Hall C Safety Stand downMarch 20, 2009

• Stephen Wood: Overview and Safety Overview• Mike Spata: Beamline overview• Kellner: Schedule and safety rules• Manzlak: Physics Division EH&S comments• Neil Wilson: Tool Safety• Bill Vulcan: Electrical work

E05-115 HES/HKS

2

Building blocks of ordinary matter

Protons Neutrons

Quarks

u u d

u d d

3

Chart of Isotopes

Neutrons

Pro

tons

Black squares:Stable or nearly stable

Exploiting “Chart”:Medical isotopesNuclear Power

Exploring and extending“Chart” still an active field:

AstrophysicsFRIB @ MSU

Exploring a third dimension

Protons Neutrons

4

Quarks

u u d

u d d

u d s

Lambda Particle

(a hyperon)Strange quark

e + p e + K+ + Producing Lambdas

N

Z

Nutron #Pro

ton#

L, S hypernuclei

Nu ~ Nd ~ Ns

Nu

mb

er o

f s

qu

ark

s

0

1

2

LL, X hypernuclei

Normal Nuclei (World of u,d quarks)

World of u, d, s quarks

Extend building blocks of the World from u,d to u,d,s!

Neutron#

K+ detection At very forward angle (~ 0 deg.) Detected by High resolution Kaon Spectrometer (HKS)

Hypernuclear productionby the (e,e’K+) reaction (E05-115)

e’

K+

e- Beam from CEBAF

Target nucleus

Eg

e’ detection Should be at extremely forward angles Detected by High resolution Electron Spectrometer (HES)

L is free from nucleons’ Pauli exclusion Probe to deep inside of nucleus

L is L in deep inside of nucleus? or should be treated as (uds)?

Extend nuclear force to baryon force

Simulation

-B L [MeV]

Evolution of 12LB spectra

E89-009~300h x 0.6mA

E01-011~120h x 30mA

E05-115~24h x 30mA

Cou

nts/

150

keV

-BL (MeV)

Accidental coincidence

coun

ts/

100k

eVYear 2000 Year 2005 Year 2009 summer!

Much sharper spectra than possible with pion or kaon beams

Hypernuclear investigation in wide mass range at JLab Hall C

Light Hypernuclei (s,p shell)

A

1 20 50 200 1057

Elementary Process

Single-particle potential

Distinguishability of a L hyperon

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

Neutron/Hyperon star,

Strangeness matter

Baryon-baryon interaction in SU(3)LS coupling in large isospin hypernucleiCluster structure, Fine structureNeutron rich hypernuclei

E05-115 6,7Li 10,11B 12C (40Ca) 52Cr 89Y

3rd Generation Experiment

E01-011 7Li 12C 28Si

E89-009 12C

Medium - Heavy hypernuclei

1st gen.:

2nd gen.:

9

2.344 GeV

CEBAF Electron beam

To the beam dump

7.5deg tilt

HES

HKS

Target

e-

K+

HKS + HES + New Splitter (dedicated system to hypernuclear study)

Fully optimized for (e,e’K+) hypernuclear spectroscopy

10

One beam in – 4 “beams” out

Kaon and electron need to be detected at small scattering angles.

Splitter magnet separates negative electron and positive kaon.

Splitter magnet also bends primary beam. Beam needs to be send to dump. Either bend beam after splitter (the way it was done last time, or bring beam in at an angle.

ElectronsPhotons

K+

e-