Commissione Scientifica Nazionale III
Torino 16 Settembre 2013
L’esperimento JLAB12 : stato e prospettive
M.Battaglieri & G.M.Urciuoli
per conto della collaborazione JLAB12
INFN -GE, INFN-RM1
Italy
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Sommario
✴ Jefferson Lab a 6 GeV e progressi verso l’ upgrade a 12 GeV
✴ Il programma di fisica a Jlab.
✴ JLAB12: la collaborazione italiana a Jlab
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I parametri del CEBAF
✴ Fascio primario: Elettroni
✴ Energia del fascio: 4 GeV (iniziale)
• 10 > λ > 0.1 fm
transizione nucleone → quark
stati eccitati barionici e mesonici
6 GeV nel passato
12 GeV prossimamente
✴100% Duty Factor (cw) Beam
• esperimenti in coincidenza
• Tre fasci simultanei di energia e intensità variabili indipendentemente e in modo
complementare, esperimenti lunghi
✴ Polarizzazione (fascio e prodotti di reazione)
• gradi di libertà di spin
• correnti neutre deboli
L > 106 x SLAC al tempo degli esperimenti originali DIS!
La luminosità di JLab12 aumenterà di un fattore 10 x
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Jefferson Lab nel passato (6 GeV)
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The 12 GeV upgrade
Il disegno e le performance del CEBAF hanno reso l’upgrade in
energia “facile”.
•Le cavità RF del CEBAF eccedono le specifiche di disegno di un 50%
•Ottenuta di routine un’energia massima di fascio di 6 GeV (energia massima
•nominale: 4 GeV)
• ARCS puo’ fornire un fascio di elettroni sino a 24 GeV
✴ Upgrade dell’acceleratore
✴ Costruzione di nuovi apparati per Hall A, B e C
✴ Costuzione di una nuova sala sperimentale (Hall D)
L’upgrade del CEBAF a 12 GeV (la più alta priorità del 2007 NSAC
Long Range Plan) è quasi ultimato
•Il progetto è “on cost and on schedule” e quasi completato
•Le operazioni iniziali con il fascio inizieranno in Hall A nella prima metà del 2014 e
l’acceleratore sarà completamente operativo entro giugno 2015
Il programma di ricerche a 12 GeV sta evolvendo rapidamente
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CEBAF @12 GeV
Add new hall
Upgrade magnets
and power supplies
CHL-2
Enhance equipment
in existing halls
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Gli apparati per Jlab a 12 GeV
Hall A – Spettrometri ad alta risoluzione e un
nuovo rivelatore multipurpose a grande
accettanza
short range
correlations,
fattori di forma
e nuovi
esperimenti :
SOLID,
MOELLER,
SBS
Hall C – Super High
Momentum
Spectrometer
(SHMS)
Determinazione precisa
delle proprietà dei q di
valenza nei nucleoni e
nei nuclei
Hall D – Rivelatore GLUEx per
esperimenti di fotoproduzione
Hall B – Rivelatore a
grande accettanza
CLAS12 for misure a
grande luminosità
(1035cm-2s-1)
Comprensione della
struttura del nucleone
via GPDs and TMDs e
spettroscopia adronica
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Le origini del
confinamento
attraverso lo
studio dei
mesoni ibridi
Time
schedule
&
Costi
18 maggio 2012:
completato il programma a 6 GeV !
16 mesi di installazione :
maggio 2012 – settembre 2013
Commissioning Hall A inizia: febbraio 2014
Commissioning Hall D inizia: ottobre 2014
Commissioning Hall B/C inizia:
gennaio/febbraio 2016
Completamento del progetto: marzo 2017
✴12 GeV - Total project cost: 310M$
✴~75% completed (~90% obligated) at
June 2013
✴Base equipment fully funded by DOE
✴JLAB12 (Italy) contributes to extra
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equipment
Missione scientifica di Jlab
✴Capire come gli adroni sono formati dai quark e dai gluoni
✴Capire le basi della QCD per la forza nucleone-nucleone
✴Esplorare i limiti della nostra comprensione della struttura nucleare
• Alta precisione
• Corte distanze
• La transizione dalla descrizione nucleone-mesone alla descrizione da QCD
✴Per fare progressi in queste aree dobbiamo rispondere a una serie di
✴interrogativi:
• Qual’è il meccanismo del confinamento?
• Dove la dinamica dell’interazione q-q compie una transizione dal regime forte (confinamento) al
regime perturbativo QCD (tipo QED) ?
Esplorare nuova fisica attraverso test di alta precisione del Modello Standard
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JLab12 science:
today and in the 12 GeV era
✴Nucleon Structure
•
•
EM, EW, and Flavor-Separated Form Factors
Transverse Momentum Distributions (TMD)
✴Nuclear Structure and the Quark Structure of Nuclei
•
Hypernuclear Physics
Quark Electro-Weak Couplings and Standard Model Tests
✴The Physics of Confinement – the Search for Hybrid Mesons
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NUCLEON STRUCTURE
from elastic form factors to TMDs & GPDs
The Proton and Neutron are
the “Hydrogen Atoms” of QCD
What we “see” changes with spatial resolution
>1 fm
Nucleons
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0.1 — 1 fm
Constituent quarks
and glue
< 0.1 fm
“bare” quarks
and glue
S=1/2
S=1/2
S=1/2
Q=1
Q=1
Q=1
NUCLEON STRUCTURE
from elastic form factors to GPDs
X. Ji, D. Müller, A. Radyushkin (19941997)
Elastic Scattering
transverse quark
distribution in
Coordinate space
(charge and current
densities)
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Deep Exclusive Scattering
fully-correlated quark
distribution in both coordinate
and momentum space
(GPD&TMD)
Deep Inelastic Scattering
longitudinal
quark distribution
in momentum space
(momentum and
helicity distributions)
JLab data on the EM form factors provide a testing ground for
theories constructing nucleons from quarks and glue
Before JLab and Recent non-JLab Data
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JLab data on the EM form factors provide a testing ground for
theories constructing nucleons from quarks and glue
Today, including new JLab Data
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JLab data on the EM form factors provide a testing ground for
theories constructing nucleons from quarks and glue
Today, including new JLab Data, compared to theory
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Form Factors – Plans for 12 GeV
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Today
Form Factors – Plans for 12 GeV
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JLab at 12 GeV
SBS Spectrometer in Hall A
•
•
•
•
High luminosity
Moderate acceptance
Forward angles
Reconfigurable detectors
⇓
Form Factors at high Q2
Precision SIDIS
JLab12 Responsibility
•Front Tracker (GEM+SiD)
•Readout Electronics (FT)
BA, CT, GE, ISS, RM1
SiD
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UVa
U. of Glasgow
JLab
Norfolk State U.
