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Exotic atoms and exotic nuclei  [PDF]
S. Hirenzaki,H. Nagahiro,N. Ikeno,J. Yamagata-Sekihara
Physics , 2015, DOI: 10.5506/APhysPolB.46.121
Abstract: We briefly review the study of the exotic atoms and exotic nuclei, and report recent research activities of eta-mesic nucleus and kaonic atoms in this article.
An Exotic Theory of Massless Spin-Two Fields in Three Dimensions  [PDF]
Nicolas Boulanger,Leonardo Gualtieri
Physics , 2000, DOI: 10.1088/0264-9381/18/8/306
Abstract: It is a general belief that the only possible way to consistently deform the Pauli-Fierz action, changing also the gauge algebra, is general relativity. Here we show that a different type of deformation exists in three dimensions if one allows for PT non-invariant terms. The new gauge algebra is different from that of diffeomorphisms. Furthermore, this deformation can be generalized to the case of a collection of massless spin-two fields. In this case it describes a consistent interaction among them.
Exotic atoms  [PDF]
Paul Indelicato
Physics , 2004, DOI: 10.1238/Physica.Topical.112a00020
Abstract: In this paper I review a number of recent results in the field of exotic atoms. Recent experiments or ongoing experiments with muonic, pionic and antiprotonic hydrogen, as well as recent measurement of the pion mass are described. These experiments provide information about nucleon-pion or nucleon-antinucleon interaction as well as information on the proton structure (charge or magnetic moment distribution).
Universality of the energy spectrum for two interacting harmonically trapped ultra-cold atoms in one and two dimensions  [PDF]
Aaron Farrell,Brandon P. van Zyl
Physics , 2009, DOI: 10.1088/1751-8113/43/1/015302
Abstract: Motivated by the recent article of P. Shea {\it et al.} [Am. J. Phys. {\bf 77} (6), 2009] we examine the exactly solvable problem of two harmonically trapped ultra-cold bosonic atoms interacting {\it via} a short range potential in one and two dimensions. A straightforward application in one dimension shows that the energy spectrum is universal, provided that the range of the potential is much smaller than the oscillator length, in addition to clearly illustrating why regularization is not required in the limit of zero range. The two dimensional problem is less trivial, requiring a more careful treatment as compared to the one dimensional case. Our two dimensional analysis likewise reveals that the low-energy physics is also universal, in addition to providing a simple method for obtaining the appropriately regularized two dimensional pseudopotential.
Universal Two-Body Spectra of Ultracold Harmonically Trapped Atoms in Two and Three Dimensions  [PDF]
N. T. Zinner
Physics , 2011, DOI: 10.1088/1751-8113/45/20/205302
Abstract: We consider the spectrum of two ultracold harmonically trapped atoms interacting via short-range interactions. The Green's function approach is used to unify the two and three dimensional cases. We derive criteria for the universality of the spectrum, i.e. its independence of the details of the short-range interaction. The results in three dimensions are examplified for narrow s-wave Feshbach resonances and we show how effective range corrections can modify the rearrangement of the level structure. However, this requires extremely narrow resonances or very tight traps that are not currently experimentally available. In the two-dimensional case we discuss the p-wave channel in detail and demonstrate how the non-universality of the spectrum arises within the Green's function approach. We then show that the spectrum is not particularly sensitive to the short-distance details in the case when the two-body interaction has a bound state.
The Two-Component Quantum Theory of Atoms in Molecules (TC-QTAIM): The unified theory of localization/delocalization of electrons, nuclei and exotic elementary particles  [PDF]
Mohammad Goli,Shant Shahbazian
Physics , 2013, DOI: 10.1007/s00214-013-1410-4
Abstract: In this contribution, pursuing our research program extending the atoms in molecules analysis into unorthodox domains, another key ingredient of the two-component quantum theory of atoms in molecules (TC-QTAIM) namely, the theory of localization/delocalization of quantum particles, is disclosed. The unified proposed scheme is able not only to deal with the localization/delocalization of electrons in/between atomic basins, but also to treat nuclei as well as exotic particles like positrons and muons equally. Based on the general reduced second order density matrices for indistinguishable quantum particles, the quantum fluctuations of atomic basins are introduced and then used as a gauge to quantify the localization/delocalization introducing proper indexes. The explicit mass-dependence of the proposed indexes is demonstrated and it is shown that a single localization/delocalization index is capable of being used for all kind of quantum particles regardless of their masses or charge content. For various non-Born-Oppenhiemer (non-BO) wavefunctions, including Hartree-product as well as singlet and triplet determinants, the indices are calculated and then employed to rationalize the localization/delocalization of particles in a series of four-body model systems consist of two electrons and two positively charged particles with variable mass. The ab initio FV-MC_MO derived non-BO wavefunctions for the four-body series are used for a comprehensive computational TC-QTAIM analysis, including topological analysis as well as basin integrations, in a wide mass region, m=10me-10^13me (me stands for electron mass), disclosing various traits in these series of species that are unique to the TC-QTAIM. Finally, it is concluded that the proposed localization/delocalization scheme is capable of quantifying quantum tunneling of nuclei for systems containing delocalized protons.
