future spin physics at jlab 12 gev and beyond kees de jager jefferson lab spin2006 kyoto

Thomas Jefferson National Accelerator Facility

SPIN2006, October 7, 2006, 1

Future Spin Physics at JLabFuture Spin Physics at JLab

12 GeV and Beyond12 GeV and Beyond

Kees de Jager

Jefferson Lab

SPIN2006

Kyoto

October 2-7, 2006


SPIN2006, October 7, 2006, 2

Highlights of the 12 GeV Program

• Revolutionize Our Knowledge of Spin and Flavor Dependence of PDFS in the Valence Region

• Strongly Enhance Our Knowledge of Distribution of Charge and Current in the Nucleon

• Totally New View of Hadron (and Nuclear) Structure: GPDs Determination of the quark angular momentum

• Exploration of QCD in the Nonperturbative Regime: Existence and properties of QCD flux-tube excitations

• New Paradigm for Nuclear Physics: Nuclear Structure in Terms of QCD Spin and flavor dependent EMC Effect Study quark propagation through nuclear matter

• Precision Tests of the Standard Model Factor 20 improvement in (2C2u-C2d) electron-quark couplings

Determination of sin2w to within 0.00025


SPIN2006, October 7, 2006, 3

Examples of the 12 GeV Upgrade Research

• Parton Distribution Functions

• Form Factors

• Generalized Parton Distributions

• Exotic Meson Spectroscopy: Confinement and the QCD vacuum

• Nuclei at the level of quarks and gluons

• Tests of Physics Beyond the Standard Model


SPIN2006, October 7, 2006, 4

Hall A at 11 GeV with BigBite

12 GeV : Unambiguous Flavor Structure x —> 1After 35 years: Miserable Lack of Knowledge of Valence d-Quarks

di-quarkcorrelations

pQCD


SPIN2006, October 7, 2006, 5

A1p at 11 GeV

Unambiguous Resolution of Valence Spin

A1n at 11 GeV


SPIN2006, October 7, 2006, 6

At RHIC with W productionAt JLab with 12 GeV upgrade

Stops at x≈0.5 AND needs valence d(x)

Complements Spin-Flavor Dependence at RHIC

12


SPIN2006, October 7, 2006, 7


• Form Factors







SPIN2006, October 7, 2006, 8

Proton Neutron

Electric

Magnetic

Experiments at 11 GeV will extend data

To 5 GeV2

To 15 GeV2

To 14 GeV2


SPIN2006, October 7, 2006, 9



• Form Factors






SPIN2006, October 7, 2006, 10

The Next Generation of Proton Structure Experiments

Elastic Scattering

transverse quark distribution in

Coordinate space

DISlongitudinal

quark distributionin momentum space

GPDsThe fully-correlated

Quark distribution in both coordinate and

momentum space


SPIN2006, October 7, 2006, 11

Generalized Parton Distributions (GPDs): New Insight into Hadron Structure

JG = 1

1

)0,,()0,,(21

21 xExHxdxJ qqq

Quark angular momentum (Ji’s sum rule)

X. Ji, Phy.Rev.Lett.78,610(1997)

e.g.

Flavor separationthrough Deeply Virtual Meson Production


SPIN2006, October 7, 2006, 12

Access GPDs through x-section and asymmetries

Accessed by cross sections

Accessed by beam/target spin asymmetry

t = 0

Quark distribution q(x)

-q(-x)

DIS measures at =0

Flavor separationthrough DVMP


SPIN2006, October 7, 2006, 13

Exclusive 0 with transverse target

Asymmetry depends linearly on the GPD E, which enters Ji’s sum rule

A ~ (2Hu +Hd)B ~ (2Eu + Ed)

L dominance Q2 =1

-t = 0.5GeV2 t = 0.2

L=1035cm-2s-1

2000hrs

AUT

K. Goeke, M.V. Polyakov, M. Vanderhaeghen, 2001

xB

AUT =−2⊥ Im(AB* ){ } / π

A 2 1−2( )−B 2 2 + t / 4m2( )−Re AB*( )22


SPIN2006, October 7, 2006, 14



• Form Factors






SPIN2006, October 7, 2006, 15

Gluonic Excitations and the Origin of ConfinementConfinement is due to the formation of “Flux tubes” arising from the self-interaction of the glue, leading to a linear confining potential

