The Effect of Errors of Fragmentation Functions on the Analysis of Parton Helicity Distribution. - 縦偏極パートン分布関数解析に対する、破砕関数の影響 -. Tokyo Tech. Y. Imazu , Y. Miyachi, T.-A. Shibata. Mar. 25, 2007. Contents. 1. Motivation 2. FF and pPDF Analyses 3. Effects of the error of FFs
on the Analysis of Parton Helicity Distribution
- 縦偏極パートン分布関数解析に対する、破砕関数の影響 -
Y. Imazu, Y. Miyachi, T.-A. Shibata
Mar. 25, 2007
2. FF and pPDF Analyses
3. Effects of the error of FFs
on pPDF analysis
The error of FFs could affect the determination of ⊿q.
How large is the effect?
Polarized Inclusive DIS :
Polarized Semi-Inclusive DIS :
Fragmentation functions (FFs) are important elements in SIDIS asymmetry.
Fragmentation Functions (FFs) :
← determined by pQCD analysis of hadron productions in e+ e－collision
“ Kretzer ” : Phys. Rev., D62, (2000) 054001
“ KKP ” : Nucl. Phys., B582, (2000) 514,
I estimated the errors of FFs based on Ktetzer parameterization
Analysis including SIDIS data from SMC and HERMES
- Brute force method for the convolution integrals in x and z.
- Analysis with inclusive data converged and are consistent with
other pPDF QCD analysis
- LO analysis ( reported in Spring 2006 )
- NLO analysis was carried out.
Error estimation of FF
- Statistical error estimation for Kretzer-FF
( reported in Autumn 2006)
: Error from fit (⊿χ2＝１)
Results of NLO ⊿q analysis with SIDIS data with central values of my FFs
⊿u = 0.85±0.05 ⊿d = -0.41±0.13 ⊿sea = -0.07±0.04 ⊿g = 0.04±0.33
With the assumption of SU(3) symmetric sea, motivated
by D. de Florian et al. (DNS05): Phys. Rev. D71, (2005) 094018
to obtain well-defined error bands; well converged covariant matrix
Hadron Production in e+ e- collision
EX. h =
EX. Results of the analysis of NLO pion FF with Kretzer parameterization
up → π +
gluon → π +
on pPDF analysis
・Comparison of σA_FF with experimental errors (bar)
and pPDF induced errors (band)
( AExp – AThe ) / σA_FF
(σA_FF : From Pion FF )
・The effect of FF on @ NLO
・Semi-Inclusive DIS, which needs information on FF,
is an important process to obtain information on flavor decomposition.
・pPDF and FF analyses are in progress in pQCD numerical calc. framework.
SIDIS Analysis at NLO
Statistical error on Kretzer-type FF
・The effect of the error of FF on pPDF analysis was studied in several ways,
based on my current results of pPDF and FF analyses.
・The effect tuned out to be small.
・Rather strong dependence on the choice of FF models
D. de Florian et al. (DNS05): Phys. Rev. D71, (2005) 094018
Investigation of new models of FF and its validity
・ Current chi-squared values of pPDF fit
・Estimation of σA_FF: A1h error from FFs
h = π+
σA_FF=Few % @ LO
Almost the same effect even @ NLO