Approved Nuclear Physics Experiments at Hadron Hall
Dept. of Physics, Tohoku University
H. Tamura
Contents
1. Experiments at Hadron Hall
2. K1.8BR: K-nucleus bound states and K- atomic X-rays
3. K1.8/SKS: and Hypernuclei, exotic hadrons
4. K1.8/KURAMA: hypernuclei, atomic X-rays
5. Summary
1. Experiments at Hadron Hall
List of Experiments at Hadron Hall
Hadron Hall
Handron Hall
Beam Dump
T1 target
K1.8
K1.8BR
K1.1S-type
KL
K0.8C-type
30~50 GeV primary beam
Productiontarget (T1)
Strangeness nuclear physics at K1.8BR and K1.8
2. K1.8BR
E15: K-nucleus bound states
E17: K- atomic X rays
ρ > ρ0
x10 !?A. Dote et al. : PLB590 (2004) 51, etc.
den
sity (fm-3)
Strong K-N attraction (← K- atomic data, K-p scattering data) -> Suggests a very deep K nuclear potential ( UK ~ -200 MeV) (1405) is a K-N bound state?
-> Deeply bound K-Nuclear states are predicted. High density nuclear matter? Kaon condensation in neutron star?
Interest of K-Nuclear systems
Experimental hints for K- nuclear
deeply bound states
T. Kishimoto et al., Prog. Theor. Phys. 118 (2007) 181
in-flight (K-, n) reaction @ 1 GeV/c
Re(V) ~ -180 MeV
Im(V) ~ 50 MeV
deep & wide KN potential
Stopped K- absorption on 6,7Li, 12CBack-to-back -p pair
M. Agnello et al., PRL 94 (2005) 212303.
Final state interaction ?Background?
invariant mass
missing mass
K-pp : lightest K-nucleus
Observation of both
CDS
K- 3He K-pp
sweeping magnet
neutron counter
E15 setup
neutron
neutron
Cylindrical Detector System
１） solenoid ２） CDC ３） hodoscope ３ He target Neutron counter Beam line detector
chargedparticleschargedparticles
neutron
proton
proton
π−
decay
formation
“formation” and “decay”
FOPI@GSI aiming the same physicscompetitor
E15 (Iwasaki, Nagae et al.)Search for Kaonic Nuclei via 3He(K-,n) reaction
E17 (Hayano, Outa et al.)
Kaonic Helium-3 X-ray spectroscopy
3d
2p
(Coulomb-only)
Width : Γ2p
Shift : ΔE2p
K- N strong interaction
Nuclear Absorption
~ 6.4 keV
att
racti
ve→
←re
pu
lsiv
e
Excluded by KEK PS E570
large (±15 eV) shiftmay be possible for
K- 3He → E17
K- 3He atom 3d-2p X-ray Energy → K-nucleus potential
U0 : kaon-nucleus potential depth
Need 35 days of DAQ @ 1/10 design beam intensity (+beam tuning)
Probably the first for physics results
pre
dic
ted
sh
ift
target
CDC
magnet
CDH
CDC region
E15: Cylindrical Spectrometer
(CDS)
Ohnishi
Ready
beamline chamber(near completion)
SDD preamplifier in the target cryostat (under test)
E15 components
3He target(in cool-down test)
1K level gauge
K-
E17 Setup
3. K1.8/SKS Hypernuclei E13: -ray spectroscopy E10: n-rich hypernuclei E05: hypernuclei Exotic hadrons E19: Pentaquark
N
Z
World of matter made of u, d, s quarksNu ~ Nd ~ Ns
Higherdensity
３ -dimensional nuclear chart
Strangeness in neutron stars ( > 3 - 4 0 )
Strange hadronic matter (A → ∞)
, Hypernuclei
, Hypernuclei
Str
ang
enes
s
0
-1
-2
“Stable”
What we know about YN, YY interactions N Attractive (~ 2/3 of NN force) <- Z -single particle orbit data Very small LS force, small spin-spin/ tensor forces <- Z p-shell -ray data etc.
NN coupling force? <- s-shell hypernuclei p-wave force? Charge symmetry breaking (p≠n)??