Experimentally, we want to “pluck” the flux tube and see how it responds

π/rground statetransverse phonon modes Hybrid mesons

Normal mesons

~1 GeV mass difference

Jpc = 1-+

An excited flux tube gives rise to hybrid mesons with conventional and exotic quantum numbers JPC


SPIN2006, October 7, 2006, 16

Glueballs and hybrid mesons

Colin Morningstar:Gluonic Excitations workshop, 2003 (JLab)


SPIN2006, October 7, 2006, 17

Physics goals and key features

The physics goal of GlueX is to map the spectrum of hybrid mesons in a mass range 1.5 to 2.5 GeV, starting with those with the unique signature of exotic JPC

Identifying JPC requires an amplitude analysis which in turn requires

linearly polarized photons detector with excellent acceptance and resolution sensitivity to a wide variety of decay modes

In addition, sensitivity to hybrid masses up to 2.5 GeV requires 9 GeV photons which will be produced using coherent bremsstrahlung from 12 GeV electrons

Final states include photons and charged particles and require particle identification

Hermetic detector with large acceptance for charged and neutral particles


SPIN2006, October 7, 2006, 18



• Form Factors






SPIN2006, October 7, 2006, 19

• Observation stunned and electrified the

HEP and Nuclear communities 20 years ago• Nearly 1,000 papers have been generated…..• What is it that alters the quark momentum in the nucleus?

Classic Illustration: The EMC effect

J. Ashman et al., Z. Phys. C57, 211 (1993)

J. Gomez et al., Phys. Rev. D49, 4348 (1994)

The EMC Effect: Nuclear PDFs


SPIN2006, October 7, 2006, 20

Unpacking the EMC effect

• With 12 GeV, we have a variety of tools to unravel the EMC effect: Parton model ideas are valid over fairly wide kinematic

range High luminosity High polarization

• New experiments, including several major programs: Precision study of A-dependence; x>1; valence vs. sea g1A(x) “Polarized EMC effect” – influence of nucleus on

spin Flavor-tagged polarized structure functions uA(xA) and

dA(xA) x dependence of axial-vector current in nuclei (can study

via parity violation) Nucleon-tagged structure functions from 2H and 3He Study x-dependence of exclusive channels on light nuclei,

sum up to EMC


SPIN2006, October 7, 2006, 21



• Form Factors






SPIN2006, October 7, 2006, 22

PV DIS at 11 GeV with an LD2 target

• 6 GeV experiment will launche PV DIS measurements at JLab• 11 GeV experiment requires tight control of normalization errors• Important constraint should LHC see anomaly

€

APV =GFQ2

2παa(x) + f (y)b(x)[ ]

€

a(x) =

C1iQi f i(x)i

∑

Qi2 f i(x)

i

∑

€

y ≡1− ′ E / E

€

b(x) =

C2iQi f i(x)i

∑

Qi2 f i(x)

i

∑

e-

N X

e-

Z* *

For an isoscalar target like 2H, structure functions largely cancel in the ratio:

€

a(x) =3

10(2C1u − C1d )[ ] +L

€

b(x) =3

10(2C2u − C2d )

uv (x) + dv (x)

u(x) + d(x)

⎡

⎣ ⎢ ⎤

⎦ ⎥+L

(Q2 >> 1 GeV2 , W2 >> 4 GeV2, x ~ 0.3-0.5)

• Must measure APV to 0.5% fractional accuracy• Luminosity and beam quality available at JLab


SPIN2006, October 7, 2006, 23

1% APV

measurements

Precision High-x Physics with PV DIS

Charge Symmetry Violation (CSV) at High x: clean observation possible

€

δu(x) = up (x) − dn (x)

δd(x) = d p (x) − un (x)

€

δAPV (x)

APV (x)= 0.3

δu(x) −δd(x)

u(x) + d(x)

Global fits allow 3 times larger effects

€

APV =GFQ2

2παa(x) + f (y)b(x)[ ]

€

a(x) =u(x) + 0.91d(x)

u(x) + 0.25d(x)

• Allows d/u measurement on a single proton!

