1 Zhangbu Xu (BNL) What are in eSTAR LoI? Electron Beam [10, 20] What infrastructure/community should IP6 build upon for eRHIC?

2 Future of STAR “When it comes to the future, there are three kinds of people: those who let it happen, those who make it happen, and those who wonder what happened.” -- John M. Richardson, Jr. Zhangbu Xu (BNL)

3 Decadal Plan with a path to eSTAR eSTAR LoI for next NSAC LRP Stage I eRHIC: luminosity electron beam <=10GeV Physics cases based on EIC whitepaper Enough technical details of proposed upgrades for a possible cost estimate Deadline: September 15 to collaboration/ALD, October 1 to BNL/DOE Charge for eSTAR LoI from ALD/BNL

4 Ernst Sichtermann reported to the STAR council in 09/19/ September 2013: submitted to BNL

5 RHIC: eight key unanswered questions Hot QCD Matter Partonic structure 6: Spin structure of the nucleon 7: How to go beyond leading twist and collinear factorization? 8: What are the properties of cold nuclear matter? 1: Properties of the sQGP 2: Mechanism of energy loss: weak or strong coupling? 3: Is there a critical point, and if so, where? 4: Novel symmetry properties 5: Exotic particles

6 Physics Deliverables (EIC whitepaper) 1.Proton Spin 2.Motion of partons 3.Imagining 4.Dense Gluonic QCD matter 5.Quark energy loss & Hadronization ~2025--

7 eSTAR Baseline Detector Configuration Fig.3.2

8 eSTAR Kinematic Coverage Figure 3.1: DIS kinematics of scattered electrons and jets with STAR existing detector coverage.

9 Resolution and Capability

10 Semi-Inclusive DIS with PID Tracking: 2.5 < η < 4 Baryon/meson separation? nucleus electron W-Powder EMCal Pb-Sc HCal Forward Calorimeter System (FCS) BSO iTPC ETTIE

11 Semi-inclusive Measurements Azimuthal correlations in di-hadron (semi-inclusive deep-inelastic scattering) measurements, e + Au  e’ + Au + h 1 + h 2 + X provide sensitivity to gluons and have been proposed as a robust probe of saturation: eSTAR projections for 10 GeV electrons scattering off 100 GeV/nucleon Au beams, 1 fb Fig.2.6 Why not flow, flux tube and multiplicity dependence? – E. Shuryak

12 Exclusive Vector Meson Production Mesons such as  or ρ, which have large wave functions, are anticipated to be considerably more sensitive to the saturation effect. eSTAR advantanges: t resolution (2.5%) low-momentum PID around mid-rapidity

13 How do we get there? BNL document on transition to eRHIC, submitted to DOE 10/14/2013

14 Beam Energy Scan II Program As published in eSTAR LOI Arxiv: Double sign change of v1

15 eSTAR Baseline Detector Configuration Fig.3.2

16 Projects, R&D and More Upgrade projectsYear of completion Total project cost (M$) Funding Sources Supplemental information iTPC potentially significant foreign in-kind contribution Foreign in-kind contribution FCS % from refurbishing E864 HCAL FTS GEM or Silicon HFT’20203faster PIXEL chips CEMC +preshower20245Generic EIC R&D ETOF+WTOF20244STAR TOF/MTD GTRD20245Generic EIC R&D Total (M$) 42FY 12 Dollars Every proposed project has an R&D currently. Science-driven proposals, for instance, in the areas of displaced vertex detection and forward particle-identification, to further strengthen the baseline eSTAR scientific capabilities and program, are missing from the current LoI.

17 On-going R&D Projects  iTPC Design reduce material and padrow arrange  Forward Calorimeter System (FCS) W-power+Fiber  Crystal Calorimeter (BSO) new crystal  GEM based TRD new TRD

18 eSTAR Baseline Detector Configuration Fig Forward Calorimeter System

19 Calorimeter Test Beam and Simulations Approved EIC R&D project from May 2011 UCLA, TAMU, PSU Simulations on jets, photons and hyperons Second testbeam in Feb. HAD Prototype for STAR

20 electron/hadron PID for 5GeV Electron beam Electron coverage: 1>eta>-2.5 PID e/h: 1000 Low material: photon conversion e  h INT report (arXiv: ) Fig.7.18.

