IFAE 2012 / Ferrara E. Cisbani / Experimental Physics at JLab 1

13 April 2012IFAE 2012 – Ferrara

Experimental Physics at JLab:where confinement meets asymptotic

freedomEvaristo Cisbani

INFN-Sanità and Istituto Superiore di Sanità

The Jefferson Laboratory and the Italian collaboration Physics (excerpt)

• Nucleon Structure (Form Factor and Quark Distribution)• Hadron Spectroscopy• Parity Violation Experiments

Technological Developments• HD Polarized Target• Photon Tagger• RICH/Clas12• GEM/SiD Trackers

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

2

Thomas Jefferson National Laboratory

• Newport News / Virginia / USA (3 ore da Washington DC)

• DOE funding + Local Universities and Organizations

• Director: H. E. Montgomery (ex-associate director for research al Fermilab)

• 2000 International Users• Fundamental Research by electron

accelerator on 3+1 experimental Halls• Applied research by FEL and other facilities• Web site: www.jlab.org

more than

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

3

CEBAF accelerator

AB

C

Lina

c

Linac

Arc

Arc

Injector

• Linear Recirculating e- Accelerator with

superconductive cavities• Polarized beam

• High current (200 mA)• Max. energy 6 GeV

• 100% duty factor• Beam released

simultaneously on three experimental Halls: A, B

and C

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

4

Hall A Hall B/CLAS Hall C

Two High Momentum Resolution + one large angular acceptance spectrometers

Dedicated neutron and gamma detectors

Large acceptanceHigh multiplicity

reconstructionSix coils Toroidal

field

Two asymmetric spectrometers

High momentum range and high resolution

Dedicated detectors

High beam currents (>100 mA), lumi 1037

cm-2 s-1

Tagged real photons beam

High beam currents (>100 mA), lumi 1037

cm-2 s-1

3He T/L Polarized target, high flexibility unpol. from H to Pb

NH3/ND3 Polarized long. target

NH3/ND3 Polarized long. target, high flexibility unpol. from H to Pb

Large and flexible installations

4p coverage Moderately large and flexible installations

Current Experimental Halls

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

5

CEBAF after 2013

CHL-2

Upgrade magnets and power supplies

add Hall D (and beam line)6 GeV CEBAF (< 2013)

Max Current: 200 mAMax Energy: 0.8 - 5.7 GeVLong. Polarization: 75-85%

12 GeV CEBAF

(>2013)Max Current: 90 mAMax Energy Hall A,B,C: 10.9 GeVMax Energy Hall D: 12 GeVLong. Polarization: 75-85%

$ 310M

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

6

Hall A Hall B/CLAS12 Hall C Hall D/GLUEX

+ 1 large angular and momentum, high lumi spectrometer with hadron ID

+ Solid detector+ Möller detectorNew beam line

New ~2p toroid detector with extended hadron ID

+ “super high” momentum spectrometer

+ dedicated equipment

Excellent hermetic coverage,

Solenoid field

High multiplicity reconstruction

+ lumi 1038 cm-2 s-1 + forward tagger for quasi-real photons

108 linearly polarized <12 GeV

real photons/s

+ targets with large thickness

+ long/trans polarized H/D target

hallaweb.jlab.org www.jlab.org/Hall-B www.jlab.org/Hall-Cwww.jlab.org/Hall-D

www.gluex.org

Experimental Halls after 2014

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

7

JLab physics

• Origin of quark and gluon confinement (B & D)

– Gluonic excitations - existence and properties of exotic mesons (and baryons)– Heavy baryon and meson spectroscopy

• Structure of the Hadrons (A,B and C)– Parton Distributions Functions (and Fragmentation Functions)– New view of nucleon structure via the Generalized Parton Distributions (GPDs)

accessed in Exclusive Reactions– Form Factors - improve knowledge of charge and current in the nucleons;

constraints on the GPDs– Quark propagation and hadron formation

• Dynamics of the nucleons in the nuclei (A, B and C)– The Quark Structure of Nuclei (resolving the EMC effect)– The Short-Range Behavior of the N-N Interaction and its QCD Basis– Cold nuclear matter

• Electroweak Interaction (A and C)– High Precision Tests of the Standard Model at low energies via Parity-Violating

Electron Scattering Experiments– Measure nuclear properties by weak interaction

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

8

Sezioni INFN partecipanti (BA, CT, GE, FE, ISS, LNF, RM, RM2):Ricercatori + Tecnologi: ~ 50 (32.3 FTE)

