eic detector r&d simulation workshop summary
DESCRIPTION
EIC Detector R&D Simulation Workshop Summary. Simulation Workshop. Workshop@BNL 8 th & 9 th of October https://wiki.bnl.gov/conferences/index.php/EIC_RD_Simulation/ Agenda Covered Topics Physics case for the EIC Golden measurements to benchmark the detector performance Software - PowerPoint PPT PresentationTRANSCRIPT
EIC Detector R&D Committee Meeting, October 2012
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EIC Detector R&D Simulation WorkshopSummary
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 2
Simulation Workshop Workshop@BNL 8th & 9th of October
https://wiki.bnl.gov/conferences/index.php/EIC_RD_Simulation/Agenda
Covered Topics Physics case for the EIC Golden measurements to benchmark the detector
performance Software
simulation tools (physics generators,fast smearing generator,..)
physics generators not discussed here summarized perfectly in
https://wiki.bnl.gov/conferences/images/d/db/TollEICRnDOctober2012.pdfdetector simulations (FairRoot@BNL, GEMC@JLab, ….)computing power and environment
eRHIC and ELIC/MEIC IR designstracking of protons and neutrons through IR
machine backgrounds (hadronic, synchrotron radiation, …)
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 3
What needs to be covered
E.C. Aschenauer
e’
t
(Q2)e
gL*x+ξ x-ξ
H, H, E, E (x,ξ,t)
~~
g, p,J/Y
p p’
Inclusive Reactions in ep/eA: Physics: Structure Fcts.: F2, FL Very good electron id find scattered lepton Momentum/energy and angular resolution of e’ critical scattered lepton kinematics
Semi-inclusive Reactions in ep/eA: Physics: TMDs, Helicity PDFs flavor separation, dihadron-corr.,… Kaon asymmetries, cross sections Excellent particle ID: p±,K±,p± separation over a wide range in h full F-coverage around g* Excellent vertex resolution Charm, Bottom identification
Exclusive Reactions in ep/eA: Physics: GPDs, proton/nucleus imaging, DVCS, excl. VM/PS prod. Exclusivity large rapidity coverage rapidity gap events ↘ reconstruction of all particles in event high resolution in t Roman pots
EIC Detector R&D Committee Meeting, October 2012 4
Inclusive DIS
E.C. Aschenauer
Measure of resolution powerMeasure of inelasticityMeasure of
momentum fraction of struck quark
e- p/A
0o 180o
+h -h
diverges forye0
depends on E’e
diverges forq’e180o
depends on E’e and q’e
Note: to measure x, y, and Q2 at low Q2 ~ 1 GeV2
Electron method
precise energy and angular resolution for q’e 180o and
high y
At low y use hadron methodHadron method:
EIC Detector R&D Committee Meeting, October 2012 5
DIS Kinematics
E.C. Aschenauer
Even for colliders: Strong x-Q2 correlation high x high Q2
low x low Q2
low y-coverage: limited by E’e resolution hadron method
high y limited byradiative correctionscan be suppressed byrequiring hadronicactivity HERA
y>0.005
Possible limitations in kinematic coverage:
EIC Detector R&D Committee Meeting, October 2012 6
Lepton Kinematics
E.C. Aschenauer
Increasing Lepton Beam Energy:5 GeV: Q2 ~ 1 GeV h ~ -210 GeV: Q2 ~ 1 GeV h ~ -4
highest E’e at most negative rapiditiesindependent of Eh
√s
EIC Detector R&D Committee Meeting, October 2012 7
Scattered Lepton Kinematics
E.C. Aschenauer
CUTS: Q2>0.1GeV2 && 0.01<y<0.95
higher √s:scattered lepton has small scattering angle negative rapidities
EIC Detector R&D Committee Meeting, October 2012 8
Pion Kinematics
E.C. Aschenauer
Cuts: Q2>1 GeV, 0.01<y<0.95, z>0.1
Increasing Hadron Beam Energy: influences max. hadron energy at fixed hIncreasing 30 GeV < √s < 170 GeV hadrons are boosted from forward rapidities to negative rapidities the same for p±, K±, p±
√s
EIC Detector R&D Committee Meeting, October 2012 9
Hadron, lepton, Photon Separation
E.C. Aschenauer
5 GeVx50 GeVhadronphotonelectron
no cuts applied
hadron/photon suppression factor needed for pe’>1GeV:-3<h<-2: ~10-2<h<-1: > 100-1<h<0: ~1000
pmax hadron for PID:-5<h<-1: < 10 GeV-1<h<-1: < 5 GeV 1<h<5: < 50 GeV
EIC Detector R&D Committee Meeting, October 2012 10