21 TPC Inner Sector Upgrade  Staggered readout Only 13 maximum possible points  Issues in Tracking: recognition and resolution Only reads ~20% of possible gas path length  Inner sectors essentially not used in dE/dx  Essentially limits TPC effective acceptance to |η|<1 Inner TPC Upgrade: 1. MWPC (SDU/SINAP) ATLAS sTGC Chinese 973 project 2. Mechanics (LBL/BNL) Eric Anderson (PI) 3. Electronics (BNL/ALICE) 4. Schedule (2017)  =±1  =±1.2  =±2

22 TRD+TOF at Endcap (-2<  <-1)  Inner tracking  TPC (endcap region): TRD + TOF/Absorber sandwich Within <70cm space inside endcap TOF as start-time for BTOF and MTD TOF + dE/dx for electron ID TOF for hadron PID Extend track pathlength with precise points High-precision dE/dx (Xe+CO2) TRD Ming Shao (USTC) TPC IP Iron Endcap TRD TOF / Absorber

23 GEM based TRD – R&D  EIC R&D support (BNL/USTC/IU/Yale)  php/June_2013 MWPC  GEM Prototype TRD with miniDrift GEM (27 time bins) Cosmic ray test results Plan test beam at FermiLab with other EIC R&D projects in October (T1037) Setups at USTC and BNL  Advantage Few ion feedback to drift volume High rate Better position resolution Less space charge effect dE/dx Drift along magnetic field

24 electron/hadron PID for 10GeV Electron beam Momentum (GeV/c)  /e h/e Electron Energy 5  10 GeV EIC task force

25 BSO Crystals for Forward Electron CrystalLong_BSOShort_BSOLong_PWOShort_PWO ID BSO L BSO S PWO-BPWO-A Size 20*20*200mmΦ=25mm,L=30mm25*25*220mm30*30*45mm Very Forward Electron Detection (eta<-2.0) BSO is produced by replacing Ge in BGO with Si, the material cost for BSO reduced by x3-4. Collaborators: USTC,SINAP,THU,UCLA Vendor: Shanghai SICCAS High Technology Coorporation (USTC/UCLA/SICCAS) R&D proposal partially funded by BNL/DOE Production Getting better over time

26 eSTAR Executive Summary  In this Letter of Intent, the STAR collaboration proposes a path to evolve STAR into a major experiment, referred to as eSTAR, at a possible future Electron-Ion Collider (EIC) at Brookhaven National Laboratory, eRHIC.  We demonstrate through simulations that eSTAR will deliver on a broad range of key measurements: inclusive structure functions in (polarized) electron-nucleon and electron nucleus scattering, semi-inclusive observables that have one or more identified particles in the current fragmentation region and dihadron correlations in the low-x regime, exclusive observables in deeply-virtual Compton scattering and in vector meson production processes, including diffractive processes. These measurements have been identified as flagship science cases in the recent EIC community white-paper for the eRHIC facility specifications envisioned in the charge for this LOI.  The baseline eSTAR plan has three essential upgrade projects for the scientific program: Endcap TOF, GTRD, CEMC  eSTAR will rely on a replacement upgrade of iTPC and on a subsequent forward upgrades (FCS and FTS) for completing of STAR’s high-priority programs at RHIC  The majority of the collaboration is strongly supportive of the eSTAR effort and multiple institutions are already actively engaged in simulations and R&D for each of the envisioned upgrade projects.  The detector configuration presented in this Letter of Intent represents the baseline instrument. New collaborators from the broader community are vitally important. Science-driven proposals to further strengthen the baseline eSTAR scientific capabilities and program, are particularly welcome.

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28 eRHIC Machine Design Document Thomas Roser, EIC IAC, 02/28/2014

29 Thomas Roser, EIC IAC, 02/28/2014

30 What happens to eSTAR with 15GeV electron? Clearly the crystal calorimeter becomes essential for covering large x-Q2 kinematics open geometry Low Detector Material Uninstrumented Forward Magnet field 0.5T Acceptance for low momentum large Mid-rapidity momentum resolution good No enough fringe field for forward PID

31 Resolutions of key Kinematics at 15 GeV Electron Energy The correlation between smeared and true y, x, and Q 2 (top left and right, and bottom left) and event purity in the (x,Q 2 ) plane (bottom right), as reconstructed using the electron method. Purity is defined as defined as (Ngen - Nout) / (Ngen - Nout + Nin), where Ngen, out, in are the number of events generated in a bin, smeared out of it, and smeared into it from other bins, respectively. The collision system is a 15 GeV electron beam and a 100 GeV hadron beam.

