Transcript Document

Fascio continuo
• Energia 0.8 ─ 5.7 GeV
• 200 mA, polarizzazione 75-85%
• 1499 MHz
• Distribuzione simultanea in 3 sale
A
B
C
few
body
heavy
nuclei
quarks
gluons
vacuum
• Correlazioni tra nucleoni
• Ipernuclei
• Spettroscopia dei barioni e dei mesoni, ricerca di esotici
• Nuove distribuzioni partoniche e origine dello spin
• Fattori di forma elastici del nucleone
Baryon spectroscopy
CLAS: FF for Roper in
Nπ
ep➞epπ+π-
A1/2(Q2) :First observation of a sign-change
for a nucleon form factor
pπ+π-
Meson spectroscopy
g p  p p+ p-
f0(980)
Future program for
quasi-photoproduction
with CLAS12
S-wave
Forward tagger for small-angle
electron detection
f2(1270)
D-wave
Known states are well
reproduced, e.g. r(770)
P-wave
r0(770)
First observation of direct
production of f0(980) (pp
S-wave) meson
Accepted by Phys. Rev. Lett. 2009
Upcoming paper on PRD
Nucleon spin: from quark spin to orbital angular momentum
Proton
spin
Extensive measurements of
structure function g1 at JLab
Hall A Winter 08-09:
First Time Direct
Measurement of
Neutron Transverse
Target Single Spin
Asymmetry:
Two important
asymmetries: Sivers
and Collins
CLAS12: COMPLETE program
of measurements on proton
withbetween
unpolarized,
Correlation
the
transverse
momentum
longitudinally and
and transverse spin of
transversely
polarized targets
quarks in longitudinally
polarized proton
 separation of all 8 leadingtwist TMDs
EXAMPLE:
Sp
-
Jq
y
D(z)
x
q(x)
z
Understanding the inner structure of the nucleon
Nucleon description at leading Twist
Q2
TMDs
D(z)
z
x
q(x)
Extensive measurements of Dq at
JLab
Hall A 08-09: First Direct
Measurement of Neutron
Transverse Target Single Spin
Asymmetry and extraction of
Sivers and Transversity
amplitudes
CLAS: Measurements of TMDs at
6 GeV in 2010 and 2011
SIDIS Process
Future Programs
CLAS12: COMPLETE program of measurements on proton with
unpolarized, longitudinally and transversely polarized targets
separation of all 8 leading-twist TMDs
Hall A+SBS: High precision multi-dimensional (Q2,x,z) p and K
asymmetries measurements on polarized neutron
EXAMPLE: Correlation between
the transverse momentum and
transverse spin of quarks in
longitudinally polarized proton
Sp
SBS
-
add Hall D
(and beam line)
L’upgrade
a 12 GeV
6 GeV CEBAF
Upgrade magnets
and power
supplies
CHL-2
Enhance equipment in
existing halls
Beam Power: 1 MW
Beam Current: 90 µA
Max Pass energy: 2.2 GeV
Max Energy Hall A-C: 10.9 GeV
Max Energy Hall D: 12 GeV
La strumentazione per i 12 GeV
Hall B – Large acceptance
detector CLAS12 for high
luminosity measurements
(1035cm-2s-1)
Hall A – High Resolution Spectrometers
and new multipurpose large acceptance
high luminosity detector (SBS)
INFN partecipa al programma
sperimentale
delle
sale
A
e
B
Hall D –
Hall C –
GLUEX detector for search of exotic
mesons in photoproduction experiments
Super High Momentum
Spectrometer (SHMS)
La tempistica
FASE ATTUALE…
Partenza misure JLab a 4 GeV
1996
Prime misure a 6 GeV
1999
Continuazione 6 GeV
2008-2012
…UPGRADE
CD-0 Mission Need
MAR-2004 (A)
CD-1 Preliminary Baseline Range
FEB-2006 (A)
CD-2 Performance Baseline
NOV-2007 (A)
Nel 2008 il DOE ha finanziato il 99 % del
progetto, a fronte di tagli significativi in
tutti gli altri settori
CD-3 Start of Construction
SEP-2008
CD-4A Accelerator Project
Completion and Start of
Operations
DEC-2014
Non ci sono costi di esercizio per
gli utenti…
CD-4B Experimental
Equipment Project Completion
and Start of Operations
JUN-2015
L’upgrade prevede un costo di 310 M$,
interamente coperto dal DOE