Upload
virginia-harrison
View
216
Download
0
Embed Size (px)
Citation preview
Error Estimation of Fragmentation Functions Based on Global QCD Analysis
Tokyo Inst. of Tech.
1. Motivation2. Analysis Method3. Results4. Summary
Contents
20th Sep., 2006
Y. Imazu, Y. Miyachi, T. Hasegawa, Xiaorui Lu,T.-A. Shibata
- 摂動論的 QCD に基づいた破砕関数の誤差評価 -
1. Motivation
Fragmentation Function : “ ” : Phys. Rev., D62:054001
HERMES SIDIS Data with Fitted Curve at
How much does the error of FFs have an effect to A 1h ??
← Determined by pQCD analysis with hadron productions in e+ e - collision
2. Analysis MethodParameterization of FFs at Initial Scale
Totally 11 parameters for π 、K eachIn the calculation of cross section
Experimental data used in my fitting
SLAC-PEP-TPC ( 0.1 < z < 0.8 )
SLAC-SLC-SLD( 0.05 < z < 0.8 )
SLAC-PEP-TPC ( 0.1 < z < 0.8 )
SLAC-SLC-SLD( 0.05 < z < 0.8 )
10
25 14 14
11
27 16 16
0 0
0 029.0
s GeV
91.2
29.0
s GeV
91.2
PION
KAONTotally 70
Totally 63
s
3. Results
PION FF results : parameters and plots
LO NLO
up → π +charm → π +gluon → π +
KAON FF results : parameters and plots
LO NLO
charm → K +up → K +
The effect of FF ambiguity to A1h (LO)
)()(),( 12 hhhh DADD
)(2 KD
)(1 KKd DA
h=kaon
12
0002.00528.0)5.2,9.0( 221 GeVQxA Kd
h=pion
12
)(2 D
)(1 DA p
001.0187.0)5.2,9.0( 221 GeVQxA p
Lagrange Multiplier Method :
4. Summary
・ By performing pQCD (LO, NLO) fit to e+ e- experimental results, We obtained the FF results, which are consistent with those of Kretzer.
・ We estimated the errors contained in the FFs.
・ The effect of FF ambiguity to SIDIS A1h calculation (LO) was evaluated
with chi-square value of FF fit (Lagrange Multiplier Method) to e+ e- data. The effect turned out to be less than 1%.
・ Fragmentation functions (FFs) are needed for pQCD calculation of SIDIS process. However, the errors of FFs had not been estimated.
・ Outlook ; chi-square of SIDIS data