1 / 11

Challenges and Innovations in PHENIX Run8 and Forward Planning for Run9

The PHENIX experiment faced significant challenges during Run8, marked by a major detector upgrade limited to the MPC. During the 500GeV longitudinal data collection, key measurements included the first W bosons in the central arm and jet kT asymmetry. Discussions for Run9 centered on the need to balance direct photon studies and W physics goals within the constraints of current machine performance. The focus was on refining integrated luminosity, addressing statistical significance issues, and determining interim goals for the 200GeV program to effectively progress in the burgeoning field of spin physics.

sebastian-ramirez
Télécharger la présentation

Challenges and Innovations in PHENIX Run8 and Forward Planning for Run9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Run8pp and Run9PHENIX Kensuke Okada April 4, 2008 RSC meeting

  2. PHENIX Run8pp It was a hard time for PHENIX. Only MPC is the major detector upgrade since Run6. 500GeV longitudinal ~5 weeks (3 weeks preparation + 2 week physics) New cross section measurement First Ws in the central arm Check muon arm condition for the trigger upgrade 200GeV transverse-radial 6 weeks IFF (at the central arms) Jet kT asymmetry A_N with MPC 200GeV transverse-vertical 6 weeks (after 3 weeks of struggling) IFF (2.3 times less statistical significance compared to with radial) Jet kT asymmetry (forward hadron + central = new trigger) A_N photon, MPC

  3. Integrated luminosity From M.Leitch pp - almost no progress on luminosity & polarization development towards future 5.2 pb-1 200 GeV p+p Transverse Vertical luminosity recorded (1.1 pb-1 FOM) Peak luminosity per day ~0.37 pb-1 (r)adial (t)ransverse Now we have a big sample of transverse data.

  4. Recorded / delivered From M.Leitch Black vertical lines are markers for Maintenance and/or APEX days • 200 GeV p+p • Live Time – 89% • PHENIX up – 69% • Overall (w/o vertex) – 62% • (where 10% correction for loss due to CNI measurements is made) The vertex cut is a big factor. (9MHz Cavity + beta squeeze) will be more effective.

  5. Run9 discussion (It is a very simplified version) • Two goals  Direct photon ALL to settle the g program (The original goal was 320/pb. It is reduced to 71/pb recorded.)  500GeV run for W physics • But both can’t be accomplished in a single (or two) run with the current machine • performance. • Options we discussed  Low energy (e.g. 62GeV) run to access larger x range?  The discriminating power is almost same as 200GeV run, because of the low pT limitation. And there may be a difficulty in the theoretical interpretation. (*) under the GRSV model.  Search for non-zero ALL evidence in 0 mode with more statistics. If there is no hint, we would postpone the g program for a while until our detector upgrades.  How much FOM do we need to make this decision?  Jump into the 500 GeV program directly. Postpone the 200GeV program.

  6. Remarks  Search for non-zero ALL evidence in 0 mode with more statistics. If there is no hint, we would postpone the g program for a while. How about 25/pb, 60% polarization? s=200 GeV, 25 pb-1 P=0.6 From the pi0 projection plot, there is no strong reason to set the goal at this FOM…. GRSV-std It is getting closer to the relative luminosity uncertainty derived from the comparison between ZDC and BBC counts. The spin flipper helps to reduce the systematic uncertainty. GRSV-0

  7. Remarks  Jump into the 500 GeV program directly. Postpone the 200GeV program. From the RSC meeting on Nov.30 10/pb/week (200GeV) *0.25 (vertex, exp. uptime) *2.5 (500GeV/200GeV) ―Parity violation process (W physics) AL measurement Central arm: W+e+ 140/week for 7.5/pb/week signal asymmetry ~0.25 Requiring 1/P/sqrt(2N)~0.25 /3 leads N~300 with P=0.5 BG contamination reduces the significance. Muon arm: A proto-type will be Installed in Run9 !! Without a trigger and a thick absorber, it’s not useful. We obtain a result with 2 weeks physics period.

  8. Summary PHENIX had a hard time in Run8. In Run9, we can’t finish the g program in a single year. Can we set a reasonable interim goal for 200GeV longitudinal program? Or we go to the 500GeV program ? More materials in the following slides • Inclusive measurements Eta in the central arm : technically similar to pi0 ± ALL : due to RICH threshold, it starts at ~5GeV/c Direct photon ALL : An isolation cut is effective from ~9GeV/c MPC forward pi0 ALL : access to low x gluon. • Model calculation Are we able to distinguish GRSV and GS-C with MPC pi0? Theory scale uncertainty in ALL

  9. astrid Central arm, based on run6 preliminary

  10. astrid

  11. Robert Central arm, With an isolation cut. At low pT, suffered by dilution factor.

More Related