Parton distribution functions and quark orbital motion. P etr Z ávada Inst itute of Physics, Prague. The 6 th Circum-Pan-Pacific Symposium on High Energy Spin Physics July 30 - August 2, 2007 Vancouver BC. Introduction.
Institute of Physics, Prague
The 6th Circum-Pan-Pacific Symposium on High Energy Spin Physics
July 30 - August 2, 2007
In this talk further questions:
[full version in arXiv: hep-ph/0706.2988 and Eur.Phys.J. C – August2007].
Sum rules were obtained
1) Relativistic covariance
2) Spheric symmetry
3) One photon exchange
Structure functions are represented by integrals from probabilistic distributions:
Calculation - solid line, data - dashed line
(left) and circles (right)
- which followsfrom covariant kinematics!
2004:Our calculation2007:Extraction from the data(for the first time)
Deconvolution of F2 :
MRST LO 4GeV2
<pval>=0.11 (0.083) GeV/c for u (d) quarks
Deconvolution of g1 :
Since G=G++G- and ∆G=G++G-
… obtained from F2 ,g1 and represent distribution of quarks with polarization ±.
Let us note:
(equality takes place only in non-covariant IMF approach)
2) q(x) & Δq(x)
MRST & LSS LO 4GeV2
xΔfq(x) are similar to xqval(x)
comes dominatly from valence region
<s>, Γ1: two ways, one result
-covariant approach is a common basisSpin and orbital motion
implies, that a room for gluon contribution can be rather sensitive to the longitudinal polarization:
For ∆∑≈1/3, 0.3 and 0.2 gluon contribution represents 0, 10 and 40%. Value empirically known ∆∑≈0.2-0.35 does not exclude any of these possibilities.
CQSM-chiral quark soliton model:
Covariant version of QPM involving quark orbital motion was studied. New (LO) results: