The Electron Ion Collider Project April 12, 2011 DIS2011, Newport News, VA Abhay Deshpande

The Electron Ion Collider ProjectThe Electron Ion Collider Project

April 12, 2011DIS2011, Newport News, VA

Abhay Deshpande

Related Talks:

4/12/2011Abhay Deshpande Overview of the US EIC Project

2

An update on eRHIC acceleraor V. Litvinenko

Design status of of MEIC at JLab V. Morozov

PDFs today and tomorrow M. Stratmann

Theory overview of e-A physics at the EIC J. Jalilian-Marian

Experimental overview of e-A physics at the EIC T. Ullrich

A new Monte Carlo event generator for eA collisions at low-x T. Toll

Theory overview of e+p physics at an EIC J. Qiu

Experimental overview of e+p physics at an EIC H. Gao

Imaging sea quarks and gluons at the EIC T. Horn

Ep physics opportunities at eRHIC T. Burton

Transverse single-spin asymmetry measurement from SIDIS at an EIC

M. Huang

Weak mixing angle measurement at EIC Y. Li

PHENIX and STAR Detector Upgrades (for use as Stage 1 eRHIC detector)

E. O’Brien, J. Dunlop

… And of course, low-x physics at LHeC is a physics connection


Success of pQCD at High Q: Jet Cross section

• Input:

– F2(x,Q2) structure function from HERA

– Next to Leading Order perturbative QCD


3

Compilation: J. Putschke

QCD definitely correct, but…Lattice QCD•Starting from QCD lagrangian Static properties of hadrons: hadron mass spectrum


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• Calculations possible in perturbation theory assuming coupling is small, at high Q

• Problematic at low Q fast rise of S(Q)

No guidance on partonic dynamics

Do we really “understand” QCD?While there is no reason to doubt QCD, our level of

understanding of QCD remains extremely unsatisfactory: both at low & high energy

• Can we explain basic properties of hadrons such as mass and spin from the QCD degrees of freedom at low energy?

• What are the effective degrees of freedom at high energy?– How do these degrees of freedom interact with each

other and with other hard probes?– What can we learn from them about confinement &

universal features of the theory of QCD?

After ~20+ yrs of experimental & theoretical progress, we are only beginning to understand the many body dynamics of QCD


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R. Venugopalan

Generation of Mass – Gluons in QCD

• Protons and neutrons form most of the mass of the visible universe

• 99% of the nucleon mass is due to self generated gluon fields– Similarity between p, n mass indicates that

gluon dynamics gluon dynamics is identicalidentical & overwhelmingly important

• Lattice QCD supports this


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Higgs Mechanism, often credited with mass generation, is of no consequence

Bhagwat et al.

HOW WELL DO WE UNDERSTAND GLUONS?

What is the role of gluons at high energy?


7

Gluon distribution at low-x understood?

• Indefinite riseIndefinite rise– Could this be an artifact artifact of

using of linearlinear DGLAP in gluon extraction?

– Infinite high energy hadron Infinite high energy hadron cross section?cross section?

• How would we find out?How would we find out?– Need theory developmentNeed theory development– Need experimental Need experimental

measurements at lower x!measurements at lower x!


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No higher energy e-p collider than HERA! other than “LHeC”

OR Use Nuclei: naturally enhance the densities of partonic

matterWhy not use Nuclear DIS at highest available Why not use Nuclear DIS at highest available

energy?energy?

No higher energy e-p collider than HERA! other than “LHeC”

OR Use Nuclei: naturally enhance the densities of partonic

matterWhy not use Nuclear DIS at highest available Why not use Nuclear DIS at highest available

energy?energy?

Low-x, higher twist & Color Glass Condensate


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McLerran, Venugopalan… See Review: F. Gelis et al., , arXiv:1002.0333)

Method of including non-non-linear linear effects in DGLAP equation Small coupling, Small coupling, high gluon densities high gluon densities Saturation Scale Saturation Scale QQSS(x,Q(x,Q22,,AA)) Some form of saturation, Some form of saturation, including Color Glass including Color Glass CondensateCondensate

No unambiguous experimental No unambiguous experimental evidence yet, evidence yet, but many but many smoking guns (HERA, RHIC & smoking guns (HERA, RHIC & now LHC!)now LHC!)

Could be explored cleanly in future with a high energy

electron-Nucleus Collider

Could be explored cleanly in future with a high energy

electron-Nucleus Collider

KowalskiTeany

PRD 68:114005

KowalskiTeany

PRD 68:114005

UNDERSTANDING NUCLEON SPIN:WHAT ROLE DO GLUONS PLAY?


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Evolution: Our Understanding of Nucleon Spin

?1980s

1990/2000s

We have come a long way, but do we understand nucleon spin?We have come a long way, but do we understand nucleon spin?4/12/2011 11Abhay Deshpande Overview of the US EIC

Project

Status of “Nucleon Spin Crisis Puzzle”

• We knowknow how to determine and g precisely: data+pQCD – ½ () ~ 0.15 : From fixed target pol. DIS experiments – RHIC-Spin: g not large not large as anticipated in the 1990s, but as anticipated in the 1990s, but

measurements & precision needed at low measurements & precision needed at low & high x& high x


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PHENIX

g(x) @ Q2=10 GeV2

• Global analysis: DIS, SIDIS, RHIC-Spin

• Uncertainly on G large at low x


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de Florian, Sassot, Stratmann & Vogelsang

Present Low x measurements=Opportunity!Low x measurements=Opportunity!

Status of “Nucleon Spin Crisis Puzzle”

• We knowknow how to measure and G precisely using pQCD – ½ () ~ 0.15 : From fixed target pol. DIS experiments – RHIC-Spin: G not large not large as anticipated in the 1990s, but as anticipated in the 1990s, but

measurements & precision needed at low measurements & precision needed at low & high x& high x

• Orbital angular momenta: Generalized Parton Distributions (GPDs): H,E,E’,H’ – Quark GPDs: 12GeV@JLab & COMPASS@CERNQuark GPDs: 12GeV@JLab & COMPASS@CERN– Gluons @ low x Gluons @ low x J JGG will need the future EIC! will need the future EIC!

• Would it not be great to have a (2+1)D tomographic image of Would it not be great to have a (2+1)D tomographic image of the proton…. (the proton…. (2: x,y position 2: x,y position and and +1:momentum in z +1:momentum in z directiondirection)?)?– Transverse Momentum Distributions, GPDs of Quarks & Gluons… full Transverse Momentum Distributions, GPDs of Quarks & Gluons… full

understanding of transverse and longitudinal hadron structure including understanding of transverse and longitudinal hadron structure including spin!spin!


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The Proposal: Future DIS experiment at an Electron Ion Collider: A high

energy, high luminosity (polarized) ep and eA collider and a suitably

designed detector

[2]

[3]

[1]Measurements:[1] Inclusive[1] and [2] or [3] Semi-Inclusive[1] and [2] and [3] Exclusive

Inclusive ExclusiveLow High LuminosityDemanding Detector capabilities

EIC : Basic Parameters• Ee=1010 GeV (55-30 GeV variable)

• Ep=250250 GeV (5050-325 GeV Variable)

• Sqrt(SSqrt(Sepep) = 100 (30-200) GeV) = 100 (30-200) GeV• Xmin = 10-4 ; Q2

max= 104 GeV• Beam polarization ~ 70% for

e,p,D, 3He• Luminosity LLuminosity Lepep = 10 = 1033-3433-34 cm cm-2-2ss-1-1

• Minimum Minimum Integrated luminosity:Integrated luminosity:– 50 fb50 fb-1-1 in 10 yrs (100 x HERA) in 10 yrs (100 x HERA)– Possible with 10Possible with 103333 cm cm-2-2ss-1-1

– Recent projections Recent projections much much higherhigher

Nuclei: • p->U; EA=20-100 (140)100 (140) GeV/N• Sqrt(SeA) = 12-63 (75)63 (75) GeV• LeA/N = 1033 cm-2s-1


