# RD-2011-05-16

Meeting to Discuss Simulation Tasks:

- Contact with Accelerator Folks
- Cartoons of what Simulation Output could look like.
- Task assignments.

Today's meeting focussed principally upon how to structure the simulation efforts to lead us to "Cartoon" figures that make the points about how the physics drives the detector choices. We followed slides posted by Abhay pdf. The notes below summarize the discussion resulting from this presentation.

**F_L Driving Momentum Resolution**

- The reduces cross section (Measured/Mott) is described as F2 + f(y)FL.
- Here f(y) is related to the inelasticity y as y/(1+(1-y)^2).
- Extraction of FL at any given x,Q^2 is made by plotting the reduced cross section vs. f(y) and determining the slope.
- EIC contributions to FL are most significant:
- In the x,Q^2 where HERA has not measured.
**In eA collisions (never before been studied).**

- Simulations in eA complicated by theoretical uncertainty.
- Requires radiative corrections.
- Z^2 dependence should be better understood.

- Our initial detector goal should be driven to roughly match the HERA resolution.
- An example cartoon for this information could be

where a boundary line would be formed as an analytic continuation of a few simulations.

**Delta-s driving PID**

- Delta-s is overly complex to draw as a cartoon calculation for our needs.
- Strangeness PDF is a better one as it contains essentially the same info in a simpler form.
- The P-Matrix is a 3x3 matrix of the probability of ID'ing particle of true type pi/K/p as type pi/K/p.
- The most important terms will be the K-as-K (efficiency) and pi-as-K (principle background).
- The cartoon plot would have:
- Strangeness PDF as known today drawn to include the error band.
- Various competing theoretical descriptions.
- Estimated band with Perfect PID and 1 month running at full Luminosity.
- Various bands with decreasing K-as-K and increasing pi-as-K contributions.

- These cartoons would likely have to be a set of several cartoons to tell the story.
- BAD performance will be clear (no improvement in PDF), good performance will require judgement.

**Other Business**

- Radiative Tails will be the toughest part of the physics to model as a simple analytic extrapolation.
- Starting with a few benchmarks for full calculations will provide best guidance.
- Rumors abound that our presentation was well received by the committee.

**Next Meeting**

- The next meeting is proposed for TUESDAY May 31 (to avoid memorial day).
- This meeting will feature a guest appearance by Vadim Ptitsyn to discuss existing work on machine backgrounds.

See you then! Tom