NStrong isospin dependence (attractive for T=1/2,S=0) <- 4
HeStrongly repulsive in average? <- 28Si (π-,K+) spectrumHow large is the repulsive (T=3/2,S=1) channel?
N Weakly attractive?? <- 12C (K-,K+) spectrum Isospin dependence???
Weakly attractive <- 6
He
-N-coupling force ???
, Unknown at all ???
Established Suggested Unknown
PRC 64 (2001) 044302
-> U = - 30 MeV (c.f. UN = -50 MeV)
J-PARC will answer
High density matter in neutron star coreLarge neutron Fermi energy -> Hyperons appear
Baryon fraction: very sensitive to YN, YY interactions
-> maximum mass, cooling speed
Hypernuclear data -> realistic calculations possible
帆座超新星残骸
かに座超新星残骸
存在
比率
密度
n star
We need N int., int., KN int. (K condensate?),
N p-wave force, NNN and YNN force,
…
E13 (Tamura et al.)Gamma-ray spectroscopy of light hypernuclei
(K-,π-) reaction (pK=1.5 GeV/c) w/ SKS + Hyperball-J (Ge array)
in a nucleus from B(M1) 7
Li
Further Study of N interaction Precise structure of hypernuclei
-> N spin-dependent forces
N-N coupling force Charge symmetry breaking (p≠n)
4He, 10
B, 11B, 19
F
Toward unified understanding
of Baryon-Baryon interactions
in s-orbit
gc
reduction of mass-> enhancement of ??
Doppler shift attenuation method -> Lifetime -> Transition rate (accuracy ~5%) ->
1000 hours with full beam (0.5M K-/spill)
2nd prio
rity
Hypernuclear -ray data since 1998
(π+,K+ ) at KEK-PS(K-, π- ) at BNL-AGS usingGe array “Hyperball”
NaI array (13C)
Extend the 3D nuclear chart much efficiently using intense K- beam
-> “Table of Hyper-Isotopes”
1.5 GeV/c
An Example of Setup
(E13)
π-
K-
1.4 GeV/c
Hyperball-J
SKS superconducting magnet
K1.8 beamline spectrometer
SKS spectrometer(SksMin
us)
E10 (Sakaguchi et al.)Study on Neutron-Rich Hypernuclei
Produce neutron-rich hypernuclei by the double charge-exchange (DCX) reaction
ordinary nucleiordinary nuclei
this studythis study
pn
unbound “Hyperheavy hydrogen”: deeply bound
6H5H
NCX: (KNCX: (K,,ππ), (), (ππ++,K,K++) reaction) reaction
SCX: (e,e’KSCX: (e,e’K++), (K), (K,,ππ), (), (ππ,K,K00) reaction) reaction
DCX: (KDCX: (K,,ππ),), (π,K+) reactionreaction
DCXDCX
SCXSCX
NCXNCX
-hypernuclei-hypernuclei
n
n
n
pnn n
n
Akaishi:Glue-like role of
(B=4.4 MeV)
NN coherentcoupling ( +1.4 MeV)
glue-likerole of
-hyperon
・ Extend 3D-nuclear chart
・ -N interaction in n-rich environment
Neutron-rich hypernucleus
First data on n-rich hypernucleus
10B (π-, K+) 10Li
Almost no background
Saha et al., PRL 94 (2005) 052502
11.1±1.9 nb/sr
(KEK E521, K6+SKS)
π- p p -> n K+
pπ~1.2 GeV/c
Physics Interest
coherent coupling -> more bound?
Behavior of n-halo with a
Production mechanism? 2-step charge exch. π-p->π0n, π0p->K+etc.) - admixture π- p->- K+, - p->n)
coherent coupling
Akaishi et al., PRL 84 (2000) 3539
First spectroscopic study of
S=-2 systems in (K-,K+) reaction First step to multi-strangeness
baryon systems
N Interaction Attractive or repulsive? How large?
<- -nuclear potential depth Isospin dependence ?
