105,340 research outputs found
Spontaneous symmetry breaking and Nambu–Goldstone bosons in quantum many-body systems
No full textSpontaneous symmetry breaking is a general principle that constitutes the underlying concept of a vast number of physical phenomena ranging from ferromagnetism and superconductivity in condensed matter physics to the Higgs mechanism in the standard model of elementary particles. I focus on manifestations of spontaneously broken symmetries in systems that are not Lorentz invariant, which include both nonrelativistic systems as well as relativistic systems at nonzero density, providing a self-contained review of the properties of spontaneously broken symmetries specific to such theories. Topics covered include: (i) Introduction to the mathematics of spontaneous symmetry breaking and the Goldstone theorem. (ii) Minimization of Higgs-type potentials for higher-dimensional representations. (iii) Counting rules for Nambu–Goldstone bosons and their dispersion relations. (iv) Construction of effective Lagrangians. Specific examples in both relativistic and nonrelativistic physics are worked out in detail
Governance, Regulation, and Privatization in the Asia-Pacific Region, NBER East Asia Seminar on Economics, Volume 12
No full textMassive Nambu-Goldstone Bosons
No full textWatanabe H, Brauner T, Murayama H. Massive Nambu-Goldstone Bosons. Physical Review Letters. 2013;111(2): 21601.Nicolis and Piazza have recently pointed out the existence of Nambu-Goldstone-like excitations in relativistic systems at finite density, whose gap is exactly determined by the chemical potential and the symmetry algebra. We show that the phenomenon is much more general than anticipated and demonstrate the presence of such modes in a number of systems from (anti) ferromagnets in a magnetic field to superfluid phases of quantum chromodynamics. Furthermore, we prove a counting rule for these massive Nambu-Goldstone bosons and construct a low-energy effective Lagrangian that captures their dynamics
Taxonomic Relationships of an Endangered Japanese Salamander Hynobius hidamontanus Matsui, 1987 with H. tenuis Nambu, 1991 (Amphibia: Caudata)
No full textWe assessed the taxonomic relationships of an endangered Japanese small salamander, Hynobius hidamontanus Matsui, 1987, and its close relative H. tenuis Nambu, 1991 electrophoretically and found that they were not clearly distinguished from each other. This result, together with available morphological and ecological information, strongly indicates that H. tenuis Nambu, 1991 is a subjective junior synonym of H. hidamontanus Matsui, 1987. By this conclusion, the total distribution range of H. hidamontanus is greatly expanded, but its endangered status and the necessity of its conservation is not be changed since the habitats of this species are fragmented and not continuous. The distribution pattern of this species is interesting from the viewpoint of biogeography
Transições de fase na matéria de quarks magnetizada com repulsão vetorial
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2015.Neste trabalho investigamos as transições de fase na matéria de quarks magnetizada usando o modelo de NJL com dois sabores na presença de acoplamento vetorial repulsivo (GV). Verificamos que a contribuição vetorial produz o encolhimento da linha de transição de primeira ordem e pode favorecer o mecanismo de back-bending no regime de acoplamento forte. Este fato permite conciliar alguns resultados da rede com as previsões teóricas sobre a existência de um ponto crítico no diagrama de fases da QCD. Analisamos como a ação de um campo magnético (B) intenso na matéria de quarks tende a fortalecer a região de primeira ordem e que também determina um padrão oscilatório na densidade. Concluímos que os efeitos opostos do acoplamento vetorial e do campo magnético na restauração da simetria quiral levam a um desdobramento de múltiplas fases magnetizadas. A ação combinada de B e GV pode originar linhas de coexistência no diagrama de fases que apresentam um comportamento exótico similar ao observado para a transição sólido-líquido da água. Mostramos como a influência da repulsão vetorial deve estabilizar fases magnéticas de densidade intermediária e que certas combinações dos parâmetros B e GV determinam pontos triplos no diagrama de fases. Exploramos as propriedades magnéticas anisotrópicas sobre os quarks e como a contribuição vetorial deve afetar a magnetização induzida determinando um comportamento diamagnético para o sistema.Abstract : In this work we investigate the phase diagram of dense magnetizedquark matter in the framework of the two-flavor Nambu-Jona-Lasiniomodel when a repulsive vector coupling (GV ) is present. We verifythat the vector contribution could shrink the first order transition lineand can support the back-bending mechanism under a strong couplingregime. This result allows one to conciliate some lattice results withtheoretical predictions about the existence of a critical point in theQCD phase diagram. Our analysis shows how an intense magnetic field(B) acts in the quark matter, strengthening the coexistence region inthe phase diagram and setting an oscillatory pattern in density values.The opposite effect of the vector coupling and magnetic field in thechiral symmetry restoration leads to a splitting of multiple magneticphases. The combined action of B and GV gives rise to coexistencelines which can render an exotic behavior resembling the solid-liquidtransition observed in the water phase diagram. We show how thevector repulsion stabilizes the intermediary magnetic phases and thatcertain B and GV parametric combinations can cause a triple point toappear in the phase diagram. We also study the anisotropic propertiesof magnetized quark matter and how the vector-like contribution affectsthe induced magnetization leading to a diamagnetic behavior
