A renormalization group approach to a Yang–Mills two matrix model

A Yang–Mills type two matrix model with mass terms is studied by use of a matrix renormalization group approach proposed by Brezin and Zinn-Justin. The renormalization group method indicates that the model exhibits a critical behavior similar to that of two-dimensional Euclidean gravity. A massless limit and the generation of quadratic terms along the renormalization group flow are discussed.     

A vector type Gürsey model and its renormalization group analysis

We start with a model classically equivalent to the vector Gürsey model. The model is coupled with a non-abelian SU(N) gauged field. For the one loop approximation, the renormalization group equations are constructed and the coupling constant solutions are found. The coupling constants behaviors are briefly investigated and non-triviality conditions of the model are presented. Under certain conditions, a non-trivial field theoretical model is obtained.     

Towards a constructive approach of a gauge invariant,massiveP(φ)2 theory

As part of a possible constructive approach to a gauge invariantP()₂ theory, we consider massive, scalar, polynomially selfcoupled fields in a fixed external Yang-Mills potentialA in two-dimensional euclidean space. For a large class ofA's we show that the corresponding euclidean Green's functions for the fields have a lower mass gap for weak coupling which is uniform inA. The result is obtained by adapting the Glimm-Jaffe-Spencer cluster expansion to the present situation through Kato's inequality, which reflects the diamagnetic effect of the Yang-Mills potential. A discussion of the corresponding gauge covariance is included.     

Squarks and gluinos at a TeV e + e − collider: testing the identity of Yukawa and gauge couplings in SUSY-QCD

Supersymmetry predicts the identity of Yukawa and gauge couplings in the QCD sector: . We examine whether the  Yukawa coupling can be determined, by methods complementary to LHC, by analyzing squark–gluino final states at a TeV e ⁺ e ⁻ collider.     

The group of local biholomorphisms of ℂ1 and conformal field theory in the operator formalism

Motivated by the operator formulation of conformal field theory on Riemann surfaces, we study the properties of the infinite dimensional group of local biholomorphic transformations (conformal reparametrizations) of ¹ and develop elements of its representation theory.     

Classical and Non-relativistic Limits of a Lorentz-Invariant Bohmian Model for a System of Spinless Particles

A completely Lorentz-invariant Bohmian model has been proposed recently for the case of a system of non-interacting spinless particles, obeying Klein-Gordon equations. It is based on a multi-temporal formalism and on the idea of treating the squared norm of the wave function as a space-time probability density. The particle’s configurations evolve in space-time in terms of a parameter σ with dimensions of time. In this work this model is further analyzed and extended to the case of an interaction with an external electromagnetic field. The physical meaning of σ is explored. Two special situations are studied in depth: (1) the classical limit, where the Einsteinian Mechanics of Special Relativity is recovered and the parameter σ is shown to tend to the particle’s proper time; and (2) the non-relativistic limit, where it is obtained a model very similar to the usual non-relativistic Bohmian Mechanics but with the time of the frame of reference replaced by σ as the dynamical temporal parameter.     

A Re-interpretation of the Concept of Mass and of the Relativistic Mass-Energy Relation

For over a century the definitions of mass and derivations of its relation with energy continue to be elaborated, demonstrating that the concept of mass is still not satisfactorily understood. The aim of this study is to show that, starting from the properties of Minkowski spacetime and from the principle of least action, energy expresses the property of inertia of a body. This implies that inertial mass can only be the object of a definition—the so called mass-energy relation—aimed at measuring energy in different units, more suitable to describe the huge amount of it enclosed in what we call the “rest-energy” of a body. Likewise, the concept of gravitational mass becomes unnecessary, being replaceable by energy, thus making the weak equivalence principle intrinsically verified. In dealing with mass, a new unit of measurement is foretold for it, which relies on the de Broglie frequency of atoms, the value of which can today be measured with an accuracy of a few parts in 10⁹.     

Stability of the scalar potential and symmetry breaking in the economical 3-3-1 model

A detailed study of the criteria for stability of the scalar potential and the proper electroweak symmetry breaking pattern in the economical 3-3-1 model, is presented. For the analysis we use and improve a method previously developed to study the scalar potential in the two-Higgs-doublet extension of the standard model. A new theorem related to the stability of the potential is stated. As a consequence of this study, the consistency of the economical 3-3-1 model emerges.     

Reanalysis of the mass spectrum of the scalar hidden charm and hidden bottom tetraquark states

In this article, we study the mass spectrum of the scalar hidden charm and hidden bottom tetraquark states which consist of the axial-vector–axial-vector type and the vector–vector type diquark pairs with the QCD sum rules.     

