# Presentation: 259907

## Heavy Quarks as a Probe of a New State of Matter       LDRD DR Pre-Proposal 20060049DR  A collaboration between P-25, T-8 and T-16

**Heavy Quarks ****as a Probe of a New State of Matter****       ****LDRD DR Pre-Proposal 20060049DR**** ** **A collaboration between P-25, T-8 and T-16**

**April 1, 2005**

****

## Heavy Quarks as a Probe of a New State of Matter 

**Principal Investigator: ****               Patrick McGaughey, P-25**
**Additional Investigators:**** ****          Melynda Brooks, P-25, **
**	****	****	****                                    ****Rajan Gupta, T-8, **
**	****	****	****                                    ****Gerd Kunde, P-25,    **
**                                                              ****David Lee, P-25, **
**	****	****	****                                    ****Emil Mottola, T-8, **
**	****	****	****                                    ****Ivan Vitev,  T-16 and P-25**
**Primary Institutional Goal:****          ****G. Office of Science**
**Additional Institutional Goal:****     A. Science-based**** ****Prediction**

- Budget Request: 1.25 M$/year

## Overview

**A ****new state of matter****, the quark-gluon plasma (****QGP****), is being probed in collisions of heavy ions **
**    ****at RHIC**
**Heavy quarks (charm and beauty) are the ****cleanest**** probe of QGP. ****Next frontier**** of QGP physics**
**We will construct a forward silicon micro-vertex detector (****SVD****) ******** ****unique**** heavy quark experimental capability**
**Close collaboration between ****theory, simulation and experiment**
** **
**World’s best determination**** of QGP properties**

## The Big Bang and Little Bang

**Recreating the Early Universe in the Laboratory**

- 10-24s

- 10-22s

- 10-8s

**Understanding matter at extreme density and temperature**

**QGP**

**Au+Au**

- 1012 deg

## The Relativistic Heavy Ion Program

**The Relativistic Heavy Ion Program**

**H.Politzer, Phys.Rev.Lett. 30, (1973)**

**D. Gross, H.D.Politzer, F.Wilczek**

** ****Fundamental theory**** (QCD) predicts the existence of  **
**  ****a new state of matter - the ****quark-gluon plasma****  (QGP)**

**2004 Nobel Prize in QCD Physics:**

*** ******Are there new states of matter at exceedingly ***
***   ******high density and temperature?***

**From : National Research Council**

**One of the Eleven Science Questions **
**for the 21st Century -**

** ****Most extreme**** and ****strongly  interacting**** **
**   ****matter yet created**
** ****Recreates conditions of ****early Universe****  **
** ****Q****uantitatively establishes**** QGP properties**
** ****Highest priority**** of national nuclear physics  **
**  ****program**

**RHIC  Physics**

## Evidence for the Quark-Gluon Plasma –  Hydrodynamic Flow

**Hydrodynamic pressure gradients**
**drive system evolution – results **
**in anisotropic particle emission**

- Au

- Au

- First time hydro limit with QGP equation-of- state is reached in heavy ion collisions!

- Anisotropy:

- No Flow

## Evidence for Strongly Interacting Opaque Plasma

**Au+Au**

**d+Au**

**Energetic quarks undergo **
**large energy loss**** in the QGP**

**Au******

******Au**

**R****AA**

**Strong suppression**** of pions from Au+Au versus p+p and d+Au collisions**

**Evidence for Strongly Interacting Opaque Plasma**

**Data – PHENIX (from cover of PRL!) **
**Predictions – Vitev, LANL JRO**

**Absence of QGP effect **

## Why Heavy Quarks ?

**Heavy quarks can provide an **_**order of magnitude**_** better determination of the properties of the plasma!**

-   **Have only qualitative evidence for QGP formation - can make  **
**   ****quantitative** **measurements with heavy quarks**
**  ****Heavy quarks (charm and beauty) - produced ****early**** in the **
**   ****collision.  ****Live long enough**** to sample the plasma**
-   **Intrinsic large mass scale** **allows precise calculations **
-   **Mass dependence of diffusion of heavy quarks determines **
**   ****plasma properties, e.g.**** viscosity and conductivity**
-   **Yields of charm and beauty pairs compared to first principle **
**   ****lattice simulations determine the ****energy density and **
**   ****temperature**
-   **Comparison between light and heavy quark suppression **
**   ****distinguishes between theoretical models of ****energy loss**** in the  **
**   ****QGP**

