-06-05
[ "hep-lat" ]
U.-J. Wiese and H.-P. Ying
hep-lat/9204014
Multigrid Methods in Lattice Field Computations
The multigrid methodology is reviewed. By integrating numerical processes at all scales of a problem, it seeks to perform various computational tasks at a cost that rises as slowly as possible as a function of $n$, the number of degrees of freedom in the problem. Current and potential benefits for lattice field computa...
1992-04-27
2009-10-22
[ "hep-lat" ]
Achi Brandt
hep-lat/9204013
The Free Energy of Spherical Bubbles in Lattice SU(3) Gauge Theory
We study the coefficients of the expansion $F(R) = 1/3 c_3 R^3 + 1/2 c_2 R^2 + c_1 R$ of the free energy of spherical bubbles at $T=T_c$ in pure glue QCD using lattice Monte Carlo techniques. The coefficient $c_3$ vanishes at $T=T_c$ and our results suggest that the sign and the order of magnitude of $c_1$ is in agreem...
1992-04-23
2009-10-22
[ "hep-lat" ]
K. Kajantie, Leo Karkkainen, K. Rummukainen
hep-lat/9204011
Phenomenology with Wilson fermions using smeared sources
We investigate the use of two types of non-local (``smeared'') sources for quark propagators in quenched lattice QCD at $\beta=6.0$ using Wilson fermions at $\kappa=0.154$ and $0.155$. We present results for the hadron mass spectrum, meson decay constants, quark masses, the chiral condensate and the quark distribution ...
1992-04-22
2014-11-17
[ "hep-lat" ]
D. Daniel, R. Gupta, G. Kilcup, A. Patel and S. Sharpe
hep-lat/9204010
Influence of the Measure on Simplicial Quantum Gravity in Four Dimensions
We investigate the influence of the measure in the path integral for Euclidean quantum gravity in four dimensions within the Regge calculus. The action is bounded without additional terms by fixing the average lattice spacing. We set the length scale by a parameter $\beta$ and consider a scale invariant and a uniform m...
1992-04-22
2016-08-31
[ "hep-lat" ]
W. Beirl, E. Gerstenmayer, H. Markum
hep-lat/9204012
Scalar and axial matrix elements of the nucleon: sea quark content
Sea quark contributions to the scalar density and the axial current matrix elements of the nucleon are studied in lattice qcd with two flavours of dynamical wilson fermions. the results are compared to trends in heavy quark mass expansions, and contrasted with the numbers obtained using dynamical staggered fermions.
1992-04-22
2010-11-01
[ "hep-lat" ]
Apoorva Patel
hep-lat/9204008
Hadron Spectrum in QCD with Valence Wilson Fermions and Dynamical Staggered Fermions at $6/g^2=5.6
We present an analysis of hadronic spectroscopy for Wilson valence quarks with dynamical staggered fermions at lattice coupling $6/g^2 = \beta=5.6$ at sea quark mass $am_q=0.01$ and 0.025, and of Wilson valence quarks in quenched approximation at $\beta=5.85$ and 5.95, both on $16^3 \times 32$ lattices. We make compari...
1992-04-21
2009-10-22
[ "hep-lat" ]
K.M. Bitar, T.A. DeGrand, R.G. Edwards, S. Gottlieb, U.M. Heller, A.D. Kennedy, J.B. Kogut, A. Krasnitz, W. Liu, M.C. Ogilvie, R.L. Renken, P. Rossi, D.K. Sinclair, R.L. Sugar, D. Toussaint, K.C. Wang
hep-lat/9204009
Spectrum of Relativistic Fermions in a 2d Doped Lattice
Motivated by some previous work on fermions on random lattices and by suggestions that impurities could trigger parity breaking in 2d crystals, we have analyzed the spectrum of the Dirac equation on a two dimensional square lattice where sites have been removed randomly --- a doped lattice. We have found that the syste...
1992-04-21
2009-10-22
[ "hep-lat" ]
D. Espriu and J. Matias
hep-lat/9204007
Chiral Perturbation Theory for the Quenched Approximation of QCD
[This version is a minor revision of a previously submitted preprint. Only references have been changed.] We describe a technique for constructing the effective chiral theory for quenched QCD. The effective theory which results is a lagrangian one, with a graded symmetry group which mixes Goldstone bosons and fermions,...
