1. Progress on 2017-LDRD-6: Geometry tagging for heavy ions at JLEIC
Guohui Wei (for 2017-LDRD-6 group)
JLEIC R&D Meeting, JLAB, Feb. 16, 2017
F. Lin

2. Outlines
Introduction
Progress
Summary

3. Geometry tagging at JLEIC
Goal
Demonstrate that with the full-acceptance detector, JLEIC can realize key EIC physics goals
Quark (color-charge) propagation and hadronization
QCD Coherence and gluon saturation

4. Geometry tagging concept
Intra-nuclear cascading increases with d (forward particle production)
Also evaporation of nucleons from excited nucleus (very forward)
Geometry tagging allows us to determine the path length d in the nucleus after the interaction by detecting the final state
Nuclear fragments & particles in ion direction
197Au with tagging
Without tagging, the average d in a nucleus scales as the radius (A1/3)
Upper right plot shows 40 < A < 208
Tagging allows us to select (bins with) events for which the average d is very different from that for the entire nucleus
Lower right plot (evaporation n-multiplicity tag)

5. Impact on key EIC measurements
Quark propagation and hadronization (BeAGLE) h e'
Knowing the path length will greatly improve our understanding of what happens when a quark propagates through nuclear matter.
Energy loss, pT broadening, etc g* pT q e
Coherence and gluon saturation (Sartre)
At low x and Q2, the probe interacts coherently with all gluons in its path
The gluon density can be increased by going to lower x (higher cm energy), or increasing the (nuclear) path length
Heavy nuclei + selection of large path lengths through geometry tagging
Extra boost from non-spherical nuclei?

6. White Paper Chapter 3: The Nucleus: A Laboratory for QCD (p59)
Geometry tagging is essential for this goal!
Low energy is, if anything, beneficial.
...
with 40 GeV/A ion energies.

7. JLEIC is designed to catch all fragments
Extended detector: 80+ m
Ion FFQs
2nd focus on
Roman pots
dp/p
proton-rich fragments
neutron-rich fragments

8. JLEIC is designed to catch all fragments
Ion e
Detector momentum resolution 12 m downstream of the 2nd ion spectrometer dipole for a characteristic set of different initial angles. The right plot is an expanded version of the left figure. The red band is the nominal ±10  beam stay-clear region.
Detector solenoid compensation, Chromaticity Compensation, Dynamic aperture study etc support a good background.

9. Team Theory Physics & generator CODE (BeAGLE & Sartre) A. Accardi
Raphaël Dupre
Tobias Toll (Shiv Nadar Uni., India)
Liang Zheng (Wuhan Uni., China)
Nuclear Physics (Supervision and Tagging detector)
Nadel-Turonski, Pawel (PI)
Mark Baker (MDBPADS)
Charles E. Hyde (ODU), and his student (ODU)
William Brooks, Kawtar Hafidi, Kijun Park
Accelerator Physics (Accelerator and ion forward detection simulation )
Vasiliy Morozov (co-PI)
Guohui Wei

10. Anticipated outcomes/results
Year 1 (FY17)
Implement new model codes (BeAGLE and Sartre) at JLab
Interface to (GEMC) simulation of the full-acceptance detector
Physics analysis of color propagation in eAu SIDIS in JLEIC kinematics
First look at diffraction using Sartre (expanded to include Au, Pb, and Ca)
Resolution for d and b in eAu for JLEIC using BeAGLE
Year 2 (FY18)
Implement 3D Glauber in BeAGLE for deformed nuclei (U)
Use combination of BeAGLE and Sartre for detailed studies of incoherent and coherent diffraction (ground state through photon detection)
Expand color propagation analysis to include U and Ca
Investigate tagging impact of including negative forward hadrons (pions)
Fully clarify the physics impact of key JLEIC detector and IR features
Implement BeAGLE for JLab 12 GeV

11. Outlines Introduction Progress
Unix Group setup in the computer system at Jlab
Improvement on eA collision physics
Implement codes (BeAGLE and Sartre) at Jlab and improvement
Interface to (GEMC) simulation of the full-acceptance detector
GEMC result and Physics analysis of color propagation in ePb collision
(Preliminary)

