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

27 Settembre 2013 XCIX Congresso SIF 2013 – Trieste

G.M. Urciuoli, M. Battaglieri

L’esperimento JLAB12

The Jefferson Laboratory and the Italian collaboration

Physics (excerpt)

• Nucleon Structure (Form Factor and Quark Distribution)

• Parity Violation Experiments

• Hypernuclei

• Nuclear Structure

Technological Developments

• HD Polarized Target

• Photon Tagger

• RICH/Clas12

• GEM/SiD Trackers

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

3

CEBAF accelerator

A B

C

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

4

Hall A Hall B/CLAS Hall C

Two High Momentum

Resolution + one

large angular

acceptance

spectrometers

Dedicated neutron and

gamma detectors

Large acceptance

High multiplicity

reconstruction

Six 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

5

CEBAF after 2013

CHLCHL--22

Upgrade magnets Upgrade magnets

and power and power

suppliessupplies

add Hall D

(and beam line) 6 GeV CEBAF (< 2013) Max Current: 200 mA Max Energy: 0.8 - 5.7 GeV Long. Polarization: 75-85%

12 GeV CEBAF (>2013)

Max Current: 90 mA Max Energy Hall A,B,C: 10.9 GeV Max Energy Hall D: 12 GeV Long. Polarization: 75-85%

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 detector

New 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-C www.jlab.org/Hall-D

www.gluex.org

Experimental Halls after 2014

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

8

Sezioni INFN partecipanti (BA, CA, CT, GE, FE, ISS, LNF, PD, RM, RM2, TO):

Ricercatori + Tecnologi: ~ 60 (41.2 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

TMD’s latest results at JLab

9

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.

D

F

TMDs @ JLab 12 GeVTMDs @ JLab 12 GeV

E12E12--0909--018018: p/k

E12E12--1010--006:006: p

3He

Hall A SBS/SOLID

HALL C HMS+SHMS

E12E12--0909--017017: p/k

C12C12--1111--102 102 p0

Hall B CLAS12

C12C12--1111--111111: p/k

H2, D2 NH3 HD H2, NH3, D2, ND3

E12E12--0606--112112: p

E12E12--0909--008: 008: k

E12E12--0707--107107: p

E12E12--0909--009: 009: k

A MultiA Multi--Hall TMDs program Hall TMDs program

-- Large variety of targetsLarge variety of targets -- Different species of detected hadronsDifferent species of detected hadrons

--High luminosity experimentsHigh luminosity experiments -- Extended phase spaceExtended phase space

1

0

E12E12--1111--107107: p

C12C12--1111--108108: p

1

1

Proton Form Factors

2tan

2

)( e

p

ebeam

l

t

Mp

Ep

M

EE

P

P

G

G mm

Polarization transfer from the incident

electron to the scattered proton

22

MpEp GGd

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 @12GeV E-12-07-109: Polarization transfer E-12-09-016: Double polarization

E-12-09-019: Cross section ratio

1

2

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

1

3

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)

1

4

First direct measurement

of the neutron skin

PREX-II Approved by PAC (Aug 2011)

Lead (208Pb) Radius Experiment: PREX E = 850 MeV, =6° electrons on lead

15

Future equipment for PaVi experiments at Jlab/Hall A

SOLID (PV e- - q scattering + SIDIS) - PV e-quark

- High precision TMD

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

precise control of the systematics

16

Pu

blis

he

d

Study -N Interaction potential Study -N Interaction potential

Hypernuclei at JLab

Experimental requirements:

- Excellent Energy Resolution

- Detection at very forward angles (6°→septum

magnets)

- Excellent PId for kaon selection →RICH

- High luminosity

Reactions Investigated:

9Be→9LiΛ (3 spin doublets, information on Δ) 12C→12BΛ (evidence of excited core states → sN contribution)

16O→16NΛ (unmatched peak may indicate

large sΛ term)

H →Λ,Σ0 (elementary process)

Experiment E94-107

Hypernuclear spectroscopy 9Be (e,e’k+) 9

ΛLi reaction

Thanks to energy resolution improvements a clear

three peak structure appears in the excitation energy

spectrum. RM1, ISS

Analisi dell’esperimento sulla produzione di ipernuclei a Jlab completamente in mano alla

collaborazione italiana:

