EICC @ Stony Brook, January 2010

1

Some thoughts to stimulateDiscussion

E.C. Aschenauer

EICC @ Stony Brook, January 2010 2

Detector Requirements from Physics

E.C. Aschenauer

ep-physics the same detector needs to cover inclusive (ep -> e’X), semi-

inclusive (ep -> e’hadron(s)X) and exclusive (ep -> e’pp) reactions

energy variability p: 50 – 250/325 e: 4 - 20 large acceptance absolutely crucial (both mid and forward-rapidity) particle identification is crucial

e, p, K, p, n over wide momentum range and scattering angleexcellent secondary vertex resolution (charm)

particle detection to very low scattering angle around 1o in e and p/A direction

in contradiction to strong focusing quads close to IP small systematic uncertainty (~1%/~3%) for e/p polarization

measurements very small systematic uncertainty (~1%) for luminosity

measurement eA-physics

requirements very similar to epchallenge to tag the struck nucleus in exclusive and diffractive reactions.difference in occupancy must be taken into account

EICC @ Stony Brook, January 2010 3

Energies Simulated in RAPGAP

Beam EnergiesEe + Ep [GeV]

Center-of-mass Energy [GeV]

Events Produced

4+50 28.34+100 40.010+50 44.74+250 63.3

10+100 63.3 One million20+50 63.3

20+100 89.410+250 10020+250 141

E.C. Aschenauer

EICC @ Stony Brook, January 2010 4

(M)eRHIC Luminosities

E.C. Aschenauer

Some luminosity numbers:for MeRHIC without CEC 4 x 250: 1x1032 cm-2s-1

for MeRHIC with CEC 4 x 250: 1x1033 cm-2s-1

for eRHIC with CEC: 20 x 325: 2.8x1033 cm-2s-1

30 x 325 with b* of 5cm: 1.4x1034 cm-2s-1

as the the luminosity does not depend on the energy of electron beam youcan write it as for eRHIC with CEC: 2.8 1033* Ep/250 cm-2s-1

so you can easily scale it going to 20x100 for example

so for MeRHIC assuming 50% operations efficiency one week corresponds to0.5 * 604800(s in a week) * (1x1032 cm-2s-1) = 3*1037 cm-1 so 30pb-1

for eRHIC with CEC we collect in one week ~1fban operations efficiency of 50% is low, but conservative at this moment.

For EIC systematic errors will be the limiting factor i.e., g1, FL, Dg, Dq

BNL S&T-Review, July 2009 5

The √s vs. minimum luminosity landscape

E.C. Aschenauer

semi-inclusive DIS

inclusive DIS

Diffraction

electro-weak

4x10010x100 20x100 20x250

exclusive DIS (DVCS)

exclusive DIS (PS & VM)

4x50

H1/ZEUS:~1031cm-2s-1

Hermes:5x1031-1033

W2-dependence of c.s. neglected

EICC @ Stony Brook, January 2010 6

Momentum vs. theta of scat. electron

Proton Energy50 GeV 100 GeV 250 GeV

Elec

tron

Ene

rgy

4

GeV

1

0 G

eV

2

0 G

eV

E.C. Aschenauer

As more symmetricbeam energies

as more thescattered lepton

goes forward

EICC @ Stony Brook, January 2010 7E.C. Aschenauer

4x50

4x10

04x

250

pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV

Q2>1GeV2 20o

after 1m ~35cm away from beam pipe

Momentum vs. angle of pions

Same CM energy (63.3 GeV)

What do we see: For DIS: distribution is more “smeared”

as energy balance becomes more symmetric

For diffractive: majority of pions at easily accessible angles, either forward or backward depending on proton/electron energy

8

EICC @ Stony Brook, January 2010 9

t for exclusive VM vs p’ angle

E.C. Aschenauer

4 x 50 4 x 100

4 x 250

very strong correlation between t and “recoiling” proton angle Roman pots need to be very well integrated in the lattice resolution on t!

