LEDA CIII - Polignano - F. Garibaldi - 14-09-04

1. LEDA CIII - Polignano - F. Garibaldi - 14-09-04 ELETTRO---> LEDA (Leptoni EDAdroni) (resp. F.G.) ELETTRO: - spokespersonship (5 esperimenti (3.7 eseguiti)) - pubblicazioni (~ 75 (25)), 10 ultimo anno - invited talks, 32 - apparati - gas ed aerogel Cherenkov - waterfal target - setti magnetici - freon/CsI RICH (aerogel RICH) INFN Bari, INFN/ISS, INFN/Roma1, INFN/Roma3 12 fisici+ 7 tecnici (aumento FTE nel 2005) (un assegno di ricerca 2005-2006 (F. Cusanno) + 1 primo ricercatore (E. Cisbani))

2. - pentaquark? (pentanuclei?????) • Pb parity • spin structure of the nucleon • - hadronization • transversity • flavor asymmetry • …….. • GDH low Q2 on p • SANE • ff. P high Q2 • ….

3. Hypernuclear Spectroscopy E-94-107 F. Garibaldi, S. Frullani, J. LeRose, P. Markowitz, T. Saito e + AZ -> e’ + K+ + A(Z -1)L LN interaction most ofinformationis carried out by thespindependent partdoublet splittingdetermined byD, sL, T 9Be (e,e’K)9LiL • forward angle (septum magnets) • very good PID (aerogel +RICH) High energy resolution and “background free” spectroscopy is needed to detect doublet splitting

4. DE=800 keV (FWHM) Hall A ~ 600 counts in the g.s DE=900 keV (FWHM) Hall C ~ 450 h. ~ 160 counts in the g.s Energy Resolution : 800 KeV ---><500 keV electron probe : 900 KeV hadron probes : 1.5 MeV

5. Energy Resolution 1.DE/E : 2.5 x 10-5 2. DP/P (HRS + septum) ~ 10-4 3. Straggling, energy loss… June 2002 optics tests (Target (12C): 114 mg/cm2) Kinematics: Ei=4.7 GeV Pe=3.8 GeV/c Phadr=1.5 GeV/c with our setup (no windows)and kinematics ~ 350 keV

6. very The plot shows the 12BL excitation energy spectrum obtained with electroproduction reaction on Carbon target. Two theoretical curves have been superimposed to the data, differing by the model used for the elementary K-Lambda production on protons, while the hypernuclear wave function is the same for the two curves as computed by M. Sotona. The solid line uses the model by Bennhold-Mart (K MAID) while the dashed line the one by Saghay Saclay-Lyon (SLA). Both curves have been normalized to the first (ground state) experimental peak. The relative intensity (with respect to the ground state) of the first excited peak at 2.6 MeVand of the strongly populated p-Lambda state at 11 MeV seems to be better reproduced by the MAID model then by the SLA one, another peak is visible. The peaks at 6 - 7 MeV are underestimated by both models. Of course, one has to wait with any conclusion for the final results of the analysis.

7. Rich Performances – PID : p/K population ratio Aero Selected p Angular resolution Aero Selected K (!) Aero Selected P Separation power Aero Selected K on a large sample of filtered data This would accept ~ 10-4 pions x p/K ratio 1/100 pion contamination …. But NON GAUSSIAN TAILS GIVE AN IMPORTANT CONTRIBUTION ! Kaon selection: Mauro Iodice - Hall A Collaboration Meeting - JLAB May 18, 2004

8. p p Pion rejection ~ 1000 K K • RICHPossible improvements : • MWPC stability for high rates • For single rates ≤ 60 KHz HV=2100 V is OK • In the range 60 KHz – 100 KHz HV=2075 V is OK • Above 100 KHz HV must be reduced further •  MWPC stability (and mechanics) needs to be studied • for high rates running. • However running at reduced gain with moderately good • performance seems to be feasable (see next slide) • p/K separation for p>2.5 GeV/c • Doable “just”replacing the radiator DAQ rate bottleneck (~1 KHz) can be ovecome replacing part of the readout

9. HV = 2100 V HV = 1900 V

10. Rich p/K separation for p > 2.5 GeV/c Radiator C5F12 n=1.24 sCh~ 5mr Radiator C6F14 n=1.29 sCh~ 5mr 4 s separation at ~ 2.5 GeV/c 4 s separation at ~ 3.0 GeV/c

12. Simmetria di isospin --> ff em esprimibili in termini di ff dei q Q2 = 0.447GeV/c2 e q=12.3° rs + 2.9 ms = 0.67 ± 0.41 ± 0.3 t=Q2/4Mp--> 0

13. Happex2 Q2 piccolo grazie ai setti - errori sistematici piccoli He-4(transizione O+ -> 0+ quindi indip.e dalla parte magnetica e assiale) AHe=-A0t[ 4sin2qw + GsE(t)/ GgT=0E(t)]  -A0t(4sin2qw + 2rst) si misura solo rs

14. A clean Measurements of the neutron skin of 208Pb through parity violating electron scattering R. Michaels, P. Souder, G.M. Urciuoli Difficolta’ sperimentali: polarizzazione < 2% asimmetria 0.5 x 10-6

20. compete with other experiments no overlap with other existing experiments Upgraded CEBAF complementary & unique Kinematics coverage for deeply exclusive experiments ELFE

21. Measurement of Flavor Asymmetry Through Charged meson Production in SIDIS • p and K SIDIS on proton and deuteron to study flavor asymmetry of the sea quark distributions. • 5-fold Improvement over HERMES. Check Fermi Lab results with completely different mechanism. • Flavor dependence of fragmentation functions in kaon production • Check factorization. • Kaon and pion momentum seetings 1.7 - 3.2 GeV/c

22. E03-004 – Neutron Transversity through 3He(e,e’p) Transverse target single spin asymmetry n(e,e’p)X First transversity measurement on neutron • high polarized luminosity • x: 0.19-0.34, Q2: 1.8-2.7 GeV2, W: 2.5-2.9 GeV • separation of Collins and Sivers effects • complementary to the proton data of HERMES run-II Also n(e,e’K)X • Kaon and pion momentum settings 1.8 and 2.4 GeV/c

23. E04-002: Hadronization • Precision measurement of cross sections of p, K and p semi-inclusive DIS on deuteron, carbon, copper and gold • Hadron formation process • Quark propagation inside nuclear medium • Input to understanding of heavy-ion interaction: help interpret RHIC data of jet quenching at high PT • Kaon and pion momentum settings 2.63 – 3.45 GeV/c

27. La proposta dei referees, data la programmazione prevista per le misure ipernucleare e' la seguente: 1) 28/02/2005 Pubblicazione risultati su esperimenti N -> Delta 2) 30/06/2005 Fine presa dati esperimento sugli ipernuclei 3) 30/06/2005 Risultati preliminari prime misure su ipernuclei (12C e 9Be) 4) 31/07/2005 Pubblicazione risultati su esperimenti 3He(e, e'p) 5) 31/08/2005 Presentazione nuove proposte di esperienza al PAC JLab 6) 31/12/2005 Risultati preliminari dati su ipenuclei (16O, campagna 2005)