Dense and Cold Nuclear Matter and Hard Exclusive ProcesssAug.24,2007 The J-PARC Hypernuclear Physics Programs - Hyperonization in dense nuclear matter

Dense and Cold Nuclear Matter and Hard Exclusive Processs Aug.24,2007

The J-PARC Hypernuclear Physics Programs

- Hyperonization in dense nuclear matter -

Toshiyuki Takahashi

IPNS, KEK


Contents

• Introduction of J-PARC Facility Hadron Hall

• Physics Programs PAC Meeting

Hypernuclear Physics at S=-2 Hypernuclear Physics at S=-2 Physics on Hadrons with Strangeness

• Summary


the Pacific Ocean

Tokai Village

Hitachinaka P.S.Hitachinaka P.S.

Tokai-2 Nuclear P.S.Tokai-2 Nuclear P.S.

J-PARC


J-PARC Facility

Linac

3GeV Rapid Cycling (25Hz) Synchrotron

(1MW)

50 GeV Synchrotron

(0.75MW)

Materials and Life Science Facility

Japan Accelerator Research Complex

Neutrino Beamline to Super-Kamiokande

Hadron Hall (Slow Extracted Beams)

Joint Project between KEK and JAEA


Phase 1 & 2• The budget for about 2/3 of the entire project has been approved by the Japanese government from

JFY2001 as Phase 1.

• Phase 1 (~151 billion Yen) consists of major accelerator components and a part of experimental facilities. 270 kW for slow extraction half size of Hadron Hall

JAEA

KEK


Construction Schedule

ConstructionStart

FacilityOperation

Current


Hadron Hall


Hadron Hall Layout (Phase 1)

Proton Beam(30-GeV)

ProductionTarget (T1)

K1.8(2009 Sep.)

K1.8BR (2008 Dec.)

K1.1

K0.8

KL(2010?) Primary beams


Secondary Beamlines

Primary proton beam 50 GeV-15A 30 GeV-9A

Length (m) 45.853

Acceptance (msr.%) 1.4

Max. momentum (GeV/c) ~2.0

Kintensity (ppp) @1.8 GeV/c 6.6E+06 1.4E+06

@1.5 GeV/c 2.7E+06 0.54E+06

@1.1 GeV/c 0.38E+06 0.08E+06

Electrostatic separator 750kV/10cm, 6m×2

Single rate @ MS2 @ 1.8 GeV/c ＞ 33E+06 ＞ 8E+06

K/(+) @ FF @ 1.8 GeV/c 4 3.5

X/Y(rms) size @ FF (mm) 19.8 / 3.2

Primary proton beam 50 GeV-15A 30 GeV-9A

Length (m) 27.573

Acceptance (msr.%) 2.5

Max. momentum (GeV/c) ~1.2

K intensity (ppp) @1.1GeV/c 5.5E+06 1.2E+06

@0.8 GeV/c 1.0E+06 0.2E+06

@0.6 GeV/c 0.1E+06 0.02E+06

Electrostatic separator 500kV/10cm, 6m

Single rate@D3out @1.1 GeV/c

＞ 30E+06 >7E+06

K/(+) @ [email protected] GeV/c 1 0.9

X/Y(rms) size @ FF (mm) 5.9 / 2.9

K1.8 K1.8BR

High intensity Kbeams are available !!

Kaon Factory

High-reslution beam spectrometer


Physics Programs

• PAC Meeting 1st Jun.31 – Jul.2, 2006 2nd Jan.10 – Jan.12, 2007 3rd Jul.6 – Jul.7, 2007

• 17 Proposals & 7 LOI’s Stage-2 Aproval 9 (5 Day-1 Experiment) Stage-1 Aproval 6 Deffered 1 Rejected 1


Hypernuclear Physics at S=-2


Physics on Hadrons with Strangeness



• E07 Systematic Study of Double Strangeness Systems with

an Emulsion-counter Hybrid Method

• E05Spectroscopic Study of -Hypernucleus, 12

Be, via the 12C(K,K) Reaction

• E03Measurement of X rays from Atom


Motivation to Study S=-2 System

• New sector of Baryon-Baryon interaction weakly attractive N attractive ? N

• Very dynamic system Small mass difference and N (and H?)

• Significant step toward multi-strangess systems Core of neutron star ...


S=2 System

N coupling

Mixing effect is more significant in S= system


Potential and Impact on Neutron Stars

• Strange baryons apear in the core of neutron star...

• What kind of baryons will apear ?• At how much density will they apear?

depend on mass, charge, interaction• Negative baryons are favorable.

reduce electron Fermi energy• was supposed to be important.

However its interaction with neutron matter is found to be strongly repulsive.

• and its interaction should be important.


