Transcript The J-PARC Hypernuclear Physics Programs

The J-PARC Hypernuclear Physics
Programs
- Hyperonization in dense nuclear matter Toshiyuki Takahashi
IPNS, KEK
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
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
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Tokai
Village
Tokai-2 Nuclear P.S.
J-PARC
the Pacific Ocean
Hitachinaka P.S.
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
J-PARC Facility
Hadron Hall (Slow
Extracted Beams)
3GeV Rapid Cycling
(25Hz) Synchrotron
(1MW)
Neutrino Beamline to
Super-Kamiokande
Linac
Materials and Life
Science Facility
Japan Accelerator Research Complex
50 GeV
Synchrotron
(0.75MW)
Joint Project between KEK and JAEA
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
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
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Construction Schedule
Current
Aug.24,2007
Construction
Start
Facility
Operation
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Hadron Hall
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Hadron Hall Layout (Phase 1)
K1.8
(2009 Sep.)
K1.8BR
(2008 Dec.)
KL(2010?)
Production
Target (T1)
Proton Beam
(30-GeV)
Aug.24,2007
Primary
beams
K1.1
K0.8
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Secondary Beamlines
K1.8
K1.8BR
Primary proton beam
50 GeV-15mA
Length (m)
30 GeV-9mA
45.853
Acceptance (msr.%)
~2.0
1.4E+06
@1.5 GeV/c
2.7E+06
@1.1 GeV/c
0.38E+06
Single rate @ MS2 @ 1.8 GeV/c
K-/(p-+m- )
@ FF @ 1.8 GeV/c
X/Y(rms) size @ FF
(mm)
2.5
Max. momentum (GeV/c)
6.6E+06
30 GeV-9mA
27.573
Acceptance (msr.%)
K- intensity (ppp) @1.8 GeV/c
Electrostatic separator
50 GeV-15mA
Length (m)
1.4
Max. momentum (GeV/c)
Primary proton beam
~1.2
K- intensity (ppp) @1.1GeV/c
5.5E+06
1.2E+06
0.54E+06
@0.8 GeV/c
1.0E+06
0.2E+06
0.08E+06
@0.6 GeV/c
0.1E+06
0.02E+06
750kV/10cm, 6m×2
＞33E+06
＞8E+06
4
3.5
19.8 / 3.2
Electrostatic separator
500kV/10cm, 6m
Single rate@D3out @1.1 GeV/c
K-/(p-+m- ) @ [email protected] GeV/c
X/Y(rms) size @ FF (mm)
＞30E+06
>7E+06
1
0.9
5.9 / 2.9
High-reslution beam spectrometer
High intensity K- beams are available !!
Kaon Factory
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Physics Programs
• PAC Meeting



1st
2nd
3rd
Jun.31 – Jul.2, 2006
Jan.10 – Jan.12, 2007
Jul.6 – Jul.7, 2007
• 17 Proposals & 7 LOI’s
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


Aug.24,2007
Stage-2 Aproval
Stage-1 Aproval
Deffered
Rejected
9 (5 Day-1 Experiment)
6
1
1
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Hypernuclear Physics at S=-2
Hypernuclear Physics at S=-1
Physics on Hadrons with Strangeness
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Hypernuclear Physics at S=-2
• E07
Systematic Study of Double Strangeness Systems with
an Emulsion-counter Hybrid Method
• E05
Spectroscopic Study of X-Hypernucleus, 12XBe, via the
12C(K-,K+) Reaction
• E03
Measurement of X rays from X- Atom
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Motivation to Study S=-2 System
• New sector of Baryon-Baryon interaction
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
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LL
XN
XN->LL
weakly attractive
attractive ?
• Very dynamic system

Small mass difference LL and XN (and H?)
• Significant step toward multi-strangess
systems

Aug.24,2007
Core of neutron star ...
Dense and Cold Nuclear Matter and Hard Exclusive Processs
S=-2 System
XN->LL coupling
Mixing effect is more
significant in S=-2 system
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
X 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
• S- was supposed to be important.
However its interaction with neutron
matter is found to be strongly
repulsive.
• X- and its interaction should be
important.
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
How to produce and study
S=-2 systems
K- + p -> K+ + Xp(K-)~1.8GeV/c
Direct production
Reaction Spectroscopy
(E05)
X-rays Measurements
(E03)
Decay measurements
Emulsion (E07)
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E07 Previous Studies on
Double-Strangeness Systems
KEK-PS-E373 (1998 - )
Twin hypernucleus
X- (binding) energy at the absorbed point
X- Nucleus interaction
Aug.24,2007
Weakly attractive LL interaction
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E07
Systematic Study of Double Strangeness
Systems with an Emulsion-counter Hybrid Method
l
t
l
l
i
(12C)
• Double L Hypernuclei
 expected ~100 events
 extend known species
 species dependence of DB
LL
 decay form
p rb l l
# of absorbed
X-
# of LLhypernuclei
# of twin
hypernuclei
• H-dibaryon
4
(expected)
1
1987-1997
(KEK-E176)
80
1
2
• X-Nucleus Interaction
 twin hypernuclei
 X-ray from atomic states
1998-present
(KEK-E373)
~800
7 (1)
3
• Unknown Phenomena
J-PARC E07
~10000
~100
20-30?
1965
D. Davis
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E05 Previous Studies on
X-Hypernucleus and X Potential
(K-,K+) Missing Mass Spectroscopy on C
KEK-E224
BNL-E885 DM=14MeV
DM=22MeV
Evidence !?
VX = -14 MeV
T.Fukuda et. al, PRC58(1998)1306
insufficient resolution
poor statistics
P.Khaustov et al,
PRC61(2000)0546
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E05
Spectroscopic Study of X-Hypernucleus,
12 Be, via the 12C(K-,K+) Reaction
X
• Missing mass spectroscopy