<- Different targets N-coupling force? <- p→ conversion width
<- andhypernuclear mixing states
-> Take a similar spectrum for (K-,K+) reaction
E05 (Nagae et al.)-hypernuclear spectroscopy by (K-,K+)1
st priorit
y K- p -> - K+
Precision:
Peak Position: 0.1 - 0.3 MeV
Width: 0.2 - 1 MeV
[counts
/0.5
MeV
]
First spectroscopic study of
S=-2 systems in (K-,K+) reactionFirst step to multi-strangeness
baryon systems
V= -20MeVV= -14MeV
-B [MeV]
s
p
4 weeks w/ full beamΔEmeas.= 3 MeVFWHM
Expected 12C (K-,K+) 12Be Spectrum
Expected Spectrum
V ~ -14 MeV ?
Previous data (BNL)
SKS spectrometerModified SKS magnet
Disassembled Jan.15-30 Under modification of cooling system Assemble at J-PARC site (2008 Sep.-Oct.)
SksPlus for (K-,K+)
Additional magnet produced
using an old iron yoke
1.4 GeV/c
Physics Motivation
E19 (Naruki et al.)E19 (Naruki et al.)
Search for Pentaquark Search for Pentaquark + + in in ππ––ppKK––X reactionX reactionE19 (Naruki et al.)E19 (Naruki et al.)
Search for Pentaquark Search for Pentaquark + + in in ππ––ppKK––X reactionX reaction
Search for Pentaquark in hadronic reactionπ- + p K- + X Previous (π-,K-) spectrum shows a hint of 2.6 We can determine the width of + with SKS.
J-PARC E19
Expected Missing Mass Spectrum
2 GeV/c, 1 x 107 π/spill (4 x 1012 protons /spill only) x 1 week only
Beam condition
Pentaquark: exotic five quark state (qqqqq) <-> meson (qq), baryons (qqq) positive evidences at low energy (LEPS, etc.) very narrow width ~ 1 MeV. Why? negative results at high energy
uーs u
d
d
4. K1.8/ KURAMA: E07: Hybrid emulsion for S=-2 ( Hypernuclei and -atomic X-rays)
E03: -atomic X-rays
Ten times more events of hypernuclei
>104 stopped -, ~102 hypernuclei Details of interaction strength correlation (H dibaryon-like state) in nucleus from “”-> p decay
Measure - -atomic X-rays with Hyperball-J Shift and width of X-rays -> -nuclear potential Stopped - events identified from emulsion
Measure tracks by counters
n
pPRL 87 (2001) 212502
Nagara event
E07 (Nakazawa, Imai, Tamura et al.) S=-2 Systems with Emulsion-Counter Hybrid Method
Setup of E07
# Beam : K- (1.7GeV/c), 3 x 105 K-/spill with K-/π- > 6 at K1.8 beam-line (~20% of 9A)
# Trigger : (K-, K+) => 104 - stopping events (more than 10 times higher statistics than E373)
Almost sameas PS-E373
Double-sided Si Strip Detector ---Newly developed, Ready
Faster emulsion scanning system
developed.Emulsion
50% purchased
Hyperball-Junder construction
KURAMA spectrometerexisting
Measure - -atomic X-rays from stopped - events using Hyperball-J
Measure tracks by counters
E03 (Tanida et al.) atomic X rays
E03 simulation
Fe（ Pb, C ・・・）
Calibration at intense beams is a key issue
If successful, extend to several other Z’s
Fe target
Handron Hall
Beam Dump
K1.8 (Fall,2009~)
K1.8BR (Dec.2008~)
K1.1 (when?)
KL
K0.8 (when?)
30 (→ 50) GeV primary beam
Productiontarget (T1)
Proposed experiments using secondary beams at
Hadron Hall (incl. LOI)
SKS
hypernuclei
hypernuclei-atomic X rays spectroscopy
n-rich hypernuclei searchWeak decays of hypernucleiPion double charge exchange nucleus
K- nucleus bound statesK- atomic X rays nucleus, nucleus
study spectroscopy hypernucleiYN scattering nucleus
5. Summary• Eight nuclear physics experiments are stage-2 approved.
• K1.8BR will be used to study K--nuclei and K--atom.
• K1.8/SKS will be used for various hypernuclear studies (-spectroscopy, n-rich hypernuclei, -hypernuclei) as well as
pentaquark search.
• K1.8/KURAMA will be used to study hypernuclei and atomic X-rays.
• Preparation of these experiments are in progress as scheduled.
• Many more experiments are proposed. More beam lines are strongly required.