How to produce and studyS=2 systems

K + p K+ +

p(K)~1.8GeV/c

Direct productionReaction Spectroscopy(E05)

Decay measurementsEmulsion (E07)

X-rays Measurements(E03)


E07 Previous Studies on Double-Strangeness Systems

KEK-PS-E373 (1998 - )

Weakly attractive interaction

Twin hypernucleus

(binding) energy at the absorbed point

Nucleus interaction


E07

i

l

llt

l lbrp

(12C)

• Double Hypernuclei expected ~100 events extend known species

species dependence of B decay form

• H-dibaryon

• -Nucleus Interaction twin hypernuclei X-ray from atomic states

• Unknown Phenomena

Systematic Study of Double Strangeness Systems with an Emulsion-counter Hybrid Method

# of absorbed

# of -hypernuclei

# of twin hypernuclei

1965

D. Davis4

(expected)

1

1987-1997

(KEK-E176)80 1 2

1998-present

(KEK-E373)

~800 7 (1) 3

J-PARC E07 ~10000 ~100 20-30?


E05 Previous Studies on -Hypernucleus and Potential

T.Fukuda et. al, PRC58(1998)1306

P.Khaustov et al, PRC61(2000)0546

KEK-E224

(K,K+) Missing Mass Spectroscopy on C BNL-E885M=14MeV

M=22MeV

Evidence !? V = 14 MeV

insufficient resolutionpoor statistics


E05

• Missing mass spectroscopy K1.8 Beam Spectrometer

p/p=3.3x10(FWHM) SksPlus Spectrometer

p/p=1.2x10(FWHM) msr

• ~3 MeV(FWHM) resolution

• ~190 bound events 1.6x106 /spill K beams 1 month data-taking

Spectroscopic Study of -Hypernucleus, 12Be, via the 12C(K,K) Reaction

expected spectrum

V=20MeV

V=14MeV

=1MeV


E03

• Nuclues potential Real part

Level energy shift Imaginary part

Width X ray yield

• Regardless of potential detail attractive / repulsive strong / weak absorption

• Complementary to E05 E03 surface region of the potential E05 inner part of the potential

Measurement of X rays from Atom

K- K+

X ray

target

l=n-1

l (orbital angular momentum)

Ene

rgy

(arb

.)

...

...

l=n-2l=n-3

nuclear absorption

Z

...

...

Z


Hypernuclear Physics at S=-1• E10

Production of Neutron-rich Lambda-Hypernuclei with the Double Charge-exchange Reaction

• E13Gamma-ray Spectroscopy of Light Hypernuclei

• E18Coincidence Measurement of the Weak Decay of 12

C and the Three-body Weak Interaction Process

• E22Exclusive Study of the Lambda-N Weak Interaction in

A=4 Lambda-Hypernuclei


E10 Neutron-rich Hypernuclei and DCX Reaction

ordinary nuclei

Double Charge eXchange(,K), (K,)

N>>Z (I=3/2, 2)

KEK-E521

No Charge eXchange(,K), (K,)

hypernuclei


E10 Motivation• coupling

important in n-rich hypernuclei

• potential in n-rich enviroment

strangeness contents in neutron stars

• Change of nuclear structureif isospin=0if isospin=0

A(I=0)

A(I=0)

A*(I=1)

energicallysupressed

if isospinif isospin00

OK!A(I0)

A(I0)

NucleusNucleus

ExcitedExcitedNucleusNucleus

Exo

ticO

rdin

ary

Core +

Deformed Core +

Hyper-Hyper-nucleusnucleus

n

Hypernucleus+ neutron halo

n-rich hypernucleus


E10 Produdution of N-rich Hypernuclei• Two step reaction

pn, pK pK0, K0pK

• Small cross section ~10 nb/sr (10 of NCX)

• Need high intensity beam 1x107 /spill beam p=~1.2GeV/c

• Need high resolution ~2 MeV/c2(FWHM) with SKS

• Yield estimate for 9He

~300 events with 3 weeks

KEK-E52110B(,K)10

Li

~45 events at bound regionNo backgound


Physics on Hadrons with Strangeness

• E15A Search for Deeply-Bound Kaonic Nuclear States

by In-flight 3He(K,n) Reaction

• E17Precision Spectroscopy of Kaonic 3He 3d2p X-rays

• E19High-Resolution Search for Pentaquark

in pK+X Reaction


E15 Kaonic Nuclear States• KpX Exp. (KEK)

strongly atractive in Kp system

• (1405) as a bound state of K and p

• Kaonic nuclear states may exist.

contour plot of nucleon density distribution by AMD

A.Dote et al., PRC70 (2004) 044313.

center = ~10 0

Ultra high density nuclear matter(c.f. core of neutron stars ) could be obtained !!