12. Unix Group Setup
LDRD group of 'ldgeom' has been created in /group.  This is also the 'O' drive on windows machines.
increase the quota of the 'ldgeom' folder in /group from the default value of 2 GB to 100 GB in order to install software and store simulation data
    Name:      Vasiliy Morozov Username:  morozov Staff:           letta Platform:  Windows,Netscape, Firefox Building:  ARC_7 Room:      704-5 Hostname:   Category:  GROUP REQUESTS Subject:   creating a new Unix group for LDRD project Submitted: 12/6/ :32 AM

13. Improvement on eA collision physics
Tobias Toll
diffraction

14. Improvement on eA collision physics
M. Baker, L. Zheng
Two different d(fid) =6.8 fm trajectories
A collision near the center with d(fid)=6.77 fm
A collision near the edge with d(fid)=6.77 fm(>R!) with almost NO material

15. BeAGLE and Sartre at Jlab
M. Baker, L. Zheng
Implement the CODE of BeAGLE at Jlab

16. BeAGLE and Sartre at Jlab
M. Baker, L. Zheng
Improvement on output of BeAGLE

17. BeAGLE and Sartre at Jlab
M. Baker, L. Zheng
Feynman diagram and structure of BeAGLE
Sartre installed at JLAB, Also installed GSL (Gnu Scientific Library)
Installed sartre trunk version 205, Latest version 221 failed to compile at JLAB
Sartre works not so well with ROOT 6
JLAB root 6.0.8, BNL uses root 5.34/18
Sartre uses $ROOTSYS/include/Math/Interpolator.h, which exists in root 5 but NOT in root 6.

18. Interface to (GEMC) simulation
Simulation process
Currently, we use a LUND format for GEMC input, which is translated from GeAGLE output
Maurizio Ungaro will make a new input format for GEMC input for BeAGLE

19. Preliminary results of color propagation in ePb
GEMC simulation with BeAGLE output
GEMC simulation with events of ePb collision
GEMC simulation with 100 events of ePb collision e-
pi-
proton
pi+
Ion
neutron-black
photons-blue

20. Preliminary results of color propagation in ePb
GEMC result plot
IP:
2nd Dipole exit: 71119
2212
Ion
12902
2112 n0
53968
321 K+ 1
211
Pi+ 7
130
K_L0 32 22
gama
4196 14
nu_mu 4
-14
nu_mu- 5
-2112
n0-
3rd FFQ exit: 72801
2212
Ion
14344
2112 n0
54097
321 K+ 6
211
Pi+ 20
130
K_L0 33 22
gama
4255 14
nu_mu 5
-14
nu_mu-
-211
Pi- 28
-321 K- 3
-2112
n0- 4
2nd Focus point: 10511
2212
Ion
10509
321 K+ 1
-12
Nu_e

21. Preliminary results of color propagation in ePb
Residual Ions in ePb collision: at all 10,000 events Pb: 208
Parton in a event
Events’ number 1
9481 2
396 3 79 4 25 5 8 6 7 9 10 11 12
Total
10,000
IP:
~ 5% of the 10,000
events have more than 2 of residual ions after collision.

22. Preliminary results of color propagation in ePb
Ions

23. Preliminary results of color propagation in ePb

24. Preliminary results of color propagation in ePb
Geometry tagging should allow us to significantly extend the reach of this “fm filter” in <d> as well as potentially providing narrower distributions in d (density weight distance).
Neutron propagation and proton propagation are studied due to d and b
The max multiplicity in color propagation are linear to d.
The max multiplicity in events are located at certain value of b.

25. Preliminary results of color propagation in ePb
Roughly, the max angle of neutron and proton in all events have the same Correlation to the d and b as Neutron propagation and proton propagation.
linear to d.
max value located at certain value of b.
For clear study, more events are needed.

26. Summary
The LDRD on geometry tagging for heavy ions at JLEIC is aimed at investigating pardon (color-charge) propagation in cold nuclear matter, as well as coherence phenomena and QCD at large gluon densities in nuclei.
A Unix group named 'ldgeom' has been created at JLAB. The two generator CODE of BeAGLE and Sartre, have been Implemented in the 'ldgeom'. An example with 10,000 events at 10x40 Gev ePb are attained from the CODE of BeAGLE.
Collision physics, CODEs, and interfaces are optimized for JLEIC cases. A preliminary study with ePb collision data is done in CODE GEMC. All final states are simulated in JLEIC ion forward detection area. And we find the max multiplicity in color propagation are linear to d, and located at certain value of b.

27. Thank you
F. Lin