JLab Hypernuclear Workshop27th May 2014

Satoshi N Nakamura, Tohoku University

Perspectives at Jefferson LabMedium mass hypernuclei

HKSHES

Study of hypernuclei

High quality medium heavy hypernuclear spectroscopy

Single particle nature of L in nuclear mediumA dependence of L potential

ls force vs. core-config. MixingInputs for mean-field theories

Collective motion of core nucleus

Tri-axial deformation of core nucleus

Modify nature of core Energy level inversion Glue like role of L

L in nuclear medium

L as an impurityL as a probe

Objectives --- Hypernuclear Physics

Medium - Heavy hypernuclei

Light Hypernuclei (s,p shell)

A 1 20 50 200 1057

Elementary ProcessStrangeness electro-production

CSB, LS coupling in large isospin hypernuclei

Hyperonization Softening of EOS ?

Single-particle potentialDistinguishability of a L hyperon

U0(r), mL*(r), VLNN, ...

Neutron/Hyperon star,Strangeness matter

Extend Nuclear Force to Baryon Interaction

Use L as a probe to see deep inside of nucleus

Medium Heavy

Hypernuclei

Precise spectroscopy of HYSingle Particle Model is OK to some extent

Hadron keeps its identities

Baryon Constitute Quark Model

HypernucleiSingle Particle Model

Precise spectroscopy of HY

NucleonValence quarks

QCD vacuumSea quarks, gluons

HypernucleiLambda particle

Nuclear mediumCore’s properties, density

Light HypernucleiBaryon InteractionModification of core

Heavy Hypernuclei Lambda’s behavior in nucleus

Proposed Programs1. Elementary L, S0

Reliable data 1H(e,e’K+)L, S0 in low Q2

2. Few-body 2D(e,e’K+) [LN] Exotic bound state, LN int. 4He(e,e’K+)4

LH LN CSB 3. Medium-heavy

40,44,48Ca(e,e’K+) 40,44,48LK L’s S.E., iso-spin

27Al(e,e’K+) 27LMg Tri-axial deformation

48Ti(e,e’K+) 48LSc Level inv. due to L

4. Heavy208Pb(e,e’K+) 208

LTl L in heaviest nucleus 5. Decay p

Weak decay of light hyper-fragments

6,7Li(e,e’K)6LHe, 7

LHe

3t(e,e’K)[nnL]19F(e,e’K)19

LO

Hypernuclear Chart

K40L K44

L K48L

K40L

[LN]

L

Tl208L

H4L

MgL27

B12L

OL19

1. Ca (e,e’K+) LK

Missing in (e,e’K) dataComplete A dependence of L S.P.Energy

Doubly LS closed 40Ca target

Clean Spectrum

isotope effect of core nuclei: 40Ca, 44Ca , 48Ca targets

P.Bydzovsky et al. NPA881 (2012)199.

2. 27Al (e,e’K+) 27LMg

Tri-axially deformed 26Mg core + L in p-shell

9LBe = a + a + L

Genuine hypernuclear state

Totally new method to search shape of nucleus with L!

M.Isaka Yesterday’s talk

3. 19F target : simplest sd-shell

A’s: p1/2-hole series, B’s: p3/2-hole series

T. Motoba, C2C WS Barcelona (2012)

Study of core-dynamics

Measured hypernuclei & expected A dependence

E05-115L40K

L27Mg

89Y139La 208Pb

L19O

InteractionCharacteristics of Core

L in medium

Few-body physics with strangeness1. 6Li (e,e’K+) 6

LHe

α

Λ

n

r.m.s α-Λ 2.8 fm α-n 5.0 fm

Larger than 6He

Three-layer structure

E.Hiyama : Yesterday’s talk

2. 7Li (e,e’K+) 7LHe

0+

2+

α+n+n0 MeV

6He

-0.98

1.797 MeV

Γ=113 ±20 keV

(2+,1-,0+)?

Γ＝ 12.1 ±1.1 MeV

Exp.1/2+

3/2+5/2+

5He+n+nΛ

α+Λ+n+n0 MeV

-6.19 MeV

-4.57

neutronhalo states

-3.12

-1.88 Γ=0.7 MeV5/2+

3/2+ -2.04, Γ=0.5 MeV

7HeΛ

2+

Λ

E.Hiyama : Yesterday’s talk

Few-body physics with strangeness

Established lightest hypernyclei = 3LH

Hyp-HI experiment at GSI a structure in d + p- , t + p- invariant mass

T.R.Saito, NUFRA2011

2d(e,e’K+)[nL]Indication of a nL , nnL bound state ?

3. Search of [nL] bound state and study of n-L interaction through FSI.

Direct method to search or set upper limit on this exotic system.

3t(e,e’K+)[nnL]

C.R

appo

ld e

t al.

PR

C88

, 041

001(

R) (

2013

)

Few-body physics with strangeness

2d(e,e’K+) nL

2. Study of n-L interaction through FSI.

2d(e,e’K+) provides also information of n-L interaction through FSI.

R.A.Adelseck & L.E.wrightPRC 39(1989) 580.

Few-body physics with strangeness4. Charge Symmetry Breaking of LN interaction

A=4,iso-doublet hypernuclei

A=7,iso-triplet hypernuclei

JLab E01-011 (HKS)

Recently measured at JLab Hall-C

Phenomenological CSB potential

Introduced to explain A=4.

NOT becessary for A=7.

Re-check of A=4 system

Decay p

4He(e,e’K+) 4LH

E13 @ J-PARC

SummaryMedium heavy hypernuclear study

Ca targets : 40Ca doubly closed, clean, 44Ca 27Al target : 27

LMg tri-axial deformed19F targets: simplest sd-target, excited-core

Other targets : SPE of L with <100 keV accuracy

Few-body hypernuclear study6Li target : 6

LHe n-halo hypernucleus7Li target : 7

LHe unbound states of 6He d target : Exotic nL state, FSI nL study

CTn target : Exotic nnL state

Subtraction of 12C effects and Accidental BG

Expected Yields

>5 times more yield than E94-107Much better S/N than E05-115

Expected Mass Resolution

Calibration for independent K, e’ spectrometers.Established in E94-107.

Absolute missing mass calibration with L,S0 massesEstablished in E05-115.