K1.8 Beam Spectrometer


Dp/p=3.3x10-4(FWHM)
SksPlus Spectrometer


Dp/p=1.2x10-3(FWHM)
~30 msr
•
~3 MeV(FWHM) resolution
•
~190 bound events


Aug.24,2007
1.6x106 /spill K- beams
1 month data-taking
expected spectrum GX=1MeV
VX=-20MeV
VX=-14MeV
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Measurement of X rays from X- Atom
E03
•
target
K-
K+
X-
X- Nuclues potential

Real part


X ray
Imaginary part

Energy (arb.)

...
l=n-3
•
l=n-1
l=n-2
X
...
nuclear absorption
...

...
X
Z
•
Width
X ray yield
Regardless of potential detail

Z
Level energy shift
attractive / repulsive
strong / weak absorption
Complementary to E05


E03 surface region of the potential
E05 inner part of the potential
l (orbital angular momentum)
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Hypernuclear Physics at S=-1
• E10
Production of Neutron-rich Lambda-Hypernuclei with
the Double Charge-exchange Reaction
• E13
Gamma-ray Spectroscopy of Light Hypernuclei
• E18
Coincidence Measurement of the Weak Decay of 12LC
and the Three-body Weak Interaction Process
• E22
Exclusive Study of the Lambda-N Weak Interaction in
A=4 Lambda-Hypernuclei
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E10 Neutron-rich L Hypernuclei
and DCX Reaction
ordinary nuclei
No Charge eXchange
(p+,K+), (K-,p-)
L hypernuclei
KEK-E521
Double Charge eXchange
(p-,K+), (K-,p+)
N>>Z (I=3/2, 2)
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E10 Motivation
• LS coupling
• Change of nuclear structure
A(I=0)
S
energically
supressed
if isospin0
A(I0)
L

OK!
A*(I=1)
S
Nucleus
Excited
A(I0)
S
important in n-rich hypernuclei
• L potential in n-rich
enviroment
Nucleus
Exotic
A(I=0)
L
Ordinary
if isospin=0
Hypernucleus
L
L
Core + L
Deformed Core
+L
n-rich hypernucleus
n
Hypernucleus
+ neutron halo
strangeness contents in neutron
stars

Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E10 Produdution of N-rich Hypernuclei
KEK-E521
10B(p-,K+)10
LLi
• Two step reaction
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
p-p->p0n, p0p->K+L
p-p->K0L, K0p->K+L
• Small cross section

~10 nb/sr (10-3 of NCX)
• Need high intensity beam
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
1x107 /spill p- beam
pp=~1.2GeV/c
• Need high resolution
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~45 events at bound region
No backgound
Aug.24,2007
~2 MeV/c2(FWHM) with SKS
• Yield estimate for 9LHe
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~300 events with 3 weeks
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Physics on Hadrons with Strangeness
• E15
A Search for Deeply-Bound Kaonic Nuclear States
by In-flight 3He(K-,n) Reaction
• E17
Precision Spectroscopy of Kaonic 3He 3d->2p X-rays
• E19
High-Resolution Search for Q+ Pentaquark
in p+p->K+X Reaction
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E15 Kaonic Nuclear States
• KpX Exp. (KEK)
-> strongly atractive in K-p system
• L(1405) as a bound state of K- and p
• Kaonic nuclear states may exist.
T.Yamazaki and Y.Akaishi
Phys. Lett. B535(2002) 70.
contour plot of nucleon density distribution by AMD
A.Dote et al., PRC70 (2004) 044313.
rcenter = ~10 r0
Ultra high density nuclear matter
(c.f. core of neutron stars )
could be obtained !!
glue-like role of KAug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
E15 Missing-Mass Spectroscopy
and Invariant-Mass Spectroscopy
3He
K-
Production
n
3He(K-,n)X
Missing-mass
spectroscopy
K-pp
L
p-
p
Decay
p
K-pp -> L p
-> p p-
n
Invariant-mass
spectroscopy
KCDS in Solenoid Magnet
Aug.24,2007
@K1.8BR beamline
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Summary
• The construction of J-PARC facility will be completed
and its operation will start soon.


