# Presentation: 025840

**PHENIX ****Beam Use  Proposal**
**W.A. Zajc**
**for the PHENIX Collaboration **
**( this talk available at**** **_**[http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/RBUP04/](http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/RBUP04/)**__**[ )](http://www.phenix.bnl.gov/phenix/WWW/publish/zajc/sp/presentations/RBUP04/)**_

- 08-Sep-04

- 08-Sep-04

## Beam Use Proposal

**Requested input:**
**Desired “beam run segments”**
**Physics from same**
**Investigate “27” and “31” week scenarios**
**Collaboration/experiment status**** **
**A note on nomenclature:**
**“****Run-1” ******** Summer-2000 Au+Au run at 130 GeV**
**“****Run-2” ******** 2001/2002 Au+Au/p+p at 200 GeV**
**“****Run-3” ******** 2003 run d+Au/p+p at 200 GeV**
**“****Run-4” ******** 2004 run Au+Au/p+p at 200 GeV**

- 08-Sep-04

##       Run-1 to Run-4 Capsule History

**Run-1**

**Run-2**

**Run-3**

-       **Run-1 to Run-4 Capsule History**

**PHENIX Successes (to date) based on ability to deliver physics at ~all scales:**
- barn      : Multiplicity (Entropy)
- millibarn: Flavor yields (temperature)
- microbarn: Charm (transport)
- nanobarn: Jets (density)
- picobarn: J/Psi (deconfinement ?)

- 08-Sep-04

## Run-1 Publications 

**“****Centrality dependence of charged particle multiplicity in Au-Au collisions at ********s****NN**** = 130 GeV”, **_**[PRL 86 (2001) 3500](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000086000016003500000001&idtype=cvips&gifs=yes)**_** **
**“****Measurement of the midrapidity transverse energy distribution from ********s****NN**** = 130 GeV Au-Au collisions at RHIC”, **_**[PRL 87 (2001) 052301](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000087000005052301000001&idtype=cvips&gifs=yes)**_**  **
**“****Suppression of hadrons with large transverse momentum in central Au-Au collisions at ********s****NN**** = 130 GeV”, **_**[PRL 88, 022301 (2002)](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**_**.**
**“****Centrality dependence of ********+/-****, K****+/-****, p and pbar production at RHIC,” **_**[PRL 88, 242301 (2002). ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000024242301000001&idtype=cvips&gifs=yes)**_**  **
**“****Transverse mass dependence of the two-pion correlation for Au+Au collisions at ********s****NN**** = 130 GeV”, **_**[PRL 88, 192302 (2002) ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000019192302000001&idtype=cvips&gifs=yes)**_
**“****Measurement of single electrons and implications for charm production in Au+Au collisions at ********s****NN**** = 130 GeV”,**_**[PRL 88, 192303 (2002)](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000019192303000001&idtype=cvips&gifs=yes)**_
**"Net Charge Fluctuations in Au+Au Interactions at ********s****NN**** = 130 GeV,"  **_**[PRL. 89, 082301 (2002)](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000008082301000001&idtype=cvips&gifs=Yes)**__** **_
**"Event-by event fluctuations in Mean p_T and mean e_T in sqrt(s_NN) = 130GeV Au+Au Collisions"  **_**[Phys. Rev. C66, 024901 (2002)](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000066000002024901000001&idtype=cvips&gifs=yes)**__** **_
**"Flow Measurements via Two-particle Azimuthal Correlations in Au + Au Collisions at ********s****NN**** = 130 GeV" , **_**[PRL 89, 212301 (2002)](http://link.aps.org/abstract/PRL/v89/e212301)**_** **** **
**"Measurement of the lambda and lambda^bar particles in Au+Au Collisions at ********s****NN**** =130 GeV", **_**[PRL 89, 092302 (2002)](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**_** **
**"Centrality Dependence of the High pT Charged Hadron Suppression in Au+Au collisions at ********s****NN**** = 130 GeV", **_**[Phys. ](http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVN-4899P6C-B&_coverDate=05/22/2003&_alid=115796574&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5539&_sort=d&view=c&_acct=C000002018&_version=1&_urlVersion=0&_userid=18704&md5=ab64ecd5f8cfe42c881e0c)**__**[Lett](http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVN-4899P6C-B&_coverDate=05/22/2003&_alid=115796574&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5539&_sort=d&view=c&_acct=C000002018&_version=1&_urlVersion=0&_userid=18704&md5=ab64ecd5f8cfe42c881e0c)**__**[.  B561, 82 (2003)](http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVN-4899P6C-B&_coverDate=05/22/2003&_alid=115796574&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5539&_sort=d&view=c&_acct=C000002018&_version=1&_urlVersion=0&_userid=18704&md5=ab64ecd5f8cfe42c881e0c)**_** **
**"Single Identified Hadron Spectra from ********s****NN**** = 130 GeV Au+Au Collisions",  to appear in Physical Review C,****  **_**[nucl-ex/0307010](http://xxx.lanl.gov/nucl-ex/0307010)**_** **** **

