Hall C Summer Workshop 2007

Aug 2007

Hall C Summer Workshop 2007

Σ Ξ

Hall C Summer Workshop2007

Ed V. Hungerford

University of Houston

[email protected]

Strangeness Happens

Y

P

N

Aug 2007


Σ Ξ

What’s so NU aboutHyper-NU-clear Physics ?

POGO – “Nuclear physics is not so new and not so clear either”

All scientific development, at least at some level, is based on “Evolution”

As an example, in 1959 Dalitz predicted the (1405) using a Dalitz plot.

However, Strange Nuclear Physics offers new perspectives on the Hadronic Many-body Problem

So What’s Nu about Strange Nuclear Physics ?

Aug 2007


Σ Ξ

K- Nuclear bound states

K- nuclear states and K condensation is not new, but the prediction by Akaishi and Yamazaki, and subsequent claim of the experimental observation of tribaryons and anti-kaon bound states, has recently generated considerable theoretical and experimental interest.

-The issue is the binding energy and widths of ħω levels-

K-

kaonic atom

kaonic nucleus

Strongly Attractive K- - N Interaction (optical potential)(1405) 27 MeV below the K- p threshold

Strong K- - Nucleus interactionStrong shifts and widths in Kaonic Atoms -

Re(VK-opt) ≈ 150-200 MeV Re(VK-

opt) ≈ 50-60 MeVRMF phenomenology Chiral anti-K amplitude

K- Atom data can be fit with either a shallow or a deep potential

Aug 2007


Σ Ξ

EK = -108 MeVΓ = 20 Mev

r fm

K- Nuclear bound states

Shrinkage!

A. Dote et al.

I = 0K- pp

ρ = ~10ρN

K- + p

MeV -27K EMeV 04Γ

1 2 3r fm0

-50

-200

-300

-400

-500

nuclKU

MeV

(1405)+

+

K- + pp

MeV -48K EMeV 61Γ

1 2 3r fm0

-50

-200

-300

-400

-500

nuclKU

MeV

H2K+

+

K- + 3He

MeV -108K EMeV 02Γ

1 2 3r fm0

-50

-200

-300

-400

-500

nuclKU

MeV

H3K

+

+

Y. Akaishi & T. Yamazaki, Phys. Rev. C 65 (2002) 044005

Aug 2007


Σ Ξ

K- Nuclear bound statesThe FINUDA Experiment at DAΦNE

6Li

(1115)(1115)

X(K-pp)→p X’

X(K-pp)→Λp -p

K- pp

2370

Aug 2007


Σ Ξ

K- Nuclear bound states(Weise -Theoretical Summary)

Realistic anti-K-N InteractionChiral SU(3) Dynamics + Coupled Channels

Include S and P-waveRealistic N-N Interaction

Short range repulsion is crucial Realistic anti-K-NN Absorption

Imaginary component determines the width

Variational and Faddeev calculations;Anti-K pp clusters may exist ;

but B < 70 MeV, Γ ~100 ρ saturates < 2 ρ0

Narrow experimental structure, if it exists, is not understood

Experimentally Structure is at least partially due to FSI

However, Quasi-bound states in Heavier K- Nuclei are possible

p K

n

p

Aug 2007


Σ Ξ

Baryon-Baryon InteractionTheoretical Input

Nijmegen Potentials (Th. A. Rijken)Meson Exchange Potentials

JPC = 0--+ ,η,η’,KJPC = 1-- ρ,ω,Φ,K*JPC = 0++ a0(962),f0(760),f0(993),κ1(900)JPC = 1++ a0(1270),f0(1285),f0(1460),K1(1430)

Broken SUF(3)Gaussian Form FactorsSoft two-pseudo-scalar meson exchangeFits to Experimental Data (NN Dominates)

20 free parameters (cutoff, coupling, F/(F+D), etc)

SummaryQuality fits and simultaneous description of NN, YN, and YYRealistic long range included SUF(3) consistent

3S1(ΣN, I=3/2) repulsive; N p wave attractive B value consistent with hypernuclear data

First movement toward rigorous QCD calculations of properties and First movement toward rigorous QCD calculations of properties and intractions of nuclei intractions of nuclei (via EFT)(via EFT) . Invaluable aid for Strangeness Nuclear . Invaluable aid for Strangeness Nuclear PhysicsPhysics

