1 News from eRHIC Matt Lamont, Thomas Ullrich, William Foreman, Anders Kirleis, Michael Savastio, Elke Aschenauer and the CAD-eRHIC Team E.C. AschenauerEIC-Convener

EIC-Convener Meeting, AUG. 2009

1

News from eRHIC

Matt Lamont,Thomas Ullrich,

William Foreman,Anders Kirleis,

Michael Savastio,Elke Aschenauer

and the CAD-eRHIC Team

E.C. Aschenauer

EIC-Convener Meeting, AUG. 2009 2

eRHIC group in Physics

E.C. Aschenauer

eRHIC taskforce formedweekly meetings on EVO Thursday@2pmconcentrate on simulating “golden physics channels” and to develop tools/software to be used by collaborationdetector – IR design together with CAD

In process of hiring 2 PostDocsHave 3 students over the summerInformation available openly for everybody at

http://www.eic.bnl.gov/https://wiki.bnl.gov/eic/index.php/Main_Page

Summer Workgenerate tools to simulate have rapgap & pythia root-trees

work to provide dvcs, pepsi and Hermes-transversity generators

simulated dis & diffractive events for several energy settings design a detector in Geant fitting in IP-2

(software based on STAR & ATLAS)generate tools to MC Geant root-treesand a lot of more

http://www.eic.bnl.gov/

https://wiki.bnl.gov/eic/index.php/Main_Page

https://wiki.bnl.gov/eic/index.php/Main_Page


Momentum vs. Theta of Scat. Electron

What we see: Differences

between DIS and diffractive events

Different angle & momentum distributions depending on electron + proton energies

Momentum (GeV/c)

Th

eta

(d

eg

rees)

4+250 GeVDIS

4+250 GeVDiffractive

10+100 GeVDIS


60

o -

18

0o

14

0o -

18

0o

What we do: Edit codes so only

information for certain particles are plotted, both in DIS and diffractive

E.C. Aschenauer

All done by William Foreman


π+ Momentum vs. Angle

What we see: Angles at which

pions are projected for different energies in both DIS and diffractive events

In DIS events, pions tend to be sent at much smaller angles compared to diffractive events

Th

eta

(d

eg

rees)

0o -

18

0o

0o -

18

0o

Momentum (GeV/c)

4+250 GeVDIS



10+100 GeVDIS

We use this information to

design the detector!

E.C. Aschenauer

EIC-Convener Meeting, AUG. 2009 E.C. Aschenauer

5

STAR

PH

EN

IX

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

Polarized e-gun

Beamdump

4 to 5 vertically separatedrecirculating passes

Cohere

nt

e-c

oole

r

5 mm

5 mm

5 mm

5 mm

20 GeV e-beam

16 GeV e-beam

12 GeV e-beam

8 GeV e-beam

Com

mon

vacu

um

ch

am

ber

Gap 5 mm total0.3 T for 30 GeV

eRHICdetector

MeRH

IC

dete

ctor

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

possibility of 30 GeV @low current operation

ERL-based eRHIC Design

EIC-Convener Meeting, AUG. 2009

Medium Energy eRHIC Concept

E.C. Aschenauer

6

Geometrical constraints: If it is possible use the existing interaction region at RHIC 2 o’clock and wider tunnel to place the superconducting linac inside it. Minimize civil construction cost and re-use for eRHIC already built and installed linac.


IR-Design for MeRHIC I

E.C. Aschenauer

no synchrotron shielding included


Detection from hadron beam fragments

Tagging from Au fragments and p in ep suppress incoherent scattering / ensure exclusivity

neutrons are detected in ZDC protons use magnetic rigidity Au:p 2.5:1

DX magnets disturbs p tagging

E.C. Aschenauer


IR-Design for MeRHIC II

E.C. Aschenauer

no synchrotron shielding included allows p and heavy ion decay product tagging


First ideas for a detector concept

E.C. Aschenauer

/ TRD

Dipol3Tm

Dipol3Tm

Solenoid (4T)

ZDC

FPD

FED// //

r: 5 ft / 1.5m

~15m


The (M)eRHIC Detetor

E.C. Aschenauer

All the work was done by Anders Kirleis with a lot of help byPavel Nevski

Still need to model EMCal in barrel and include the already modeled DIRC


Solenoid Magnetic Field in Z Dimension

Magnetic Field (KG)

Radial Dimension (cm)

Z Dimension (cm)

E.C. Aschenauer



Z Dimension (cm)

Solenoid Magnetic Field in Z Dimension

E.C. Aschenauer


Magnetic Field (KG)

Dipole Magnetic Field in Y Dimension

Z Dimension (cm)


E.C. Aschenauer


Dipole Magnetic Field in Y Dimension

Z Dimension (cm)


E.C. Aschenauer

EIC-Convener Meeting, AUG. 2009 16E.C. Aschenauer















HITS DATA FROM A MYLAR TRACKING DETECTOR

E.C. Aschenauer


The √s vs. luminosity landscape

E.C. Aschenauer

semi-inclusive DIS

inclusive DIS

Diffraction

electro-weak

4x10010x100 20x100 20x250

exclusive DIS (DVCS)

exclusive DIS (PS & VM)


Existing Experiment LuminositiesHera :

H1 and Zeus: 1031cm-2s-127GeV e+/e- 920GeV p √s = 320GeV did measure:

inclusive & semi-inclusive DISexclusive reactions (DVCS)diffractive physicselectro-weak

Hermes:fixed target 27GeV e+/e- √s=7.2GeVpolarised: 5x1031cm-2s-1; unpol: 1032-33cm-2s-1;did measure:

inclusive & semi-inclusive DISexclusive reactions (DVCS, pS, VM)spin physics

E.C. Aschenauer


Existing Experiment LuminositiesCERN

Compassfixed target 160GeV m+/m- √s=17GeVpolarised: ~1031cm-2s-1; unpol: 1032-33cm-2s-1;did measure:

inclusive & semi-inclusive DISexclusive reactions (VM)spin physics

plan to measure:exclusive reactions (DVCS, PS)Drell Yan

SMC, NMC and EMC very similar, with different beam energies

E.C. Aschenauer

Documents

1 News from eRHIC Matt Lamont, Thomas Ullrich, William Foreman, Anders Kirleis, Michael Savastio, Elke Aschenauer and the CAD-eRHIC Team E.C. AschenauerEIC-Convener