arXiv subjects

Giuseppe Di Carlo

Publications and source records attributed to Giuseppe Di Carlo.

26 records · Page 2Linked to original sources

arXiv2004

Strong coupling analysis of diquark condensation

The phenomenon of diquark condensation at non-zero baryon density and zero temperature is analyzed in the strong coupling limit of lattice QCD. The results indicate that there is attraction in the quark-quark channel also at strong coupling, and that the attraction is more effective at high baryon density, but for infinite coupling it is not enough to produce diquark condensation. It is argued that the absence of diquark condensation is not a peculiarity of the strong coupling limit, but persists at sufficiently large finite couplings.

hep-lat↗

arXiv2004

New Ideas in Finite Density QCD

We introduce a new approach to analyze the phase diagram of QCD at finite chemical potential and temperature, based on the definition of a generalized QCD action. Several details of the method will be discussed, with particular emphasis on the advantages respect to the imaginary chemical potential approach.

hep-lat↗

arXiv2002

New proposal for numerical simulations of systems with a theta-vacuum term

A new approach to perform numerical simulations of systems with a theta-vacuum term is proposed, tested, and applied to CP3 The main new ingredient of this approach is the method used to compute the probability distribution function of the topological charge at theta=0. We comment also on the possibility of applying this approach to QCD at finite baryon density.

hep-lat↗

arXiv2002

New proposal for numerical simulations of theta-vacuum like systems

We propose a new approach to perform numerical simulations of theta-vacuum like systems, test it in two analytically solvable models, and apply it to CP^3. The main new ingredient in our approach is the method used to compute the probability distribution function of the topological charge at theta=0. We do not get unphysical phase transitions (flattening behavior of the free energy density) and reproduce the exact analytical results for the order parameter in the whole theta-range within a few percent.

hep-lat↗

arXiv2001

Larger physical volume with a noncompact lattice regularization of SU(N) theories

Recently it has been found that in a noncompact formulation of the SU(2) gauge theory on a lattice the physical volume is larger than in the Wilson theory with the same number of sites. In its original formulation such noncompact regularization is directly applicable to U(N) theories for any N and to SU(N) theories for N=2 only. In this work we extend it to SU(N) for any N and investigate some of its properties.

hep-lat↗

arXiv2000

Numerical study of the scaling properties of SU(2) lattice gauge theory in Palumbo non-compact regularization

In the framework of a non-compact lattice regularization of nonabelian gauge theories we look, in the SU(2) case, for the scaling window through the analysis of the ratio of two masses of hadronic states. In the two-dimensional parameter space of the theory we find the region where the ratio is constant, and equal to the one in the Wilson regularization. In the scaling region we calculate the lattice spacing, finding it at least 20% larger than in the Wilson case; therefore the simulated physical volume is larger.

hep-lat↗

arXiv1997

Frustration in Lattice Gauge Theory

We introduce a U(1) lattice gauge theory which incorporates explicit frustration in $d>2$. We show, by identifying an appropiate order parameter and through computer simulations, the existence of a frustrated region in the phase diagram of the model. We study this phase diagram and the nature of the transition lines.

hep-lat↗

arXiv1997

Continuous Chiral Transition in Strongly Coupled Compact QED with the Standard Torus Topology

We analyze the phase diagram of compact QED on the torus with a chirally symmetric four fermion interaction added to the usual Wilson action. Inside a mean field approximation for the four fermion term, a line of first order phase transitions and another one of second order are found in the $(β, G)$ plane. Approaching the second order line a continuum limit can be defined. Critical exponents vary along this line in a similar way as in the non-compact model, suggesting that a non trivial interacting continuum theory can be constructed.

hep-lat↗