scholarly journals Gliding Down the QCD Transition Line, from Nf = 2 till the Onset of Conformality

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1833
Author(s):  
Andrey Yu Kotov ◽  
Maria Paola Lombardo ◽  
Anton Trunin
Keyword(s):  
Coupling Strength ◽  
Critical Line ◽  
Mean Field ◽  
Universality Class ◽  
Transition Line ◽  
First Order ◽  
Conformal Window ◽  
Singular Behaviour ◽  
First Order Transition ◽  
Field Behaviour

We review the hot QCD transition with varying number of flavours, from two till the onset of the conformal window. We discuss the universality class for Nf=2, along the critical line for two massless light flavours, and a third flavour whose mass serves as an interpolator between Nf=2 and Nf=3. We identify a possible scaling window for the 3D O(4) universality class transition, and its crossover to a mean field behaviour. We follow the transition from Nf=3 to larger Nf, when it remains of first order, with an increasing coupling strength; we summarise its known properties, including possible cosmological applications as a model for a strong electroweak transition. The first order transition, and its accompanying second order endpoint, finally morphs into the essential singularity at the onset of the conformal window, following the singular behaviour predicted by the functional renormalisation group.

Phase transitions in perovskites near the tricritical point: an experimental study of KMn1–xCaxF3 and SrTiO3

2000 ◽  
Vol 64 (6) ◽  
pp. 971-982 ◽  
Author(s):  
M. C. Gallardo ◽  
F. J. Romero ◽  
S. A. Hayward ◽  
E. K. H. Salje ◽  
J. del Cerro
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Phase Transitions ◽  
Order Parameter ◽  
Tricritical Point ◽  
Mean Field ◽  
Calorimetric Data ◽  
X Ray ◽  
First Order ◽  
Field Behaviour

AbstractWe present experimental data for the Pm3m-I4/mcm phase transitions in the perovskite crystals KMn1-xCaxF3 and SrTiO3. Comparison of calorimetric data (latent heat and specific heat) with order parameter data (measured with X-ray rocking methods) indicates that these transitions follow mean-field behaviour, and may be described using Landau potentials where the free energy expansion includes terms up to Q6. This potential is characteristic of transitions close to the tricritical point. Comparison of the behaviour of SrTiO3 and KMnF3 indicates that KMnF3 is closer to the tricritical point; a small amount of substitution of Ca for Mn causes the transition to cross the tricritical point from first order to second order behaviour.

scholarly journals SUPERCONDUCTIVITY NEAR POMERANCHUK INSTABILITIES IN THE SPIN CHANNEL

2013 ◽  
Vol 27 (14) ◽  
pp. 1350102 ◽  
Author(s):  
DANIEL G. BARCI ◽  
PAULO S. A. BONFIM
Keyword(s):  
Cooper Pair ◽  
Mean Field ◽  
P Wave ◽  
Strong Coupling Regime ◽  
Coupling Constant ◽  
Field Phase ◽  
S Wave ◽  
Spin Channel ◽  
First Order ◽  
First Order Transition

We study the competition between a Pomeranchuk instability in the spin channel with angular momentum ℓ = 1 and an attractive interaction, favoring Cooper-pair formation. We found that the superconducting gap strongly suppresses the phase space for the Pomeranchuk instability. We computed a mean-field phase diagram displaying a first order transition between two superconductor phases with different symmetries: p-wave (with spontaneously generated spin-orbit interaction) and s-wave for greater values of the coupling constant. Moreover, we have looked for a possible modulated superconducting phase. We have found that this phase appears only as a metastable state in the strong coupling regime.

scholarly journals Finite temperature QCD phase transition and its scaling window from Wilson twisted mass fermions

2022 ◽  
Vol 258 ◽  
pp. 05012
Author(s):  
A.Yu. Kotov ◽  
M.P. Lombardo ◽  
A. Trunin
Keyword(s):  
Phase Transition ◽  
Finite Temperature ◽  
Chiral Limit ◽  
Mean Field ◽  
Universality Class ◽  
Chiral Phase ◽  
Scaling Properties ◽  
Twisted Mass ◽  
Finite Temperature Qcd ◽  
Field Behaviour

We study the properties of finite temperature QCD using lattice simulations with Nf = 2 + 1 + 1 Wilson twisted mass fermions for pion masses from physical up to heavy quark regime. In particular, we investigate the scaling properties of the chiral phase transition close to the chiral limit. We found compatibility with O(4) universality class for pion masses up to physical and in the temperature range [120 : 300] MeV. We also discuss other alternatives, including mean field behaviour or Z2 scaling. We provide an estimation of the critical temperature in the chiral limit, T0 = 134−4+6 MeV, which is stable against various scaling scenarios.