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Machine DesignsDetails in Talks by V. Litvinenko & V. Morozov

eRHIC at Brookhaven National Laboratory using the existing RHIC

complex

ELIC at Jefferson Laboratory using the Upgraded 12GeV CEBAF

Both planned to be STAGED

MEIC : Medium Energy EIC

Three compact rings:• 3 to 11 GeV electron• Up to 12 GeV/c proton (warm)• Up to 60 GeV/c proton (cold)

low-energy IP

polarimetry

medium-energy IPs


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Exists

ELIC: High Energy & Staging

Stage Max. Energy (GeV/c)

Ring Size (m)

Ring Type IP #

p e p e

Medium

96 11 1000 ColdWarm

3

High 250 20 2500 ColdWarm

4

Serves as a large booster to the full energy collider ring

Arc

Straight section


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V.N. Litvinenko eSTAR

ePHEN

IX

Coh

eren

t e-

cool

er

Beam dump

Polarized e-gun

New detector

0.6 GeV

30 GeV

30 GeV

27.55 GeV

22.65 GeV

17.75 GeV

12.85 GeV

3.05 GeV

7.95 GeV

Lina

c 2.

45 G

eVLinac

2.45 GeV

100 m

25.1 GeV

20.2 GeV

15.3 GeV

10.4 GeV

30.0 GeV

5.50 GeV

27.55 GeV

eRHIC: polarized electrons with Ee ≤ 30 GeV will collide with either polarized protons with Ee ≤ 325 GeV or heavy ions EA ≤ 130 GeV/u

eRHIC staging:All energies scale

proportionally

Small gap magnets5 mm gap

0.3 T @ 30 GeV


20


21

nucleus electron

proton nucleus

eSTARSee J. Dunlop’s talk

ePHENIXSee E. O’Brien’s talk

4/10/11Abhay Deshpande on EIC Collaboration's Perspective 22

Emerging eRHIC Detector Concept


high acceptance -5 < < 5 central detectorgood PID and vertex resolution (< 5m)tracking and calorimeter coverage the same good momentum resolution, lepton PIDlow material density minimal multiple scattering and bremsstrahlungvery forward electron and proton detection dipole spectrometers

Forward / BackwardSpectrometers:

E. Aschenauer et al.BNL EIC Task Force &EIC Collaboration

eRHIC IRs, β*=5cm, l*=4.5 m

Up to 30 GeV e- beam

325 GeV p

beam

Spin

-Rota

tor

10 mrad, with

crab crossing

L=1.4x1034cm-2s-1, 200 T/m gradient

0.4

5 m

Nb3Sn

200 T/m

Star detector©Dejan Trbojevic

90.m

325 GeV p

beam

Exploit LARP development of Nb3Sn SC quads with 200 T/m gradient

Integrated with “new” detector design. Field-free electron pass thru hadron triplet magnets minimal SR background.

Integrated with “new” detector design. Field-free electron pass thru hadron triplet magnets minimal SR background.

IR combined function magnet design

IR combined function magnet design

See talk by Litvinenko’sSee talk by Litvinenko’s

solenoid

electron FFQs50 mrad

0 mrad

ion dipole w/ detectors

ions

electrons

IP

ion FFQs

2+3 m 2 m 2 m

Detect particles with angles below 0.5o beyond ion FFQs and in arcs.

detectors

Detect particles with angles down to 0.5o before ion FFQs.Need 1-2 Tm dipole.

Central detector

EM

Ca

lorim

ete

r

Ha

dro

n C

alo

rime

ter

Mu

on

De

tect

or

EM

Ca

lorim

ete

r

Solenoid yoke + Muon DetectorTOF

HT

CC

RIC

H

RICH or DIRC/LTCC

Tracking

2m 3m 2m

4-5m

Solenoid yoke + Hadronic Calorimeter

Very-forward detectorLarge dipole bend @ 20 meter from IP (to correct the 50 mr ion horizontal crossing

angle) allows for very-small angle detection (<0.3o)

Detector & IR Design: ELIC

Nadel-Turonski, Horn, EntAnd EIC Collaboration


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Impact of EIC….“golden measurements”

Science of EIC:Institute of Nuclear Theory (INT) Program at U. of Washington: Sep-Nov 2010Organizers: D. Boer, M. Diehl, R. Milner, R. Venugopalan, W. Vogelsang

See the INT workshop for details of all studies http://www.int.washington.edu/INT_03/

Details in the EIC talks in this conference….


