Finite temperature QCD with $$N_f=2+1+1$$ N f = 2 + 1 + 1 Wilson twisted mass fermions at physical pion, strange and
- PDF / 367,574 Bytes
- 5 Pages / 595.276 x 790.866 pts Page_size
- 3 Downloads / 138 Views
Regular Article - Theoretical Physics
Finite temperature QCD with N f = 2 + 1 + 1 Wilson twisted mass fermions at physical pion, strange and charm masses Andrey Yu. Kotov1,2,3,a , Maria Paola Lombardo4 , Anton M. Trunin5 1
Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow region 141700, Russia National University of Science and Technology MISIS, Leninsky Prospect 4, Moscow 119049, Russia 3 Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia 4 INFN, Sezione di Firenze, 50019 Sesto Fiorentino, FI, Italy 5 Samara National Research University, Samara 443086, Russia
2
Received: 15 April 2020 / Accepted: 2 August 2020 © Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020 Communicated by Laura Tolos
Abstract We discuss recent progress in studying Quantum Chromodynamics at finite temperature using N f = 2 +1+1 Wilson twisted mass fermions. Particular interest is in QCD symmetries and their breaking and restoration. First, we discuss the behaviour of the η meson at finite temperature, which is tightly connected to the axial and chiral symmetries. The results suggest a small decrease of the η mass in the pseudo-critical region coming close to the non-anomalous contribution and subsequent growth at large temperatures. Second, we present the first results of lattice simulations of Quantum Chromodynamics with N f = 2 + 1 + 1 twisted mass Wilson fermions at physical pion, strange and charm masses. We estimate the chiral pseudo-critical temperatures for different observables. Our preliminary results are consistent with a second order transition in the chiral limit, however other scenarios are not excluded.
1 Introduction Quantum Chromodynamics under extreme conditions has been the subject of numerous theoretical and experimental studies [1]. In the experiments on heavy ion collisions at Relativistic Heavy Ion Collider, Brookhaven and Large Hadron Collider, CERN a droplet of strongly coupled matter at large temperatures is believed to be produced, thus providing a great opportunity to study thermal QCD. One of the most famous experimental discoveries was the observation of the Quark-Gluon Plasma — a new state of matter, characterized by unbound deconfined quarks and gluons. From the theoretical side, the existing information on finite temperature QCD a e-mail:
is based on first-principle lattice supercomputer simulations, see e.g. Ref. [2] for a recent review. Properties of strongly interacting matter at nonzero temperature are tightly related to the symmetries and symmetry breaking pattern of QCD [3]. The chiral symmetry SU L (2)×SU R (2), being broken in the vacuum state of QCD, becomes effectively restored at temperature Tc ≈ 160 MeV [4–6]. Approximately at the same temperature the transition to the deconfined phase of Quark-Gluon Plasma occurs with both transitions being analytical crossovers, rather than the phase transitions [7]. The behaviour of U A (1) axial symmetry at finite temperature is
Data Loading...
