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
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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%
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
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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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
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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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