1. Parametrization of nuclear parton distributions
Shunzo Kumano
Saga University
Collaborators: M. Hirai (Saga),
M. Miyama (Tokyo)
Ref. SAGA-HE-170, to be submitted
International Symposium
on Nuclear Physics
Mumbai, India, Dec , 2000
Dec. 20, 2000

2. - Contents - Introduction parton distributions in the nucleon
parton distributions in nuclei
EMC effect, shadowing
Parametrization of
nuclear parton distributions
1. functional form of fiA(x)
2. constraints: A dependence,
conservation laws
3. 2 fitting to experimental data
4. results: optimum nuclear parton
distributions
Summary 

4. Current status on unpolarized distributions in the nucleon
Parton distributions are determined
by fitting various experimental data.
electron/muon
neutrino
Drell-Yan
direct photon
...
(1)
(3)
(2)

5. Available data for determining
parton distributions
(Ref. MRST, hep/ph )

6. Recent unpolarized distributions
CTEQ5, Eur. Phys. J. C12 (2000) 375
GRV98, Eur. Phys. J. C5 (1998) 461
MRST99, Eur. Phys. J. C14 (2000) 133
Unpolarized distributions are well known
in the nucleon.

7. parton distributions in nuclei
Nuclear modification of F2A / F2D is
well known in electron/muon scattering.
Fermi motion
shadowing
original EMC finding
(binding, subnucleon?)

8. Convolution

9. Parametrization of
nuclear parton distributions
without relying on models!

10.  

11. A dependence  “surface” “volume” R= r0A1/3
Ref. I. Sick and D. Day, Phys. Lett. B 274 (1992) 
R= r0A1/3
“surface”
“volume”

14. 7 parameters for 309 data points

15. x Experimental data on F2A/F2D Q2 (GeV2) NMC: He, Li, C, Ca
SLAC: He, Be, C, Al, Ca, Fe, Ag, Au
EMC: C, Ca, Cu, Sn
E665: C, Ca, Xe, Pb
BCDMS: N, Fe
Q2 (GeV2) x

16. DGLAP Q2 evolution equation
x  divided　into Nx step 
t (=lnQ2)  divided　into Nt step
See our studies in Comput. Phys. Commu.
94 (1996) 185; (1998) 38; 111 (1998) 150.
Evolution programs could be obtained upon request.
See

18. Analysis results

21. Obtained F2A/F2D

22. 2 contributions
* next figs *

23. Example of 2 contributions

24. Weight functions wi(x,A)

25. Errors in the weight functions

26. Obtained parton distributions

27. Summary