Intensa attività sperimentale al JLab/6 GeV (prevalentemente in sala A e B)

Forte coinvolgimento negli sviluppi legati al raddoppio di energia del fascio e aggiornamento degli apparati nelle sale sperimentali

Esperimento INFN formalmente attivo

dal 2009 per 7 anni, nasce dalla

sinergia delle ex sigle AIACE + LEDA

per sfruttare al meglio le opportunità

sperimentali offerte

dall’aggiornamento a 12 GeV

new deputy per la fisica al JLab !Coordinatori Nazionali: E. Cisbani, P. Rossi

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

9

Nucleon (Spin) Structure

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

10

The “ultimate” description of the nucleon

3D view of the nucleonTransverse Momentum Dependent (TMD) parton distribution and fragmentation functions • Describe correlations between the transverse

momentum of quarks/gluons and spin• 3D picture of nucleon in momentum space

Generalized Parton Distribution functions (GPD) • Describe correlations between the transverse

coordinates of quarks and spin• 3D picture of nucleon in mixed momentum and

transverse spaceN

ucle

on

Quark

Information on: nucleon spin origin, quark orbital angular momentum,relativistic effects in QCD, quark/gluon Q2 evolution,

QCD gauge invariances ...

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

11Adapted from P. Rossi, JLab 2012

TMD’s latest results at JLab

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

12

First ‘direct’ measurement on neutron

n - Collins small, largely compatible to 0; Sivers negative (?) for p+, zero for p-

Collins Moment = h1 Collins FF Clean probe of relativistic effects

Sivers Asymmetry = f1T TMD Unpol. FF

Link to quark Orbital Angular Momentum

Experimental limits:Modest statistics, integrated on the relevant kinematical variables (x,z,pT),no access to large x, valence region, no clean interpretation of the data.

Adapted from A. Puckett, JLab 2011

D

F TMDs @ JLab 12 GeV

E12-09-018: p/kE12-10-006: p

3He

Hall A SBS/SOLID

HALL CHMS+SHMS

E12-09-017: /p kC12-11-102 p0

Hall BCLAS12

C12-11-111: /p k

H2, D2NH3HDH2, NH3, D2,

ND3

E12-06-112: pE12-09-008: k

E12-07-107: pE12-09-009: k

A Multi-Hall TMDs program

- Large variety of targets- Different species of detected hadrons

-High luminosity experiments- Extended phase space

Adapted from P. Rossi, JLab 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

13

E12-11-107: p

C12-11-108: p

Some TMDs projections

SOLID: e3He →e’p+/-X

E12-11-007

E12-09-009

CLAS12: e p →e’K+/-X longitudinally polarized target

6 GeV data

SBS: e3He →e’K+/- X(transverse target)

E12-09-018

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

14Adapted from P. Rossi. JLab 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

15

Proton Form Factors

2tan

2

)( e

p

ebeam

l

t

Mp

Ep

M

EE

P

P

G

G

Polarization transfer from the incident electron to the scattered proton

22MpEp GG

d

d

Rosenbluth Separation: assume single photon approximation

Prior to JLab, expectations were that Gep/GMp was fairly constant with Q2

New focus on nucleon structure and description of elastis scattering (two photon exchange); possible role of quark OAM

e + p → e’ + p’

e→ + p → e’ + p →’

At JLab, new class of experiments show GE/GMp decreasing linearly with Q2

Extended measurements of p/n form

factors at high Q2

Test different models (including

different contributions from the quark

OAM)

Investigate the transition region

(perturbative / non perturbative)

Constraint the H and E GPDs

Electromagnetic Nucleon Form Factors @12GeVE-12-07-109: Polarization transfer E-12-09-016: Double polarization

E-12-09-019: Cross section ratio

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

16

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

17

Confinement Mechanism

(hadronization and spectroscopy)

Hadronization of quarks

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

18

H. Matevosyan et al., Phys. Rev. D85 (2012) 014021

Transverse momentum distributions in hadronization may be flavor dependent

Employ nuclei as analyzers of

hadronization processes, to probe:

- The hadronization formation length

(0-10 fm)

- The time scale on which a qq pair

becomes dressed with its own

gluonic field

Study the SIDIS reaction on nuclei;

observables:

- The hadronic multiplicity ratio

- The transverse momentum

broadeningAdapted from P. Rossi, JLab 2012 E12-06-117

How hadrons form inscattering processes ?

