2,599 research outputs found
Deformed Supersymmetric Mechanics
Motivated by a recent interest in curved rigid supersymmetries, we construct
a new type of N=4, d=1 supersymmetric systems by employing superfields defined
on the cosets of the supergroup SU(2|1). The relevant worldline supersymmetry
is a deformation of the standard N=4, d=1 supersymmetry by a mass parameter m.
As instructive examples we consider, at the classical and quantum levels, the
models associated with the supermultiplets (1,4,3) and (2,4,2) and find out
interesting interrelations with some previous works on non-standard d=1
supersymmetry. In particular, the d=1 systems with "weak supersymmetry" are
naturally reproduced within our SU(2|1) superfield approach as a subclass of
the (1,4,3) models. A generalization to the N=8, d=1 case implies the
supergroup SU(2|2) as the candidate deformed worldline supersymmetry.Comment: 1 + 36 pages, Substantial revision: new comments, footnotes,
references and Appendix B added, typos corrected; published versio
The Role of Higher Twist in Determining Polarized Parton Densities from DIS data
Different methods to extract the polarized parton densities from the world
polarized DIS data are considered. The higher twist corrections to
the spin dependent proton and neutron structure functions are found to be
non-negligible and important in the QCD analysis of the present experimental
data. Their role in determining the polarized parton densities in the framework
of the different approaches is discussed.Comment: To appear in the Proceedings of the Spin2004 Symposium, Trieste,
11-16 Oct 200
Target Mass Effects in Polarized Deep Inelastic Scattering
The target mass effects in polarized DIS have been studied. It was
demonstrated that taking into account the first order target mass corrections
to g1 a very good approximation of the exact formula is achieved. It was also
shown that their magnitude in the preasymptotic DIS region is small except for
x > 0.65, where their large effect is partially suppressed by the large values
of due to the cut . The difference between the size of the
target mass and higher twist corrections is illustrated.Comment: 8 pages, LaTeX, 5 figures, typo in Eq. 3 corrected, comment added, to
appear in Mod. Phys. Lett.
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