Article
Astronomy & Astrophysics
A. Jakovac, P. Mati, P. Posfay
Summary: This article proposes an approach to describe spontaneous symmetry breaking without relying on the order parameter dependent free energy. Instead, a Ward ratio is used to represent the symmetry breaking, and a unified scale evolution of the effective potential is applicable in both phases.
Article
Physics, Multidisciplinary
Pedro Liendo, Junchen Rong, Haoyu Zhang
Summary: We study conformal field theories with finite group symmetries and spontaneous symmetry breaking (SSB) phases that persist at all temperatures. By coupling two λϕ4 theories through their mass terms, we investigate the cases where the cubic symmetry group or the tetrahedral symmetry group is preserved. Our one-loop calculation in the 4-ε expansion reveals the existence of infinitely many fixed points capable of hosting SSB phases at all temperatures. Analysis of the renormalization group (RG) stability matrix shows that these fixed points have at least three relevant operators, indicating that they are tetracritical points.
Article
Physics, Multidisciplinary
Yang-yang Tan, Yong-rui Chen, Wei-jie Fu
Summary: This paper investigates the real-time dynamics of the O(4) scalar theory using the Schwinger-Keldysh closed time path. The flow equations for effective action and correlation functions are derived, and an analytic expression for the four-point vertex is obtained. Spectral functions at different temperatures and momentums are calculated. Furthermore, the dynamical critical exponent for the phase transition near the critical temperature in the 3+1 dimensional O(4) scalar theory is calculated to be approximately 2.023.
Article
Astronomy & Astrophysics
R. L. P. G. Amaral, V. E. R. Lemes, O. S. Ventura, L. C. Q. Vilar
Summary: After the phase transition of a grand unified theory, the couplings of the basic interactions split from the single coupling. In the symmetric phase, the couplings associated with SU(2) and U(1) symmetries were already distinct before the electroweak breaking, as determined by the measurement of the Weinberg mixing angle. Each independent coupling should be associated with independent cocycles defined on a cohomological basis from the perspective of BRST symmetry.
Article
Astronomy & Astrophysics
Marcela Pelaez, Urko Reinosa, Julien Serreau, Matthieu Tissier, Nicolas Wschebor
Summary: By introducing an approximation scheme, we are able to incorporate the realistic running of parameters and study the unquenched gluon and ghost propagators to a first nontrivial order, allowing for a more stringent test of our approach with available lattice data. Our results for various two-point functions compare well with lattice data, while the model parameters are strongly constrained.
Article
Materials Science, Multidisciplinary
Hetian Chen, Di Yi, Ben Xu, Jing Ma, Cewen Nan
Summary: By using first-principles simulations, the properties of an edge dislocation core in SrTiO3 were explored, revealing spontaneous symmetry breaking and proposing a model to quantitatively estimate the atomic configuration of SrTiO3 under complex strain conditions.
MATERIALS TODAY PHYSICS
(2021)
Review
Multidisciplinary Sciences
Owe Philipsen
Summary: The article discusses the thermal restoration of chiral symmetry in QCD and the expected transition into a phase transition with a critical endpoint as baryon density increases. By simulating at zero and imaginary baryon chemical potential, the location of a potential non-analytic phase transition and its critical endpoint can be constrained. Studies show a possible critical point bound to μ(B) & GSIM; 3T.
Article
Astronomy & Astrophysics
Zhibin Li, Jingmin Liang, Song He, Li Li
Summary: Baryon number fluctuations can be used to explore the QCD phase diagram experimentally, and may provide insights into the critical endpoint (CEP). We used a holographic QCD model to compute higher-order baryon number susceptibilities and found that the model agrees well with experimental data, suggesting that it can be used to locate the CEP.
Article
Astronomy & Astrophysics
Christopher Jung, Jan-Hendrik Otto, Ralf-Arno Tripolt, Lorenz von Smekal
Summary: This paper explores practicable ways for self-consistent calculations of spectral functions using analytically continued functional renormalization group (aFRG) flow equations. A particularly straightforward approach proposed is to include parametrizations of self-energies based on explicit analytic one-loop expressions. The results show the importance of self-consistency at all momenta in fixing the relation between particle masses and decay thresholds, offering a sound and practicable basis for calculations in more realistic effective theories.
Review
Physics, Multidisciplinary
Wei-jie Fu
Summary: In this paper, the recent progress in the studies of QCD at finite temperature and densities using the functional renormalization group (fRG) approach is presented. The fRG approach integrates quantum, thermal, and density fluctuations successively with the evolution of the renormalization group (RG) scale, providing nonperturbative results for various aspects of QCD. The results include the QCD phase structure, the location of the critical end point (CEP), equation of state (EoS), spectral functions, critical exponents, baryon number fluctuations, and more. Recent calculations using fRG and Dyson-Schwinger equations converge to a small region for the location of the CEP at baryon chemical potentials of about 600 MeV.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2022)
Article
Physics, Nuclear
Kun Hao, Kangjie Shi
Summary: The study examines the relationship between the symmetry group of a Feynman diagram and its reduced diagrams, and proves that counterterms in the BPHZ renormalization scheme are consistent with adding counterterms to the interaction Hamiltonian in all cases, including those with symmetry factors.
Article
Astronomy & Astrophysics
S. Aoki, Y. Aoki, G. Cossu, H. Fukaya, S. Hashimoto, T. Kaneko, C. Rohrhofer, K. Suzuki
Summary: By conducting experiments within a temperature range, it was found that the axial U(1) anomaly above the critical temperature is consistent with zero within statistical errors. The quark mass dependence suggests that its disappearance rate is comparable to that of SU(2)(L) x SU(2)(R) symmetry breaking.
Article
Physics, Multidisciplinary
Bipasha Pal, Arvind Kumar Gupta
Summary: The study investigates a system composed of an exclusion process coupled with a reservoir, exploring the impact of limited resources on entities entering and exiting pathways in transport systems. The findings reveal rich behavior in the system, with reservoir crowding effects leading to symmetric and asymmetric phases. Even with very few particles in the system, spontaneous symmetry breaking phenomena can occur.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Astronomy & Astrophysics
Szabolcs Borsanyi, Zoltan Fodor, Matteo Giordano, Jana N. Guenther, Sandor D. Katz, Attila Pasztor, Chik Him Wong
Summary: In order to understand the limitations of various approximation schemes, researchers compared them to direct results at finite baryon density, using reweighting techniques without an overlap problem. They calculated the equation of state of the quark gluon plasma and covered a wide range of baryochemical potential.
Article
Physics, Multidisciplinary
Bo Huang, Jian-You Guo, Quan Liu, Shou-Wan Chen
Summary: Pseudospin symmetry (PSS) is an important concept in the study of atomic nuclei. Using the relativistic point-coupling model, this research explores the origin and breaking mechanism of PSS in real nuclei with 208Pb as an example. The presence of PSS in the single particle spectra of heavy nuclei is confirmed, and the influence of different point-coupling interactions on PSS is investigated. It is found that the four-fermion scalar and vector couplings play a dominant role in PSS.