Search results for " PRIN"
showing 10 items of 1809 documents
Rotating electrons in quantum dots: Classical limit
2007
We solve the problem of a few electrons in a two-dimensional harmonic confinement using a quantum mechanical exact diagonalization technique, on the one hand, and classical mechanics, on the other. The quantitative agreement between the results of these two calculations suggests that, at low filling factors, all the low energy excitations of a quantum Hall liquid are classical vibrations of localized electrons. The Coriolis force plays a dominant role in determining the classical vibration frequencies.
New structures in the theory of the laser model. II. Microscopic dynamics and a nonequilibrium entropy principle
1998
In a recent article, Alli and Sewell [J. Math. Phys. 36, 5598 (1995)] formulated a new version of the Dicke-Hepp-Lieb laser model in terms of quantum dynamical semigroups, and thereby extended the macroscopic picture of the model. In the present article, we complement that picture with a corresponding microscopic one, which carries the following new results. (a) The local microscopic dynamics of the model is piloted by the classical, macroscopic field, generated by the collective action of its components; (b) the global state of the system carries no correlations between its constituent atoms after transient effects have died out; and (c) in the latter situation, the state of the system at …
X(3872) and its charmonium content in Heavy Quark limit
2016
X (3872) still presents many puzzles more than a decade after its discovery. Some of its properties, like the isospin violating decays, can easily be accommodated in a molecular model, whereas its other properties, such as radiative decays can be more naturally explained in the quarkonium picture. The best of these schemes can be combined in a picture of X (3872) where it is dominantly a molecular state with some charmonium components. In this work, we present a model based on heavy quark symmetry which describes X (3872) as a superposition of molecular and charmonium components.
On Green's function for cylindrically symmetric fields of polarized radiation
2009
Analytic expressions for Green's function describing the process of transfer of polarized radiation in homogeneous isotropic infinite medium in case of cylindrical symmetry and nonconservative scattering are obtained. The solution is based on the set of systems of Abel integral equations of the first kind obtained using the principle of superposition, and the known expression of Green's function for radiation fields with plane-parallel symmetry. Eigenvalue decompositions for the corresponding matrices of generalized spherical functions are found. Using this result the systems of Abel integral equations are diagonalized, and the final solution is obtained.
Testing electromagnetic proton form factors in the annihilation process p+p¯→π0+e−+e+
2011
We study the annihilation channel in proton antiproton collisions with production of a single neutral pion and an electron-positron pair. It is shown that this reaction allows access to the proton electromagnetic form factors in the ‘unphysical’ region and to the difference between complex phases of the Dirac and Pauli proton form factors. The differential cross section is given in the laboratory frame in an experimental setup where all outgoing particles are fully detected.
Scattering on Riemannian Symmetric Spaces and Huygens Principle
2018
International audience; The famous paper by L. D. Faddeev and B. S. Pavlov (1972) on automorphic wave equation explored a highly romantic link between Scattering Theory (in the sense of Lax and Phillips) and Riemann hypothesis. An attempt to generalize this approach to general semisimple Lie groups leads to an interesting evolution system with multidimensional time explored by the author in 1976. In the present paper, we compare this system with a simpler one defined for zero curvature symmetric spaces and show that the Huygens principle for this system in the curved space holds if and only if it holds in the zero curvature limit.
ELASTIC WAVES: MENTAL MODELS AND TEACHING/LEARNING SEQUENCES
2006
In last years many research studies have pointed out relevant student difficulties in understanding the physics of mechanical waves. Moreover, it has been reported that these difficulties deal with some fundamental concepts as the role of the medium in wave propagation, the superposition principle and the mathematical description of waves involving the use of functions of two variables. In the context of pre-service courses for teacher preparation a teaching/learning (T/L) sequence based on using simple RTL experiments and interactive simulation environments aimed to show the effect of medium properties on the propagation speed of a wave pulse, has been experimented. Here, preliminary resul…
Energy deposition in hard dihadron triggered events in heavy-ion collisions
2008
The experimental observation of hadrons correlated back-to-back with a (semi-)hard trigger in heavy ion collisions has revealed a splitting of the away side correlation structure in a low to intermediate transverse momentum (P_T) regime. This is consistent with the assumption that energy deposited by the away side parton into the bulk medium produced in the collision excites a sonic shockwave (a Mach cone) which leads to away side correlation strength at large angles. A prediction following from assuming such a hydrodynamical origin of the correlation structure is that there is a sizeable elongation of the shockwave in rapidity due to the longitudinal expansion of the bulk medium. Using a s…
Composite Operator Method analysis of the underdoped cuprates puzzle
2014
The microscopical analysis of the unconventional and puzzling physics of the underdoped cuprates, as carried out lately by means of the Composite Operator Method (COM) applied to the 2D Hubbard model, is reviewed and systematized. The 2D Hubbard model has been adopted as it has been considered the minimal model capable to describe the most peculiar features of cuprates held responsible for their anomalous behavior. COM is designed to endorse, since its foundations, the systematic emergence in any SCS of new elementary excitations described by composite operators obeying non-canonical algebras. In this case (underdoped cuprates - 2D Hubbard model), the residual interactions - beyond a 2-pole…
Multimode squeezing of frequency combs
2006
We have developed a full multimode theory of a synchronously pumped type-I optical parametric oscillator. We calculate the output quantum fluctuations of the device and find that, in the degenerate case (coincident signal and idler set of frequencies), significant squeezing is obtained when one approaches threshold from below for a set of well-defined ``supermodes,'' or frequency combs, consisting of a coherent linear superposition of signal modes of different frequencies which are resonant in the cavity.