1,729 research outputs found
Electron-hydrogen scattering in Faddeev-Merkuriev integral equation approach
Electron-hydrogen scattering is studied in the Faddeev-Merkuriev integral
equation approach. The equations are solved by using the Coulomb-Sturmian
separable expansion technique. We present - and -wave scattering and
reactions cross sections up to the threshold.Comment: 2 eps figure
Resonant-state solution of the Faddeev-Merkuriev integral equations for three-body systems with Coulomb potentials
A novel method for calculating resonances in three-body Coulombic systems is
proposed. The Faddeev-Merkuriev integral equations are solved by applying the
Coulomb-Sturmian separable expansion method. The S-state
resonances up to threshold are calculated.Comment: 6 pages, 2 ps figure
Continued fraction representation of the Coulomb Green's operator and unified description of bound, resonant and scattering states
If a quantum mechanical Hamiltonian has an infinite symmetric tridiagonal
(Jacobi) matrix form in some discrete Hilbert-space basis representation, then
its Green's operator can be constructed in terms of a continued fraction. As an
illustrative example we discuss the Coulomb Green's operator in
Coulomb-Sturmian basis representation. Based on this representation, a quantum
mechanical approximation method for solving Lippmann-Schwinger integral
equations can be established, which is equally applicable for bound-, resonant-
and scattering-state problems with free and Coulombic asymptotics as well. The
performance of this technique is illustrated with a detailed investigation of a
nuclear potential describing the interaction of two particles.Comment: 7 pages, 4 ps figures, revised versio
Three-potential formalism for the three-body scattering problem with attractive Coulomb interactions
A three-body scattering process in the presence of Coulomb interaction can be
decomposed formally into a two-body single channel, a two-body multichannel and
a genuine three-body scattering. The corresponding integral equations are
coupled Lippmann-Schwinger and Faddeev-Merkuriev integral equations. We solve
them by applying the Coulomb-Sturmian separable expansion method. We present
elastic scattering and reaction cross sections of the system both below
and above the threshold. We found excellent agreements with previous
calculations in most cases.Comment: 12 pages, 3 figure
Effective Q-Q Interactions in Constituent Quark Models
We study the performance of some recent potential models suggested as
effective interactions between constituent quarks. In particular, we address
constituent quark models for baryons with hybrid Q-Q interactions stemming from
one-gluon plus meson exchanges. Upon recalculating two of such models we find
them to fail in describing the N and \Delta spectra. Our calculations are based
on accurate solutions of the three-quark systems in both a variational
Schr\"odinger and a rigorous Faddeev approach. It is argued that hybrid {Q-Q}
interactions encounter difficulties in describing baryon spectra due to the
specific contributions from one-gluon and pion exchanges together. In contrast,
a chiral constituent quark model with a Q-Q interaction solely derived from
Goldstone-boson exchange is capable of providing a unified description of both
the N and \Delta spectra in good agreement with phenomenology.Comment: 21 pages, LaTe
Refinement of the and fish-bone potential
The fishbone potential of composite particles simulates the Pauli effect by
nonlocal terms. We determine the and fish-bone potential
by simultaneously fitting to the experimental phase shifts. We found that with
a double Gaussian parametrization of the local potential can describe the
and phase shifts for all partial waves.Comment: 3 pages, 3 figure
Verifying multi-partite mode entanglement of W states
We construct a method for verifying mode entanglement of N-mode W states. The
ideal W state contains exactly one excitation symmetrically shared between N
modes, but our method takes the existence of higher numbers of excitations into
account, as well as the vacuum state and other deviations from the ideal state.
Moreover, our method distinguishes between full N-party entanglement and states
with M-party entanglement with M<N, including mixtures of the latter. We
specialize to the case N=4 for illustrative purposes. In the optical case,
where excitations are photons, our method can be implemented using linear
optics.Comment: 11 pages, 12 figure
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