A B C Fascio continuo Energia GeV 200 A, polarizzazione 75-85% 1499 MHz Distribuzione simultanea in 3 sale

Distanza Energia heavy nuclei few body quarks gluons vacuum Spettroscopia dei barioni e dei mesoni, ricerca di esotici Nuove distribuzioni partoniche e origine dello spin Fattori di forma elastici del nucleone Correlazioni tra nucleoni Ipernuclei

Baryon spectroscopy CLAS: FF for Roper in ep epπ + π - A 1/2 (Q 2 ) :First observation of a sign-change for a nucleon form factor Meson spectroscopy p p + - r 0 (770) P-wave D-wave f 2 (1270) f 0 (980) S-wave Known states are well reproduced, e.g. (770) First observation of direct production of f 0 (980) ( S-wave) meson Accepted by Phys. Rev. Lett Upcoming paper on PRD Nπ pπ + π - Future program for quasi-photoproduction with CLAS12 Forward tagger for small-angle electron detection

y x z q(x) D(z) Proton spin J q Nucleon spin: from quark spin to orbital angular momentum Extensive measurements of structure function g 1 at JLab Hall A Winter 08-09: First Time Direct Measurement of Neutron Transverse Target Single Spin Asymmetry: Two important asymmetries: Sivers and Collins Correlation between the transverse momentum and transverse spin of quarks in longitudinally polarized proton - CLAS12: COMPLETE program of measurements on proton with unpolarized, longitudinally and transversely polarized targets separation of all 8 leading- twist TMDs SpSp EXAMPLE:

Q2Q2 x z q(x) D(z) Understanding the inner structure of the nucleon Extensive measurements of q 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 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 (Q 2,x,z) and K asymmetries measurements on polarized neutron Nucleon description at leading Twist TMDs SIDIS Process - SpSp SBS EXAMPLE: Correlation between the transverse momentum and transverse spin of quarks in longitudinally polarized proton

6 GeV CEBAF CHL-2 Upgrade magnets and power supplies Lupgrade a 12 GeV Enhance equipment in existing halls add Hall D (and beam line) 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

Hall D – Hall D – GLUEX detector for search of exotic mesons in photoproduction experiments Hall C – Hall C – Super High Momentum Spectrometer (SHMS) Hall A – Hall A – High Resolution Spectrometers and new multipurpose large acceptance high luminosity detector (SBS) Hall B – Large acceptance detector CLAS12 for high luminosity measurements (10 35 cm -2 s -1 ) La strumentazione per i 12 GeV INFN partecipa al programma sperimentale delle sale A e B

Partenza misure JLab a 4 GeV1996 Prime misure a 6 GeV1999 Continuazione 6 GeV Lupgrade prevede un costo di 310 M$, interamente coperto dal DOE Nel 2008 il DOE ha finanziato il 99 % del progetto, a fronte di tagli significativi in tutti gli altri settori Non ci sono costi di esercizio per gli utenti… CD-0 Mission NeedMAR-2004 (A) CD-1 Preliminary Baseline RangeFEB-2006 (A) CD-2 Performance BaselineNOV-2007 (A) CD-3 Start of Construction SEP-2008 CD-4A Accelerator Project Completion and Start of Operations DEC-2014 CD-4B Experimental Equipment Project Completion and Start of Operations JUN-2015 FASE ATTUALE… …UPGRADE La tempistica