Longstanding issue: d/u as x1

For hydrogen 1H:

Londergan & Thomas

• Direct observation of CSV at parton-level • Implications for high-energy collider pdfs• Could explain large portion of the NuTeV

anomalyNeed 1% APV measurement at x ~ 0.75


SPIN2006, October 7, 2006, 24

• Comparable to single Z pole measurement: shed light on disagreement

• Best low energy measurement until ILC or -Factory • Could be launched ~ 2015

Future Possibilities (Purely Leptonic)-e in reactor can test neutrino coupling: sin2W to ± 0.002

Møller at 11 GeV at Jlab sin2W to ± 0.00025!ee ~ 25 TeV reach!Higher luminosity and acceptance

JLab e2e @ 12 GeV

e.g. Z’ reach ~ 2.5 TeV

Does Supersymmetry (SUSY) provide a candidate for dark matter?•Neutralino is stable if baryon (B) and lepton (L) numbers are conserved•B and L need not be conserved (RPV): neutralino decay


SPIN2006, October 7, 2006, 25

CHL-2CHL-2

Upgrade magnets Upgrade magnets and power and power suppliessupplies

Enhance equipment in Enhance equipment in existing hallsexisting halls

6 GeV CEBAF1112Add new hallAdd new hall


SPIN2006, October 7, 2006, 26

HALL A - 12 GeV Upgrade Summary

Infrastructure for

Large Installations


SPIN2006, October 7, 2006, 27

A Vision for Precision PV DIS Physics

• Hydrogen and Deuterium targets• Better than 2% errors

It is unlikely that any effects are larger than 10%

• x-range 0.25-0.75• W2 well over 4 GeV2

• Q2 range a factor of 2 for each x

(Except x~0.75)• Moderate running times

• CW 90 µA at 11 GeV• 40 cm liquid H2 and D2 targets• Luminosity > 1038/cm2/s

• solid angle > 200 msr• count at 100 kHz• on-line pion rejection of 102 to 103

Goal: Form a collaboration, start real design and simulations, and make pitch to US community at the next nuclear physics Long Range Plan (2007)


SPIN2006, October 7, 2006, 28

Beamline Instrumentation

Preshower Calorimeter

Forward Drift Chambers

Inner Cerenkov(HTCC)

SuperconductingTorus Magnet

Central Detector

Forward Calorimeter

Forward Time-of-Flight

Detectors

* Reused detectors from CLAS

Forward Cerenkov(LTCC)

Inner Calorimeter

Hall B - CLAS12

New TOF Layer


SPIN2006, October 7, 2006, 29

Hall C - Side View of SHMS Design


SPIN2006, October 7, 2006, 30

Argon/Neon Cerenkov

HGCS1XS1Y

AGCDC1 DC2

TRD S2X S2Y LGCA1

C4F10 Cerenkov

ElevationS2Y

SHMS/HMS: Detector Systems

Option: Replace Cherenkov with Focal Plane Polarimeter

(for π/e at high E’ only, otherwise vacuum)

Space for aerogel, etc.

Quartz Hodoscope


SPIN2006, October 7, 2006, 31

SHMS/HMS: Detector Systems

Option: Replace Cherenkov with Focal Plane Polarimeter,with a similar option in SHMS!

Argon/Neon Cerenkov

AGC

DC1 DC2 LGC

FPP FPP

S1XS1YS2X S2Y LGC

(Q2 > 12 GeV2)

(for π/e at high E’ only, otherwise vacuum)


SPIN2006, October 7, 2006, 32

flu

x

photon energy (GeV)

12 GeV electron beam

This technique provides requisite energy, flux and

linear polarization

collimated

Incoherent &coherent spectrum

tagged(0.1% resolution)

40%polarization

in peak

electrons in

photons out

spectrometer(two magnets)

diamondcrystal

Hall D - Coherent Bremsstrahlung


SPIN2006, October 7, 2006, 33

Tagger Spectrometer(Upstream)

