Publications (34)0 Total impact
-
[show abstract]
[hide abstract]
ABSTRACT: A scaling analysis is made of the order parameter describing monopole condensation at the deconfining transition of N_f=2 QCD around the chiral point. In accordance with scaling properties of the specific heat, studied in a previous paper, scaling is consistent with a first order transition. The status of dual superconductivity of the vacuum as a mechanism of color confinement is reviewed.
04/2005;
-
[show abstract]
[hide abstract]
ABSTRACT: The transition is studied by means of a disorder parameter detecting condensation of magnetic monopoles in the vacuum. The deconfining transition is found to coincide with the chiral transition and the susceptibility \rho, related to the disorder parameter, is consistent with a first order phase transition.
09/2004;
-
[show abstract]
[hide abstract]
ABSTRACT: The order and the nature of the finite-temperature phase transition of QCD with two flavors of dynamical quarks is investigated. An analysis of the critical exponent of the specific heat is performed through finite-size and finite-mass scaling of various susceptibilities. Dual superconductivity of QCD vacuum is investigated using a disorder parameter, namely the v.e.v. of a monopole creation operator. Hybrid R simulations were run at lattice spatial sizes of $12^3$, $16^3$, $20^3$ and $32^3$ and temporal size $N_t=4$, with quark masses in the range $am_q = 0.3 - 0.01$.
10/2003;
-
[show abstract]
[hide abstract]
ABSTRACT: We report on evidence from lattice simulations that confinement is produced by dual superconductivity of the vacuum in full QCD as in quenched QCD. Preliminary information is obtained on the order of the deconfining phase transition.
10/2002;
-
[show abstract]
[hide abstract]
ABSTRACT: We present evidence that in full QCD with two dynamical quarks confinement is produced by dual superconductivity of the vacuum as in the quenched theory. Preliminary information is obtained on the nature of the deconfining transition.
10/2002;
-
[show abstract]
[hide abstract]
ABSTRACT: We report on evidence that confinement is related to dual superconductivity of the vacuum in full QCD, as in quenched QCD. The vacuum is a dual superconductor in the confining phase, whilst the U(1) magnetic symmetry is realized a la Wigner in the deconfined phase.
06/2002;
-
[show abstract]
[hide abstract]
ABSTRACT: The abelian projection in SU(N) gauge theories is discussed in detail, as well as the construction of a disorder parameter to study dual superconductivity as a mechanism for color confinement. If the ideas of the large N limit are correct, a universal N-independent behavior is expected for the suitable rescaled disorder parameter as a function of lambda = g^2 N.
04/2002;
-
[show abstract]
[hide abstract]
ABSTRACT: A disorder parameter detecting dual superconductivity of the vacuum is measured across the chiral phase transition in full QCD with two flavours of dynamical staggered fermions. The observed behaviour is similar to the quenched case.
11/2001;
-
[show abstract]
[hide abstract]
ABSTRACT: We demonstrate that the disorder parameter $<\mu>$ to detect dual superconductivity in the confining phase of QCD is the v.e.v. of a magnetically charged, Dirac like, gauge invariant operator $\mu$. We also show that the abelian projection on the lattice is determined up to terms O(a^2) (a = lattice spacing).
11/2001;
-
[show abstract]
[hide abstract]
ABSTRACT: The existing evidence for dual superconductivity as mechanism of color confinement is reviewed. We also discuss what is known on the dual excitations, which produce confinement by condensation, and what are the open problems
10/2001;
-
[show abstract]
[hide abstract]
ABSTRACT: It is demonstrated that monopole condensation in the confined phase of SU(2) and SU(3) gauge theories is independent of the specific Abelian projection used to define the monopoles. Hence the dual excitations which condense in the vacuum to produce confinement must have magnetic U(1) charge in all the Abelian projections. Some physical implications of this result are discussed.