A Lattice Hierarchy with a Free Function and Its Reductions to the Ablowitz-Ladik and Volterra Hierarchies

By embedding a free function into a compatible zero curvature equation, we propose a lattice hierarchy with the free function which still admits zero curvature representation. It is interesting that the hierarchy can reduce the Ablowitz-Ladik hierarchy, the Volterra hierarchy and a new hierarchy by properly choosing the embedded function. Moreover, the new hierarchy is integrable in Liouville’s sense and possess multi-Hamiltonian structure.     

In-situ formation and detailed analysis of imine bonds for the construction of conjugated aromatic monolayers on Au(111)

We present the synthesis of 4′-amino-4-mercaptobiphenyl (AMB) and its deposition from solution onto Au(111) substrates. The resulting organic thin films were characterized by contact angle, infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) measurements. It is demonstrated that the majority of AMB molecules are coupled to the gold surface via S–Au covalent bonds, although only little orientational order of the AMB layer could be detected by NEXAFS. Furthermore, aromatic imine bonds between AMB and 4-hydroxybenzaldehyde (HB), 4-carboxybenzaldehyde (CB), 4-methylbenzaldehyde (MB), or 4-(trifluoromethyl) benzaldehyde (TMB) have been successfully formed. As a result of the limited order, this coupling reaction was incomplete. Nevertheless, the experimental results confirmed the formation of conjugated aromatic imine bonds.     

More on the renormalization of the horizon function of the Gribov–Zwanziger action and the Kugo–Ojima Green function(s)

In this paper we provide strong evidence that there is no ambiguity in the choice of the horizon function underlying the Gribov–Zwanziger action. We show that there is only one correct possibility which is determined by the requirement of multiplicative renormalizability. As a consequence, this means that relations derived from other horizon functions cannot be given a consistent interpretation in terms of a local and renormalizable quantum field theory. In addition, we also discuss that the Kugo–Ojima functions u(p ²) and w(p ²) can only be defined after renormalization of the underlying Green function(s).     

Zariski closure of subgroups of the symplectic group and Lyapunov exponents of the Schrödinger operator on the strip

We consider the Schrödinger equation with a random potential

A multidisciplinary approach for the conservation of a building of the seventeenth century

A long-term multidisciplinary conservation study is actually in progress inside the Villa della Regina, a prestigious Savoy residence built in the seventeenth century and recently restored. The walls of some rooms of the Villa are decorated with precious tin–mercury mirrors, that are baked with a reflective coating constituted of a tin–mercury compound surrounded by liquid mercury. The reflective layer is very soft, thus any restoration is difficult to be performed and can lead to a complete destruction of the artifact. Amalgam corrosion is a very slow process and, although there is no way to prevent the oxidation of the reflective layer, the conservation state of the artifacts may be improved by keeping them in a controlled environment. For this reason, a monitoring system has been designed and installed that is based on a wireless network of extremely compact sensors, for temperature and relative humidity measurements. The sensors have been specifically designed to satisfy the requirements for use in cultural heritage field and the system allows one to automatically collect the data that can be analyzed with the final aim to establish a correlation between the environmental conditions and the conservation state of the artifacts. A restoration has been carried out by producing in situ an amalgam inlay on the corroded area to slow down the release of liquid mercury in order to avoid also possible unsafe conditions for staff and visitors. In addition, a sensor has been developed which is based on a prototypical plastic optical fiber for the detection of low concentration Hg vapors to ensure the safe conditions in the Villa rooms. The sensor is being tested in laboratory.     

A Higher Dimensional Cosmological Model in a Scale-Covariant Theory of Gravitation

Kaluza-Klein space-time is considered in the presence of a perfect fluid distribution in the scale-covariant theory of gravitation by Canuto et al. (Phys. Rev. Lett. 39:429, 1977). With the help of special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983), a cosmological model in five dimensions with a negative constant deceleration parameter is presented in this theory. Some physical and kinematical properties of the model are also discussed.     

Ablation and surface modifications of PMMA using a laser-plasma EUV source

Surface modification and micro-structuring of polymers for different application is mainly performed using ultraviolet (UV) radiation from excimer lamps or excimer lasers. In this case, however, the radiation penetration depth may exceed 100 μm, thereby degrading the polymer deep inside. On the other hand, extreme ultraviolet (EUV) radiation is absorbed in a layer approximately 100 nm thick only. In this work, the radiation from a laser-plasma EUV source based on a double-stream gas-puff target is focused with a gold-coated ellipsoidal collector for surface modification of polymethylmethacrylate (PMMA). The spectrum of the focused radiation consists of a narrow feature with maximum at 10 nm and a long-wavelength tail up to 70 nm. The PMMA samples are mounted in the focal plane of the EUV collector or at some distance downstream this plane and irradiated for 10–60 s with 10-Hz repetition rate. The irradiated polymer samples were investigated using a scanning electron microscope. When the EUV fluence exceeds 10 mJ/cm², smooth ablation of PMMA was obtained. For lower fluences but close to this value, strong surface modifications appeared.