(F.Cusanno, M.Iodice et al,Phys. Rev. Lett.103 202501 (2009).

670 keV FWHM

(M. Iodice,F.Cusanno et al. Phys.Rev.Lett. 99,052501 (2007)

12C(e,e’K)12BL

16O(e,e’K)16NL

The WATERFALL target: reactions on 16O and 1H nuclei

High Resolution Hypernuclear Spectroscopy at Jefferson Lab Hall A

Radiative corrected experimental excitation energy vs theoretical data (thin curve). Thick curve: three gaussian fits of the radiative corrected data

Experimental excitation energy vs Monte Carlo Data (red curve) and vs Monte Carlo data with radiative Effects “turned off” (blue curve)

Radiative corrections do not depend on the hypothesis on the peak structure producing the experimental data

9Be(e,e’K)9Li L (g. M Urciuoli, F. Cusanno, S. Marrone et al) to be submitted to Phys. Rev.

hadron arm

septum magnets

RICH Detector

electron arm

aerogel first generation

aerogel second generation

To be added to do the experiment

Hall A deector setup

HRS – HKS: (e, e’K+) experiments for mass spectroscopyHKS – Enge or HKS – HES: New decay - spectroscopy experiment

Unified collaboration from the previous Hall A and C collaborations

Enge ()

HES () HKS (K)

HRS (e’)Septum

Septum

Combine the features of previous Hall A and C experiments, create an optimized future program w/ the CEBAF CW beam

Future Project: Super Hypernuclear Physics at JlabA Study with High Precision on the Electro-production of the and -Hypernuclei

in the Full Mass Range

5

1.Elementary , L S0

2.Few-body 2D(e,e’K+) [LN] - Exotic bound state, LN interaction 4He(e,e’K+)4LH - LN, Charge Symmetry Breaking( CSB)

e,e’ reaction spectroscopy

4. Heavy208Pb(e,e’K+) 208

LTl L in heaviest nucleus

3.Medium-heavy

40,44,48Ca(e,e’K+) 40,44,48LK

27Al(e,e’K+) 27LMg

48Ti(e,e’K+) 48LSc

- LN, L’s S.E., iso-spin, A dependence of BL

- Mean field approximation- Single particle nature of L- Tri-axial deformation-,Level inversion due to L

- Reliable data from 1H(e,e’K+) ,L S0 at low Q2

- Dynamis, f.f.,…

- LN, A dependence of BL - Mean field approximation- Single particle nature of L- The role of three body forces- Neuron stars structure and dynamics

Decay Pion Spectroscopy to Study -Hypernuclei

Direct Production

p

e’

e12C K

+

Example:

Low lying Hypernuclear States

12Bg.s.

E.M.

12C

-

Weak mesonic two body decay (~10-10s)

*

Fragmentation Process

pe

12C

*

s12B*

e’ K +

Highly Excited Hypernuclear States

4H

Fragmentation (<10-16s)

4Hg.s.

4He

-

7

High resolution, high yield, and systematic study is essential

using electromagnetic probe

and

BNL 3 MeV

Improving energy resolution

KEK336 2 MeV

~ 1.5 MeV

- Energy resolution

- Spin flip

635 KeV670 KeV

hadron probe vs e.m. probe

H.Hotchi et al. PRC 64 (2001)044302

51LV

P.H.Pile et al. PRL 66 (1991) 2585

A = 40 A ~ 50

40Ca = (Z=20, N=20) : 40

LK = one proton hole + L

Be windows H2O “foil”

H2O “foil”

The WATERFALL target: reactions on 16O and 1H nuclei

1H (e,e’K)L

16O(e,e’K)16NL

1H (e,e’K) ,L S

L

SEnergy Calibration Run

Results on the WATERFALL target - 16O and 1H

Water thickness from elastic cross section on H Precise determination of the particle momenta and beam energy using the L and S peak reconstruction (energy scale calibration)