1992-04-17
2009-10-22
[ "hep-lat" ]
Claude Bernard and Maarten Golterman
hep-lat/9204005
Microcanonical cluster algorithms
I propose a numerical simulation algorithm for statistical systems which combines a microcanonical transfer of energy with global changes in clusters of spins. The advantages of the cluster approach near a critical point augment the speed increases associated with multi-spin coding in the microcanonical approach. The m...
1992-04-16
2009-10-22
[ "hep-lat" ]
Michael Creutz
hep-lat/9204006
Point-Split Lattice Operators for B Decays
The matrix element which determines the B meson decay constant can be measured on the lattice using an effective field theory for heavy quarks. Various discretizations of the heavy-light bilinears which appear in this and other B decay matrix elements are possible. The heavy-light bilinear currently used for the determ...
1992-04-16
2010-11-01
[ "hep-lat" ]
Oscar F. Hernandez and Brian R. Hill
hep-lat/9204002
A Numerical Test of KPZ Scaling: Potts Models Coupled to Two-Dimensional Quantum Gravity
We perform Monte Carlo simulations using the Wolff cluster algorithm of the q=2 (Ising), 3, 4 and q=10 Potts models on dynamical phi-cubed graphs of spherical topology with up to 5000 nodes. We find that the measured critical exponents are in reasonable agreement with those from the exact solution of the Ising model an...
1992-04-13
2015-06-25
[ "hep-lat" ]
C.F. Baillie (Colorado) and D. A. Johnston (Heriot Watt)
hep-lat/9204003
Multiple Potts Models Coupled to Two-Dimensional Quantum Gravity
We perform Monte Carlo simulations using the Wolff cluster algorithm of {\it multiple} $q=2,3,4$ state Potts models on dynamical phi-cubed graphs of spherical topology in order to investigate the $c>1$ region of two-dimensional quantum gravity. Contrary to naive expectation we find no obvious signs of pathological beha...
1992-04-13
2009-10-22
[ "hep-lat" ]
C.F. Baillie (Colorado) and D. A. Johnston (Heriot Watt)
hep-lat/9204004
Critical Behavior of Dynamically Triangulated Quantum Gravity in Four Dimensions
We performed detailed study of the phase transition region in Four Dimensional Simplicial Quantum Gravity, using the dynamical triangulation approach. The phase transition between the Gravity and Antigravity phases turned out to be asymmetrical, so that we observed the scaling laws only when the Newton constant app...
1992-04-13
2009-10-22
[ "hep-lat" ]
M.E. Agishtein, A.A. Migdal
hep-lat/9201001
Monte Carlo Simulations of Higgs-Fermion Systems
To gain understanding of the Higgs-fermion sector of the standard model, we study the one-component $Z_2$ symmetric and the four-component O(4) symmetric scalar models coupled to staggered fermions using the hybrid Monte Carlo algorithm. We map out the phase diagrams, and show that the $Z_2$ model has a tree level pert...
1992-04-08
2007-05-23
[ "hep-lat" ]
Jonas Berlin
hep-lat/9203002
Multimagnetical Simulations
We modified the recently proposed multicanonical MC algorithm for the case of a magnetic field driven order--order phase transition. We test this {\it multimagnetic} Monte Carlo algorithm for the D=2 Ising model at $\beta=0.5$ and simulate square lattices up to size $100 \times 100$. On these lattices with periodic bou...
1992-04-08
2007-05-23
[ "hep-lat" ]
U. Hansmann, B.A. Berg and T. Neuhaus
hep-lat/9112001
Vectorized Cluster Search
Contrary to conventional wisdom, the construction of clusters on a lattice can easily be vectorized, namely over each ``generation'' in a breadth first search. This applies directly to, e.g., the {\it single cluster} variant of the Swendsen-Wang algorithm. On a Cray Y-MP, total CPU time was reduced by a factor 3.5 -- 7...
1992-04-08
2007-05-23
[ "hep-lat" ]
Hans Gerd Evertz
hep-lat/9201004
How to Put a Heavier Higgs on the Lattice
The cutoff dependence of the Scalar Sector of the Minimal Standard Model can result in an increase of the existing triviality bound estimates of the Higgs mass. We present a large $N$ calculation and some preliminary N=4 results that suggest that the increase can be as large as 30%, resulting to a bound of about 850 G ...
1992-04-08
2009-10-22
[ "hep-lat" ]
U.M. Heller, M. Klomfass, H. Neuberger, and P. Vranas
hep-lat/9204001
A New Approach to Spin Glass Simulations
We present a recursive procedure to calculate the parameters of the recently introduced multicanonical ensemble and explore the approach for spin glasses. Temperature dependence of the energy, the entropy and other physical quantities are easily calculable and we report results for the zero temperature limit. Our data ...