Aug 2007


Σ Ξ

ab Initio Structure Calculations ofLight Hypernuclei

In a systematic calculation of all S-shell single and double hypernuclei 4

H was bound but 3

H was not bound

S shell hypernuclei are sensitive to -Σ coupling and 3-body forces

Aug 2007


Σ Ξ

Hyperon-Nucleus Interactionin Bound Strange Nuclei

Hypernuclei provide;Baryon-meson octet coupling constants and vertices in a simple mean-field model;

gσ, gω, fω

Self-Energies ~ Schroedinger single particle potentials;mean-field dynamical correlations;

Systematics of Binding EnergiesNon-locality and density dependence of the interaction

() = -g

() = g

Vc ~ +30 MeV

Vls ~ -~ 0 MeV

DWIA for (e;e’K + )

Aug 2007


Σ Ξ New Structure from Symmetry and

Complementary Reactions

(π+,K + )

( K-,π- )

Super Symmetric

α α

9Be Analog

SS

8Be Analog

1-

2+

4+3-

2-

0+

1-

The Strangeness degree of freedomallows the system symmetrize lowering

the energy.

Aug 2007


Σ Ξ Quark Flow Diagrams

Aug 2007


Σ Ξ Production Kinematics

Recoilless Production

High Momentum Transfer

Aug 2007


Σ Ξ

(K-,π-)in-flight

(K-, π-)stop

(π+,K+)

Effects of high momentum transferProduction of 56

Fe

Q F

Q F

Q F

High Penetration

Fe Target

Aug 2007


Σ Ξ

Hypernuclear γ’s(Tamura, Millener)

V( r ) = V0 + VsSn* SY + VtS12 + Vls(L x S+) + Vals(L x S-)S12 is the usual spin-tensor operatorS+- = ½(Sn +-SY) are the symmetric and anti-symmetric spin operators

Interesting to see that summation and cancellation between terms works to give a reasonable results. There are still Details to resolve , e.g. the 10

B gs splitting, and a possiblechange in Δ for nuclei in the later p shell

Aug 2007


Σ Ξ

12C p-shell states

(Emulsion Data)

K-stop + 12C → - + p + 11

B3 states 2+, 2+, 0+ with resolution ~160 keV

S ShellCore Excitations

p7p(P Shell)6 hyperfine states

11 MeV2+

2+

0+

p emission

12C

Aug 2007


Σ Ξ

# -B(MeV)

1 -10.94±0.06

2 -8.4±0.2

3 -5.9±0.1

4 -3.8±0.1

5 -1.6±0.2

6 0.27±0.06

7 2.1±0.2

Hypernuclear StructureFINUDA

12C(K-stop,π-)12

C

Targets 12C, 7Li, 51V

Apply the i

nversion te

st

Aug 2007


Σ Ξ

Electromagnetic Production - Jlab

1212 C C (e,e’K(e,e’K++) ) 1212 BB

Jlab Hall AJlab Hall A

Jlab Hall CJlab Hall C

Pre

limin

ary

Pre

limin

ary

Binding and SeparationBinding and Separation

Energies are important;Energies are important;

consistent p-shellconsistent p-shell

binding binding

1616O bindingO binding

Aug 2007


Σ Ξ Beam Energy Stability

Value of absolute energyis not important ----------1. Must remain stable – Feedback lock2. Absolute Value/angle – Must be Calibrated

Locus Shifts as Energy and Angles vary

Aug 2007


Σ Ξ 12B

P Shell Structure

Aug 2007


Σ Ξ

Hyperon-Nucleus InteractionTheoretical Input

Nuclear Matter S = 28 MeV Density Dependent NN and N Dirac-Brueckner Vertices

Density dependence is crucial

Aug 2007


Σ Ξ

Hypernuclear Level Decay

Aug 2007


Σ Ξ

Weak DecayThe Baryon-Baryon Weak interaction

After much theoretical and experimental work

Γn/Γp seems to be resolved

Main problem was FSI but also heavy meson exchange is required, e.g. σ

However the asymmetry is experimentally very small buttheory predicts a reasonable negative value

