Pelissetto, Andrea and Vicari, Ettore (2013) *Relevance of the axial anomaly at the finite-temperature chiral transition in QCD.* Physical review. D, Particles, fields, gravitation, and cosmology, 88 . p. 105018. ISSN 1550-7998

## Abstract

We investigate the nature of the finite-temperature chiral transition in QCD with two light flavors, in the case of an effective suppression of the the U(1)_A symmetry breaking induced by the axial anomaly, which implies the symmetry breaking U(2)_L X U(2)_R -> U(2)_V, instead of SU(2)_L X SU(2)_R -> SU(2)_V. For this purpose, we perform a high-order field-theoretical perturbative study of the renormalization-group (RG) flow of the corresponding three-dimensional multiparameter Landau-Ginzburg-Wilson Phi4 theory with the same symmetry-breaking pattern. We confirm the existence of a stable fixed point (FP), and determine its attraction domain in the space of the bare quartic parameters. Therefore, the chiral QCD transition might be continuous also if the U(1)_A symmetry is effectively restored at Tc. However, the corresponding universality class differs from the O(4) vector universality class which would describe a continuous transition in the presence of a substantial U(1)_A symmetry breaking at Tc. We estimate the critical exponents of the U(2)_L X U(2)_R -> U(2)_V universality class by computing and analyzing their high-order perturbative expansions. These results are important to discriminate among the different scenarios for the scaling behavior of QCD with two light flavors close to the chiral transition.

Item Type: | Article |
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Additional Information: | Imported from arXiv |

Subjects: | Area02 - Scienze fisiche > FIS/02 - Fisica teorica, modelli e metodi matematici |

Divisions: | Dipartimenti (from 2013) > DIPARTIMENTO DI FISICA |

Depositing User: | dott.ssa Sandra Faita |

Date Deposited: | 09 Apr 2015 13:57 |

Last Modified: | 09 Apr 2015 13:57 |

URI: | http://eprints.adm.unipi.it/id/eprint/1775 |

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