1. Kao, Chung-Wen Chung Yuan Christian University
Kaon and Pion Fragmentation functions and SIDIS off deuteron
Kao, Chung-Wen
Chung Yuan Christian University
In collaboration of D.-J. Yang, F.-J.Jiang (NTNU, Taiwan)
W.-C.Chang (AS), S-.i. Nam (Pukyong National University, Korea)

2. How to extract Fragmentation functions?

4. SIDIS using deuteron target
p: proton, n: neutron

5. SIDIS using deuteron target
Charge Conjugation

6. SIDIS using deuteron target
Assume PDFs are charge symmetric:

7. SIDIS using deuteron target

8. Constrains on A and B
Since S(x)>0, Q(x)>0, then S(x)/Q(x) is positive!
Note that the values of A and B are independent of x!

9. HERMES Data of Pion multiplicity

10. HKNS (LO)
HKNS (NLO)
DSS (LO)
DSS (NLO)
5.NJL-Jet Model
6.Nonlocal Chiral Quark Model
7.AKK08
8.SMKA 9.DSEHS

11. Analysis of A and B

12. Kaon Multiplicity

13. HERMES Kaon Data
A. Airapetian et al. (HERMES Collaboration), Phys. Rev. D , (2014).

14. HKNS (LO)
HKNS (NLO)
DSS (LO)
DSS (NLO)
5.NJL-Jet Model
6.Nonlocal Chiral Quark Model
7.AKK08

15. M.Stolarski (COMPASS Collaboration), in SPIN2014, 21st International Symposium on Spin Physics, Beijing, October 19–24, 2014

16. HKNS (LO)
HKNS (NLO)
DSS (LO)
DSS (NLO)
5.NJL-Jet Model
6.Nonlocal Chiral Quark Model
7.AKK08
8.SMKA

17. Analysis

19. HERMES Pion Data:

20. HERMES Kaon Data:

21. COMPASS Kaon Data:

22. Best fit values of A and B
Aπ<Bπ!
Bk<0!

23. Conclusion
To be consistent with HERMES data, the u quark is more likely to fragment to pion rather than kaon.
Only Nonlocal chiral quark model can be compatible with both HERMES data of pion and kaon.
But the S(x)/Q(x) derived from pion and kaon multiplicity of SIDIS are not consistent
with the one from PDFs.

24. Outlook: NLO analysis

25. Outlook: NLO analysis
Analysis will become formidable!