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http://www.int.washington.edu/INT_03/

Summary: Science of EIC: Precise Investigations of the “Glue”


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Spin program at the EIC:


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ScienceDeliverable

BasicMeasurement

Uniqueness FeasibilityRelevance

Requirements

spin structure at small x

contribution of Δg, ΔΣ

to spin sum rule

inclusive DIS ✔need to reach

x=10-4 large x,Q2 coverage

about 10fb-1

full flavor separation

in large x,Q2 range

strangeness, s(x)-s(x)

polarized sea

semi-inclusive DIS

✔very similar to

DISexcellent particle IDimproved FFs (Belle,LHC,…)

electroweak probes

of proton structure

flavor separationelectroweak parameters

inclusive DIS at high Q2

✔some unp. results from HERA

20x250 to 30x325

positron beam ?polarized 3He

beam ?

M. Stratmann

Nucleon Spin: Precision measurement of G


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Yellow band (left) reduces to the band shown with red dashed line (right) Yellow band (left) reduces to the band shown with red dashed line (right)

Sassot & Stratmann


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See more in talks by: T. Ullrich, J. Jalilian-Marian See more in talks by: T. Ullrich, J. Jalilian-Marian

C. Marquet

Nuclear Tomography: (2+1)D images


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x < 0.1 x ~ 0.3 x ~ 0.8

Fourier transform in momentum transfer

x ~ 0.001

EIC:EIC:1) x < 0.1: 1) x < 0.1: gluonsgluons!2) ~ 0 the “take out” and “put back” gluons act coherently.

2) ~ 0 x - x +

d

Diffractive vector meson production in eA


32

d

See T. Ullrich’s talk on eA physics at the EIC

Precise transverse imaging of the gluons proton-heavy nucleiLater, how low x dynamics modifies this transverse gluon distribution

Exclusive coherent (at small t)and incoherent (intermediate t) Diffraction

Experimental challenges beingStudied.

EIC Project status and plans• A “collaboration” of highly motivated people intends to take this project to

realization: – EIC Collaboration Web Page: http://web.mit.edu/eicc/

BNL: https://wiki.bnl.gov/eic/index.php/Main_Page JLab: http://www.jlab.org/meic

– 100+ dedicated physicists from 20+ institutes – Details of many recent studies: Recent Workshop @ INT at U. of

Washington: http://www.int.washington.edu/program/INT_03– Task Force at BNL (E. Aschenaur, T. Ullrich) and at Jefferson Laboratory

(R. Ent) – Steering Committee (contact: AD and R. Milner)

• International Advisory Committee formed by the BNL & Jlab Management to steer this project to realization: W. Henning (ANL, Chair), J. Bartels (DESY),A. Caldwell (MPI, Munich) A. De Roeck (CERN), R. Gerig (ANL), D. Hetrzog (U of W), X. Ji (Maryland), R. Klanner (Hamburg), A. Mueller (Columbia), S. Nagaitsev (FNAL), N. Saito (J-PARC), Robert Tribble (Texas A&M), U. Wienands (SLAC), V. Shiltev (FNAL)

• Plan to go to the NSAC Long Range Plan (2012/13) with the science case & Plan to go to the NSAC Long Range Plan (2012/13) with the science case & machine/detector designs (including costs & realization plans)machine/detector designs (including costs & realization plans)


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http://web.mit.edu/eicc/

http://www.int.washington.edu/program/INT_03

http://www.int.washington.edu/program/INT_03

Generic Detector R&D for an EIC

• Community wide call for R&D Detector proposals for EIC• Program run from BNL (RHIC R&D funds), NOT site specific• Very Recent: Deadline April 4th, 2011 (more opportunities in future)

