Physics with the HFT prototype? Motivation Results of simulation : Acceptance optimization studies Tracking efficiency studies with TPC+PXL Next steps J. Bouchet for the HFT-soft group 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 Motivation PIXEL detector is the inner sub-system of the HFT tracker in STAR 3 (or 2 or 4) PXL sectors (out of 10) will be installed in STAR next year for Run-13 as an engineering run Question : Which geometry is the most efficient for track pointing and physics measurement ? for low Pt D0, opening angle between daughters is large. For higher Pt D0, the opening angle decreases. Different Pt D0 regimes lead to different configurations of the sectors. cosine(φpion-φkaon) vs. PtD0 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

2 configurations studied =108 =72 =144 =36 =180 =0 =216 =324 =252 =288 Triangle-shape Joined-shape 1 sector covers 36 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 Simulation Setup Input: Generate 100k D0 with flat Pt in [0,5], ||<3,|Vz|<10 cm Count : NN : # of D0 input N0 : # of D0 after Pt cut for both daughters and|| <1 N1 : # of D0 with above cuts + TPC>10,PXL=2 N2 : # of D0 in triangle configuration N3 : # of D0 in joined configuration Single track efficiency/ghosting Modify the existing geometry file with Removal of SSD and IST Localization of 3 pxl sectors according the patches configuration ~500 central AuAu Hijing events but NO PILEUP Plus minbias AuAu hijing events for creating pile-up 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Cuts on Daughters: ||<1, TPC>10,PIXL=2, triangle(N2) 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Cuts on Daughters: ||<1, TPC>10,PIXL=2, triangle(N3) 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

What physics can be achieved ? Can we do anything substantial here ? Any physics with the prototype? Charm cross-section Charm Rcp 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

TPC+PXL Efficiency/ghosting studies BFC chain reconstruction and tracking (Sti) with only pixel prototypes geometry = no material form SSD nor IST. 350 hijing events, no pile up. Vertex cuts : |Vreco -VMC| < 0.01 cm : good reconstruction vertex |Vreco | < 10 cm Tracks cuts : Reco TPC hits >15 |η|<1 The definition is : effSiGoodRc = # of tracks with 2 good pixels hit / # of tracks with 2 MC pixel hits Ghosting = # of tracks with 2 good pixels hits / # of tracks with 2 pixel hits 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 Efficiency with TPC+PXL prototype Good tracking efficiency (but no pile-up yet) Hijing – NO Pile-up TPC+PXL TPC+SSD+IST+PXL 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 http://www.star.bnl.gov/protected/jetcorr/kapitan/HFT/upgr15_2010/productionQA/thin/CD1/single/ Ghosting with TPC+PXL prototype Low Ghosting Hijing – NO Pile-up TPC+PXL TPC+SSD+IST+PXL 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 Next steps Include pile-up events : Will increase single track ghosting Study reconstruction of D0 in this environment So far it looks encouraging We have two configurations for x-section and Rcp measurements (if everything else goes well) Please think of what physics YOU would like to do. We will help you run the simulation. 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 Back-up 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 SSD+PXL SSD layer Pixel outer layer Pixel inner layer Note : the x-axis scale changes with the layer 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 PXL only SSD layer Pixel outer layer Pixel inner layer Note : the x-axis scale changes with the layer 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 comments With SSD : Residuals in r/phi for the outer pixel layer is better than w/o SSD Residuals in r/phi for the inner pixel are slightly better than w/o SSD Residuals in r/phi and Z are asymetric (due to the asymetric resolution of SSD) for both outer and inner layer w/o SSD: Residuals in r/phi and Z are symmetric (due to the same resolution of the pixel) 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Some precautions to make Optimization wrt TPC sectors : TPC has 12 sectors PIXEL has 10 sectors 2. TPC sectors health during a physics run : we want to avoid to place a PXL sector matching a unhealthy TPC sector 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011

Star Coll. Meeting, LBNL, Nov. 2011 MRPC ToF barrel 100% ready for run 10 (now!) BBC PMD FPD FMS EMC barrel EMC End Cap DAQ1000 FGT Completed Ongoing MTD R&D HFT TPC FHC HLT 8/2/2018 Star Coll. Meeting, LBNL, Nov. 2011