Lepton Identification
E.C. Aschenauer
20 GeVx250 GeVhadronphotonelectron
no cuts applied
hadron/photon suppression factor needed for pe’>1GeV:-4<h<-3: >100-3<h<-2: ~1000-2<h<-1: > 104
pmax hadron for PID:-5<h<-1: < 30 GeV-1<h<-1: < 10 GeV 1<h<5: < 100 GeV
EIC Detector R&D Committee Meeting, October 2012 11
Fast Simulator: What was modeled Magnetic field: Solenoid with 3.0 Tesla Tracking:
“Central” +/-1: TPC-like: 45 fit points; 0.03 radiation length, position resolution: 80 m
“Forward” 1-3: GEM-like: 6 planes; 0.03 radiation length, position resolution: 80 m
“Far Forward” 3-4.5: Si-Pixel-like: 12 planes; 0.03 radiation length, position resolution: 20 m
radiation length needs to be checked no bremsstrahlung for electrons yet
Ecal “Central” +/-1: like submitted proposal
10%√E+1.5% hadron: MIP + 0.4Eh with s=0.2Eh (50:50) “Forward” 1-5: like submitted proposal
10%√E+1.5% hadron: MIP + 0.4 with s=0.2Eh (50:50) “Backward” -1 to -5: PWO crystal calorimeter
2.5%/√E + 0.9% + 1%/E hadron: MIP + 0.4Eh with s=0.2Eh (50:50) “Hcal:
Forward” 1-5: like current STAR forward R&D project: 38%√E+3%
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 12
Fast Simulator: Check Used fast smearing simulator
multiple scattering and momentum smearing included according to PDG
check against STAR results at central region looks okay for details: https://wiki.bnl.gov/conferences/images/d/d1/R%26DOctoberSmearing.pdf
-1< h <1assumed 0.05 radiation lengths
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 13
Momentum resolutions
E.C. Aschenauer
0.5<h<1.5 1.5<h<2.5
2.5<h<3.5 3.5<h<4.5
To improve momentum resolution for
h>3need to look in Magnet design with
more radial field
EIC Detector R&D Committee Meeting, October 2012 14E.C. Aschenauer
compare performance of tracking to F_L requirements as determined by Chiapas
want plot to compare Calo. resolutions with tracking for different rapidity
EIC Detector R&D Committee Meeting, October 2012 15
Improve Momentum Resolution: Magnet Design
E.C. Aschenauer
Discuss on one slide our results for the ILC-concept 4 magnet vs. normal Solenoid
EIC Detector R&D Committee Meeting, October 2012 16
Resolution for E/p
E.C. Aschenauer
Ee: 5 GeV Q2>1 GeV -1<h<-1 Ee: 20 GeV Q2>1 GeV -1<h<-1
1<p<3
7<p<9
1<p<2
4<p<5
EIC Detector R&D Committee Meeting, October 2012 17
Resolution for E/p
E.C. Aschenauer
Ee: 5 GeV Q2>1 GeV -2.2<h<-1 Ee: 20 GeV Q2>1 GeV -3.7<h<-1
1<p<3
7<p<9
1<p<2
4<p<5
EIC Detector R&D Committee Meeting, October 2012 18
LHC-b: possible RICH design concepts
E.C. Aschenauer
RICH-1 (modern HERMES RICH) RICH-22<p<60 GeV 17<p<100 GeV25-300 mrad 10-120 mrad5cm Aerogel (n=1.030) ~200 cm CF4 (n=1.0005)85 cm C4F10 (n=1.0014)
EIC Detector R&D Committee Meeting, October 2012 19
Cerenkov and momentum resolution
dp/p<0.1% dp/p< 1.0% dp/p< 3.0%
p K p
E.C. Aschenauer
no resolution due to photon detector is yet modeled momentum resolution absolutely critical for good p, K, p separation
Exclusive Reactions: Event Selection
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 20
proton tag method
o Measurement of t o Free of p-diss backgroundo Higher MX rangeo to have high acceptance (roman
Pots) challenging IR design
Diffractive peak
x L=p' zp z
≈1− x IP
Large Rapidiy Gap method
oX system and e’ measuredoProton dissociation backgroundoHigh acceptance
MY
Q2
W
How can we select events: two methods
Need for roman pots
spectrometer
Need for Hcal in the
forward region
Scattered proton acceptance
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 21
Main detector
Roman Pots
leading protons are never
in the main detector acceptance at
EIC (stage 1 and 2)
eRHIC detector acceptance
Cuts: Q2>1 GeV, 0.01<y<0.95, Eg>1 GeV
Increasing Hadron Beam Energy: influences max. photon energy at fixed hIncreasing 30 GeV < √s < 170 GeV photons are boosted from symmetric to negative rapidities
5x100 GeV 5x100 GeV20x250 GeV
t-Measurement using RP