1992-04-08
2009-01-23
[ "hep-lat" ]
Bernd A. Berg and Tarik Celik
hep-lat/9202004
Multicanonical Ensemble: A New Approach to Simulate First-order Phase Transitions
Relying on the recently proposed multicanonical algorithm, we present a numerical simulation of the first order phase transition in the 2d 10-state Potts model on lattices up to sizes $100\times100$. It is demonstrated that the new algorithm $lacks$ an exponentially fast increase of the tunneling time between metastabl...
1992-04-08
2009-10-22
[ "hep-lat" ]
B.A. Berg and T. Neuhaus
hep-lat/9107002
Spectral Density Study of the SU(3) Deconfining Phase Transition
We present spectral density reweighting techniques adapted to the analysis of a time series of data with a continuous range of allowed values. In a first application we analyze action and Polyakov line data from a Monte Carlo simulation on $L_t L^3 (L_t=2,4)$ lattices for the SU(3) deconfining phase transition. We calc...
1992-04-08
2009-10-22
[ "hep-lat" ]
Nelsons A. Alves, Bernd Al. Berg and Sergiu Sanielevici
hep-lat/9201007
On the Dynamics of Light Wilson Quarks
We describe recent results obtained as part of the High Energy Monte Carlo Grand Challenge (HEMCGC) project concerning the behaviour of lattice QCD with light dynamical Wilson quarks. We show that it is possible to reach regions of parameter space with light pions $m_\pi\ll0.2/a$, but that the equilibration time for su...
1992-04-08
2007-05-23
[ "hep-lat" ]
A.D. Kennedy and R.G. Edwards
hep-lat/9201005
QCD Hadron Spectroscopy with Staggered Dynamical Quarks at $\beta = 5.6$
We present preliminary results from the 1991 HEMCGC simulations with staggered dynamical fermions on a $16^3 \times 32$ lattice at $\beta = 5.6$ with sea quark masses $am_q = 0.025$ and 0.01. The spectroscopy was done both for staggered valence quarks with mass equal to the sea quark masses and for Wilson valence quark...
1992-04-08
2009-10-22
[ "hep-lat" ]
K.M. Bitar, R. Edwards, T.A. DeGrand, Steven Gottlieb, U.M. Heller, A.D. Kennedy, J.B. Kogut, A. Krasnitz, W. Liu, M.C. Ogilvie, R.L. Renken, D.K. Sinclair, R.L. Sugar, D. Toussaint, and K.C. Wang
hep-lat/9201002
A Study of Symmetry Restoration at Finite Temperature in the O(4) Model Using Anisotropic Lattices
Results of investigations of the O(4) spin model at finite temperature using anisotropic lattices are presented. In both the large $N$ approximation and the numerical simulations using the Wolff cluster algorithm we find that the ratio of the symmetry restoration temperature $T_{\rm SR}$ to the Higgs mass $m_{\rm H}$ i...
1992-04-08
2009-10-22
[ "hep-lat" ]
R.V. Gavai, U.M. Heller, F. Karsch, B. Plache, and T. Neuhaus
hep-lat/9202002
Random Walks and the Correlation Length Critical Exponent in Scalar Quantum Field Theory
The distance scale for a quantum field theory is the correlation length $\xi$, which diverges with exponent $\nu$ as the bare mass approaches a critical value. If $t=m^{2}-m_{c}^{2}$, then $\xi=m_{P}^{-1} \sim t^{-\nu}$ as $t \to 0$. The two-point function of a scalar field has a random walk representation. The walk ta...
1992-04-08
2007-05-23
[ "hep-lat" ]
Joe Kiskis, Rajamani Narayanan and Pavlos Vranas
hep-lat/9202001
Monte Carlo Calculation of the Surface Free Energy for the 2d 7-state Potts Model, and an Estimate for 4d SU(3) Gauge Theory
Using the recently proposed multicanonical ensemble, we perform Monte Carlo simulation for the 2d 7-state Potts model and calculate its surface free energy density (surface tension) to be $2 f^s = 0.0241 \pm 0.0010$. This is an order of magnitude smaller than other estimates in the recent literature. Relying on existin...
