Brandt, Bastian B. and Francis, Anthony and Meyer, Harvey B. and Philipsen, Owe and Robaina, Daniel and Wittig, Hartmut (2016) On the strength of the U (A) (1) anomaly at the chiral phase transition in N (f)=2 QCD. JOURNAL OF HIGH ENERGY PHYSICS (12): 158. ISSN 1029-8479,
Full text not available from this repository. (Request a copy)Abstract
We study the thermal transition of QCD with two degenerate light flavours by lattice simulations using O(a)-improved Wilson quarks. Temperature scans are performed at a fixed value of N (t) = (aT)(-1) = 16, where a is the lattice spacing and T the temperature, at three fixed zero-temperature pion masses between 200 MeV and 540 MeV. In this range we find that the transition is consistent with a broad crossover. As a probe of the restoration of chiral symmetry, we study the static screening spectrum. We observe a degeneracy between the transverse isovector vector and axial-vector channels starting from the transition temperature. Particularly striking is the strong reduction of the splitting between isovector scalar and pseudoscalar screening masses around the chiral phase transition by at least a factor of three compared to its value at zero temperature. In fact, the splitting is consistent with zero within our uncertainties. This disfavours a chiral phase transition in the O(4) universality class.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | MESON SCREENING MASSES; HIGH-TEMPERATURE PHASE; QUARK-GLUON PLASMA; LATTICE QCD; WILSON FERMIONS; HADRONIC SPECTRUM; O(A) IMPROVEMENT; U(1)(A) SYMMETRY; GAUGE-THEORIES; STRANGE QUARK; Global Symmetries; Lattice QCD; Phase Diagram of QCD; Spontaneous Symmetry Breaking |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 08 Apr 2019 09:21 |
| Last Modified: | 08 Apr 2019 09:21 |
| URI: | https://pred.uni-regensburg.de/id/eprint/3765 |
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