170 likes | 316 Views
The STAR Heavy Flavor Tracker in 10 slides or less Jim Thomas Lawrence Berkeley Laboratory 19 - January - 2007. “Heavy Flavor” is the Final Frontier. The QGP is the universally accepted hypothesis at RHIC
E N D
The STAR Heavy Flavor Tracker in 10 slides or less Jim Thomas Lawrence Berkeley Laboratory 19 - January - 2007
“Heavy Flavor” is the Final Frontier • The QGP is the universally accepted hypothesis at RHIC • The next step in confirming this hypothesis is the proof of thermalization of the light quarks in RHIC collisions • The key element in proving this assertion is to observe the flow of charm … because charm and beauty are unique in their mass structure • If heavy quarks flow • frequent interactions among all quarks • light quarks (u,d,s) likely to be thermalized Current quark: a bare quark whose mass is due to electroweak symmetry breaking Constituent quark: a bare quark that has been dressed by fluctuations in the QCD sea
Direct Topological Identification of Open Charm Goal: Put a high precision detector near the IP to extend the TPC tracks to small radius The STAR Inner Tracking Upgrades will identify the daughters in the decay and do a direct topological reconstruction of the open charm hadrons. No Mixed events, no random background subtraction.
The HFT: 2 layers of Si at mid rapidity The Heavy Flavor Tracker • A new detector • 30 mm silicon pixels to yield 10 mm space point resolution • Direct Topological reconstruction of Charm • Detect charm decays with small ct, including D0 K • New physics • Charm collectivity and flow to test thermalization at RHIC • Charm Energy Loss to test pQCD in a hot and dense medium at RHIC • R&D with HFT + SSD • A proposal has been submitted and a TDR is in preparation
R&D is Driven by the Fabrication Schedule Driven by the availability of CMOS Active Pixel Sensors Build a full detector with each
Surround the Vertex with Si The HFT is a thin detector using 50 m Si to finesse the limitations imposed by MCS Add the IST, and SSD to form the STAR Inner Tracking Upgrade ( ITUp )
Inside the IFC ~ 1 m • Goal: graded resolution from the outside – in • TPC – SSD – IST – HFT • TPC pointing resolution at the SSD is ~ 1 mm • SSD pointing at the IST is ~ 300 mm • IST pointing at the HFT is ~ 150 mm • HFT pointing at the VTX is better than 50 mm
Keep the SSD, it is a beautiful detector! • The SSD is thin • 1% - double sided Si • The SSD lies at an ideal radius • 23 cm - midway between IP and IFC • The SSD has excellent resolution • (rumor says better than design) • The SSD is too large to be replaced • The money is better spent, elsewhere
Summary • The STAR Inner Tracking Upgrade will explore the Charm sector • We will do direct-topological-reconstruction of open Charm • Our measurements will be unique at RHIC • The key measurements include • V2 • Energy Loss • Charm Spectra, RAA & Rcp • Vector mesons • Angular Correlations • The technology is available on an appropriate schedule
Install and run MimoSTAR IV Detector (Full) Install MimoSTAR III Ladder Install MimoSTAR IV Prototype Detector Install UltraSTAR Detector (Full) X X X X X 06 07 08 09 10 Install and test Prototype detector. Reduced diameter BP is required. HFT R&D and Installation Timeline Install MimoSTAR II Telescope Proposed HFT Timeline – the IST comes about 1 year later X marks the installation dates. Running comes after installation.
R&D in Run 7 A Three Layer Telescope with MimoSTAR II Chips. A full system test from pixel to DAQ using an extension of one TPC sector trigger line.
SSD ~ 60 cm • Double sided Si wafers 300 mm thick with 95 mm x 4.2 cm strips • Crossed at 35 mrad – effectively 30 mm x 900 mm • One layer at 23 cm radius • 20 ladders, 67 cm long • air cooled • < 1.2 • 1 % radiation length @ = 0
IST ~ 36 cm • Singled sided Si wafers 300 mm thick with 60 mm x 4.0 cm strips • Si pads ~ 1 mm**2 on the other side of each ladder • Two layers at 17 & 12 cm radius • 27 ladders, 52 cm long • 19 ladders, 40 cm long • air cooled • < 1.2 • 1.5 % per layer @ = 0
HFT ~ 17 cm • Active Pixel Sensors, thinned to 50 mm thickness • 30 mm x 30 mm pixels • Two layers at 7 & 2.5 cm radius • 24 ladders, 19.2 cm long • 9 ladders, 19.2 cm long • air cooled • < 1.2 • 0.28 % radiation length @ = 0