Floquet-engineered emergent massive Nambu-Goldstone modes
No full textWe present a general framework to implement massive Nambu-Goldstone quasiparticles in driven many-body systems. The underlying mechanism leverages an explicit Lie group structure imprinted into an effective Hamiltonian that governs the dynamics of slow degrees of freedom; the resulting emergent continuous symmetry is weakly explicitly broken, giving rise to a massive Nambu-Goldstone mode, with a spectral mass gap scaling linearly with the drive period. We discuss explicit and experimentally implementable realizations, such as Heisenberg-like spin models that support gapped spin-wave excitations. We provide a protocol to certify the existence of the massive Nambu-Goldstone mode from the dynamics of specific observables, and analyze the dispersion spectrum and their lifetime in the presence of weak explicit symmetry breaking
Effects of inhomogeneity on the Shukla–Nambu–Salimullah potential in a magnetized plasma
No full textDetailed properties of the electrostatic Shukla–Nambu–Salimullah potential in an inhomogeneous magnetoplasma in the presence of ion streaming due to diamagnetic drift as in a laboratory discharge plasma have been examined analytically. The potential becomes a sensitive function of the external static magnetic field, the scalelength of inhomogeneity, and the diamagnetic ion streaming velocity. For a decreasing ion density gradient, there is a limit of existence of this static modified shielding potential
Generalization of n-ary Nambu algebras and beyond
No full textThe aim of this paper is to introduce n-ary Hom-algebra structures generalizing the n-ary algebras of Lie type including n-ary Nambu algebras, n-ary Nambu-Lie algebras and n-ary Lie algebras, and n-ary algebras of associative type including n-ary totally associative and n-ary partially associative algebras. We provide examples of the new structures and present some properties and construction theorems. We describe the general method allowing one to obtain an n-ary Hom-algebra structure starting from an n-ary algebra and an n-ary algebra endomorphism. Several examples are derived using this process. Also we initiate investigation of classification problems for algebraic structures introduced in the article and describe all ternary three-dimensional Hom-Nambu-Lie structures with diagonal homomorphism. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3167801
Calculating dihadron fragmentation functions in the Nambu-Jona-Lasinio-jet model
No full textThe Nambu-Jona-Lasinio-jet model provides a framework for calculating fragmentation functions without the introduction of ad hoc parameters. We develop the Nambu-Jona-Lasinio-jet model to investigate dihadron fragmentation functions (DFFs) of the form Dqh 1,h 2(z 1,z 2). Here we studied DFFs for q→{π +π -}, {π +K -} and {K +K -} with q=u, d, s. The driving terms, which represent the probability of one of the hadrons being emitted in the first emission step of the quark-jet hadronization picture, dominate the solutions of the DFFs where either z 1 or z 2 is large, and z 1 (z 2) is the light-cone momentum fraction of the emitted hadron, h 1 (h 2). The higher order terms, which represent the probability of neither of the hadrons being emitted in the first emission step of the quark-jet, become more significant as z 1 (z 2) is lowered. Finally, we present a sample result for QCD evolution of DFFs, that significantly modify the model solutions when evolved to typical experimental scale of 4GeV2. © 2012 American Physical Society.Andrew Casey, Hrayr H. Matevosyan and Anthony W. Thoma
Is there any Nambu monopolium out there?
No full textMagnetic monopoles have been a subject of study for more than a century since the first ideas by A. Vaschy and P. Curie, circa 1890. In 1974, Y. Nambu proposed a model for magnetic monopoles exploring a parallelism between the broken symmetry Higgs and the superconductivity Ginzburg-Landau theories in order to describe the pions quark-antiquark confinement states. There, Nambu described an energetic string where its end points behave like two magnetic monopoles with opposite magnetic charges —quark and antiquark. Consequently, not only the interaction among monopole and antimonopole, mediated by a massive vector boson (Yukawa potential), but also the energetic string (linear potential) contribute to the effective interaction potential. We propose here a monopole-antimonopole non-confining attractive interaction of the Nambu type, and then investigate the formation of bound states, the monopolium. Some necessary conditions for the existence of bound states to be fulfilled by the proposed Nambu-type potential, Kato weakness, Setô and Bargmann conditions, are verified. In the following, ground-state energies are estimated for a variety of monopolium reduced mass, from 102 MeV to 102 TeV, and Compton interaction lengths, from am to pm, where discussion about non-relativistic and relativistic limits validation is carried out.
Dedicated to the memory of Dr. César Augusto Parga Rodrigues (1939–2021)
- …