- M. Iodice, F. Cusanno et al., Phys. Rev. Lett. 99, 052501 (2007) (ipernucleo 12ΛB)

- F. Cusanno, G.M. Urciuoli et al., Phys Rev. Lett. 103 202501 (2009) (ipernucleo 16ΛN)

- G.M. Urciuoli, F. Cusanno, S. Marrone et al. Sottomesso a PHYS REV C

Experiment E06-007 208Pb(e,e’p)207Tl and 209Bi(e,e’p)207Pb cross sections at true quasielastic

kinematics (xB=1, q=1 GeV/c, ω=0.433 GeV/c ) and at both sides of q

Never been done before for A>16 nucleus

RM1, ISS

★ Determine the spectroscopic factors dependence with Q2

★ Long range correlations: not needed!

★ Relativistic effect in nuclei: needed!

Search for dark force: HPS in Hall-B

18

1

9

- - - - - - - - - - - -

1 week 1.1 GeV

- - - - - - - - - - - -

1 week 2.2 GeV

3 months 2.2 GeV

3 months 6.6 GeV

Bump hunting

Bump hunting

+ vertexing

Phase 1

expected

2014/15

Phase 2

2015 or

later

HPS Projected results

JLab12

12 GeV era / Equipment

• HD Target,

• Forward Tagger,

• RICH,

• High Lumi Tracker

HD-ice: polarized frozen spin HD target Polarized target of high dilution factor, made of solid Deuterium-Hydride:

Longitudinal and Transverse Polarizations: up to 75% H and 40% D

Relaxation time: > 1 year

Polarization procedure » 3 months

Data taking: » months

Wide acceptance

Target cell Target 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 2

1

The Forward Tagger for CLAS12

22

New system to detect electrons at small angle and

perform quasi-real photo-production experiments

Calorimeter

electron energy/momentum

Photon energy (ν=E-E')

Polarization ε-1 ≈1 + ν2/2EE’

PbWO4 crystals with

APD/SiPM readout

Scintillation Hodoscope

veto for photons

Scintillator tiles with WLS

readout,…

Tracker

electron angles

Polarization scattering plane

MicroMegas detectors

Moller Shield

Calorimeter

Tracker

Scintillation Hodoscope

HTCC Moller cup

GEMC implementation

e-

*

CLAS12

p

e-

Forward

Tagger

Adapted from M. Battaglieri, Genova 2012

2

2

Aerogel Elliptical mirrors

Photo-detectors

+ Planar mirrors

Proximity Focusing RICH + MirrorsProximity Focusing RICH + Mirrors

RICH Conceptual DesignRICH Conceptual Design

Goal: 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 > 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)

-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)

2

3

Uva

JLab

INFN

Rutgers U.

College WM

U. of Glasgow

Norfolk 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

2

4

40x150 cm2 GEM Tracker

70 mm spatial resolution

High photons up to 250 MHz/cm2 and

electrons 160 kHz/cm2 background

Spare

RICH detector for CLAS12RICH detector for CLAS12

DC R3 R2 R1

DC R3 R2 R1

E

C E

C

Torus Torus

TOF TOF

PCAL PCAL

HTCC HTCC

Solenoid Solenoid INSTITUTIONS

ARGONNE NL

INFN Bari, Ferrara, Genova, Frascati, Roma/ISS

GLASGOW U.

JLAB

U. CONN

UTFSM (Chile)

GeV/

c

1 2 3 4 5 6 7 8 9 10

p/K

p/p

K/p

TOF

HTCC LTCC

TOF

TOF

LTCC HTCC

full pion / kaon / proton separation in 2–8 GeV/c range

p/K separation of 4-5 @ 8 GeV/c for a

rejection factor ~1000

x RICH

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

Option under investigation:Option under investigation: proximity focusing RICH + mirrors (innovative geometry)proximity focusing RICH + mirrors (innovative geometry)