32 A more compact eSTAR

33 Is STAR Detector too antique for eRHIC Richard Majka (Yale) STAR Decadal Plan 2003 Carl Gagliardi (TAMU) STAR Decadal Plan DetectorYear inst TPC1999 BEMC2005 BSMD2005 EEMC2005 TPC FEE2010 DAQ1K2010 TOF2010 TCU/QT HFT2014 MTD2014 HLT2015 iTPC2017 FCS2020 What left from original: magnet and TPC field cage Trigger System: DSM EMC Readouts

34 Is STAR Collaboration too ancient for eRHIC? Management team (40s) 140 registered juniors Produce 178 Ph.D. (in 15 years) Publish 156 refereed papers Collaboration meeting in 02/14/2014, Blizzard Day

35 eSTAR Executive Summary  In this Letter of Intent, the STAR collaboration proposes a path to evolve STAR into a major experiment, referred to as eSTAR, at a possible future Electron-Ion Collider (EIC) at Brookhaven National Laboratory, eRHIC.  We demonstrate through simulations that eSTAR will deliver on a broad range of key measurements: inclusive structure functions in (polarized) electron-nucleon and electron nucleus scattering, semi-inclusive observables that have one or more identified particles in the current fragmentation region and dihadron correlations in the low-x regime, exclusive observables in deeply-virtual Compton scattering and in vector meson production processes, including diffractive processes. These measurements have been identified as flagship science cases in the recent EIC community white-paper for the eRHIC facility specifications envisioned in the charge for this LOI.  The baseline eSTAR plan has three essential upgrade projects for the scientific program: Endcap TOF, GTRD, CEMC  eSTAR will rely on a replacement upgrade of iTPC and on a subsequent forward upgrades (FCS and FTS) for completing of STAR’s high-priority programs at RHIC  The majority of the collaboration is strongly supportive of the eSTAR effort and multiple institutions are already actively engaged in simulations and R&D for each of the envisioned upgrade projects.  The detector configuration presented in this Letter of Intent represents the baseline instrument. New collaborators from the broader community are vitally important. Science-driven proposals to further strengthen the baseline eSTAR scientific capabilities and program, are particularly welcome.

36 What’s in it for us? WwHA47U&feature=player_detailpage [Linda walks him out of her shop] Tulio: This could be our last chance. Linda: Have a safe flight. [she shuts her shop door in his face and walks away] Tulio: Linda, please listen to me! If we don't do this, his whole species will be gone! [he throws his business card through her shop door post flap] Tulio: Just think about it. Lead Marmoset: Oh, yeah! What's in it for us? Nigel: Well, that's a fair question. [he suddenly takes the lead Marmoset and flies him high into the sky] Nigel: Let's discuss it. [Nigel let's him go making him fall through the sky] Nigel: I certainly see you point. [to the lead marmoset as he's falling down] Nigel: But what could I possibly do for you in return? Mmm? Lead Marmoset: Save me! Save me! Nigel: Oh! Well, that's a thought. Yeah. But is it enough? I don't want to feel like I'm cheating you. Lead Marmoset: Help me! Help me! Help me! We'll do it! We'll do it! Save me! Please! Save meeeee! [just before he hits the ground he stops as Nigel catches him] Nigel: All right, you've twisted my wing. Deal. Now then, anymore questions? [the group of monkeys remain silent] Blu: You want honesty? Fine. Fine, I can be honest. I don't belong here. In fact, I never wanted to come here in the first place. And...and...and you know what? I hate Samba! [Rafael, Nico and Pedro gasp with shock and Nico bursts into tears] Pedro: Hey! That's a little too far! [to Pedro] Nico: Make the mean bird take it back! Blu: Yeah! I said it! Every song sounds exactly the same. [he mimics the samba music and dance] Blu: Tico-taco, ya-ya-ya! Tico-taco, ya-ya-ya! Urrgh! I'm tico-taco outta here. Jewel: Blu, you're flying! Blu: Yeah! Woohoo! I'm flying! I'm really flying! You're right! I'm not an ostrich! I'm not an ostrich! [last lines; Linda watches as Blu flies away behind Jewel towards the jungle] Linda: That's my big, brave boy.

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