## The PHENIX Detector

**The PHENIX Detector**

**Muon Arm**

**Muon Arm**

- Muon trackers were designed and built by LANL

- Au

- Au

- J/

## D (charm)  e + X  Data from PHENIX Au+Au

**S/N < 1/1**

- 20+% Systematic error on yield

- v2 from electron measurement
- Note large errors, electrons (and muons) are difficult, but provide heavy quark signal

-  Charm and beauty inferred from
-  electrons, but electrons come
-  from many sources  Poor S/N!

**No flow**

**Large flow**

## Silicon Vertex Detector Upgrade

**Silicon Vertex Detector Upgrade**

- Au 

-  Au

**Endcaps detect following by **
**displaced vertex (********r, ********z) of muons:**
**    ****D (charm) ******** μ**** + X**** **
**    ****B (beauty)******** μ**** + X**
**    ****B ******** J/ ******** + X ******** μ****+ ****μ******

- Si planes constructed of strips 50 m by few mm long

- Pinpoint the decay vertex
- to eliminate backgrounds!

## Design of SVD

** ****4 Tracking stations composed of Si pixels, 50 um by few mm long**
** ****Cover 1⁄4 of one muon arm**
** ****Electronics recently developed by FNAL, ~250,000 channels / pixels. **
**  ****First low power, high speed and high resolution pixel detector**
** ****Can detect  ****> 10K B decays ****and **** > 10M D decays per year**** at RHIC**

**Design of SVD**

- x

- x

- x

- x

****

## Dramatic Signal / Background Improvement 

**Dramatic Signal / Background Improvement **
**             ****for Heavy Quarks with SVD**

- _charm_

- beauty

- pT  (GeV/c)

**Simulated Signal to Noise for D********    +X without SVD and with SVD, 10 X improvement is signal / background  ******** accurate  ****yield, slope**** of charm**

- pT  (GeV/c)

- Muon Events

- _charm_

- _Background__ _

- _Background_

- Before vertex cuts

- After vertex cuts

## Taking the Plasma Temperature

**Taking the Plasma Temperature**

**  ****Improved ****lattice QCD calculations **
**    ****of  charmonium  dissociation**

- Currently large theoretical spread
- of "melting" temperatures of heavy
- quark bound states

- Light quark energy loss

-  **State-of-the-art ****heavy **
**   ****quark E-loss calculations**

- To pinpoint the plasma temperature

- To independently constrain              and        to                  and to incorporate
- non-equilibrium field theory transport coefficients into the evaluation of
- energy loss

**Ivan Vitev**

## Why LANL?  

** ****Relativistic Heavy Ion Physics is a ****strategic priority of  LDRD****  **
**  ****DR program ****(Sec. 7.3 Nuclear matter under extreme conditions)**
** ****Extensive experience**** - P-25 developed muon physics program of **
**  ****PHENIX. We built the muon trackers at RHIC and vertex detectors **
**  ****at CERN and FNAL**
** ****Convergence of theory, simulation and experiment**** - T- 8 and **
**  ****T - 16  expertise in non-equilibrium field theory, lattice QCD   **
**  ****simulations and perturbative QCD predictions**
** ****Essential LANL capability**** development - Science Based **
**  ****Prediction for matter under extreme conditions**
** ****Recruitment of outstanding staff**** - Oppenheimer fellow **
**  ****Ivan Vitev (T-16 and P-25) is one of the world’s experts in  **
**  ****relativistic heavy-ion theory**

## Why Now?

**  ****Successful ER**** forward silicon design ****program completed**** **
**   ****(2004), electronics just now available**
**  ****First direct measurement of heavy quarks at RHIC will ****clinch **
**    ****LANL leadership role**** in national nuclear physics program**
**  ****Successful completion of this R&D expected to ****leverage **
**   ****several**** ****$M in DOE funding**** for full detector covering both **
**   ****PHENIX forward arms**
**  ****Demonstrate performance of silicon vertex technology by **
**   ****deploying ****detector covering 1⁄4 of muon spectrometer**** before**
**   ****long Au-Au run in 2008. **
**  ****Window of opportunity** **to make the pivotal measurements **
**   ****which will ****influence the future of RHIC and heavy ion physics****.**