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 22
Accepted in“Roman Pot”(example) at s=20mPlots from J-H Lee
Quadrupoles
acceptance
10s from the beam-
pipe
• high‐|t| acceptance mainly limited by magnet aperture
• low‐|t| acceptance limited by beam envelop (~10σ)
• |t|‐resolution limited by– beam angular divergence ~100μrad for small |t|– uncertainties in vertex (x,y,z) and transport– ~<5-10% resolution in t (RP at STAR)
Simulation based on
eRHIC
REQUIREMENTS• Acceptance at large-|t|
proper design of quadrupole magnets
• Acceptance in the whole solid angle
• High momentum resolution
• radiation hardness
Photon-Lepton discrimination
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 23
g
eDq
N.B. - Need for a ECal with a granularity to distinguish clusters down to Dq=1 deg
This is also important for Df calculation in asymmetries
measurement an for BH rejection in the xsec measurement
BH rejection
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 24
In DVCS most of the photon are less “rear”Than the electrons:(θel-θg) > 0 rejects most of the BH
BH and DVCSBH dominated
BH Rejection
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 25
Eel
EγEel
Eel
Eel
Eγ
Eγ
Eγ
1. BH electron has very low energy (often below 1 GeV)
2. Photon for BH (ISR) goes often forward (trough the beam pipe)
Important: ECal must discriminate clusters above noise down to 1 GeV
EIC Detector R&D Committee Meeting, October 2012 26
Start full Geant Simulations
E.C. Aschenauer
Postdoc Alexander Kiselev started 3rd of Dec. 2012 Framework: virtual MC using FairRoot
EIC Detector R&D Committee Meeting, October 2012 27
Cross section:
Pythia sep: 0.030 – 0.060 mbLuminosity: 1034 cm-1 s-1 = 107 mb-1 s-1
Some thought about rates
E.C. Aschenauer
low multiplicity4-6 √s = 40-65 GeVNch (ep) ~ Nch (eA) < Nch(pA) no occupancy problem
Interaction rate:300 -600 kHz
EIC Detector R&D Committee Meeting, October 2012 28
Summary
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 29E.C. Aschenauer
BACKUP
EIC Detector R&D Committee Meeting, October 2012 30E.C. Aschenauer
Executive Summary-----------------------------Physicists representing several of the current EIC R&D efforts met for two days at Brookhaven Lab. Thepurpose of the meeting was to consolidate simulation efforts to most efficiently formulate:
1) Physics-driven detector performance constraints.2) Radiation dose estimates (including machine-specific backgrounds).3) Coherent simulation strategies.
Presentations included discussion on:
* The physics scope of EIC.* Processes that drive detector performance.* Current software efforts.* Available computing resources.* Detailed machine designs.* Current machine-background estimates.
In the concluding session, the participants formulated both their broad goals and a short-term To-Do list.
BROAD GOALS:1) Formulate Requirement Tables/Maps.Each requirement table/map stipulates the limiting values of a detector performance parameter (e.g. dp/p,material budget, PID purity) as functions of both polar angle and particle momentum. These tables/maps inprinciple can be made for each driving physics process.
2) Formulate a Dose Table/Map.Dose Tables/maps specify the radiation load on detector systems from various sources (collisions,backgrounds) as functions of detector location.
3) Build a Full Simulation.The full simulation should follow modern coding practices as a "virtual simulation framework" (e.g. FairRootor GEMC) and incorporate both physics and background sources.
EIC Detector R&D Committee Meeting, October 2012 31E.C. Aschenauer
4) Formulate Systematic Error Estimates.EIC will be systematics-limited, not statistics-limited. Experimental sources of systematic error(calibration, scale determination, final state radiation, machine background) should be evaluated relativeto attainable theoretical uncertainties. Clearly this task requires the detailed full detector simulationfor measurements of inclusive, exclusive, and SIDIS channels.