T.Yamazaki and Y.Akaishi Phys. Lett. B535(2002) 70.

glue-like role of K


E15 Missing-Mass Spectroscopy and Invariant-Mass Spectroscopy

K- 3He

K-pp

n 3He(K,n)XMissing-mass spectroscopy

K

n

p

p

-

Production

Decay

Kpp p p

@K1.8BR beamline

Invariant-massspectroscopy

CDS in Solenoid Magnet


Summary• The construction of J-PARC facility will be completed and

its operation will start soon. MR operation 2008 May First beam to Hadron Hall 2008 Dec.

K1.8BR 2008 Dec. K1.8 2009 Sep.

• Hadron facility is “Kaon Factory”. 1.4 x 106 K/spill, K/( + )=3.5 @1.8GeV/[email protected] 1.2 x 106 K/spill K/( + )=0.9 @1.1GeV/[email protected]

• A lot of physics programs on hypernuclear & strangeness physics are waiting the beam. Research on S=2 system is main subject among them


Backup


J-PARC PAC System and Beamtime Charge

PAC for Particle & Nuclear Proposals PAC for Materials & Life Proposals

Beamtime Charge


Commissioning & Linac Energy Recovery

Construction needs to start from JFY2008, hopefully for 3 years, as shown in this figure.

Issue and Concern:This budget plan has not been included in the current plan at JAEA.

JFY2008 JFY2009 JFY2010 JFY2011 JFY2012 JFY2013

Phase 1Completion


Cost Analysis for Operational Budget

190 Oku Yen / year ($190M/y if $1=100Yen)


U , and Partial Wave Contributions in Nuclear Matter

• OBE (NHC-D, Ehime) no t-channel meson exchange odd-state attraction strong A-dependence of V

small width

Model T 1S03S1

1P13P0

3P13P2 U

NHC-D

Ehime

ESC04d*

(MeV)

• ESC04d* strong attraction of 3S1(T=0) large width


Selection of targets• Physics view: Batty et al. PRC59(1999)295

For given state, there is optimal target Nuclear absorption is reasonably small X-ray energy shift and width are the largest (~1 keV)

They suggested 9F, 17Cl, 53I, and 82Pb for n=3,4,7,9.

• The choice depends on the optical potential itself

We can’t know before the 1st experiment

n:43 54 65 76 87 98 109

F(Z=9) Cl(17) ? ? I(53) ? Pb(82)

131 (keV) 223 ? ? 475 ? 558

n:43 54 65 76 87 98 109

F(Z=9) Cl(17) Co(27)? Y(39)? I(53) Ho(67)? Pb(82)

131 (keV) 223 314? 394? 475 518? 558


• We chose Fe (Iron) because of (mostly) experimental reason Production rate: A-0.62 as cross section scales with A0.38

Stopping probability: requires high target density ( range: 10-20 g/cm2, c ~ 2cm)

X-ray absorption: significant at large Z

Small Z(A), yet high density• Koike calculated the energy shift (width) & yield of th

e Fe X ray (n=6 5) Woods-Saxon potential: 24 3i MeV Energy shift: 4.4 keV, width: 3.9 keV Yield per stopped : 0.1 (~0.4 without absorption)

For the 1st experiment


Yield & sensitivity estimation• Total number of K-: 1.0x1012 for 100 shifts.• Yield of

production: 　 3.7×106

stopped: 7.5×105

• X-ray yield ：　 2500 for n=65 transition 7200 for n=76

• Expected sensitivity Energy shift: ~0.05 keV (systematic dominant)

Good for expected shift (~1 keV, 4.4 keV by Koike ) < 5% accuracy for optical potential depth Width: directly measurable down to ~ 1 keV X-ray yield gives additional (indirect) information on absor

ption potential.


Expected X-ray spectrum

n= 65

shift & width0 keV


Expected X-ray spectrum(2)

n= 65

shift & width4 keV


Exotic -hypernuclei

• Example of “hydrogen”

55H No evidenceH No evidence

66H Stable ?H Stable ?

77H Stable ?H Stable ?

22H Not boundH Not bound

33H StableH Stable

44H StableH Stable

11H StableH Stable22H StableH Stable33H StableH Stable

44H No evidenceH No evidence55H ResonanceH Resonance66H No evidenceH No evidence

n

pSuper Heavy HydrogenSuper Heavy Hydrogen

Hyper Heavy HydrogenHyper Heavy Hydrogen

glue like role of glue like role of

We can produce at J-PARCWe can produce at J-PARC


Requirement: Resolution (1)

• Clear identification of hypernuclei Binding energy (guess) : 9

He ~8MeV, 6H ~3MeV

Strong quasi-free -production backgroundIn the case of 6H hypernucleus

Energy resolution ≤ 2.5MeV (FWHM)


Production cross section

4He(g.s., 0+) production

estimation with DWIA by T. Harada

Documents

Dense and Cold Nuclear Matter and Hard Exclusive ProcesssAug.24,2007 The J-PARC Hypernuclear Physics Programs - Hyperonization in dense nuclear matter