1. Photoproduction of charged pions on deuteron
Yuncheng HAN(韩运成)
for the NKS2 Collaboration
School of Nuclear Science and Technology, Lanzhou University
Department of Physics, Tohoku University
A workshop on Hadron Lanzhou
7/31- 8/1, 2009

2. A workshop on hadron physics@LZU, Lanzhou
Collaboration List
Department of Nuclear Science, Lanzhou University, China ,
Y.C. Han , T.S. Wang
Department of Physics, Tohoku University, Japan
N. Chiga, Y. Fujii, T.Fujibayashi, K. Futatsukawa, O. Hashimoto, K. Hosomi,
A. Iguchi, H. Kanda, M. Kaneta, M. Kawai, D. Kawama, T. Kawasaki, S. Kiyokawa,
T. Koike, Y. Ma, K. Maeda, N. Maruyama, M. Matsuzawa, A. Matsumura,
M. Mimori, Y. Miyagi, K. Miwa, S.N. Nakamura, Y. Okayasu, T. Otani,
K. Shirotori, H. Tamura, N. Terada, K. Tsukada, T. Yamamoto, K. Yokota
Laboratory of Nuclear Science, Tohoku University
K. Hirose, T. Ishikawa, H. Shimizu, K. Suzuki, T. Tamae, H. Yamazaki
Ichinoseki National College of Technology
O. Konno
Department of Electrical and Electric Engineering, Akita University,
A. Sasaki
7/31- 8/1, 2009
A workshop on hadron Lanzhou

3. A workshop on hadron physics@LZU, Lanzhou
Content
Introduction
Experimental setups
Analysis and results
Summary
7/31- 8/1, 2009
A workshop on hadron Lanzhou

4. Study of pion photoproduction
Photoproduction on proton:
Locate and identify pion nucleon resonances.
Photoproduction on neutron (deuteron):
Elementary production amplitude, isospin symmetry.
Photoproduction on nuclei:
Modifications of the resonance excitation and their subsequent propagation and decay, brought by the nuclear medium.
7/31- 8/1, 2009
A workshop on hadron Lanzhou

5. Motivation: gd→p-pp, esp. NQF process
Quasi-Free process
Non Quasi-Free process
7/31- 8/1, 2009
A workshop on hadron Lanzhou

6. Motivation: Study of gd→npp+p- reaction
D++ (uuu)
D- (ddd)
7/31- 8/1, 2009
A workshop on hadron Lanzhou

7. Tagged Photon Beam at LNS-Tohoku
Neutral Kaon
Spectrometer 2
200 MeV
electron beam
from LINAC
Sweep magnet
Photon tagging
system
Stretcher-Booster Ring
Emax=1.2 GeV
Radiator
7/31- 8/1, 2009
A workshop on hadron Lanzhou

8. A workshop on hadron physics@LZU, Lanzhou
Photon Tagging System
Photon beam
Electron beam on carbon fiber
Tagged by scattering electron
E= GeV from 1.2 GeV mood electron beam mode
6 MeV coverage per tagging counter
Tagger
Backup
Tagger
Finger
Radiator
7/31- 8/1, 2009
A workshop on hadron Lanzhou

9. A workshop on hadron physics@LZU, Lanzhou
NKS2 Setup
Electron Veto Counter (EV)
680 Dipole Magnet
Inner Hodoscope (IH)
& Outer Hodoscope (OH)
20 cm
LD2Target
Photon beam
1 m
Cylindrical Drift Chamber (CDC)
& Straw Drift Chamber (SDC)
Photon beam
7/31- 8/1, 2009
A workshop on hadron Lanzhou

10. A workshop on hadron physics@LZU, Lanzhou
Analysis
Time selection
Track selection
Vertex position
Particle Identify
Channel selection for gd→p-pp and gd→ np p+p-
→ suppress accidental coincidence
→ suppress noisy of Drift Chamber
→ target region select
7/31- 8/1, 2009
A workshop on hadron Lanzhou

11. Channel selection of gd→(p-pp)3Tr
For reconstructed gd→p-pX mass Mmissing ,
0.8<Mmissing<1.1 (GeV/c2);
For reconstructed gX→p-pp mass Mtarget ,
1.75<Mtarget<2.1 (GeV/c2);
7/31- 8/1, 2009
A workshop on hadron Lanzhou

12. Channel selection of gd→npp+p-
Px<0.2 GeV/c: quasi-free;
Px>0.3 GeV/c: non-quasi-free process;
mx ~ mpeak±3s;
7/31- 8/1, 2009
A workshop on hadron Lanzhou

13. Sub-channel fitting for gd→(npp+p-)NQF
7/31- 8/1, 2009
A workshop on hadron Lanzhou

14. Calculation and various parameters
The cross section is obtained as,
Y is the yield,
Ng is the number of photon,
Nt is the effective deuteron target thickness,
εDAQ is efficiency of data acquisition system,
εaccptance is the acceptance decided by simulation.
εtrack is the efficiency of track reconstructing.
7/31- 8/1, 2009
A workshop on hadron Lanzhou

15. Cross section of gd→(p-pp)QF
Author Eg Bin/ MeV
Benz
Scheffler
Hirose
This work
7/31- 8/1, 2009
A workshop on hadron Lanzhou

16. Cross section of gd→(p-pp)NQF
Errors are 10%
300 MeV
7/31- 8/1, 2009
A workshop on hadron Lanzhou

17. Eg calibration by gd→(p-pp)3Tr
4-momentum conservation: Lg=Lp+Lp1+Lp2-Ld
HAN Yun-Cheng, Wang Tie-Shan, et. al., Chin. Phys. C, Accepted
7/31- 8/1, 2009
A workshop on hadron Lanzhou

18. Comparison of s(gd→ D++D-)
7/31- 8/1, 2009
A workshop on hadron Lanzhou

19. A workshop on hadron physics@LZU, Lanzhou
Summary
Photoproduction gd→p-pp and gd→npp+p- are studied with tagged photons by using
s (gd→(p-pp)QF) agrees well with the previous obtained data.
we get s (gd→(p-pp)NQF),and used to calibrate Eg;
s (gd→D++D- ) are smaller than the previous obtained data
and theory study;
In the future, differential cross sections will be studied, and experiments in the lower energy region are scheduled.
7/31- 8/1, 2009
A workshop on hadron Lanzhou

20. Thanks for your attention!
7/31- 8/1, 2009
A workshop on hadron Lanzhou