# Presentation: 214046

##  Physics Program - Vector Meson suppression

- PHENIX
- simulated  +-  mass spectrum

- NA50 -- Anomalous J/ suppression. Evidence for QGP??

- But J/’s are also suppressed by non-QGP effects such as absorption, shadowing, etc; as seen in the results from our E866/NuSea measurements at Fermilab.

- A signature of Quark-gluon plasma (QGP) is the suppression of J/ production. The formation of J/’s in a QGP is predicted to be inhibited by color-screening.

- A = pA

- LANL/PHENIX - MJL

##  Physics Program - High-pT Single ’s

**High-p****T**** single-********’s come from heavy mesons, i.e. D’s or B’s**
**These mesons are produced primarily through gluon fusion and thus are sensitive to the gluon structure functions.**
**In p-A collisions the shadowing of gluons can be studied**

**With polarized beams the gluon polarization, ********G, can be studied.**
**W********  ******** ************ ************ can be identified by high-p****T**** single-********’s and W****+****/W****- ****can be used to measure the flavor asymmetry in the nucleon sea including its spin decomposition**

- LANL/PHENIX - MJL

## MVD Physics Program

- Multiplicity & Vertex detector (MVD), e.g. for:
- dN/d for charged particles over very broad rapidity range
- fluctuations in charge particle distributions, e.g. DCC.
- (Zvertex) < 2 mm for the rest of PHENIX

**dN/d******** from MVD**
**for 125 Au-Au events**

**dN/d******** from MVD**
**for one Au-Au event**

- PHENIX w/o MVD : |  | < 0.35

- STAR : |  | < 0.5

- LANL/PHENIX - MJL

## MVD vertex resolution & efficiency for p-p,  p-Au & Au-Au collisions

**MVD vertex resolution & efficiency for p-p,  p-Au & Au-Au collisions**

- LANL/PHENIX - MJL

## Parton Energy Loss

- Analysis of our p-A Drell-Yan data using the Kopeliovich model. Dashed lines with shadowing only; solid lines with parton energy loss of,
- dE/dz = 2.32  0.52   0.5 GeV/fm

- Charged hadron and 0 production at PHENIX versus pT for central collisions which, when compared to pQCD models that work well for peripheral collisions, suggest that jet-quenching or energy-loss may be present.

- dE/dx = 0

- dE/dx =0.25

- LANL/PHENIX - MJL

## Accomplishments

**Completion of South ********-arm**
- chamber construction
- develop, prototype, debug FEE
- install chambers and FEE
- integrate with PHENIX
- shakedown without beam and reduction of FEE noise levels
- Brooks, Mischke, Lee, Leitch, McGaughey, Barnes, Liu (PD), Towell (PD)
- Sondheim, Boissevain (engineers)
**Commisioning of MVD (60%)**
- MCM problems - poor yield --> cost overruns
- DAQ electronics problems identified and fixed
- Sullivan, Van Hecke, Hansen (PD)
**Quark energy-loss in nuclei using FNAL Drell-Yan data**
- approach with Kopeliovich using his model
- Johnson, Moss, Peng, Garvey, McGaughey, Leitch
**J/******** Nuclear dependence in p-A paper** - Leitch+E866
**Hard Processes & RHIC Physics workshop** held last summer right after Cerro Grande fire -       Johnson, Leitch.
**eRHIC**** **- Garvey, Peng; **NPP long-range plan** - Peng, Garvey, Moss, McClelland ....
**Secured **_**construction **_**$ for North ********-arm FEE and began planning, purchases, fabrication - **Brooks ...
**Emerging into physics phase, but hampered by remaining construction, notably North ********-arm!!**

- LANL/PHENIX - MJL

## PHENIX South -spectrometer

**South-******** Spectrometer**
**completed & now installed at intersection region - a huge success for the LANL led team!**

**Three very large detector stations in 8 octants with 20,000 anode wires and 22,000 cathode strips, each  cathode strip read out by a low noise electronics channel**
**8 meters high and weighs around 300 tons**
**over 10 miles of cables**

**Intersection region (and where MVD goes)**

- LANL/PHENIX - MJL

## muTr Mechanics

**Station-2 Chamber being hoisted into South ******** magnet**

**Station-3 Chamber at the construction factory**

**Winding wires for Station-3 at the BNL factory**

- LANL/PHENIX - MJL

## South- FEE

**Station-3**

**Chassis**

**CROC board**

- LANL/PHENIX - MJL

## Supporting  Tr Electronics

**Transition between fiber (outside magnet) and copper signals (inside magnet)**

**Cathode strip calibration system**

- LANL/PHENIX - MJL

## MVD

** ****< 1% radiation length**
-  **38,000 channels of strips & pads**
** ****MCM’s : 256 channels compressed on to a 4-layer board smaller than a credit card**
** ****70 cm long x 2 feet diameter**
** ****Total weight ~20 lbs**

**After a valiant effort by a core group of 3 LANL people, 60% of total channels will be installed and ready for beam in May****. ****(90% by late 2002)**

_**1/4 of **__**partially**__** populated MVD**_

**200 ********m silicon strips**

**Multi-chip Modules (MCM)’s**

_**MVD in its enclosure**_

_**MCM with a dime for scale**_

- LANL/PHENIX - MJL

## People & Highlights of Responsibilities

**Staff  **(widespread involvement in new physics initiatives not listed here)
**Barnes** (1/2 on EDM, return-to-research $ ends this year) : N mechanics, S physics.
**Brooks**** **: -tracking PHENIX DC & manager, -software, N FEE, S physics
**Garvey** (1/2 & retiring soon) : not involved in PHENIX, E866, eRHIC workshops, advisor to BNL & John Browne, RHIC program supporter.
**Lee** : N mechanics manager, HV, S physics.
**Leitch**** **: HENP team leader, N FEE, -calibration system, -software, S physics, J/ suppression, E866 spokesman, PHENIX Executive Council
**McGaughey** : N FEE, -calibration system, -software, S physics, parton enegy-loss, former E866 spokesman.
**Mischke** (moving to other areas) : was S FEE manager, N-FEE consultant, S physics.
**Moss** : spin physics, parton energy-loss, APS DNP chair.
**Peng** (1/4 time on EDM) : E866 physics, parton energy-loss, p-A, PHENIX upgrades, parton physics at PHENIX, FNAL P906, JHF.
**Sullivan**** **: MVD PHENIX DC & manager,  hadron physics, MVD FEE & software.
**Van Hecke** : MVD ancillary systems & DAQ, hadron physics
*** *****Postdocs**
**Hansen** : hadron physics, MVD FEE & software.
-  **Liu** : S FEE, -software & physics, spin physics
-  **Towell** : S & N mechanics & physics
**Engineers**
**Boissevain **(1/4) : MVD constuction,  layout.
**Sondheim** (on construction $) : lead engineer PHENIX 
- 	(NIS Engineering and technicians not listed here )

- LANL/PHENIX - MJL

## Large Presence at BNL

**Full time at BNL:**
**John Sullivan : change-of-station for one year (starting 1/15/01)**
**Three postdocs : Hansen, Liu & Towell**
**More than half-time at BNL:**
**Brooks : more than 80% for recent months**
**Leitch : more than 80% for recent months **
**Mischke**
**Sondheim**
**Substantial time at BNL:**
**Lee, Van Hecke, Boissevain, Barnes**
**Large contributions to Long-range planning exercise:**
**Peng, Moss, Garvey**

- LANL/PHENIX - MJL