New detector technology for fiber sampling calorimetry for EIC and STAR. UCLA, Texas A&M, Penn StateFront end readout modules for data acquisition and trigger system. Jefferson LabDIRC based PID for EIC Central Detector. Catholic U. of America, Old Dominion U., JLab, GSI (Darmstadt)Liquid scintillator calorimeter for the EIC. Ohio State U.Test of improved radiation tolerant silicon PMTs. Jefferson LabLetter of Intent for detector R&D towards an EIC detector (Low mass tracking and

PID). BNL, Florida Inst. Tech., Iowa State, LBNL, LANL, MIT, RBRC, Stony Brook, U. of Virginia, Yale

U.

Exploring possible new technologies & attracting new collaborators….


Luminosity upgrade:

Further luminosity upgrades (pp, low-E)

Staged approach to eRHIC

LHC HI starts

RHIC-II science by-passing RHIC-II project

Opportunity for up-grade* or 1st EIC stage (eRHIC-I)

EIC = Electron-Ion Collider; eRHIC = BNL realization by adding e beam to RHIC

Further luminosity upgrades (pp, low-E)

eRHIC-I physics

* New PHENIX and STAR Decadal Plans provide options for this period. Dedicated storage ring for novel charged-particle EDM measurements

another option.

© V. Litvinenko

eRHIC will add electron ERL inside RHIC tunnel, going from 5 to 30 GeV in stages

eRHIC will add electron ERL inside RHIC tunnel, going from 5 to 30 GeV in stages

electron recirc-ulation mag-nets

electron recirc-ulation mag-nets

S. Vigdor, BNL Associate DirectorS. Vigdor, BNL Associate Director

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EIC at JLab Realization Imagined

Activity Name 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

12 Gev Upgrade

FRIB

EIC Physics Case

NSAC LRP

CD0

Machine Design/R&D

CD1/D’nselect

CD2/CD3

Construction

H. Montgomery, Jeff. Laboratory DirectorH. Montgomery, Jeff. Laboratory Director

SummaryScience Case for EIC: “Precision study of the role of gluons & sea quarks in QCD”Many body dynamics in QCD is an essential focus of this study.Possibilities of precision EW & other physics being explored.

The EIC Collaboration & the BNL+Jlab managements are moving (together) towards realization: NSAC approval 2013 Next Milestone•Machine R&D, detector discussions, simulation studies towards making the final case including cost considerations needs to occur within the next two years…

INVITATION: Ample opportunities to get involved and influence the design of this machine according to your own physics interests and participate in the exploration of the “next QCD frontier…”!


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Related detailed talks: Reminder…


38

An update on eRHIC acceleraor V. Litvinenko

Design status of of MEIC at JLab V. Morozov

PDFs today and tomorrow M. Stratmann

Theory overview of e-A physics at the EIC J. Jalilian-Marian

Experimental overview of e-A physics at the EIC T. Ullrich

A new Monte Carlo event generator for eA collisions at low-x T. Toll

Theory overview of e+p physics at an EIC J. Qiu

Experimental overview of e+p physics at an EIC H. Gao

Imaging sea quarks and gluons at the EIC T. Horn

Ep physics opportunities at eRHIC T. Burton

Transverse single-spin asymmetry measurement from SIDIS at an EIC

M. Huang

Weak mixing angle measurement at EIC Y. Li

PHENIX and STAR Detector Upgrades (for use as Stage 1 eRHIC detector)

E. O’Brien, J. Dunlop



EIC: the Machines, IR and Detector

Both BNL and JLab machine designs have progressed significantly.In spite of very different starting points for collider concepts:•Both designs are now converging to similar luminosities:

– Few x 1034 cm-2 sec-1 for high energy– 1033-34 cm-2 sec-1 for low energy• Both plan a staged realization

•Both designs have settled on more than one IR point•Both machine designs integrate detector design in to the machine lattice•Both detectors concepts include a central solenoid and forward dipole, extensive low mass tracking for low x and good particle ID


Measurement of Glue at HERA• Scaling violations of F2(x,Q2)

