A. F

elic

iello

/ IE

EE N

ucle

ar S

cien

ce S

ympo

sium

and

Med

ical

Imag

ing

Con

fere

nce,

Hon

olul

u, H

awai

i, U

SA, O

ctob

er 2

7-N

ovem

ber 3

, 200

7.

Alessandro FelicielloI.N.F.N. -

Sezione di Torino

The new FINUDA challenge: γ-ray spectroscopy of hypernuclei

at DAΦNE

The new FINUDA challenge: γ-ray spectroscopy of hypernuclei

at DAΦNE

γn

nnn

np

pp

p ppΛ

2A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

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nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. Outline Outline

Discovery potential of the strangeness nuclear physics

Need of sub-MeV resolutionapparatuses

γ-ray spectroscopy

Ideas for FINUDA spectrometer upgrade at DAΦNE/DAΦNE2

3A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

(low-energy) YN interaction

detailed knowledge of the hypernuclear fine structure

→ evaluation of the spin dependent terms of the ΛN interaction

measurement of angular distribution of γ–rays

→ determination of spin and parity of each observed level

Impurity nuclear physicsmeasurement of transition probability B(E2)

→ information on the size and deformation of hypernuclei

→ measurement of nucleus core shrinking → glue-like role of Λ

Properties of hyperons in nuclear matter (medium effect)measurement of transition probability B(M1)→ g-factor value for Λ in nuclear matter

Open questionsOpen questions

4A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

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nd M

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al Im

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g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

energy 510 MeV

luminosity 5 1032

cm-2

s-1

σx (rms) 2.11 mm

σy (rms) 0.021 mm

σz (rms) 35 mm

bunch length 30 mm

crossing angle 12.5 mrad

frequency (max) 368.25 MHz

bunch/ring up to 120

part./bunch 8.9 1010

current/ring 5.2 A (max)

FINUDA @ DAΦNE FINUDA @ DAΦNE

−Λ

−

+−+−

+→+

→→+

π

φ

ZZΚΚΚee

AAstop

→Λ ZA

nnZnpZ

Z

A

A

A

++

++−

++

−

−

−

)2(

)2( )1()1( π

5A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. The status of the artThe status of the art

ΔE ~

1.6

5 MeV

FW

HM

ΔE ~

1.6

5 MeV

FW

HM

ΔE ~

1.9

5 MeV

FWHM

ΔE ~

1.9

5 MeV

FWHM

ΔE ~ 1.29 MeV

FWHMΔE ~ 1.29 MeV

FWHM

−BΛ (MeV)

Cap

ture

rat

e/0.

25 M

eV x

10−

3

0

0.1

0.2

0.3

0.4

0.5

0.6

−25 −20 −15 −10 −5 10 150 5

#6

#4#3

#2

#1#5

#7

b)M. Agnello et al., Phys. Lett. B 622 (2005) 35 M. Agnello et al., Phys. Lett. B 622 (2005) 35

( ) CK,π 12Λ

++

ΔE ~

1.4

5 MeV

FWHM

ΔE ~

1.4

5 MeV

FWHM

f-orb

it sp

littin

g

into t

wo pea

ks ob

serve

d?

f-orb

it sp

littin

g

into t

wo pea

ks ob

serve

d?

6A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. The status of the artThe status of the art

7Li(K-

,π-)12C7Li(K-

,π-)12C−stopK Li7

Λ

KEK E419

KEK E419

ΔE ~ 1.1 MeV FWHMΔE ~ 1.1 MeV FWHM

ΔE ~ 2 keV

FWHMΔE ~ 2 keV

FWHM

3

order of magnitude!!!3

order of magnitude!!!

7A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. The γ-ray spectroscopy domain The γ-ray spectroscopy domain

The region of high excitation

energy

in heavy Λ-hypernucleicannot

be explored with

γ-spectroscopy

The region of high excitation

energy

in heavy Λ-hypernucleicannot

be explored with

γ-spectroscopyHyperball2

@ Tohoku Cyclotron

Jun 2005 FINUDA@ DAΦNE

FINUDA@ DAΦNE

8A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. Parallel vs. serialParallel vs. serial

one-arm spectrometer →

small acceptance• ∆E ~ 4 MeV (FWHM)• ∆Ω ~ 110 msr

HPGe array →

large acceptance• ∆E ~ 1 ÷ 2 keV (FWHM)• ε

~ 7%

(@ 1 MeV)

HyperballProject

@J-PARC

10A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

Do HPGe crystals

work in (strong) magnetic field?

Penning effect? (sparks)Hall effect? (FET breakdown)

VEGA @ GSI

Experimental challengesExperimental challengesJRA6

11A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

Do HPGe crystals work in (strong) magnetic field?

Penning effect? (sparks)Hall effect? (FET breakdown)

To what extent the energy resolution is affected?

Experimental challengesExperimental challengesJRA6

12A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. HPGe energy resolution in magnetic fieldHPGe energy resolution in magnetic field

NIM A 573 (2007) 410

VEGA @ GSI

Euroball

@ GSI

JRA6

19A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

Do HPGe crystals work in (strong) magnetic field?

Penning effect? (sparks)Hall effect? (FET breakdown)

To what extent the energy resolution is affected?

How to minimize

the mechanical interferences?

Experimental challengesExperimental challengesJRA6

20A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

Hyperball

FINUDA

An exacting integrationAn exacting integration

21A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

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al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. The hyper-triple cluster concept designThe hyper-triple cluster concept design

thermal studies

mechanical

design

X –

COOLER II, AMETEC, ORTECJRA6

22A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007.

Geometrical acceptancereduced to 82%

Geometrical acceptancereduced to 82%

A look to the futureA look to the future

HPGe detectors

straw tubes

scintillator barrel

targets andμstrip detectors

drift chambers

straw tubes

targets andμstrip detectors drift chambers

HPGe detectors

scintillator barrel

24A.

Fel

icie

llo /

IEEE

Nuc

lear

Sci

ence

Sym

posi

um a

nd M

edic

al Im

agin

g C

onfe

renc

e, H

onol

ulu,

Haw

aii,

USA

, Oct

ober

27-

Nov

embe

r 3, 2

007. SummarySummary

strangeness nuclear physics still has a great discovery potential

explorative run on γ-ray spectroscopy

is feasible with:

present DAΦNE machineminor investment on FINUDA apparatus

DAΦNE luminosity upgrade will allow European Groups to carry on a significantscientific program