1992-04-08
2009-10-22
[ "hep-lat" ]
Wolfhard Janke, Bernd A. Berg, and Mohammad Katoot
hep-lat/9202003
Thermodynamics of Lattice QCD with 2 Light Dynamical (Staggered) Quark Flavours on a $16^3\times 8$ Lattice
Lattice QCD with 2 light staggered quark flavours is being simulated on a $16^3\times8$ lattice to study the transition from hadronic matter to a quark gluon plasma. We have completed runs at $m_q=0.0125$ and are extending this to $m_q=0.00625$. We also examine the addition of a non-dynamical "strange" quark. Thermodyn...
1992-04-08
2009-10-22
[ "hep-lat" ]
S. Gottlieb, U.M. Heller, A.D. Kennedy, J.B. Kogut, A. Krasnitz, W. Liu, R.L. Renken, D.K. Sinclair, R.L. Sugar, D. Toussaint and K.C. Wang
hep-lat/9203001
Is there a $\rho$ in the O(4) $\lambda \phi^4_4$ theory?
A Monte Carlo simulation of the O(4) $\lambda \phi^4$ theory in the broken phase is performed on a hypercubic lattice in search of an I=1, J=1 resonance. The region of the cutoff theory where the interaction is strong is investigated since it is there that a resonance would be expected to have a better chance to form. ...
1992-04-08
2009-10-22
[ "hep-lat", "hep-ph" ]
Khalil M. Bitar and Pavlos M. Vranas
hep-lat/9112002
Multi-Grid Monte Carlo III. Two-Dimensional O(4)-Symmetric Nonlinear $\sigma$-Model
We study the dynamic critical behavior of the multi-grid Monte Carlo (MGMC) algorithm with piecewise-constant interpolation applied to the two-dimensional O(4)-symmetric nonlinear $\sigma$-model [= SU(2) principal chiral model], on lattices up to $256 \times 256$. We find a dynamic critical exponent $z_{int,{\cal M}^2}...
1992-04-08
2009-10-22
[ "hep-lat" ]
Robert G. Edwards, Sabino Jos\'e Ferreira, Jonathan Goodman, Alan D. Sokal
hep-lat/9201006
Path Integrals and Voronin's Theorem on the Universality of the Riemann Zeta Function
We explore a new approach to the path integral for a latticized quantum theory. This talk is based on work with N. Khuri and H. Ren.
1992-04-08
2009-10-22
[ "hep-lat" ]
Khalil M. Bitar
hep-lat/9201003
Dynamic Critical Behaviour of Wolff's Algorithm for $RP^N$ $\sigma$-Models
We study the performance of a Wolff-type embedding algorithm for $RP^N$ $\sigma$-models. We find that the algorithm in which we update the embedded Ising model \`a la Swendsen-Wang has critical slowing-down as $z_\chi \approx 1$. If instead we update the Ising spins with a perfect algorithm which at every iteration pro...
1992-04-08
2011-08-05
[ "hep-lat" ]
S. Caracciolo, R.G. Edwards, A. Pelissetto, and A.D. Sokal
hep-lat/9107001
How to Put a Heavier Higgs on the Lattice
Lattice work, exploring the Higgs mass triviality bound, seems to indicate that a strongly interacting scalar sector in the minimal standard model cannot exist while low energy QCD phenomenology seems to indicate that it could. We attack this puzzle using the 1/N expansion and discover a simple criterion for selecting ...
1992-04-08
2009-10-22
[ "hep-lat" ]
U.M. Heller, H. Neuberger and P. Vranas
hep-ph/9212316
Paradoxes in Strange Quark Contributions to Hyperon Spins
Data for magnetic moments and semileptonic decays show disagreements between experimental values and theoretical predictions not easily explained by simple models for $\Lambda$ and $\Sigma$ hyperons.
1992-12-31
2007-05-23
[ "hep-ph" ]
Harry J. Lipkin
hep-ph/9212317
A Signal for Technicolor?
We propose an interpretation for the ($l\bar l\gamma \gamma ,\ M_{\gamma \gamma }=60{\rm GeV}$) events, which have recently been reported by L3 group at LEP. This may be a first signal of `Technicolor' theory.
1992-12-31
2015-06-25
[ "hep-ph" ]
Masako Bando and Nobuhiro Maekawa
hep-ph/9212318
Planck-Scale Physics and Solutions to the Strong CP Problem without Axion
We analyse the impact of quantum gravity on the possible solutions to the strong CP problem which utilize the spontaneously broken discrete symmetries, such as parity and time reversal invariance. We find that the stability of the solution under Planck scale effects provides an upper limit on the scale $\Lambda$ of rel...