Beyond the quark model: hybrids and exotics

mesons

Quarks are confined inside colorless hadronsthey combine to 'neutralize' color force

baryons

Other quark-gluon configuration can give colorless objects

QCD does not prohibit such states but not yet unambiguously observed

qq

q qq

molecules glueball mesons hybrid mesonspentaquarks

q

qqq

q

q

q q

qqq

Adapted from M. Battaglieri, Genova 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

19

Hybrid mesons and glueballs mass range

1.4 – 3.0 GeV

Lattice-QCD predictions for the lowest exotics states:

0+- 1.9 GeV1-+ 1.6 GeV

This mass range is accessible in photoproduction experiments with a beam energy in the range 5 GeV < Eg <12 GeV

Perfectly matched to JLab12 energy!

QCD Lattice calculations

Exotics

ρ

Standard mesons

J.Dudek et al Phys.Rev.D82 (2010) 034508

Adapted from M. Battaglieri, Genova 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

20

Unambiguous experimental signature for the presence of gluonic degrees of freedom in the spectrum of mesonic states

S=S1+S2 J= L+S P = (-1) L+1 C= (-1) L+S

Combine excited glue quantum number with those of the quarks

Normal meson:flux tube in ground statem=0CP=(-1) S+1

Hybrid meson:flux tube in excited statem=1CP=(-1) S

Flux tube JPC 1-+ , 1+-

Search for mesons with 'exotic' quantum numbers(not compatible with quark-model)

Not-allowed: JPC = 0-- , 0+- , 1-+ , 2+- ...

Meson spectroscopy with photons at JLab

Adapted from M. Battaglieri, Genova 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

21

Hall-D - GlueX Detector Hall-B - CLAS12 Detector

Meson spectroscopy with photons at JLab-12 GeV

• Good resolution• Good pID• Reasonable hermeticity• Un-uniform acceptance

• Good hermeticity• Uniform acceptance• Limited resolution• Limited pID

Forward Tagger

• Determination of JPC of meson states requires PWA• Decay and production of exclusive reactions• Good acceptance, energy resolution, particle identification

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

22Adapted from M. Battaglieri, Genova 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

23

PVES(parity violating electron scattering)

0Z

e e

+

2

Esperimenti di Violazione della Parità• Misura accurata della asimmetria nei processi elastici (e DIS) di elettroni

polarizzati longitudinalmente su nucleone/nucleo non polarizzato

• Accesso alle costanti di accoppiamento deboli elettroni-quark (u/d) delle correnti neutre, ovvero alla corrente debole del protone, ovvero all’angolo di mixing debole

• Pone limiti su esistenza di nuova fisica (PVDIS, QWeak, Möller) • Ha permesso la misura del contributo dei quark s ai fattori di forma del

nucleone (HAPPEX, G0)• Permette la misura di importanti grandezze nucleari soppressi nei

processi elettromagnetici PREX

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

24

Lead (208Pb) Radius Experiment: PREX

Z0 is a clean probe that couples mainly to neutrons

E = 850 MeV, J=6° electrons on lead

Elastic Scattering Parity Violating Asymmetry

~ 0.5 ppm

)(0130.0)(0604.0

6571.0

syststat

ppm

Statistics limited (9%)

Systematic error 2%!

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

25

Measure of the radius of the neutron distribution in Pb

Relevant to astrophysics model contraints

Adapted from G.M. Urciuoli, Roma 2012

A neutron skin established at ~93 % CL

Neutron Skin = RN - RP = 0.33 + 0.16 - 0.18 fm

Neutron Radius = RN = 5.78 + 0.15 - 0.17 fm

Pins down the symmetry energy (1 parameter)

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

26Adapted from G.M. Urciuoli, Roma 2012

First direct measurement

of the neutron skin

PREX-II Approved by PAC (Aug 2011)

“A” Rating 35 days run in 2013 / 2014

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

27Adapted from G.M. Urciuoli, Genova 2012

Standard Model Test at low energy

Parity Violation Physics to test the SM at low energy: require high luminosity and

precise control of the systematics

IFA

E 2

012

/ F

erra

ra28

E. C

isb

ani

/ E

xp

eri

me

nta

l P

hy

sic

s a

t J

La

b

Accuracy projection

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

29

JLab12

12 GeV era / Equipment

• HD Target,

• Forward Tagger,

• RICH,

• High Lumi Tracker

HD-ice: polarized frozen spin HD targetPolarized target of high dilution factor, made of solid Deuterium-Hydride:Longitudinal and Transverse Polarizations: up to 75% H and 40% DRelaxation time: > 1 year Polarization procedure » 3 monthsData taking: » monthsWide acceptance