- 08-Sep-04

## Run-2 Publications 

**"Suppressed ********0**** Production at Large Transverse Momentum in Central Au+Au Collisions at ********s****NN**** = 200 GeV" , **_**[Phys. Rev. ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072301000001&idtype=cvips&gifs=yes)**__**[Lett](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072301000001&idtype=cvips&gifs=yes)**__**[. 91, 072301 (2003) ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072301000001&idtype=cvips&gifs=yes)**__** **_
**"Scaling Properties of Proton and Anti-proton Production in ********s****NN**** = 200 GeV Au+Au Collisions“,**** Phys. Rev. Lett 91, 172301 (2003). **** **
**"J/******** Production in Au-Au Collisions at ********s****NN**** =200 GeV at the Relativistic Heavy Ion Collider", ****Phys. Rev. C 69, 014901 (2004). **** **
**"Elliptic Flow of Identified Hadrons in Au+Au Collisions at ********s****NN**** = 200 GeV" ,  Phys.Rev.Lett. 91 (2003) 182301 **** **
**"Midrapidity Neutral Pion Production in Proton-Proton Collisions at ********s = 200 GeV“, ****Phys. Rev. Lett. 91, 241803 (2003) **** **
**"Identified Charged Particle Spectra and Yields in Au-Au Collisions  at ********s****NN****= 200 GeV", **_**[Phys. Rev. C 69, 034909 (2004)](http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000069000003034909000001&idtype=cvips&gifs=Yes)**_** **
**"J/******** production from proton-proton collisions at ********s = 200 GeV“, Phys. Rev. Lett. 92, 051802 (2004) **
**"High-pt Charged Hadron Suppression in Au+Au Collisions at ********s****NN**** = 200 Gev”, Phys. Rev. C 69, 034910 (2004) **
**"Measurement of Non-Random Event-by-Event Average Transverse Momentum Fluctuations in ********s****NN**** =200 GeV Au+Au Collisions" , S.S. Adler et al., Phys. Rev. Lett. 93, 092301 (2004), **** **
**"Bose-Einstein Correlations of Charged Pion Pairs in Au+Au Collisions at ********s****NN**** =200 GeV" ****to appear in PRL, **_**[nucl-ex/0401003](http://arxiv.org/abs/nucl-ex/0401003)**__** **_
**"Deuteron and anti-deuteron production in Au+Au collisions at \sqrt{s} = 200 GeV" , submitted to PRL June 1, 2004,****Preprint: **_**[nucl-ex/0406004](http://arxiv.org/abs/nucl-ex/0406004)**_** **** **** **
**"Identified Leading Particle Correlations in Au+Au and d+Au collisions at ********s****NN**** =200 GeV" , submitted to PRL Aug. 7, 2004, **_**[nucl-ex/0408007](http://arxiv.org/abs/nucl-ex/0408007)**_** **

**Also contains Run-3 d+Au data**

- 08-Sep-04

**Notes:**
BRAHMS Collaboration (I. Arsene et al.)" Transverse Momentum Spectra in Au+Au and d+Au collisions at sqrt(s_NN)=200 GeV and the Pseudorapidity Dependence of High pt SuppressionPhys. Rev. Lett 91, 072305 (2003)

BRAHMS Collaboration"Rapidity dependence of Charged Anti-particle-to-Particle ratios in Au+Au Collisions at sqrt(s_NN) = 200 GeV"Phys. Rev. Lett. 90,102301 Mar. 2003.2002