Hermetic detectionof charged and neutral particles

Hall D - GluEx Detector


SPIN2006, October 7, 2006, 34

12 GeV Upgrade: Project Schedule

• 2004-2005 Conceptual Design (CDR)• 2004-2008 Research and Development

(R&D)• 2006 Advanced Conceptual Design (ACD)• 2007-2009 Project Engineering & Design

(PED)• 2008-2009 Long Lead Procurement• 2009-2013 Construction• 2012-2014 Pre-Ops (beam commissioning)

Critical Decision (CD) Presented at IPR

CD-0 Mission Need 2QFY04 (Actual)

CD-1 Preliminary Baseline Range 2QFY06 (Actual)

CD-2A/3A Construction and Performance Baseline of Long Lead Items

4QFY07

CD-2B Performance Baseline 4QFY08

CD-3B Start of Construction 2QFY09

CD-4 Start of Operations 1QFY15

• JLab Upgrade only present construction project in DOE-NP

• First 12 GeV beam expected in ~2012

• However, plans for next upgrade already being developed now


SPIN2006, October 7, 2006, 35

Why Electron-Ion Collider?

• Polarized DIS and e-A physics: in past only in fixed-target mode• Collider geometry allows complete reconstruction of final state• Better angular resolution between beam and target fragments

• Lepton probe provides precision but requires high luminosity to be effective

• High Ecm large range of x, Q2 Qmax2= ECM

2•x

x range: valence, sea quarks, glueQ2 range: utilize evolution equations of QCD

• High polarization of lepton and nucleon a requisite


SPIN2006, October 7, 2006, 36

Ring-Ring Concept

• Use present CEBAF as injector to electron storage ring

• Add light-ion complex

Linac 200 MeV

Ion Collider Ring

Pre-Booster3 GeV/c

C≈75-100 m

Ion Large Booster 20 GeV

(Electron Storage Ring)

spin


SPIN2006, October 7, 2006, 37

Achieving the Luminosity of ELIC

For 150 GeV protons on 7 GeV electrons, L~ 8 x 1034 cm-2 s-1 is compatible with realistic Interaction Region design.

Beam Physics Issues

• High energy electron cooling

• Beam – beam interaction between electron and ion beams

(i ~ 0.01 per IP; 0.025 is presently utilized in Tevatron)

• Interaction Region

High bunch collision frequency (f = 1.5 GHz)

Short ion bunches (z ~ 5 mm)

Very strong focus (* ~ 5 mm)

Crab crossing

*24i e

b

N NL f

π=


SPIN2006, October 7, 2006, 38

Polarization of Electrons/Positrons

• Spin injected vertical in arcs (using Wien filter) • Self-polarization in arcs to support injected polarization • Spin rotators matched with the cross bends of Interaction Points• Electrons at 200 MeV yield unpolarized positron accumulation of ~100

mA/min• ½ hr to accumulate 3 A of positron current• Sokolov-Ternov polarization for positrons (2 hrs at 7 GeV – varies as E-5)

spin rotator

spin rotator

spin rotator

spin rotator

collision point

spin rotator with 90º

solenoid snake

collision point

collision point

collision point

spin rotator with 90º

solenoid snake


SPIN2006, October 7, 2006, 39

Summary of Future Spin Physics at JLab

• The Upgrade to 12 GeV at JLab is well underway (preparing for CD-2 review)

• It will allow ground-breaking studies of

the structure of the nucleon

exotic mesons and the origin of confinement

the QCD basis of nuclear structure

the Standard Model at the multi-TeV scale

All requiring the use of highly polarized beams (and/or targets)

• The schedule of LQCD calculations at JLab is commensurate with the physics goals of the 12 GeV Upgrade

• Design studies at JLab have led to a promising design of an electron-ion collider

a luminosity of up to ~1035 cm-2 s-1

at a center-of-mass energy between 20 and 65 GeV

for collisions between polarized electrons/positrons and light ions (A≤40)

future spin physics at jlab 12 gev and beyond kees de jager jefferson lab spin2006 kyoto

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