# Presentation: 757199

## The PHENIX Detector

- Muon ID
- Panels

- Central
- Arms

- North Muon
- Arm

- South Muon
- Arm

- Ring Imaging
- Cerenkov

- EM Calorimeter

- Muon Tracking
- Chambers

- Beam-Beam
- Counter

- Multiplicity/Vertex
- Detector

- Time Expansion
- Chamber

- Drift Chambers

- Pad Chambers

- Time of Flight
- Panels

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## J/’ in CuCu 200 GeV

- J/ clearly seen in LVL2 filtered events:

**MUID North**

**MUID South**

**(~300 ********b****-1**** processed through LVL2 and reconstruction, ~400 J/Y per arm)**

- Results obtained in semi-real time! (less than 2 days from data to go through LVL2, calibration, and production).

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## J/’e+e- in CuCu 200 GeV

- J/ also seen in central arm data:

**(~350 ********b****-1**** processed through LVL2 and reconstruction**,**~130 events in peak)**

- Results obtained in semi-real time! (less than 2 days from data to go through LVL2, calibration, and production).

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## You say tomato...

- The PHENIX request in the beam use proposal (BUP) was for 7nb-1 _delivered_ luminosity.
- “Delivered” means luminosity useable by the experiment
- BUP assumes 0.7 for vertex cut, 0.6 for PHENIX duty cycle
- This gives the PHENIX goal of 2.9 nb-1.
- The PHENIX minimum bias trigger is the BBC LL1.
- Sees ~90% of the CuCu inelastic cross section
- (3.228 barns x 0.9 = 2.91 barns)
- We believe the ZDC sees ~90% of the BBC LL1 cross section
- (2.91 barns x 0.9 = 2.62 barns)
- Use CAD nominal value of 2.5 barns when we report ZDCNS luminosity
- We report “live” luminosity (seen by DAQ)

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## 200GeV CuCu Integrated Luminosity

**200GeV CuCu Integrated Luminosity**

**668 ********b****-1 ****live BBCLL1 (********=2.91 b)**

**(575 ********b****-1 ****with MuID North)**

**1.14 nb****-1 ****live ZDCNS (********=2.5 b)**

**(830 ********b****-1 **** in last week!)**

**PHENIX Goal 2.9 nb****-1 ****live BBCLL1**

**1.9 B BBCLL1 events **_**sampled**_
**292 M events **_**recorded**_

**(As of 2/1/2005)**

**(43 days)**

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## Converting to RHIC Delivered

- We need two numbers to convert RHIC delivered to PHENIX sampled:
- The 1.14 nb-1 of ZDCNS corresponds to 0.668 nb-1 BBC LL1
- Conversion factor 0.59  **(approx. the PHENIX vertex cut)**
- Since Jan 18th, RHIC delivered ~2.8 nb-1 ZDCNS while PHENIX sampled 1.14 nb-1
- Conversion factor 0.41 **(This is **_**NOT**_** the PHENIX duty cycle!)**
- So, 2.9 nb-1 of PHENIX BBC LL1 corresponds to a “RHIC delivered” number of:

**(Jan. 11****th**** offset)**

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## What PHENIX Needs...

- While current projections look promising, we need to work to get an additional “safety factor” to insure we reach our goals:
- Suggest that weekday day-shift machine development continue through Feb 11th
- Focus on increasing luminosity w/o “dramatic” changes
- bunch intensity
- 37x37 to 40x40, maybe higher?
- PHENIX rare triggers good to ~90kHz ZDC rate
- From Feb. 14th through the end of the run the focus shifts to reproducibility of stores and duty cycle
- Machine development two day shifts per week/ as needed
- The above suggestions serve two purposes
- Maximize the probability of reaching our goals even with “disasters”
- Keep the machine tuned for optimal performance

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## 62 GeV CuCu?

- PHENIX is _very interested_ in a low-energy CuCu run, provided:
- PHENIX has reached the 200 GeV goal of 2.9nb-1.
- Currently projected ~50 days after Jan 11th physics start (March 2nd)
- There is sufficient time allocated to integrate a comparable “pp equivalent” luminosity:
- AuAu pp equivalent luminosity at 62 GeV was 0.36 pb-1
- Assuming _current_ CuCu 200 GeV luminosity (~415 b/week):
- Drop a factor of ~10 for lower energy
- “pp equivalent” = 63 x 63 x 41.5 = 0.165 pb-1 /week
- Need two weeks of running plus three days setup time

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## BACKUP

- J. Lajoie - RHIC Time Meeting

- 2/1/2005

## Optimal Store Length

**~5% loss **

**Long lifetime – less sensitive to store length.**

- J. Lajoie - RHIC Time Meeting

- 2/1/2005