INFN
Rutgers U. Carnegie Mellon U.
College WM U. of New Hampshire
SBS Tracker :
• Based on the recent GEM technology and Silicon Microstrips
• Large chamber, small dead area, minimum material budget, for high luminosity
experiments
Front Tracker GEM construction process
Revision
Foils from GEM
CT
Stretching
Gluing the next
frame with spacers
GE
Sanità/BA: Test and
characterization by cosmics
(Analysis example)
Noise level ~ 10 ADC unit
Electronics based on APV25 chip
Radiation Tolerant Components in FEC
VME64x compliant readout
Modular
Front Tracker GEM construction process
Revision
Stretching
Foils from CERN
Gluing
Frame
CT/Clean Room
Integrate
electronics, gas
pipes, HV ...)
Compressing
(uniform gluing,
remove air from
glue and contact
surfaces)
GE
Sanità/BA: Test and characterization
by cosmics
(Analysis example)
Noise level ~ 10 ADC unit
Electronics based on APV25 chip
Radiation Tolerant Components in FEC
VME64x compliant readout
Modular
Primi moduli GEM finali 40x50 cm2
Solenoid
2x2 small scintillators as telescope for trigger
One big GEM in solenoid open space
One big GEM beyond the magnet as reference
tracking
Basically all final components under test (big
GEMs, electronics, gas system, cabling ...)
Analysis in progress --Beam Profile
BigGEM in solenoid
X
y
Clean hits vs time
x
Small GEM, ref.
y
BigGEM as 2xGEM, ref.
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Rivelatore a microstrisce di silicio:
105 mm
Strip Pitch
50 µm
DC PAD
for bonding
(200x40 µm2)
Guard Ring PAD
(500x90 µm2)
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Circuiti stampati per il piano X e il piano Y
Piano X
Piano Y
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Sistema completo con
elettronica di lettura
APV25
Backplane
Kapton
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SBS Tracker: summary
• Participants:
•
•
•
•
•
•
INFN/BA – gas system and test
INFN/CT – GEM assembling, mechanics, test, analysis
INFN/GE – electronics design
INFN/ISS – design, test, analysis and coordination
INFN/RM1 – Silicon tracker
JLab, Glasgow, UvA, Ruthers, UNH, CMU – SBS collaboration
• Funding: (prototyping and realization) 1 M$
• Status: most of the components procured or ordered; GEM
assembling underway; characterization in progress. Silicon
Microstrip prototype ready by the end of 2013. Silicon microstrip
planes ready by the end of 2014.
• Expected installation 2015 (delayed by JLab/HallA schedule)
• Note: project delayed by ~ 1 year – due mainly to foil delivery
and first quality check failures. Do not affect JLab plan!
HCAL-J Design
24 Modules (360cm)
HCAL-J based on COMPASS HCAL1
Each module:
15 cm x 15 cm
Layered scintillator and
iron
Replicate
with small
design modifications
288 modules for JLab HCAL
Integral WLS/ Light guide
Acrylic with Coumarin-7
impregnated surface
5 mm thick
40 layers
20 mm iron /
5 mm scintillator
Light Guide /WLS
Existing HCAL1 in COMPASS
Novel light guide
for 1 in PMTS
Steel casing
Hole in downstream light guide
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Hypernuclei at JLab
Study -N Interaction potential
Experimental requirements:
- Excellent Energy Resolution
- Detection at very forward angles (6°→septum
magnets)
- Excellent PId for kaon selection →RICH
- High luminosity
Experiment E94-107
Hypernuclear spectroscopy
9Be (e,e’k+) 9 Li reaction
Λ
Published
Reactions Investigated:
9Be→9Li (3 spin doublets, information on Δ)
Λ
12C→12B (evidence of excited core states →
Λ
sN contribution)
16O→16N (unmatched peak may indicate
Λ
large sΛ term)
H →Λ,Σ0 (elementary process)
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
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RM1, ISS
Thanks to energy resolution improvements a clear
three peak structure appears in the excitation energy
spectrum.
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
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Determine the spectroscopic factors dependence with Q2
Long range correlations: not needed!
Relativistic effect in nuclei: needed!
Lead (208Pb) Radius Experiment: PREX
Elastic Scattering Parity Violating Asymmetry
Hall A Collaboration Experiment
E=1GeV, J=5o e on lead
A neutron skin
established at ~93 %
CL
208Pb
Neutron Radius
RN = 5.78 + 0.16 - 0.18 fm
Neutron Skin
RN - RP = 0.33 + 0.16 - 0.18 fm
PREX-II
Approved by JLabPAC (Aug 2011) with
high rating
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RM1
Future equipment for PaVi experiments at JLab
SOLID (PV e- - q scattering + SIDIS)
- PV e-quark
- High precision TMD
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