SHORT TERM TO DO LIST:1) Constraint Maps:Develop requirement maps for SIDIS & DVCS to complement those for inclusive cross sections.
2) Dose Maps:Starting with the physics dose map, add backgrounds from the electron beam (bremsstrahlung) and hadron beam(beam-gas).
3) Simulation Development:a- Implement a double-solenoid field map.b- Stipulate by Email and Phone Conference the radial budgets for detector subsystems.c- Assign initial coding options to people with appropriate interests.
EIC Detector R&D Committee Meeting, October 2012 32
lepton kinematics
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 33
Simulation Example
E.C. Aschenauer
Cuts: Q2>1 GeV, 0.01<y<0.95, z>0.1
EIC Detector R&D Committee Meeting, October 2012 34
Integration into Machine: IR-Design
E.C. Aschenauer
space for low-Q e-tagger
Outgoing electron direction currently under detailed design detect low Q2 scattered leptons want to use the vertical bend to separate very low-Q e’ from beam-electrons can make bend faster for outgoing beam faster separation for 0.1o<Q<1o will add calorimetry after the main detector
EIC Detector R&D Committee Meeting, October 2012 35
Emerging Detector Concept
Backward SpectrometerFor very low Q2-electrons:
Magnet 2-3T
space for low-Qe-tagger
E.C. Aschenauer
high acceptance -5 < h < 5 central detectorgood PID (p,K,p and lepton) and vertex resolution (< 5mm)tracking and calorimeter coverage the same good momentum resolution, lepton PID
Barrel: MAPS & TPC, Forward: MAPS & GEMlow material density minimal multiple scattering and brems-strahlungvery forward electron and proton/neutron detection Roman Pots, ZDC, low e-tagger
EIC Detector R&D Committee Meeting, October 2012 36
Kinematics of Breakup Neutrons
E.C. Aschenauer
Results from GEMINI++ for 50 GeV Au
by Thomas Ullrich+/-5mrad acceptance seems sufficient
Results:With an aperture of ±3 mrad we are in relative good shape• enough “detection” power for t > 0.025 GeV2
• below t ~ 0.02 GeV2 we have to look into photon detection‣ Is it needed?Question:• For some physics rejection power for incoherent is
needed ~104
How efficient can the ZDCs be made?
EIC Detector R&D Committee Meeting, October 2012 37
Diffractive Physics: p’ kinematics
5x250
5x100
5x50
E.C. Aschenauer
t=(p4-p2)2 = 2[(mpin.mpout)-(EinEout - pzinpzout)]
“ Roman Pots” acceptance studies see later?
Diffraction:
p’
Simulations by J.H Lee
EIC Detector R&D Committee Meeting, October 2012 38
proton distribution in y vs x at s=20 m
20x250 5x50
E.C. Aschenauer
without quadrupole aperture limit
20x250 5x50with quadrupole aperture limit
EIC Detector R&D Committee Meeting, October 2012 39
Accepted in“Roman Pot”(example) at s=20m
20x250 5x50
E.C. Aschenauer
20x250 5x50
GeneratedQuad aperture limitedRP (at 20m) accepted
Summary:
Still a lot of work to be done
But we have started to address all the important
issues integration of detector and forward particle
reconstruction into
machine design
Synchrotron radiation
………
EIC Detector R&D Committee Meeting, October 2012 40
Exclusive Vector Meson Production Golden channel: e + A → e’ + A’ +
VM‣ Only channel where t can be
derived from VM and e’‣ Detecting neutron emission from
nuclear breakup allows to separate coherent from incoherent
Dipole Cross-Section:
J/ψf
E.C. Aschenauer
EIC Detector R&D Committee Meeting, October 2012 41
Detection efficiency of Breakup Neutrons
E.C. Aschenauer
Results:With an aperture of ±3 mrad we are in relative goodshape even for 50 GeV Au beams• enough “detection” power for t > 0.025 GeV2
• below t ~ 0.02 GeV2 we have to look into photon detection‣ Is it needed?Assumptions:• Gemini++ is correct, was verified by SMM• E* ~ -t/2mN• Can we make a ZDC 100% (>99.9999%) efficient‣ do we understand neutron detection on the 10-4 level?