317 research outputs found
Hybrid Monte Carlo Simulation of Graphene on the Hexagonal Lattice
We present a method for direct hybrid Monte Carlo simulation of graphene on
the hexagonal lattice. We compare the results of the simulation with exact
results for a unit hexagonal cell system, where the Hamiltonian can be solved
analytically.Comment: 5 pages, 4 figure
Gravitating Semilocal strings
We discuss the properties of semilocal strings minimally coupled to gravity.
Semilocal strings are solutions of the bosonic sector of the Standard Model in
the limit (where is the Weinberg angle) and
correspond to embedded Abelian-Higgs strings for a particular choice of the
scalar doublet. We focus on the limit where the gauge boson mass is equal to
the Higgs boson mass such that the solutions fulfill the
Bogomolnyi-Prasad-Sommerfield (BPS) bound.Comment: Contribution to the Proceedings of the Spanish Relativity Meeting
(ERE) 2009, Bilbao, Spai
A highly optimized vectorized code for Monte Carlo simulations of SU(3) lattice gauge theories
New methods are introduced for improving the performance of the vectorized Monte Carlo SU(3) lattice gauge theory algorithm using the CDC CYBER 205. Structure, algorithm and programming considerations are discussed. The performance achieved for a 16(4) lattice on a 2-pipe system may be phrased in terms of the link update time or overall MFLOPS rates. For 32-bit arithmetic, it is 36.3 microsecond/link for 8 hits per iteration (40.9 microsecond for 10 hits) or 101.5 MFLOPS
Instanton-Like Processes in Particle Collisions: a Numerical Study of the SU(2)-Higgs Theory below the Sphaleron Energy
We use semiclassical methods to calculate the probability of inducing a
change of topology via a high-energy collision in the SU(2)-Higgs theory. This
probability is determined by a complex solution to a classical boundary value
problem on a contour in the complex time plane. In the case of small particle
number it is the probability of instanton-like processes in particle
collisions. We obtain numerically configurations with the correct topological
features and expected properties in the complex time plane. Our work
demonstrates the feasibility of the numerical approach to the calculation of
instanton-like processes in gauge theories. We present our preliminary results
for the suppression factor of topology changing processes, which cover a wide
range of incoming particle numbers and energies below the sphaleron energy.Comment: 19 pages, 5 figures. To be published in proceedings of XI-th
International School "Particles and Cosmology", Baksan, Russia 200
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