Approved Nuclear Physics Experiments at Hadron Hall Dept. of Physics, Tohoku University H. Tamura.

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.