• NLO pQCD analyses: fits with linearlinear DGLAP* equations


41

Gluondominates

*Dokshitzer, Gribov, Lipatov, Altarelli, Parisi

EIC Detector will aim to catch:

• Wide range in x-Q2 extremely important to understand longitudinal & transverse spin/momentum distributions and dynamics – Not available at any other existing or future facility with

polarized hadron beams being considered…– Lessons learnt from HERA (about measurements at low-x)


42

Electroweak & beyond

• High energy collisions of polarized electrons and protons and nuclei afford a unique opportunity to study electro-weak deep inelastic scattering– Electroweak structure functions (including spin)– Significant contributions from W and Z bosons which

have different couplings with quarks and anti-quarks

• Parity violating DIS: a probe of beyond TeV scale physics– Measurements at higher Q2 than the PV DIS 12 GeV at

Jlab

– Precision measurement of Sin2W

• New window for physics beyond SM?– Lepton flavor violation search 3/24/11A. L. Deshpande, Precision study of gluons in QCD 43

arXiv: 006.5063v1 [hep-ph]M. Gonderinger et al.arXiv: 006.5063v1 [hep-ph]M. Gonderinger et al.

BNL LDRD: Deshpande, Marciano, Kumar & Vogelsang

Some examples of “other” studies initiated….


Some examples of “other” studies initiated….


In part supported by BNL LDRDWrite-Ups in the INT Workshop Proceedings

Charged & Neutral Currents…

3/24/11A. L. Deshpande, Precision study of gluons in QCD 46

20 × 250 GeV, Q2 > 1 GeV2, 0.1 < y < 0.9, 10 fb-1, DSSV PDFs

(Could begin the program with 5x250 GeV )

Two studies: (1) Ringer & Vogelsang (these figures),

(2) Taneja, Riordin, Deshpande, Kumar & PaschkeCC NC

Sin2W with the EIC• Deviation from the “curve” may be hints of BSM

scenarios including: Lepto-Quarks, RPV SUSY extensions, E6/Z’ based extensions of the SM


Y. Li, W. Marciano

Opportunity for EIC• Limits on LFV(1,3) LFV(1,3) experimental searches are significantly

worse than those for LFV(1,2)• Especially if there are BSM models which specifically allow

and enhance LFV(1,3) over LFV(1,2)– Minimal Super-symmetric Seesaw model

• J. Ellis et al. Phys. Rev. D66 115013 (2002)– SU(5) GUT with leptoquarks

• I. Dorsner et al., Nucl. Phys. B723 53 (2005)• P. Fileviez Perez et al., Nucl. Phys. B819 139 (2009)

• M. Gonderinger & M.Ramsey Musolf, JHEP 1011 (045) (2010); arXive: 1006.5063 [hep-ph]

• Clearly there is an opportunity for EIC: if a search can be effectively launched with it’s planned (high luminosity) and large large acceptance detector suitable for the GPD/Exclusive physics program

3/24/11 48A. L. Deshpande, Precision study of gluons in QCD

How does this compare with HERA?

Private communications: M. Gonderinger


SM vs. LPQ Comparisons

miss – jet = Acoplanarity

Very different for SM vs. LPQ3/24/11A. L. Deshpande, Precision study of gluons in QCD 50

C. Faroughy, S. Taneja, M. Gonderinger, A. Deshpande & K. Kumar

Pythia for Standard Model event topologies

LQGENEP Event generator for Lepto-Quark events. By L. Bellagamba Comp. Phys. Comm. 141, 83 (2001)

SM vs. LPQ Ptmiss

10 x 250

20 x 325


Acoplanarity: miss-jet

10 x 250

20 x 325


To do:

• Inclusion of detector efficiencies • A detailed study of efficiency of cuts/selection

criteria and its efficiency.

Only then can we calculate the effective sensitivity per event not seen

A GEANT based simulation of the detector is needed… and being planned.


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Documents

The Electron Ion Collider Project April 12, 2011 DIS2011, Newport News, VA Abhay Deshpande