Parton distribution functions and quark orbital motion. P etr Z ávada Inst itute of Physics, Prague. The 6 th CircumPanPacific Symposium on High Energy Spin Physics July 30  August 2, 2007 Vancouver BC. Introduction.
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Petr Závada
Institute of Physics, Prague
The 6th CircumPanPacific Symposium on High Energy Spin Physics
July 30  August 2, 2007
Vancouver BC
In this talk further questions:
[full version in arXiv: hepph/0706.2988 and Eur.Phys.J. C – August2007].
Sum rules were obtained
from:
1) Relativistic covariance
2) Spheric symmetry
3) One photon exchange
Structure functions are represented by integrals from probabilistic distributions:
E155
Calculation  solid line, data  dashed line
(left) and circles (right)
 which followsfrom covariant kinematics!
2004:Our calculation
2007:Extraction from the data(for the first time)Deconvolution of F2 :
Input q(x)
MRST LO 4GeV2

qval=qq
—
<pval>=0.11 (0.083) GeV/c for u (d) quarks
Deconvolution of g1 :
Since G=G++G and ∆G=G++G
d3p
dp/M
… obtained from F2 ,g1 and represent distribution of quarks with polarization ±.
Let us note:
but
!!
(equality takes place only in noncovariant IMF approach)
2) q(x) & Δq(x)
MRST & LSS LO 4GeV2
Remark:
xΔfq(x) are similar to xqval(x)
spin contribution
comes dominatly from valence region
Second scenario:
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 ∆∑≈0.20.35 does not exclude any of these possibilities.
CQSMchiral quark soliton model:
He
Covariant version of QPM involving quark orbital motion was studied. New (LO) results: