1,329 research outputs found
Relativistic Quantum Dynamics of Many-Body Systems
Relativistic quantum dynamics requires a unitary representation of the
Poincare group on the Hilbert space of states. The dynamics of many-body
systems must satisfy cluster separability requirements. In this paper we
formulate an abstract framework of four dimensional Euclidean Green functions
that can be used to construct relativistic quantum dynamics of N-particle
systems consistent with these requirements. This approach should be useful in
bridging the gap between few-body dynamics based on phenomenological mass
operators and on quantum field theory.Comment: Latex, 9 Pages, Submitted to World Scientific - 50 Years of Quantum
Many-Body Theory - A Conference in Honor of the 65-th Birthdays of John W.
Clark, Alpo J. Kallio, Manfred L. Ristig, and Sergio Rosat
From Light Nuclei to Nuclear Matter. The Role of Relativity?
The success of non-relativistic quantum dynamics in accounting for the
binding energies and spectra of light nuclei with masses up to A=10 raises the
question whether the same dynamics applied to infinite nuclear matter agrees
with the empirical saturation properties of large nuclei.The simple unambiguous
relation between few-nucleon and many-nucleon Hamiltonians is directly related
to the Galilean covariance of nonrelativistic dynamics. Relations between the
irreducible unitary representations of the Galilei and Poincare groups indicate
thatthe ``nonrelativistic'' nuclear Hamiltonians may provide sufficiently
accurate approximations to Poincare invariant mass operators. In relativistic
nuclear dynamics based on suitable Lagrangeans the intrinsic nucleon parity is
an explicit, dynamically relevant, degree of freedom and the emphasis is on
properties of nuclear matter. The success of this approach suggests the
question how it might account for the spectral properties of light nuclei.Comment: conference proceedings "The 11th International Conference on Recent
Progress in Many-Body Theories" to be published by World Scientifi
Scaling of Hadronic Form Factors in Point Form Kinematics
The general features of baryon form factors calculated with point form
kinematics are derived. With point form kinematics and spectator currents
hadronic form factors are functions of
and, over a range of values are insensitive to unitary scale
transformations of the model wave functions when the extent of the wave
function is small compared to the scale defined by the constituent mass, . The form factors are sensitive to the shape of such compact wave
functions. Simple 3-quark proton wave functions are employed to illustrate
these features. Rational and algebraic model wave functions lead to a
reasonable representation of the empirical form factors, while Gaussian wave
functions fail. For large values of point form kinematics with spectator
currents leads to power law behavior of the wave functions
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