  BRAHMS Collaboration"Pseudorapidity distributions of charged particles from Au+Au collisions at the maximum RHIC energy"Phys. Rev. Lett. 88, 202301(2002)

ρ0 Production and Possible Modification in Au+Au and p+p Collisions at sqrt(snn) = 200 GeV J. Adams et al, submitted to Phys. Rev. Lett. July 30, 2003. [nucl-ex/0307023](PS| PDF) 

Particle dependence of azimuthal anisotropy and nuclear modification of particle production at moderate pT in Au+Au collisions at sqrt(snn) = 200 GeVJ. Adams et al, submitted to Phys. Rev. Lett. [nucl-ex/0306007] PDF) 

Transverse momentum and collision energy dependence of high pT hadron suppression in Au+Au collisions at ultrarelativistic energiesJ. Adams et al, submitted to Phys. Rev. Lett. [nucl-ex/0305015]. PDF) 

Disappearance of back-to-back high pT hadron correlations in central Au + Au collisions at sqrt(snn) = 200 GeVC. Adler et al. Phys. Rev. Lett. 90, 082302 (2003)(PS PDF) as published: 28 February 2003 

Centrality dependence of charged antiparticle to particle ratios near mid-rapidity in d+Au collisions at sqrt(s_NN)=200 GeVSubmitted to Phys. Rev. C Rapid Comm.     Links: Local, LANL, Figures, and Data 

Charged hadron transverse momentum distributions in Au+Au collisions at sqrt(s_NN) = 200 GeVSubmitted to Phys. Lett.B             Links: Local, LANL, Figures, and Data 

Comparison of the Total Charged-Particle Multiplicity in High-Energy Heavy Ion Collisions with e+e- and pp/pbar-p DatasSubmitted to Phys. Rev. Lett.       Links: Local, LANL, Figures, and Data 

Significance of the fragmentation region in ultrarelativistic heavy ion collisionsPhys. Rev. Lett. 91, 052303 (2003).           Links: Local, LANL, Figures, and Data 

Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(sNN)=200 GeVPhys. Rev. C 67, 021901R (2003)                   Links: Local, LANL, Figures, and Data 

Centrality Dependence of the Charged Particle Multiplicity near Mid-Rapidity in  Au+Au Collisions at sqrt(sNN)=130 and 200 GeV Phys. Rev. C65, 061901R (2002).                  Links: Local, LANL, Figures, and Data 

## Run-3 Publications 

**"Absence of Suppression in Particle Production at Large Transverse Momentum in ********s****NN**** = 200 GeV d+Au Collisions”, **_**[PRL 91, 072303 (2003) ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072303000001&idtype=cvips&gifs=yes)**_
**PID-ed particles (********0****’s) out to the highest p****T****’s PHENIX’s unique contribution to  ****June  ’03 ****“press event”**

- 08-Sep-04

## First (Run-3) Results on ALL

**First results on A****LL****(********0****) :**
**"Double Helicity Asymmetry in Inclusive Mid-Rapidity neutral pion Production for Polarized p+p Collisions at sqrt(s)=200 GeV" ****Preprint: hep-ex/0404027 **
**Submitted to ****Physical Review Letters**
**Compared to calculations by**
- B.Jäger *et al*., PRD67, 054005 (2003)
- M. Glück *et al*., PRD63, 094005 (2001)
**Consistent with GRSV-std****(C.L. ~ 16-20%)**

- 08-Sep-04

## Forthcoming d+Au Results

**Range of papers in preparation:**
**Identified hadron yields**
**Jet properties**
**J/******** yields**
**Centrality dependence of “jet” yields**
**R****CP**** at forward and backward rapidities (next slides)**

**SOUTH ARM**

**NORTH ARM**

- 08-Sep-04

## d

- Au

**Phenix**** ****Preliminary**

- 08-Sep-04

## d

- Au

**Phenix**** ****Preliminary**

- 08-Sep-04

## d

- Au

**Phenix**** ****Preliminary**

- 08-Sep-04

## RCP summary plot

- 08-Sep-04

## Publication Summary

**Run-1**
**12 publications**
**8 are “TopCites”**
**3 of these are “famous”**
**One “archival” summary**
**Run-2**
**12 publications to date**
** ****4 are “TopCites”**
**1 of these is “famous”**
**One “archival” summary**
**Several more nearing completion**
**Direct photons, open charm, energy survey...**
**Run-3**
**2 publications**
**d+Au suppression (a TopCite/famous)**
**First result on A****LL****(********0****)**
**Several in progress**
**Run-4:  > x 10 *****data-size compared to Run-2 Au+Au***

