Comparison of form factors calculated with different expressions for the boost transformation

Self Cite

This paper describes a tentative relativistic quantum mechanics approach inspired by Dirac's point-form, which is based on the physics description on a hyperboloid surface. It is mainly characterized by a non-standard relation of the constituent momenta of some system to its total momentum. Contrary to instantand front-form approaches, where it takes the form of a 3-dimensional δ(· · ·) function, the relation is given here by a Lorentz-scalar constraint. Thus, in the c.m. frame, the sum of the constituent momenta, which differs from zero off-energy shell, has no fixed direction, in accordance with the absence of preferred direction on a hyperboloid surface. To some extent, this gives rise to an extra degree of freedom entering the description of the system of interest. The development of a consistent formalism within this picture is described. Comparison with other approaches is made.

Section: Resultsmentioning

confidence: 78%

Section: Resultsmentioning

confidence: 99%

“…The problem was considered in Ref. [11] with some details. We therefore only remind the main point underlying the solution.…”

Section: Equation For the Wave Function And Mass Operatormentioning

confidence: 99%

Section: • Change Of Variables In Different Formsmentioning

confidence: 99%

“…How to solve this problem was considered by Bakamjian and Thomas [13] (see also Ref. [11] for a practical application of interest here).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Relativistic quantum mechanics: a Dirac's point-form inspired approach

Desplanques

2005

Self Cite

Scaling of hadronic form factors in point form kinematics

Coester

Riska

2003

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 η := 1 4 (v out − v in ) 2 and, over a range of η 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, r 2 ≪ 1/m 2 . 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 η point form kinematics with spectator currents leads to power law behavior of the form factors.

Baryon magnetic moments in relativistic quark models

Juliá-Dı́az

Riska

2004

It is shown that the phenomenological description of the baryon magnetic moments in the quark model carries over to the Poincaré covariant extension of the model. This applies to all the three common forms of relativistic kinematics with structureless constituent currents, which are covariant under the corresponding kinematic subgroups. In instant and front form kinematics the calculated magnetic moments depend strongly on the constituent masses, while in point form kinematics the magnetic moments are fairly insensitive to both the quark masses and the wave function model. The baryon charge radii and magnetic moments are determined in the different forms of kinematics for the light-flavor, strange and charm hyperons. The wave function model is determined by a fit to the electromagnetic form factor of the proton.