•
MR operation
First beam to Hadron Hall
 K1.8BR
 K1.8
2008 May
2008 Dec.
2008 Dec.
2009 Sep.
Hadron facility is “Kaon Factory”.


1.4 x 106 K-/spill, K-/(p- + m-)=3.5 @1.8GeV/[email protected]
1.2 x 106 K-/spill K-/(p- + m-)=0.9 @1.1GeV/[email protected]
• A lot of physics programs on hypernuclear &
strangeness physics are waiting the beam.

Aug.24,2007
Research on S=-2 system is main subject among them
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Backup
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
J-PARC PAC System and
Beamtime Charge
PAC for Particle & Nuclear Proposals
PAC for Materials & Life Proposals
Beamtime
Charge
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Commissioning & Linac Energy
Recovery
Construction
needs to start
from JFY2008,
hopefully for 3
years, as shown
in this figure.
JFY2008
Phase 1
Completion
JFY2009
JFY2010
JFY2011
JFY2012
JFY2013
Issue and
Concern:
This budget plan
has not been
included in the
current plan at
JAEA.
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Cost Analysis for Operational
Budget
190 Oku Yen / year ($190M/y if $1=100Yen)
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
UX , GX and Partial Wave
Contributions in Nuclear Matter
(MeV)
3S
1
1P
1
3P
0
3P
1
0
1
-2.6
-3.2
0.1
-2.3
-2.1
-3.0
-0.2
-0.0
-0.7
-3.1
-1.9
-6.3
-25.2
0.9
0
1
-0.9
-1.3
-0.5
-8.6
-1.0
-0.8
0.3
-0.4
-2.4
-1.7
-0.7
-4.2
-22.3
0.5
6.3 -18.4
7.2 -1.7
1.2
-0.8
1.5
-0.5
-1.3
-1.2
-1.9
-2.8
-12.1
12.7
T
NHC-D
Ehime
ESC04d*
0
1
• OBE (NHC-D, Ehime)




Aug.24,2007
no t-channel meson exchange
odd-state attraction
strong A-dependence of VX
small width
3P
2
GX
1S
0
Model
UX
• ESC04d*


strong attraction of 3S1(T=0)
large width
Dense and Cold Nuclear Matter and Hard Exclusive Processs
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.
n:43
54
65
76
87
98
109
F(Z=9)
Cl(17)
Co(27)?
?
Y(39)?
?
I(53)
Ho(67)?
?
Pb(82)
131 (keV)
223
314?
?
394?
?
475
518?
?
558
• The choice depends on the optical potential itself
 We can’t know before the 1st experiment
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
For the 1st experiment
• 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
(X- range: 10-20 g/cm2, bgct ~ 2cm)
X-ray absorption: significant at large Z
 Small Z(A), yet high density
• Koike calculated the energy shift (width) & yield of
the Fe X ray (n=6  5)



Aug.24,2007
Woods-Saxon potential: -24 - 3i MeV
Energy shift: 4.4 keV, width: 3.9 keV
Yield per stopped X-: 0.1 (~0.4 without absorption)
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Yield & sensitivity estimation
• Total number of K-: 1.0x1012 for 100 shifts.
• Yield of X


production: 3.7×106
stopped: 7.5×105
• X-ray yield： 2500 for n=65 transition

7200 for n=76
• Expected sensitivity



Aug.24,2007
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
absorption potential.
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Expected X-ray spectrum
n= 65
shift & width
0 keV
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Expected X-ray spectrum(2)
n= 65
shift & width
4 keV
Aug.24,2007
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Exotic L-hypernuclei
• Example of “hydrogen”
Super Heavy Hydrogen
p
n
1H
Stable
2H Stable
3H Stable
4H
No evidence
5H Resonance
6H No evidence
glue like role of L
L
2
LH Not bound
3 H Stable
L
4
LH
Stable
We can produce at J-PARC
Aug.24,2007
5
LH
6 H
L
7 H
L
No evidence
Stable ?
Stable ?
Hyper Heavy Hydrogen
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Requirement: Resolution (1)
• Clear identification of hypernuclei


Aug.24,2007
Binding energy (guess) : 9LHe ~8MeV, 6LH ~3MeV
Strong quasi-free
background
In the caseL-production
of 6LH hypernucleus
Energy resolution ≤ 2.5MeV (FWHM)
Dense and Cold Nuclear Matter and Hard Exclusive Processs
Production cross section
 4L

Aug.24,2007
He(g.s., 0+) production
estimation with DWIA by T. Harada
Dense and Cold Nuclear Matter and Hard Exclusive Processs