- 08-Sep-04

## Run-4 Additions

**Rφ**

**Z**

**160 Cells**

**PMT’s**

**Aluminum Box**

**Aerogel Array**

**Aerogel in here**

**Light Mixer**

**The Aerogel detector is a threshold Cerenkov counter**
**Aerogel is a very low density, SiO****2**** – based solid**
**Aerogel has index of refr. between gases & liquids. **
**Ident. charged particles in a range inaccessible with other  technologies.**** **

**Run-4 Additions**

- 08-Sep-04

## Aerogel Performance

- 08-Sep-04

## Previous Run Request

**Au+Au at 200 GeV, ****with goal of developing highest possible integrated luminosity**
**An aggressive program of luminosity and polarization development for p+p, ****with the goal of the earliest practicable measurement of ********G**
**Light-ion running, ****to investigate dependence on system size**
**A reduced energy run, ****again with emphasis on obtaining highest possible integrated luminosity**
**High integrated luminosities achieved via minimal variations in species and energies, ****as per CAD guidance**

**✔**

**✔**

**✔**

**✔**

- 08-Sep-04

## Note on Methodology

**Projections based on methodology developed for last year’s 5-year request**
**Implements**
**(Revised) CAD guidance, “linear growth model”**
***Calibrated*****  physics yields for representative measurements based on PHENIX *****measurements ****** ***
**Assumes**
**Overheads:**
**Cool-down: 2 weeks**
**Warm-up   : 1 week**
**Set-up        :**
**Initial set-up = 2 weeks**
**Second species = 1 week (2 for polarized protons)**
**Ramp-up:**
**Useful stable initial luminosity = 2 weeks (1 week for 2****nd**** species)**
**Useful stable initial luminosity = 25% of final value**
**Linear ramp over 8 weeks to final luminosity value**
**PHENIX **
**70% useful vertex fraction**
**60% efficiency**
**Takes geometric mean of CAD minimal and maximal guidance**
**Physics Weeks:**
**1-mode: N Cryo Weeks – 2 –(2 +2) -1 = N Cryo Weeks – 7**
**2-mode: N Cryo Weeks – 2 –(2 +2)-(2+1) -1 = N Cryo Weeks - 10**
**General PHENIX approach: When ever possible, develop equivalent parton+parton luminosity for all species studied**

- 08-Sep-04

## The Run Plan At A Glance

**An quantitative, integrated, planning exercise:**
**Quantitative:**
**Direct implementation of CAD guidance**
**Yield estimates (whenever possible) based on existing PHENIX measurements and known scaling laws**
**Integrated: ****Sequential set of measurements designed to deliver comparable sensitivities in ~ all channels**
**Planning: ****Based on *****current, improved ***** knowledge**** ****of machine, detector, physics and future developments**

- 08-Sep-04

## Current Run Request

**An extensive program of luminosity and polarization development for p+p, ****with the goal of the earliest practicable measurement of ********G**
**Light-ion running, ****to investigate dependence on system size**
**A reduced energy run, ****again with emphasis on obtaining highest possible integrated luminosity**
**High integrated ****luminosities achieved ****via minimal variations**** in species ****and energies, ****as per ****CAD guidance**
**In particular, now****provide for several****consecutive years****of p+p development**

- 08-Sep-04

## Run-5

**31 weeks**
**Cu+Cu 200 GeV**
**10 physics weeks**
**Many rare channels**
**p+p 200 GeV**
**11 physics weeks**
**A****LL****(********0****)**
**27 weeks**
**Cu+Cu 200 GeV**
**8 physics weeks**
**Many rare channels**
**p+p 200 GeV**
**9 physics weeks**
**A****LL****(********0****)**

- 08-Sep-04

## On the Run-5 Species Choice

**On the Run-5 Species Choice**

**0-th order:**
**It’s moot**
**1****st****-order:**
**We desire the species that will lead to highest possible integrated (parton-parton) luminosities**
**CAD guidance ~neutral in this respect**
**2****nd****-order:**
**Clearly depends on assumptions regarding (length, surface, volume) effects**
**We have consistently requested a spectrum of species ****(Run-2, 3 Beam Use Proposals)**
**In hard processes, Cu+Cu offers**
**Some overlap with existing Au+Au data**
**Maximum separation from d+Au data**