## Summary

**Definitive Physics of New State of Matter:**
- Charm and beauty production cross sections
- Energy loss and flow of charm and beauty in QGP
- Measurement of QGP properties – energy density, temperature, transport properties, viscosity, conductivity
**State-of-the-Art Silicon Vertex Detector:**
- Si end cap covering 1⁄4 muon arm (4 mini-strip layers)
**Unique Opportunity for new LANL Leadership Role: **
- Theory, simulation and experiment of quark-gluon plasma formation and decay in the laboratory
**Nuclear Science Advisory Council Review**:
- Recommends highest priority of RHIC upgrades for PHENIX vertex detector

## Backup slides

## Cocktail Calculation

_**Cocktail Calculation**_

-  p**T** distribution of 0 are constrained
-   with PHENIX 0  and  measurement
-  p**T** slope of , ’  and  are
-   estimated with m**T** scaling
-   p**T** = sqrt(p**T****2 **+ Mhad**2**** – **M**2**)
-  Hadrons are relatively normalized by
-   0 at high p**T** from the other
-   measurement at SPS, FNAL, ISR, RHIC
-  Material in acceptance are studied for
-   photon conversion
- Signal above cocktail calculation can  be seen at high p**T**

**Notes:**
We calculated the cocktail of electron from the sources we considered.
In this calculation, pt spectra of pi0 are constrained with PHOENIX neutral 
and charged pion measurement. 
Spectral shape of the other hadrons are estimated by using mT scaling.
The yield of the other hadrons are relatively normalized by pi0 at
High pt. That normalization factor are taken from the other measurement
In proton induced collisions at those place.
Amount of material in our detector are studied to estimate the contribution 
From photon conversions.
Right figure shows the expected electron yield from several sources
and this black line is a total yield of all expected sources. 
You can see some difference between data and expected yield at
High pt.

## Direct Observation of Open Charm and Beauty

**will allow clean identification of **
**charm and bottom decays**

**Need secondary vertex resolution < 50 ********m (barrel), ****	****< 150 ********m (barrel) **

**Direct Observation of Open Charm and Beauty**

_**Detection options:**_
** ****Beauty and low p****T**** charm through   ****	****displaced e and/or ******
** ****Beauty via displaced J/******
** ****Charm through D ******** ******** K **

- Central arm
- & barrel VTX

- muon arm & endcap VTX

## Simulation of B-> J/-> with Endcap VTX

- Decay Distance (cm)

- 1mm vertex cut eliminates
- >99.95% of prompt J/

- B decays

- Prompt
-    J/

- 1mm cut

- Ratio of B decay
- to prompt J/
- ~ 1%

- =133u

- RHIC 10*L0
- ~400 B-> J/
- per day

- p+p
- S=200 GeV
- L=1036

- Events

## PHENIX Run Plans from Beam Use Proposal

- _Done_

- _Now_

- 

## PHENIX Decadal Plan

## Slide 24

## Example of PHENIX Muon Arm J/ data from Run 4, shown at QM04

- We Also measure single muons from hadron decays

- J/

**Notes:**
Un slide sur l’analyse ??? 

## Silicon Vertex Upgrade

**Endcaps detect following by **
**displaced vertex of muons :**
**D ******** μ** **+ X**
**B ******** μ** **+ X**
**B ******** J/ ****** **+ X** ****** μ****+ ****μ******

**IP**

**μ**

**B**

**Secondary vertex resolution ~133 ********m**

**Endcap mini-strips :**** **
**50 ********m x few mm long**
**~1.0% X****0 ****per layer**
**Instrumented with BTeV ASICs**

## Yields for Heavy Quark Decays to Muons, with a 1⁄4 Arm Si Endcap

| Run | Ions | Luminos. on tape | D   triggered
counts | B   triggered
counts | BJ/ with 1  in SiVTX |
| --- | --- | --- | --- | --- | --- |
| 2007 | p+p | 67 pb-1 | 56*106 | 48*103 | 480* |
| 2008 | Au+Au | 760b-1 | 15*106 | 12*103 | 320* |

- * Rate before application of a vertex cut.

## PHENIX DETECTOR

- 

- Muon trackers were designed and built by LANL