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6

CLAS12 PIDCLAS12 PID

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

HTCC EC/PCAL

LTCC

LTCC RICH

LTCC LTCC RICH

LTCC RICH

4-5 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

01

2 / F

err

ara

E

. C

isb

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Ex

pe

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en

tal P

hys

ics

at

JL

ab

2

7 Adapted from P. Rossi, JLab 2012

New RICH geometry

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8

Aerogel

Flat Mirror + Aerogel Active Photon Detector

Adapted from L. Pappalardo Roma 2011

RICH preliminary prototypeRICH preliminary prototype

10

H8500

8

R8900

Aerogel

MA-PMTs

Electronics

Maroc2 front end electronics developed for nuclear medicine

• preamplifier, adjustable from 1/8 to 4 • ADC, about 80fC per channel

Hit distributionsHit distributions

Ebeam

(GeV)

Aerogel <d>

(cm)

<R(p)>

cm

t (cm) n

10 1 1.05 35.1 11.2

10 2 1.05 34.6 11.1

10 3 1.05 34.1 10.9

10 3 1.03 48.8 12.0

4 1 1.03 49.8 12.2

N.B. 1 and 2 cm means 2 or 3 blocks of 1 cm

1cm 2cm 3cm

aerogel n=1.03

aerogel n=1.05

integrated distributions of hits above

threshold 3cm

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Meson Spectroscopy in CLAS12

The study of the light-quark meson spectrum

and the search for exotic quark-gluon

configurations is crucial to reach a deep

understanding of QCD:

• identify relevant degrees of freedom

• understand the role of gluons and the origin of

confinement

Photo-production is the ideal tool:

• linearly polarized photon beam (NEW!)

• large acceptance detector (CLAS12)

Forward Tagger

E’ 0.5-4.5 GeV

n 7-10.5 GeV

q 2.5-4.55 deg

Q2 0.007 – 0.3 GeV2

W 3.6-4.5 GeV

Photon Flux 5 x 107 /s @ Le=1035

Quasi-real photoproduction with CLAS12

(Low Q2 electron scattering)

e-

γ*

CLAS12

p

e-

Forward

Tagger

Tracker Electron angle

Hodoscope Photon veto

Calorimeter Electron Momentum/Energy Adapted from R. De Vita, Roma/2011

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Choice of the technology

System Requirements Tracking Technology

Drift MPGD Silicon

High Background Rate (up to):

(low energy and e) 1 MHz/cm2 NO MHz/mm2 MHz/mm2

High Resolution (down to):

70 mm Achievable 50 mm 30 mm

Large Area:

from 40×150 to 80×300 cm2 YES Doable

Very

Expensive

… and modular: reuse in

different geometrical

configurations Flexibility in readout geometry

and lower spark rate

GEM mMs

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GEM working principle

Ionization

Multiplication

Readout

Multiplication

Multiplication

Readout independent from ionization and multiplication stages

Recent technology: F. Sauli, Nucl. Instrum. Methods A386(1997)531

GEM foil: 50 mm Kapton + few

mm copper on both sides with

70 mm holes, 140 mm pitch

Strong electrostatic

field in the GEM holes

SBS Tracker GEM Chambers configuration

Modules are composed to form larger

chambers with different sizes

Electronics along the borders and

behind the frame (at 90°) – cyan

and blue in drawing

Carbon fiber support frame around

the chamber (cyan in drawing);

dedicated to each chamber

configuration

Front Tracker

Geometry

x6

Back Trackers Geometry

X(4+4)

GEp(5) SBS

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MonteCarlo + Digitazation + Tracking

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5

High + e background hits

MHz/cm2

(Signal is red)

Bogdan Wojtsekhowski + Ole Hansen

+ Vahe Mamyan et al.

6 GEM chambers with x/y readout

Use multisamples (signal shape)

for background filtering

Assembling the first 40x50 cm2 module

Stretching

Gluing the next

frame with

spacers

Foil Tension: T = 2 kg/cm Spacer Sector: S = 170 cm2 Expected maximum pressure on foil P 10 N/m2

Maximum foil deformation: u 0.0074 * P * S / T = 6.4 mm

Use stretching and spacers to keep foil flat

Stretcher design from LNF / Bencivenni et al.