- Log10(Nbinary) 

- 08-Sep-04

## ALL(0) in Run-5

**Assumptions:**
**11 physics weeks**
**‘****Usual’ geometric mean of minimum and maximum guidance**
**<P> = 45%**
**Integrated luminosity: 5.5 pb****-1**** **
**Figure of merit: ~100 x Run-3**
**Implications**
**Current errors reduced by ****> factor of ten**
**p****T**** reach extended to ~ 7 GeV/c**
**Access to g+q, ****in addition to  g+g,****production mechanism**

**Run-3 Result****(submitted to PRL)**

- 08-Sep-04

## Quantifying the End Game

**There is a developing tendency to argue for deviations from nominal run plan at the end of each long run**
**Based on the usual √0.90 = 1 arguments**
**Tends to ignore “quality time”**
**If we’re going to do it, let’s  *****plan*****  to do it :**
**PHENIX Conditional Requests for Run-5**
**CR #1: Cu+Cu at 62.4 GeV**
**Clearly 62.4 GeV is our major “reference energy”**
**Clear benefit taking advantage of Cu+Cu setup**
***Provided***** we have met integrated luminosity goal of *****at least*****  2.9 nb****-1**** (recorded)**
**CR #2: p+p at 62.4 GeV**
**The world’s reference data is not up to RHIC standards (next slide)**
**This is a major limitation in *****quantitative***** exploration of R****AA**** vs energy**
***Provided***** we have met integrated luminosity goal of *****at least*****  5.5 pb****-1**** (recorded)**

- 08-Sep-04

## 62.4 GeV Limitations

**The resolving power of R****AA**** from Au+Au 62.4 GeV data is limited by *****world’s reference data***** for identified particle production at this energy:**
**The resolving power of R****AA**** from Au+Au 62.4 GeV data is limited by *****the statistical reach***** of this too-short first look at 62.4 GeV:**
**Hence our Run-6 request for A+A : ****Au+Au at 62.4 GeV**

- 08-Sep-04

## Run-6

**27 weeks**
**Au+Au 62.4 GeV**
**9 physics weeks**
***Some***** rare channels**
**(New): p+p 200 GeV**
**8 physics weeks**
**Use cold snake**
**Continue spin development**
**31 weeks**
**Au+Au 62.4 GeV**
**10 physics weeks**
**Some rare channels**
**p+p 200 GeV**
**11 physics weeks**
**Use cold snake**

- 08-Sep-04

## After Run-1 (Discovery)

- 08-Sep-04

## After Run-2 (Discovery)

- 08-Sep-04

## After Run-3 (Control)

**The “Eureka” combination leading to June ‘03 press event**

- 08-Sep-04

## After Run-4 (Frontier)

- 08-Sep-04

## After Run-5 (Nominal)

- 08-Sep-04

## After Run-5 (Supplement 1)

- 08-Sep-04

## After Run-5 (Supplement 2)

**The optimal ****post Run-5 data sets ****at 62.4 GeV**

- 08-Sep-04

## After Run-6

**After Run-6**

**Optimizing rare probe reach at 62.4 GeV**

- 08-Sep-04

## After Run-7

**After Run-7**

**“****Gold-plated” spin run at 200 GeV**

- 08-Sep-04

## Run-7

**27 weeks**
**p+p 200 GeV**
**20 physics weeks**
**Spin***** production *****run**
**“****Ultimate” comparison set**
**31 weeks**
**p+p 62.4 GeV**
**5 physics weeks**
***Some***** rare channels**
**ISR *****extension***
**(No species change)**
**p+p 200 GeV**
**16 physics weeks**
**Spin***** production *****run**
**“****Ultimate” comparison set**
**In either case, likely that we would provide a conditional request for 500 GeV development**
**Machine studies**
**Trigger studies**

