A remark on the BRST symmetry in the Gribov-Zwanziger theory

We show that the soft breaking of the BRST symmetry arising in the Gribov-Zwanziger theory can be converted into a linear breaking upon introduction of a set of BRST quartets of auxiliary fields. Due to its compatibility with the Quantum Action Principle, the linearly broken BRST symmetry can be directly converted into a suitable set of useful Slavnov-Taylor identities. As a consequence, it turns out that the renormalization aspects of the Gribov-Zwanziger theory can be addressed by means of the cohomology of a nilpotent local operatorComment: 11 pages, final version to appear in Phys. Rev.

Vector supersymmetry of Chern-Simons theory at finite temperature

The existence of the vector supersymmetry is analysed within the context ofthe finite temperature Chern-Simons theory

Renormalizability of the linearly broken formulation of the BRST symmetry in presence of the Gribov horizon in Landau gauge Euclidean Yang-Mills theories

In previous work arXiv:1009.4135 we have shown that the soft breaking of the BRST symmetry arising within the Gribov-Zwanziger framework can be converted into a linear breaking, while preserving the nilpotency of the BRST operator. Due to its compatibility with the Quantum Action Principle, the linearly broken BRST symmetry directly translates into a set of Slavnov-Taylor identities. We show that these identities guarantee the multiplicative renormalizability of both Gribov-Zwanziger and Refined Gribov-Zwanziger theories to all orders. The known property that only two renormalization factors are needed is recovered. The non-renormalization theorem of the gluon-ghost-antighost vertex as well as the renormalization factor of the Gribov parameter are derived within the linearly broken formulation.Comment: 20 pages, references added, version accepted for publication in Physical Review

Phonon-like hydrogen-bond modes in protic ionic liquids

Gigahertz- to terahertz-frequency infrared and Raman spectra contain a wealth of information concerning the structure, intermolecular forces, and dynamics of ionic liquids. However, these spectra generally have a large number of contributions ranging from slow diffusional modes to underdamped librations and intramolecular vibrational modes. This makes it difficult to isolate effects such as the role of Coulombic and hydrogen-bonding interactions. We have applied far-infrared and ultrafast optical Kerr effect spectroscopies on carefully selected ions with a greater or lesser degree of symmetry in order to isolate spectral signals of interest. This has allowed us to demonstrate the presence of longitudinal and transverse optical phonon modes and a great similarity of alkylammonium-based protic ionic liquids to liquid water. The data show that such phonon modes will be present in all ionic liquids, requiring a reinterpretation of their spectra

Perturbing Topological Field Theories

The abelian Chern-Simons theory is perturbed by introducing local gauge-invariant interaction terms depending on the curvature. The computation of the correlation function of two Wilson lines for two smooth closed nonintersecting curves is reported up to four loops and is shown to be unaffected by radiative corrections. This result ensures the stability of the linking number of the two curves with respect to the local perturbations which may be added to the Chern-Simons action.Comment: 13 pages, 5 figures, corrected some typo

Two loop effective potential for < A^2_\mu > in the Landau gauge in quantum chromodynamics

We construct the effective potential for the dimension two composite operator 1/2 A^{a 2}_\mu in QCD with massless quarks in the Landau gauge for an arbitrary colour group at two loops. For SU(3) we show that an estimate for the effective gluon mass decreases as N_f increases.Comment: 17 latex page