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Beam test @ DESY / Full Module Size 40x50 cm2

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Electronics Readout (GEM and SiD)

GEM FEC MPD DAQ

2D

Readout

75 mm

49.5

mm

8 mm

Up to 10m

twisted,

shielded

copper cable

(HDMI)

Passive backplane

(optional)

Main features:

• Use analog readout APV25 chips (analog and time information)

• 2 “active” components: Front-End card and VME64x custom module

• Copper cables between front-end and VME

• Optional backplane (user designed) acting as signal bus, electrical

shielding, GND distributor and mechanical support

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+ Small Silicon Detector

Track

Angular Range

Chamber doublet

Dipole SD

(x/y)

21 Set 2009 / CSN III JLab12 - E. Cisbani 39

5mm

5mm

10mm

10mm

8.5mm 8.5mm 6.5mm

A

A

B

B

C

C

D

D 103500

Disegno custom per JLAB12Disegno custom per JLAB12 da un wafer di 6” (152mm)da un wafer di 6” (152mm)

4

0

30 cm

23 cm

41

fori di fissaggio

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Fan Out PCB

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Equipment / Physics Matrix @ 12 GeV

Equipment

Physics

HD

Target RICH

Forward

Tagger

GEM

Tracker

Si

Detector

TMDs,

nucleon

spin

structure

X X X X

Meson

Study X

Form

Factors X X

Parity

Violating

Electron

Scattering

X

Intensa attività di sviluppo tecnologico per un esteso programma di fisica

4

3

The “ultimate” description of the nucleon

3D view of the nucleon3D view of the nucleon Transverse Momentum Dependent (TMD) Transverse Momentum Dependent (TMD) partonparton distribution and fragmentation functions distribution and fragmentation functions • Describe correlations between the transverse

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

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

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

transverse spacetransverse space N

ucle

on

Quark

Information on: nucleon spin origin, quark orbital angular momentum,

relativistic effects in QCD, quark/gluon Q2 evolution,

QCD gauge invariances ...

4

4 Adapted from P. Rossi, JLab 2012

Some TMDs projectionsSome TMDs projections e3He →e’p+/-X

E12E12--1111--007007

E12E12--0909--009009

e p →e’K+/-Xlongitudinally polarized target

6 GeV data

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

E12E12--0909--018018 4

5 Adapted from P. Rossi. JLab 2012

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Different (e,e’h) experimental configurations

Experiments Luminosity

(s·cm2)-1

Tracking Area

(cm2)

Resolution

Angular

(mrad)

Vertex

(mm)

Momentum

(%)

GMn - GEn up to 7·1037 40x150

and 50x200

< 1 <2 0.5%

GEp(5) up to

8·1038

40x120,

50x200 and

80x300

<0.7

~1.5

~ 1 0.5%

SIDIS up to 2·1037

40x120,

40x150 and

50x200

~ 0.5 ~1 <1%

Maximum reusability: same trackers in different setups

HighHigh

RatesRates

LargeLarge

AreaArea

Down to Down to ~ 70 ~ 70 mmmm

spatial resolutionspatial resolution

4

7

Confinement

Mechanism

(hadronization and

spectroscopy)

Hadronization of quarks

4

8

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

broadening Adapted from P. Rossi, JLab 2012

How hadrons form in

scattering processes ?

Beyond the quark model: hybrids and exotics

mesons

Quarks are confined inside colorless hadrons

they 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

q

q q q

q

molecules glueball mesons hybrid mesons pentaquarks

q

q q q

q

q

q q

q q q

Adapted from M. Battaglieri, Genova 2012

4

9

Hybrid mesons and

glueballs mass range

1.4 – 3.0 GeV

Lattice-QCD predictions

for the lowest exotics

states:

0+- 1.9 GeV 1-+ 1.6 GeV

This mass range is accessible in photoproduction experiments with a

beam energy in the range 5 GeV < E <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

5

0

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 state m=0

CP=(-1) S+1

Hybrid meson: flux tube in excited state m=1

CP=(-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

5

1

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

5

2 Adapted from M. Battaglieri, Genova 2012