- 08-Sep-04

## Beyond Run-7

**For Run-8 and beyond, various PHENIX upgrades become available:**
**Si-Vertex**
**Hadron Blind Detector**
**Inner tracker**
**Muon trigger**
**Nose Cone Calorimeter**
**These greatly extend our physics reach, and make re-visiting various canonical systems very attractive**
**Precise strategy of course depends on time sequence of availability**
**NSAC (preliminary) guidance: *****“Invest in near-term detector upgrades of the two large experiments, PHENIX and STAR, to take full advantage of the existing accelerator capabilities.”***

- 08-Sep-04

## Run-8

**27 weeks**
**Au+Au 200 GeV**
**20 physics weeks**
**“****Penultimate” Au+Au run**
**First run with upgrades**
**31 weeks**
**Au+Au 200 GeV**
**16 physics weeks**
**“****Ultimate” Au+Au run**
**First run with upgrades**
**p+p 500 GeV**
**5 physics weeks**
**Important acceleration of schedule for 500 GeV running**

- 08-Sep-04

## Summary

**PHENIX successes in Runs 1-4 have paralleled those of the accelerator **
**Ongoing, productive enterprise engaged in timely publication of an extraordinarily broad spectrum of results (Au+Au, p+p, d+Au)**
**Proposed program will extend **
**Investigation of rare processes to address fundamental questions in heavy ion physics**
**Demonstrated spin physics capabilities to higher p****T**** and to new channels**
**Proposed program depends critically on (demonstrated success of) timely development of luminosity and polarization through extended periods of beam development and steady running**

- 08-Sep-04

## Back-up

- 08-Sep-04

## 25 Weeks ???

**Experiments were informed on Friday, Sep. 3****rd**** that default planning assumption for Run-5 is 25 cryo weeks.**
**Comments:**
**IMPOSSIBLE to develop a collaboration run plan in response in intervening 4 (holi)-days**
**HOWEVER:**
**Both the process and the result are unacceptable**
**Regarding this point, BNL is officially on record to this effect:****" In fact, we concluded and indicate in this report, that *****27 weeks per year is sub-critical for the type of running required for the RHIC program***** and 32 weeks is really the proper threshold level for a healthy program in both heavy ion and spin physics at RHIC.”**
**In particular, 2-mode running becomes exceptionally unattractive at 25 weeks, with subsequent disastrous implications for spin and/or heavy ion program.**

- 08-Sep-04

## On Energy Scans

**Nearly all phenomena measured thus far exhibit smooth variation with energy:**
**Those that don’t(?)****(e.g., kaon slopes)****already present in pp data (next slide)**
**Absent compelling arguments, and given **
**Natural smearing from Fermi momentum**
**Scarce beam hours**
**Give higher priority to investigating with highest possible sensitivity the signals that are new at RHIC**

-  **K****–****/K****+**

**p/p**

- 08-Sep-04

- 08-Sep-04

## Why 62.4 GeV?

**Select an energy to make the suppression go away**

- RAA ~  0.4
- (130 GeV)
-                           RAA~0.2
-                          (200 GeV)

- RAA ~  2.0
- (17 GeV)

- RAA ~1.5
- (31 GeV)

***At a ************s  that still allows “full” coverage in p******T******.***
**Nota Bene: **
**RHIC luminosity scales as *****s***** (i.e., E****2**** )**
**ISR p+p comparison data **

- 08-Sep-04

## Run-1 Configuration

**Two central arms**
**Mechanically **** ~complete**
**Roughly half of aperture instrumented**
**Global detectors**
**Zero-degree Calorimeters (ZDCs)**
**Beam-Beam Counters (BBCs)**
**Multiplicity and Vertex Detector ****(MVD, engineering run)**

- 08-Sep-04

## From Run-1 to Run-2

**For 2001 Run:**

- Run-1 (2000)

