Paper Proposal: Run 9 pp200 Forward Di-jet Asymmetry

Title: Longitudinal Double-Spin Asymmetries for Di-jet Production at intermediate pseudorapidity in Polarized $pp$ Collisions at $\sqrt{s}$ = 200 GeV

PA: Ting Lin, Scott Wissink, Brian Page

Target Journal:
Physical Review D Regular Articles

Abstract:  We present the first measurement of longitudinal double-spin asymmetries $A_{LL}$ for di-jets within the intermediate pseudorapidity range $0.8 < \eta < 1.8$. The di-jets are produced in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s}$ = 200 GeV. Values for $A_{LL}$ are determined for several distinct event topologies, defined by the jet pseudorapidities, and span a range of Bjorken-x down to $x$ ≈ 0.01, a regime where the gluon helicity distribution $\Delta g(x)$ is poorly constrained. The measured asymmetries are found to be consistent with the predictions of global analyses that incorporate the results of previous STAR measurements.

Paper Draft:
General Outline 
1.  Introduction and Motivation
2.  Experiment:  STAR @ RHIC, detector subsystems 
3.  Data and Simulation 
    3.1  Data sets, QA
    3.2  Simulation / embedding details
4.  Jet and Di-jet 
    4.1  Jet reconstruction, underlying event 
    4.2  Di-jet event selection
5.  Experimental methods 
    5.1  Challenges in the forward (EEMC) region
    5.2  Machine Learning approaches and corrections
    5.3  Biases and systematic error estimate
6.  Double spin asymmetries
    6.1  Final results
    6.2  Comparison to theory, prior results
7.  Conclusions

Analysis Note: Analysis Code: 
  • $CVS/offline/paper/PSN0686
Proposed Figure:

Figure 1:Jet Pt, Eta, Phi

Figure 2: Jet Rt

Figure 3: Dijets Mass, Delta-Eta, Delta-Phi

Figure 4: UE delta Mass:

Figure 5: Endcap Jet Pt corrections

Figure 6: Dijet Pt imbalance

Figure 7:

Figure 8: Di-jet kinematic, Figure 9: Di-jet double spin asymmetry.

Back Up:
Preliminary Result Request Talk to Spin PWG
Recent Update to Final Results