1992-12-31
2010-11-01
[ "hep-ph" ]
Z.G.Berezhiani, R.N.Mohapatra and G.Senjanovic
hep-ph/9212315
Chiral Perturbation Theory for $B \rightarrow D^*$ and $B \rightarrow D$ Semileptonic Transition Matrix Elements at Zero Recoil
Heavy quark symmetry predicts the value of $B \rightarrow D$ and $B \rightarrow D^*$ transition matrix elements of the current $\bar c \gamma_\mu (1 - \gamma_5)b$, at zero recoil (where in the rest frame of the $B$ the $D$ or $D^*$ is also at rest). We use chiral perturbation theory to compute the leading corrections t...
1992-12-30
2009-09-15
[ "hep-ph" ]
L. Randall and M. B. Wise
hep-ph/9212314
On the 545 keV Line in the Spectrum of the Crab Nebula
The GRANAT group (R. Sunyaev {\it et al.\/}, Central Bureau of Astronomical Telegrams, International Astronomical Union, Circular No.~5481) recently reported the observation of a $(545 \pm 11)$ keV line in the spectrum of the Crab Nebula. It is tempting to associate this with the positron-electron annihilation line at ...
1992-12-30
2007-05-23
[ "hep-ph" ]
Myron Bander and H. R. Rubinstein
hep-ph/9212313
Dynamical CP Violation in Composite Higgs Models
The dynamical origin of the CP violation in electroweak theory is investigated in composite Higgs models. The mechanism of the spontaneous CP violation proposed in other context by Dashen is adopted to construct simple models of the dynamical CP violation. Within the models the size of the neutron electric dipole mom...
1992-12-28
2010-11-01
[ "hep-ph" ]
S.Hashimoto, T.Inagaki, T.Muta
hep-ph/9212312
Measuring the Beam Polarizations and the Luminosity at Photon-Photon Colliders
We present methods to measure the beam polarizations and the luminosity of $\gamma \gamma$ colliders at TeV energy scale. The beam polarizations of a $\gamma \gamma$ collider can easily be monitored by comparing the numbers of events of the processes $\gamma \gamma$ $\rightarrow$ $\ell^+ \ell^-$ and $\gamma \gamma$ $...
1992-12-28
2011-07-19
[ "hep-ph" ]
Y. Yasui, I. Watanabe, J. Kodaira and I. Endo
hep-ph/9212311
An Orbifold Compactification with Three Families from Twisted Sectors
We obtain a three generational $SU(3)_c\times SU(3)_w \times U(1)^4\times [SO(12)\times U(1)^2]^\prime$ model from an orbifold construction with the requirement that three generations arise from twisted sectors. There exist supersymmetric vacua realizing the standard model. In one example the anomalous $U(1)$ breaks th...
1992-12-26
2009-10-22
[ "hep-ph" ]
Hang Bae Kim and Jihn E. Kim
hep-ph/9212310
Gluon Condensates, Chiral Symmetry Breaking and Pion Wave Function
We consider here chiral symmetry breaking in quantum chromodynamics arising from gluon condensates in vacuum. Through coherent states of gluons simulating a mean field type of approximation, we show that the off-shell gluon condensates of vacuum generate a mass-like contribution for the quarks, giving rise to chiral sy...
1992-12-25
2009-10-22
[ "hep-ph" ]
A. Mishra and S.P. Misra
hep-ph/9212308
Dimensionally Regulated One-Loop Integrals
We describe methods for evaluating one-loop integrals in $4-2\e$ dimensions. We give a recursion relation that expresses the scalar $n$-point integral as a cyclicly symmetric combination of $(n-1)$-point integrals. The computation of such integrals thus reduces to the calculation of box diagrams ($n=4$). The tensor int...
1992-12-24
2008-11-26
[ "hep-ph", "hep-th" ]
Z. Bern, L. Dixon and D.A. Kosower
hep-ph/9212307
The Equivalence Theorem and Global Anomalies
In the presence of some forms of global anomalies, the equivalence theorem, which relates the interactions of longitudinal gauge bosons to those of the Goldstone bosons, is not always valid. This can occur when the Goldstone sector contains an anomaly which is canceled in the gauge currents by the effects of a differen...
1992-12-23
2009-10-22
[ "hep-ph" ]
John F. Donoghue and Jusak Tandean