- 08-Sep-04

## Accomplishments and Discoveries

**First measurement**** of the dependence of the **_**[charged particle pseudo-rapidity density  ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000086000016003500000001&idtype=cvips&gifs=yes)**_**and **_**[the transverse energy ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000087000005052301000001&idtype=cvips&gifs=yes)**_**on the number of participants in Au+Au collisions at ********s****NN**** ****=130 GeV.**
**Discovery**** of **_**[high p](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**__**[T](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**__**[ suppression in ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**__**[p](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**__**[0](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**__**[ and charged particle production ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000002022301000001&idtype=cvips&gifs=Yes)**_**in  Au+Au collisions at ********s****NN**** ****=130 GeV and a systematic study of the scaling properties of the suppression; **_**[extension of these results to much higher transverse momenta ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072301000001&idtype=cvips&gifs=yes)**_**in Au+Au collisions  at ********s****NN**** ****=200 GeV **
**(Co)-****Discovery**** of **_**[absence of high p](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072303000001&idtype=cvips&gifs=yes)**__**[T](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072303000001&idtype=cvips&gifs=yes)**__**[ suppression in  d+Au collisions ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000091000007072303000001&idtype=cvips&gifs=yes)**_**at ****s****NN**** =200~GeV.**
**Discovery**** of the **_**[anomalously large proton and anti-proton yields at high transverse momentum ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000024242301000001&idtype=cvips&gifs=yes)**_**in  Au+Au collisions at ********s****NN**** ****=130 GeV through the systematic study of  ********±**** , K****±**** , p****±**** spectra; **_**[measurement of ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**__**[L](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**__**[ and anti-](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**__**[L](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**__**[ ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000009092302000001&idtype=cvips&gifs=Yes)**_**in Au+Au collisions at ********s****NN**** ****=130 GeV ;  study of the **_**[scaling properties of the proton and anti-proton yields ](http://xxx.lanl.gov/nucl-ex/0305036)**_**in Au+Au collisions at ********s****NN**** ****=200 GeV.**
_**[Measurement of HBT correlations ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000019192302000001&idtype=cvips&gifs=yes)**_**in ********+ ********+ ****and ********- ********-**** pairs in Au+Au collisions at ********s****NN**** ****=130 GeV , establishing the ``HBT puzzle'' of R****OUT**** ~ R****SIDE**** extends to high pair momentum; **_**[extension of these results ](http://arxiv.org/abs/nucl-ex/0401003)**_**to ******** ****s****NN**** ****= 200 GeV**
**First measurement**** of **_**[single electron spectra ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000019192303000001&idtype=cvips&gifs=yes)**_**in Au+Au collisions at ********s****NN**** ****=130~GeV, suggesting that charm production scales with the number of binary collisions.**
**Sensitive measures of **_**[charge fluctuations ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000089000008082301000001&idtype=cvips&gifs=Yes)**_**and **_**[fluctuations in mean p](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000066000002024901000001&idtype=cvips&gifs=yes)**__**[T](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000066000002024901000001&idtype=cvips&gifs=yes)**__**[ and transverse energy ](http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000066000002024901000001&idtype=cvips&gifs=yes)**_**per particle in Au+Au collisions at at ********s****NN**** ****=130~GeV.**
**Measurements of **_**[elliptic flow for charged particles ](http://link.aps.org/abstract/PRL/v89/e212301)**_**from Au+Au collisions at ********s****NN**** ****=130~GeV and **_**[identified charged hadrons ](http://xxx.lanl.gov/nucl-ex/0305013)**_**from Au+Au collisions at ********s****NN**** ****=200~GeV.       **
**Extensive study of **_**[hydrodynamic flow, particle yields, ratios and spectra ](http://xxx.lanl.gov/nucl-ex/0307010)**_**from Au+Au collisions at ********s****NN**** ****=130 GeV and **_**[200 GeV](http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRVCAN000069000003034909000001&idtype=cvips&gifs=Yes)**_**.**
**First observation**** of **_**[J/](http://xxx.lanl.gov/nucl-ex/0305030)**__**[Y](http://xxx.lanl.gov/nucl-ex/0305030)**__**[ production in Au+Au collisions ](http://xxx.lanl.gov/nucl-ex/0305030)**_**at ********s****NN**** ****=200~GeV.**
**Measurement of ****crucial baseline data**** on **_**[p](http://arxiv.org/abs/hep-ex/0304038)**__**[0](http://arxiv.org/abs/hep-ex/0304038)**__**[ spectra ](http://arxiv.org/abs/hep-ex/0304038)**_**and **_**[J/ ](http://xxx.lanl.gov/hep-ex/0307019)**__**[Y](http://xxx.lanl.gov/hep-ex/0307019)**__**[ production ](http://xxx.lanl.gov/hep-ex/0307019)**_**in p+p collisions at ********s****NN**** ****=200~GeV. **

- 08-Sep-04