283 research outputs found

    0ν2β0\nu2\beta Nuclear Matrix Elements and Neutrino Magnetic Moments

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    We compare different methods of obtaining the neutrinoless double beta decay nuclear matrix elements (NME). On the example of 76Ge we use the NME to calculate the Majorana neutrino transition magnetic moments, generated through particle-sparticle R-parity violating loop diagrams whithin the minimal supersymmetric standard model.Comment: I've decided to move the collection of my papers to arXiv for easier access. Proceedings of the Nuclear Physics Workshop in Kazimierz Dolny, Poland, 200

    Neutralino Induced Majorana Neutrino Transition Magnetic Moments

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    We calculate the effect of neutrino-neutralino mixing on the neutrino magnetic moment and compare it with the contribution of pure particle-sparticle loop. We have found that the dominated mechanism is still the bare loop, and that the bilinear insertions on the external neutrino lines contribute at least one order of magnitude weaker.Comment: I've decided to move the collection of my papers to arXiv for easier access. Proceedings of the Nuclear Physics Workshop in Kazimierz Dolny, Poland, 200

    Quantum constraints, Dirac observables and evolution: group averaging versus Schroedinger picture in LQC

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    A general quantum constraint of the form C=T2BIHC= - \partial_T^2 \otimes B - I\otimes H (realized in particular in Loop Quantum Cosmology models) is studied. Group Averaging is applied to define the Hilbert space of solutions and the relational Dirac observables. Two cases are considered. In the first case, the spectrum of the operator (1/2)π2BH(1/2)\pi^2 B - H is assumed to be discrete. The quantum theory defined by the constraint takes the form of a Schroedinger-like quantum mechanics with a generalized Hamiltonian B1H\sqrt{B^{-1} H}. In the second case, the spectrum is absolutely continuous and some peculiar asymptotic properties of the eigenfunctions are assumed. The resulting Hilbert space and the dynamics are characterized by a continuous family of the Schroedinger-like quantum theories. However, the relational observables mix different members of the family. Our assumptions are motivated by new Loop Quantum Cosmology models of quantum FRW spacetime. The two cases considered in the paper correspond to the negative and, respectively, positive cosmological constant. Our results should be also applicable in many other general relativistic contexts.Comment: RevTex4, 32 page

    The kernel and the injectivity of the EPRL map

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    In this paper we prove injectivity of the EPRL map for |\gamma|<1, filling the gap of our previous paper.Comment: 17 pages, 3 figure

    Dust reference frame in quantum cosmology

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    We give a formulation of quantum cosmology with a pressureless dust and arbitrary additional matter fields. The system has the property that its Hamiltonian constraint is linear in the dust momentum. This feature provides a natural time gauge, leading to a physical hamiltonian that is not a square root. Quantization leads to Schr{\"o}dinger equation for which unitary evolution is directly linked to geodesic completeness. Our approach simplifies the analysis of both Wheeler-deWitt and loop quantum cosmology (LQC) models, and significantly broadens the applicability of the latter. This is demonstrated for arbitrary scalar field potential and cosmological constant in LQC.Comment: 8 pages, iopart style + BibTe

    One vertex spin-foams with the Dipole Cosmology boundary

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    We find all the spin-foams contributing in the first order of the vertex expansion to the transition amplitude of the Bianchi-Rovelli-Vidotto Dipole Cosmology model. Our algorithm is general and provides spin-foams of arbitrarily given, fixed: boundary and, respectively, a number of internal vertices. We use the recently introduced Operator Spin-Network Diagrams framework.Comment: 23 pages, 30 figure

    Feynman diagrammatic approach to spin foams

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    "The Spin Foams for People Without the 3d/4d Imagination" could be an alternative title of our work. We derive spin foams from operator spin network diagrams} we introduce. Our diagrams are the spin network analogy of the Feynman diagrams. Their framework is compatible with the framework of Loop Quantum Gravity. For every operator spin network diagram we construct a corresponding operator spin foam. Admitting all the spin networks of LQG and all possible diagrams leads to a clearly defined large class of operator spin foams. In this way our framework provides a proposal for a class of 2-cell complexes that should be used in the spin foam theories of LQG. Within this class, our diagrams are just equivalent to the spin foams. The advantage, however, in the diagram framework is, that it is self contained, all the amplitudes can be calculated directly from the diagrams without explicit visualization of the corresponding spin foams. The spin network diagram operators and amplitudes are consistently defined on their own. Each diagram encodes all the combinatorial information. We illustrate applications of our diagrams: we introduce a diagram definition of Rovelli's surface amplitudes as well as of the canonical transition amplitudes. Importantly, our operator spin network diagrams are defined in a sufficiently general way to accommodate all the versions of the EPRL or the FK model, as well as other possible models. The diagrams are also compatible with the structure of the LQG Hamiltonian operators, what is an additional advantage. Finally, a scheme for a complete definition of a spin foam theory by declaring a set of interaction vertices emerges from the examples presented at the end of the paper.Comment: 36 pages, 23 figure

    The EPRL intertwiners and corrected partition function

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    Do the SU(2) intertwiners parametrize the space of the EPRL solutions to the simplicity constraint? What is a complete form of the partition function written in terms of this parametrization? We prove that the EPRL map is injective for n-valent vertex in case when it is a map from SO(3) into SO(3)xSO(3) representations. We find, however, that the EPRL map is not isometric. In the consequence, in order to be written in a SU(2) amplitude form, the formula for the partition function has to be rederived. We do it and obtain a new, complete formula for the partition function. The result goes beyond the SU(2) spin-foam models framework.Comment: RevTex4, 15 pages, 5 figures; theorem of injectivity of EPRL map correcte

    Parameters of scalar resonances from the combined analysis of data on processes ππππ,KKˉ,ηη\pi\pi\to\pi\pi,K\bar{K},\eta\eta and J/ψJ/\psi decays

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    A combined analysis of data on isoscalar S-wave processes ππππ,KK,ηη\pi\pi\to\pi\pi,K\overline{K},\eta\eta and on decays J/ψϕππ,ϕKKJ/\psi\to\phi\pi\pi,\phi K\overline{K} from the DM2, Mark III and BESIII collaborations is performed to study f0f_0 mesons. The method of analysis is based on analyticity and unitarity and uses an uniformization procedure. In the analysis limited only to the multi-channel ππ\pi\pi-scattering data, two possible sets of parameters of the f0(500)f_0(500) were found: in both cases the mass was about 700 MeV but the total width was either about 600 or 930 MeV. The extension of the analysis using only the DM2 and Mark III data on the J/ψJ/\psi decays does not allow to choose between these sets. However, the data from BESIII on the di-pion mass distribution in the decay J/ψϕπ+πJ/\psi\to\phi\pi^+\pi^- clearly prefers the wider f0(500)f_0(500) state. Spectroscopic implications from results of the analysis are also discussed.Comment: the formalism is also described (text overlap) in arXiv:1108.3725; new extended analysis of data; revised PRD versio
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