LEDALEDACIII - Polignano - F. Garibaldi - 14-09-04

ELETTRO---> LEDA (Leptoni ED Adroni) (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/Roma312 fisici+ 7 tecnici (aumento FTE nel 2005)

(un assegno di ricerca 2005-2006 (F. Cusanno) + 1 primo ricercatore (E. Cisbani))

- pentaquark? (pentanuclei?????)

- Pb parity

- GDH low Q2 on p

- SANE

-ff. P high Q2

-….

spin structure of the nucleon- hadronization- transversity- flavor asymmetry-……..

e + AZ -> e’ + K+ + A(Z -1)

Hypernuclear Spectroscopy E-94-107 F. Garibaldi, S. Frullani, J. LeRose, P. Markowitz, T. Saito

• forward angle (septum magnets)

• very good PID (aerogel + RICH)

High energy resolution and “background free” spectroscopy is needed to detect doublet splitting

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

9Be (e,e’K)9Li

most of information is carried out by the spin dependent part doublet splitting determined by , s, T

N interaction

Hall C ~ 450 h.

~ 160 counts in the g.s

E=900 keV (FWHM)

E=800 keV (FWHM)

Hall A~ 600 counts in the

g.s

Energy Resolution : 800 KeV ---> <500 keV electron probe : 900 KeV hadron probes : 1.5 MeV

1. E/E : 2.5 x 10-5

2. P/P (HRS + septum) ~ 10-4

3. Straggling, energy loss…

Energy Resolution

June 2002 optics tests (Target (12C): 114 mg/cm2) Kinematics: Ei=4.7 GeV Pe=3.8 GeV/c Phadr=1.5 GeV/c

SOURCE Resolution

FWHM

Contribution

FWHM (keV)

Beam 5 x 10-5 x 2.36 554

e’ 9.4 x 10-4 357

hadron (p) 1.4 x 10-5 198

Straggling 211

Total 720

with our setup (no windows)and kinematics

~ 350 keV

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

The plot shows the 12B 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 MeV and 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.

very

Mauro Iodice - Hall A Collaboration Meeting - JLAB May 18, 2004

Aero Selected

Aero Selected P

Aero Selected K (!)

Aero Selected Kon a large sample of filtered data

Separation power

cK ϑ σϑϑ 7≈−

mrad c

5≈ϑσAngular resolution

/K population ratio

100≈

Kaon selection:cK ϑσϑ 3±

This would accept ~ 10-4 pions x /K ratio

1/100 pion contamination

…. But NON GAUSSIAN TAILS GIVE AN

IMPORTANT CONTRIBUTION !

Rich Performances – PID :

RICH Possible 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/cDoable “just” replacing the radiator

DAQ rate bottleneck (~1 KHz) can be ovecome replacing part of the readout

pK

KPion rejection

~ 1000

HV = 2100 V HV = 1900 V

PC40 scan

0

10

20

30

40

50

60

0 20000 40000 60000 80000 100000 120000

chamber gain [e-]

MIP IN 19,25

MIP IN 30,25

MIP IN 41,25

MIP IN 55,25

MIP IN 18,32

MIP IN 27,32

MIP IN 41,32

MIP IN 53,32

1900 V

1950 V

2000 V

2050 V

2100 V

2150 V

Rich /K separation for p > 2.5 GeV/c

Radiator C6F14 n=1.29 σCh ~ 5mr

Radiator C5F12 n=1.24 σCh ~ 5mr

4 σ separation at ~ 2.5 GeV/c 4 σ separation at ~ 3.0 GeV/c

€

ρs = dGEs (τ ) /dτ

μ s = GMs (τ )

t = Q2 /4M p2

Q2 = 0.447GeV/c2 e =12.3°

ρs + 2.9 s = 0.67 ± 0.41 ± 0.3

Simmetria di isospin --> ff em esprimibili in termini di ff dei q

Qp --> 0

Happex2 Q2 piccolo grazie ai setti- errori sistematici piccoli

He-4 (transizione O+ -> 0+ quindi indip.e dalla parte magnetica e assiale) AHe=-A0[ 4sin2w + Gs

E()/ GT=0E()]

-A0(4sin2w + 2ρs)

si misura solo ρs

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

Kinematics coverage for deeply exclusive experiments

ELFE

no overlap with otherexisting experiments

compete with other experiments

Upgraded CEBAFcomplementary& unique

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

Transverse target single spin asymmetry

n(e,e’p)XFirst 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-IIAlso n(e,e’K)X• Kaon and pion momentum settings

1.8 and 2.4 GeV/c

E03-004 – Neutron Transversity through 3He(e,e’p)

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

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)