t=(p4-p2)2 = 2[(mpin.mpout)-(EinEout - pzinpzout)] t=(p3–p1)2 = mρ2-Q2 - 2(Eγ*Eρ-pxγ*pxρ-pyγ*pyρ-

pzγ*pzρ)

EICC @ Stony Brook, January 2010 10

IR-Design for MeRHIC IP-2

E.C. Aschenauer

no synchrotron shielding included allows p and heavy ion decay product tagging IP-2: height beam-pipe floor ~6’ (with digging ~10’)

EICC @ Stony Brook, January 2010 11

First ideas for a detector concept

E.C. Aschenauer

Dipole3Tm

Dipole3Tm

Solenoid (4T)

ZDC

FPD

FED// //

Dipoles needed to have good forward momentum resolution Solenoid no magnetic field @ r ~ 0

DIRC, RICH hadron identification p, K, p high-threshold Cerenkov fast trigger for scattered lepton radiation length very critical low lepton energies

EICC @ Stony Brook, January 2010 12

MeRHIC Detector in Geant-3

E.C. Aschenauer

DIRC: not shown because of cut; modeled following Babar no hadronic calorimeter in barrel, because of vertical space @ IP-2

Drift Chambers central tracking

ala BaBar

Silicon Stripdetectorala Zeus

EM-CalorimeterLeadGlas

High ThresholdCerenkov

fast trigger on e’e/h separation

Dual-Radiator RICH

ala HERMES

Drift Chambers ala HERMES FDC

EICC @ Stony Brook, January 2010 13E.C. Aschenauer

BACKUP

EICC @ Stony Brook, January 2010E.C. Aschenauer

14

STAR

PHENIX

2 x 200 m SRF linac4 (5) GeV per pass5 (4) passes

Polarized e-gun

Beamdump

4 to 5 vertically separatedrecirculating passes

Cohe

rent

e-

cool

er

5 mm

5 mm

5 mm

5 mm

20 GeV e-beam16 GeV e-beam

12 GeV e-beam

8 GeV e-beam

Com

mon

vac

uum

ch

ambe

r

Gap 5 mm total0.3 T for 30 GeV

(M)eRHICdetector

MeRHIC

detector

10-20 GeV e x 325 GeV p 130 GeV/u Au

possibility of 30 GeV @low current operation

ERL-based eRHIC Design

EICC @ Stony Brook, January 2010 15

Zeus @ HERA I

E.C. Aschenauer

EICC @ Stony Brook, January 2010 16

Zeus @ HERA II

E.C. Aschenauer

EICC @ Stony Brook, January 2010 17

Hera I vs. Hera II

E.C. Aschenauer

Focusing Quads close to IPProblem for forward acceptance

EICC @ Stony Brook, January 2010 18

ions

electrons

solenoid dipole bendingscattered protons “up”

IP withcrossing angle electron FFQs

ion FFQs

Distance from IP to electron FFQ: 6 m to ion FFQ: 9m

Electron FF quad

Distance from IP

length Field strength

Beam size sx@ 3 GeV

Beam size sy@ 3 GeV

Quad 1 6.0 meter 50 cm -1.14 kG/cm

5 mm 4 mm

Quad 2 6.75 meter

120 cm 0.71 kG/cm

8 mm 3 mm

Quad 3 8.7 meter 50 cm -0.75 kG/cm

4 mm 4 mm

Modest electron final focusing quad field requirements quads can be made small

ELIC Detector/IR Layout

E.C. Aschenauer

by R. Ent

EICC @ Stony Brook, January 2010 19

8 meters (for scale)

140 degrees

Tracking

TOF

dipole

solenoid

RICH

ECAL

DIRC

HCAL

HTCC

Offset IP?

Ion beame beam

dipole1st (small) electron FF quad @ 6 m

ELIC detector cartoon - Oct. 09

E.C. Aschenauer

Additional electron detection (tracking, calorimetry) for low-Q2 physics not on cartoon

by R. Ent

EICC @ Stony Brook, January 2010 20

Event kinematics produced hadrons (p+)

E.C. Aschenauer

DIS

DIFFRACTIVE

4x50 4x250

withoutmagneticfield

DIS:smalltheta important

20x250