A consistent understanding is still lacking

Non-Mesonic(NMWD)

q ～ 400MeV/c

ΓΓππ__ (→ ｐ + π － )

ΓΓππ00 　　　　 ( → ｎ + π ０ )

ΓΓpp ( +“ ｐ”→ ｎ + ｐ )ΓΓnn ( +“ ｎ”→ ｎ + ｎ )Γ2N (ΛNN →NNN)

Mesonic q ～ 100MeV/c

1/HY =Γtot

Γm

Γnm

Aug 2007


Σ Ξ

Single proton/neutron spectra from Single proton/neutron spectra from 55

ΛΛHe and He and 1212ΛΛCC

Calculation byGarbarino et al.

10

W()p = 1 + P α cos()

Theory: - 0.6 ～ - 0.7

NM=0.08±0.08+0.08 -0.00Note that the mesonic decay seems understood.

I thought I understood the difference as due to long range vs short behavior. If not why the ΔI = ½ rule?Are other processes important even for Γn/Γp ? (example)

Aug 2007


Σ Ξ

α

X

28MeV

α +x+N+ Ξ

Spectroscopy of and Ξ hypernuclei at J-PARC

RG calculations of and Ξ hypernuclei

(e.g. 6 Ξ He; 7ΞHe; 7

ΞLi, 8ΞLi, 9

ΞLi; 9ΞBe;

10ΞBe)

Show interesting B Ξ Structuredue to spin, isospin potentialWidths should be small ~6Mev

= n;p;d;t;3He;αN

= ; Ξ pYY

NYYThreshold Ξ + p

28 MeV

Aug 2007


Σ Ξ Hybrid Emulsion Techniques

E964 Layout

Similar Layout used for Charm studies at FNAL

Consider A(D+,+)LcA ?

Tagged (K-,K+) ProductionEmulsion Tracking for Spectroscopy

Aug 2007


Σ Ξ

Double Lambda Hypernuclei (Exp and Th B )

4H 0.13 -0.12 -0.14 4107 <Exp>[1]

5H 2.04 3.26 -0.82 5038 Th[2]

5He 2.39 3.80 -0.98 5037 Th[3]

6He 3.12 7.25 1.0 5953 Exp[4]

6He 3.12 10.9 4.7 5953 Exp[5]

7He 4.18 9.36 <1.0> 6891 Exp[6]

10 Be 9.71 17.7 -1.72 9665 Exp[7]

10 Be or --- --- --- --- Exp[8]

13 B ]

BA B(A-1) B B M Ref

[1] PRL 87(01)132504 [4]PRL 87(01)212502 [7]PRL 11(63)29[2] PRL 89(02)172502 [5]PRL 17(66)782 [8]Pro.Th.Phy 85(91)87; PRC 44(91)1905[3]NP A754(05)91c [6]NP A754(05)103c NP A754(05)103c

M(YYA) = M(A-2) + 2 M() - B; B = B - 2 B(A-1)

Aug 2007


Σ Ξ

K- + 9Be K+ + Y + X

+ p + Y

+ p + X’

Re-analysis of the 4H Events

Simulation of 7He Decay

Aug 2007


Σ Ξ

1. Coalescence in Heavy Ion Collisions2. Strangelets Strange matter having approximately equal numbers of s,u,and d quarks interacting via QCD e.g. the H3. Hadronic Matter Composite of hadrons interacting by QHD e.g. Neutron Stars 4. Quark matter High temperature and/or high density

Strange Structures at High Densitymulti-hyperon states

Neutron Stars Strange Quark Objects –

Quark Hadronization

Aug 2007


Σ Ξ Systems With Multiple Strangeness can

Be Stable

Binding Energy for systems with at 208 Pb core with N

I and II correspond to different parameter sets

Stability against = Ξ p

Aug 2007


Σ Ξ

Minimum at 10% -content: B0=-18MeV at ρ0=0.21fm-3

DDRH Hypermatter Equation of State (Binding Energy per Baryon)

Stability as a function of Density and Strangeness

Aug 2007


Σ Ξ Inside a Supernova

Dense core

100 km M.

3x107 km

3000 km

n*10 km M

.

