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Revai J.,Wigner Research Center for Physics | Shevchenko N.V.,Nuclear Physics Institute of Czech Republic
Physical Review C - Nuclear Physics | Year: 2014

New calculations of the quasibound state in the K-pp system using Faddeev-type equations in Alt-Grassberger-Sandhas (AGS) form with coupled K¯NN and πΣN channels were performed. A chirally motivated K¯N potential together with phenomenological models of K¯N interaction with one- and two-pole structure of the Λ(1405) resonance were used. All three potentials reproduce experimental data on low-energy K-p scattering and kaonic hydrogen with the same level of accuracy. A new method of calculating the subthreshold resonance position and width in a three-body system was proposed and used together with the direct search of the resonance pole. We obtained binding energy of the K-pp quasibound state ≈32 MeV with the chirally motivated and 47-54 MeV with the phenomenological K¯N potentials. The width is about 50 MeV for the two-pole models of the interaction, while the one-pole potential gives ≈65 MeV width. The question of using an energy-dependent potential in few-body calculations is discussed in detail. It is shown that "self-consistent" variational calculations using such a potential are unable to produce a reasonable approximation to the exact result. © 2014 American Physical Society. Source

Diosi L.,Wigner Research Center for Physics
Foundations of Physics | Year: 2014

The gravity-related model of spontaneous wave function collapse, a longtime hypothesis, damps the massive Schrödinger Cat states in quantum theory. We extend the hypothesis and assume that spontaneous wave function collapses are responsible for the emergence of Newton interaction. Superfluid helium would then show significant and testable gravitational anomalies. © 2013 Springer Science+Business Media New York. Source

Racz I.,Wigner Research Center for Physics
Classical and Quantum Gravity | Year: 2014

We consider n + 1 dimensional smooth Riemannian and Lorentzian spaces satisfying Einsteins equations. The base manifold is assumed to be smoothly foliated by a one-parameter family of hypersurfaces. In both cases - likewise it is usually done in the Lorentzian case - Einsteins equations may be split into 'Hamiltonian' and 'momentum' constraints and a 'reduced' set of field equations. It is shown that regardless of whether the primary space is Riemannian or Lorentzian, whenever the foliating hypersurfaces are Riemannian the 'Hamiltonian' and 'momentum' type expressions are subject to a subsidiary first order symmetric hyperbolic system. Since this subsidiary system is linear and homogeneous in the 'Hamiltonian' and 'momentum' type expressions, the hyperbolicity of the system implies that in both cases the solutions to the 'reduced' set of field equations are also solutions to the full set of equations provided that the constraints hold on one of the hypersurfaces foliating the base manifold. © 2014 IOP Publishing Ltd. Source

Revai J.,Wigner Research Center for Physics
Few-Body Systems | Year: 2013

Neutron spectra from the reaction K- + d → π + Σ + n were calculated in the energy range EcmK- = 0-50 MeV using coupled channel Faddeev equations for the description of the K̄ N N - πΣN three-body system. The aim was to trace the signature of the Λ(1405) resonance in the spectra. We found, that while in the direct spectra kinematic effects mask completely the peak corresponding to the resonance, the deviation spectrum method of Esmaili et al. (Phys. Rev. C 83:055207, 2011) is able to eliminate kinematics and differentiate between different models of Λ(1405). Four different phenomenological K̄ N - πΣ interactions were used in order to study the effect of their pole positions on the neutron spectra. © 2013 Springer-Verlag Wien. Source

Diosi L.,Wigner Research Center for Physics
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

If gravity were an emergent phenomenon, some relativistic as well as non-relativistic speculations claim it is, then a certain emergence time scale τ? would characterize it. We argue that the available experimental evidences have poor time resolution regarding how immediate the creation of Newton field of accelerated mass sources is. Although the concrete theoretical model of gravity's 'laziness' is missing, the concept and the scale τ?∼1 ms, rooted in an extrapolation of spontaneous wave function collapse theory, might be tested directly in reachable experiments. © 2013 Elsevier B.V. Source

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