scholarly journals The Haus-Tanaka Model for the Ice VII-Ice VIII Phase Transition

1980 ◽  
Vol 33 (1) ◽  
pp. 107 ◽  
Author(s):  
J Ho-Ting-Hun ◽  
J Oitmaa
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Field Approximation ◽  
Order Transition ◽  
Mean Field Approximation ◽  
First Order ◽  
Second Order Transition ◽  
The Mean ◽  
First Order Transition ◽  
Temperature Susceptibility

The high temperature susceptibility series of the model proposed by Haus and Tanaka (1977) to account for the transition of the orientationally disordered ice VII phase to the orientationally ordered ice VIII phase does not provide evidence for the possible occurrence of a first-order transition, as predicted by the mean field approximation, but gives a second-order transition instead.

scholarly journals Random critical point separates brittle and ductile yielding transitions in amorphous materials

2018 ◽  
Vol 115 (26) ◽  
pp. 6656-6661 ◽  
Author(s):  
Misaki Ozawa ◽  
Ludovic Berthier ◽  
Giulio Biroli ◽  
Alberto Rosso ◽  
Gilles Tarjus
Keyword(s):  
Critical Point ◽  
Amorphous Materials ◽  
Mean Field ◽  
Universality Class ◽  
Particle Interactions ◽  
Molecular Glasses ◽  
First Order ◽  
Initial Stability ◽  
Dynamics Simulations

We combine an analytically solvable mean-field elasto-plastic model with molecular dynamics simulations of a generic glass former to demonstrate that, depending on their preparation protocol, amorphous materials can yield in two qualitatively distinct ways. We show that well-annealed systems yield in a discontinuous brittle way, as metallic and molecular glasses do. Yielding corresponds in this case to a first-order nonequilibrium phase transition. As the degree of annealing decreases, the first-order character becomes weaker and the transition terminates in a second-order critical point in the universality class of an Ising model in a random field. For even more poorly annealed systems, yielding becomes a smooth crossover, representative of the ductile rheological behavior generically observed in foams, emulsions, and colloidal glasses. Our results show that the variety of yielding behaviors found in amorphous materials does not necessarily result from the diversity of particle interactions or microscopic dynamics but is instead unified by carefully considering the role of the initial stability of the system.

FIRST-ORDER PAIRING TRANSITION AND PHASE SEPARATION IN THE ATTRACTIVE HUBBARD MODEL

2003 ◽  
Vol 17 (04n06) ◽  
pp. 590-596
Author(s):  
M. CAPONE ◽  
C. CASTELLANI ◽  
M. GRILLI
Keyword(s):  
Phase Separation ◽  
Hubbard Model ◽  
Mean Field Theory ◽  
Mean Field ◽  
First Order ◽  
Symmetric Subspace ◽  
Normal State Properties ◽  
First Order Transition ◽  
Attractive Hubbard Model ◽  
Two Phases

The normal state properties of the Hubbard model are studied by means of the Dynamical Mean-Field Theory. Even in the gauge-symmetric subspace, a first-order transition occurs between a Fermi-liquid phase and a strong-coupling bound-pairs phase, which can be thought as a "disordered" superconductor. The transition is of first order for all densities different from n = 1, and it is accompanied by a region of phase separation between the two phases at different densities.

scholarly journals The Effect of Topology on Phase Behavior under Confinement

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1220
Author(s):  
Arnout M. P. Boelens ◽  
Hamdi A. Tchelepi
Keyword(s):  
Phase Behavior ◽  
Density Functional ◽  
Capillary Condensation ◽  
Good Description ◽  
Functional Theory ◽  
Minkowski Functionals ◽  
First Order ◽  
Lennard Jones ◽  
And Topology ◽  
First Order Transition

This work studies how morphology (i.e., the shape of a structure) and topology (i.e., how different structures are connected) influence wall adsorption and capillary condensation under tight confinement. Numerical simulations based on classical density functional theory (cDFT) are run for a wide variety of geometries using both hard-sphere and Lennard-Jones fluids. These cDFT computations are compared to results obtained using the Minkowski functionals. It is found that the Minkowski functionals can provide a good description of the behavior of Lennard-Jones fluids down to small system sizes. In addition, through decomposition of the free energy, the Minkowski functionals provide a good framework to better understand what are the dominant contributions to the phase behavior of a system. Lastly, while studying the phase envelope shift as a function of the Minkowski functionals it is found that topology has a different effect depending on whether the phase transition under consideration is a continuous or a discrete (first-order) transition.

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