>8 M evolves ~107 yr

Extreme temp: photodissociates nuclei back to protons, neutrons and alphas.

Neutronisation: p+e- n+e

e++e- + ; + x + x (all flavours equally)~ few x nuclear

Huge thermal emission of neutrinos ~5-10 seconds

Core bounces

Aug 2007


Σ Ξ

Stability at higher densities

Σ- does not appear becausePotential is repulsive

Aug 2007


Σ Ξ


Max. Neutron Star Mass asA Function of Radius

Addition of Hyperons makesthe EOS too Soft

Aug 2007


Σ Ξ New Facilities

Aug 2007


Σ Ξ

Production of Multi-strange systems p p Ξ - + Ξ +

p n Ξ - + Ξ0

Hypernuclei Ω Atoms γ Transitions

Production of Multi-strange systems p p Ξ - + Ξ +

p n Ξ - + Ξ0

Hypernuclei Ω Atoms γ Transitions

New FacilitiesMAMI C

Plans

A1 Collaboration Gen, Gep, Gmp VCS 3He Structure and Correlation K Electroproduction& HypernucleiA2 Collaboration Crystal Ball & TAPS Frozen Spin Target Recoil PolarizationA4 Collaboration Parity violating ep scattering

A1 Collaboration Gen, Gep, Gmp VCS 3He Structure and Correlation K Electroproduction& HypernucleiA2 Collaboration Crystal Ball & TAPS Frozen Spin Target Recoil PolarizationA4 Collaboration Parity violating ep scattering

KAOS Spectrometer

1.5 GeV

PANDA

Aug 2007


Σ Ξ

New Facilities(Arends, Nakamura, Feliciello, Achenbach, Nagae)

J-Lab

Upgrade HESImprovement of rate and resolutionMedium-A systems

Other experiments are under discussion

Upgrade HESImprovement of rate and resolutionMedium-A systems

Other experiments are under discussion

Aug 2007


Σ Ξ New Facilities

J-PARC

J-PARC Construction: 2001 ~~70% completed

Beam commissioning: LINAC( Dec., 06), RCS( Sep., 07), MR( May, 08)

Beam from MR: ~ end of 2008

Day-1 Experiments in preparationΞ hypernuclei

Hypernuclear gamma-ray spectroscopy

Deeply-bound Kaonic nuclei, etc.

Aug 2007


Σ Ξ Strangeness from Beginning

to … end?

Strange Nuclear Physics is more than nuclear physics revisited. It can illuminate features that are obscuredin conventional nuclear systems. It offers a selective probe of the hadronic many-body problem. It is of little interest to reproduce

nuclear physics with strange baryons. Experiments should illuminate a process where the addition of a hyperonadds a unique feature, e.g. three body forces, “polarization” of the medium, SU(3)f symmetry, multi-strangeness, etc,

Aug 2007


Σ Ξ

K- Atom Datafrom X-rays

Sensitive to the tails ofthe Nuclear density

Atomic states are modified by shifts and widthsdue to KN Interactions

The Kaon is ~1000 x the mass of an electronSo it orbits close to or within the nuclear radius

Aug 2007


Σ Ξ Atomic States

However K- D data are inconsistent with DEAR results

-500 0

200

400

600

800

1000

shift 1s [eV]

Dav

ies

et a

l, 19

79

Izyc

ki e

t al,

1980

Bir

d et

al,

1983w

idth

1

s[e

V] KpX

Repulsive-type attractive

KpX (KEK)M. Iwasaki et al, 1997

DEAR

isospin dependent antikaon-nucleon scattering lengths

aK-p = (a0 + a1)/2 aK-n = a1

Shift: 1s = - 193 ± 37 (stat.) ± 6 ev Width: 1s = 249 ± 111 (stat.) ±30ev

Aug 2007


Σ Ξ 12

CS x 11C States

Aug 2007


Σ Ξ

Magnetic Moments

1 In RMF expect hypernuclear moments to be near the Schmidt limits2 Σ mixing in JN = 0 core corrections small, but for JN = 1 moments can be

suppressed by ~10-20%

Aug 2007


Σ Ξ


Rotating Neutron StarWith Quark or mixed PhaseCore

Hall C Summer Workshop 2007

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