Target cellTarget cell

Comparison of signal over background ratio:HD versus conventional polarized target

INFN contribution:• Dilution Refrigerator• Contribution to the construction of the new In-

Beam Dilution Refrigerator Cryostat• Raman analysis of ortho-hydrogen and para-

deuterium contents in HD gas• Magnetic Vari-Temp Cryostat for HD

condensation and NMR polarization measurements

Target Transfer Target Transfer

In-beam cryostat

Run with polarized deuterons from HD-ice & circularly polarized photons started on Dec. 2011: D polarization 27%

Run with polarized deuterons from HD-ice & linearly polarized photons started on April 2012: D polarization 30%

Test of HD-ice & electron beam performed in February: on-going analysis

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

30Adapted from A. D’Angelo, Roma 2012

The Forward Tagger for CLAS12

31

New system to detect electrons at small angle and perform quasi-real photo-production experiments

Calorimeter

electron energy/momentumPhoton energy (ν=E-E')Polarization ε-1 ≈1 + ν2/2EE’PbWO4 crystals with APD/SiPM readout

Scintillation Hodoscope

veto for photonsScintillator tiles with WLS readout,…

Tracker

electron anglesPolarization scattering planeMicroMegas detectors

Moller Shield

Calorimeter

Tracker

Scintillation Hodoscope

HTCC Moller cup

GEMC implementation

e-

g*

CLAS12

p

e-

ForwardTagger

Adapted from M. Battaglieri, Genova 2012

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

31

CLAS12 PID

RICH

GeV/c 1 2 3 4 5 6 7 8 9 10

p/K

p/p

K/p

e/p

HTCC

TOF

TOF

TOF

HTCC

HTCC

HTCCEC/PCAL

LTCC

RIC

HRIC

H

LTCCRICH

LTCCLTCCRICH

LTCCRICH

4-5 s p/K separation @ 8 GeV/c

Aerogel mandatory to separate hadrons in the 2-8 GeV/c momentum range collection of visible Cherenkov light use of PMTs

Challenging project, crucial to minimize Detector area

Option under investigation: proximity focusing RICH + mirrors

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

32Adapted from P. Rossi, JLab 2012

AerogelElliptical mirrors

Photo-detectors

+ Planarmirrors

Proximity Focusing RICH + Mirrors

RICH Conceptual Design

Goal: reduce the photon detection area of MA-PMTs H8500 to ~ 1m2/sector

Elliptical and planar mirrors to focus the Cherenkov light of particles emitted at angles J > 12°

10 H8500

8 R8900

- Test with hadron beam at CERN with a prelininary RICH prototype (summer 2011)

number of Np.e obtained for direct ring in consistent with simulations- Test with electron beam at LNF (july 2012)- test of full prototype with p/K beam at CERN (august 2012)

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

33Adapted from P. Rossi, JLab 2012

UvaJLabINFNRutgers U.College WMU. of GlasgowNorfolk State U.Carnegie Mellon U.U. of New Hampshire

SBS Spectrometer in Hall A

SiD

High luminosity ~1039/s/cm2

Moderate acceptance

Forward angles

Reconfigurable detectors

High luminosity ~1039/s/cm2

Moderate acceptance

Forward angles

Reconfigurable detectors

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

34

40x150 cm2 GEM Tracker70 mm spatial resolution

High photons up to 250 MHz/cm2 and electrons 160 kHz/cm2 background

IFA

E 2

012

/ F

erra

raE

. Cis

ban

i /

Ex

pe

rim

en

tal

Ph

ys

ics

at

JL

ab

35

QCD and confinement

Large DistanceLow Energy

Small DistanceHigh Energy

Perturbative QCDDIS ScatteringParton models

Strong QCDSpectroscopy

Phenomenological Models

s ~ QED QCDHigh luminosityPolarization (initial and final states)High beam stabilityComplementary EquipmentsDedicated, optimized detectors

JLaboffers

+ Test Standard Model

+ Dark matter search

www.iss.infn.it/webg3/cebaf