04/2001;
-
[show abstract]
[hide abstract]
ABSTRACT: We study dual superconductivity of the ground state of SU(2) gauge theory, in connection with confinement. We do that measuring on the lattice a disorder parameter describing condensation of monopoles. Confinement appears as a transition to dual superconductor, independent of the abelian projection defining monopoles. Some speculations are made on the existence of a more appropriate disorder parameter. A similar study for SU(3) is presented in a companion paper.
07/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: The dual superconductivity of the vacuum in SU(3) gauge theory is investigated by constructing a disorder parameter which signals monopole condensation in various abelian projections and by studying numerically on the lattice its behaviour at finite temperature. We find that the vacuum is a dual superconductor with respect to each U(1) of the residual gauge group after abelian projection independently of the abelian projection chosen. Like in the SU(2) case (discussed in a companion paper) a finite size scaling analysis enables us to extract the indices of the phase transition and our analysis is consistent with independent determinations. Comment: Some typos corrected, acknowledgements added; to appear on Phys. Rev. D
06/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: The Heisenberg model in 3d is studied from a dual point of view. It is shown that it can have vortex configurations, carrying a conserved charge(U(1) symmetry). Vortices condens in the disordered phase. A disorder parameter $\leftangle\mu\rightangle$ is defined dual to the magnetization $\leftangle\vec n\rightangle$, which signals condensation of vortices, i.e. spontaneous breaking of the dual U(1) symmetry. This study sheds light on the procedure known as abelian projection in non abelian gauge theories.
06/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: New evidence is discussed of monopole condensation in the vacuum of SU(2) and SU(3) gauge theories. Monopoles defined by different abelian projections do condense in the transition to the confined phase and show the same behavior. For SU(2) critical indices are determined by finite size scaling analysis and the results agree with the 3d Ising Model, as expected. Comment: LATTICE98(confinement),3 pages,4 figures
09/1998;
-
[show abstract]
[hide abstract]
ABSTRACT: The 3d Heisenberg model is studied from a dual point of view. It is shown that the disordered phase corresponds to condensation of vortices in the vacuum, and the critical indices are computed from the corresponding disorder parameter. Comment: LATTICE98(spin)
08/1998;
-
[show abstract]
[hide abstract]
ABSTRACT: A detailed discussion is given of the disorder parameter for dual superconductivity of lattice gauge theories, introduced in a previous paper, and of its relation to other approaches. New lattice data are reported. Among other results, we find that the dual superconductivity of compact U(1) is type II. Comment: 8 pages,5 postscript figures, revtex
07/1997;
-
[show abstract]
[hide abstract]
ABSTRACT: We study the behaviour of a suitably defined disorder parameter, showing for the first time monopole condenssation in the ground state of QCD. Comment: 3 pages, contribution to the Lattice '94 conference, shell archive containing uuencoded .ps file
11/1994;
-
[show abstract]
[hide abstract]
ABSTRACT: We find the explicit operatorial form of renormalon-type singularities in abelian gauge theory. Local operators of dimension six take care of the first U.V. renormalon, non local operators are needed for I.R. singularities. In the effective lagrangian constructed with these operators non local imaginary parts appearing in the usual perturbative expansion at large orders are cancelled. Comment: 17 pages + uuencoded file with 7 figures, REVTeX, IFUP-TH-31-94
06/1994;
-
[show abstract]
[hide abstract]
ABSTRACT: We explicitly construct a monopole creation operator: its vacuum expectation value is an order parameter for dual superconductivity, in that, if different from zero, it signals a spontaneous breaking of the $U(1)$ symmetry corresponding to monopole charge conservation. This operator is tested by numerical simulations in compact $U(1)$ gauge theory. Our construction provides a general recipe for detection of the condensation of any topological soliton. In particular our operator can be used to detect dual superconductivity of the QCD vacuum. Comment: 10 pages, 3 figures avalaible on request. REVTEX
03/1994;
Institutions
-
1997–2002
-
Università di Pisa
Pisa,
Tuscany,
Italy