Unified approach to nuclear densities from exotic atoms  [PDF]
E. Friedman
Physics , 2008, DOI: 10.1007/s10751-009-0066-x
Abstract: Parameters of nuclear density distributions are derived from least-squares fits to strong interaction observables in exotic atoms. Global analyses of antiprotonic and pionic atoms show reasonably good agreement between the two types of probes regarding the average behaviour of root-mean-square radii of the neutron distributions. Apparent conflict regarding the shape of the neutron distribution is attributed to different radial sensitivities of these two probes.
Induced p-wave superfluidity in two dimensions: Brane world in cold atoms and nonrelativistic defect CFTs  [PDF]
Yusuke Nishida
Physics , 2008, DOI: 10.1016/j.aop.2008.10.011
Abstract: We propose to use a two-species Fermi gas with the interspecies s-wave Feshbach resonance to realize p-wave superfluidity in two dimensions. By confining one species of fermions in a two-dimensional plane immersed in the background three-dimensional Fermi sea of the other species, an attractive interaction is induced between two-dimensional fermions. We compute the pairing gap in the weak-coupling regime and show that it has the symmetry of p_x+ip_y. Because the magnitude of the pairing gap increases toward the unitarity limit, it is possible that the critical temperature for the p_x+ip_y-wave superfluidity becomes within experimental reach. The resulting system has a potential application to topological quantum computation using vortices with non-Abelian statistics. We also discuss aspects of our system in the unitarity limit as a "nonrelativistic defect conformal field theory (CFT)". The reduced Schr\"odinger algebra, operator-state correspondence, scaling dimensions of composite operators, and operator product expansions are investigated.
From heavy ions to exotic atoms  [PDF]
Paul Indelicato,Martino Trassinelli
Physics , 2005,
Abstract: We review a number of experiments and theoretical calculations on heavy ions and exotic atoms, which aim at providing informations on fundamental interactions. Among those are propositions of experiments for parity violation measurements in heavy ions and high-precision mesurements of He-like transition energies in highly charged ions. We also describe recent experiments on pionic atoms, that make use of highly-charged ion transitions to obtain accurate measurements of strong interaction shift and width.
Exotic Spaces in Quantum Gravity I: Euclidean Quantum Gravity in Seven Dimensions  [PDF]
Kristin Schleich,Donald Witt
Physics , 1999, DOI: 10.1088/0264-9381/16/7/319
Abstract: It is well known that in four or more dimensions, there exist exotic manifolds; manifolds that are homeomorphic but not diffeomorphic to each other. More precisely, exotic manifolds are the same topological manifold but have inequivalent differentiable structures. This situation is in contrast to the uniqueness of the differentiable structure on topological manifolds in one, two and three dimensions. As exotic manifolds are not diffeomorphic, one can argue that quantum amplitudes for gravity formulated as functional integrals should include a sum over not only physically distinct geometries and topologies but also inequivalent differentiable structures. But can the inclusion of exotic manifolds in such sums make a significant contribution to these quantum amplitudes? This paper will demonstrate that it will. Simply connected exotic Einstein manifolds with positive curvature exist in seven dimensions. Their metrics are found numerically; they are shown to have volumes of the same order of magnitude. Their contribution to the semiclassical evaluation of the partition function for Euclidean quantum gravity in seven dimensions is evaluated and found to be nontrivial. Consequently, inequivalent differentiable structures should be included in the formulation of sums over histories for quantum gravity.
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