Transcript Document

核物理学（12月１４日、特別講義）
研究の内容についての発表を外部で活発に行っていますが、内部
の学生に余り伝える機会がありません。
（今年１０月：北海道地区の学生に集中講義
来年後期：大阪大学で集中講義
国内学会：岡山大学２件、九州工業大学２件、高エネ研
国際学会：ポーランド２回、スペイン２件、韓国（来年予定）、大阪（先週）２件）
＝＝ 比連崎＋永廣分のみ、ほとんどが招待講演＝＝
そこで、外部で使ったスライドで、内部の学生にも研究に関して、
お話しする機会を持とうと思います。研究内容の紹介に併せて、
「研究」と「勉強」の違い、研究室の紹介もしようと思っています。
まずは、研究内容に関するイントロです。
Interests of
Meson-Nucleus systems
Nara Women’s University
Satoru Hirenzaki
Hokkaido area school, 2010

1. Introduction and Motivation

2. Some formulation

3. Recent Topics

4. Summary
1. Introduction and Motivation

Object

Hadron – Nucleus bound systems.


Coulomb + Strong ・・・ Exotic Atoms
(Deeply Bound) p atom, Kaonic Atom, p atom …
Strong
・・・ Exotic Nuclei
Mesic Nuclei (K, η, η(958), ω, Φ…), Hypernuclei, …
ex.)
1s
2s
3s
Nuclear radius of
Kaonic Atoms
And
15N
Kaonic Nuclei
By J. Yamagata

K meson（mK～
Kaonic Atoms
500
MeV)
Binding energy
order of 10keV～MeV
K－
cf.) Normal atom
electron（me～0.5MeV)
Binding Energy -- order of eV～keV

Kaonic Nuclei
Very Deep !!
Binding Energy
10 ～100 MeV
K－
1. Introduction and Motivation

1. Exotic Many Body Physics
1s
2s
3s
Ex.)
Nuclear radius of
15N
Pionic Atoms in halo nuclei
Co-existence of Pion-Neutron-halo

2. Hadron Physics at finite density
Fundamental theory (QCD)
Effective theory
Hadron property at finite r
Infinite System
Finite System
Mesic Atoms and Mesic Nuclei
Kunihiro, Hatsuda, PLB206(88)385, Fig.3
Anomaly effect in vacuum
• Higgs mechanism
• Spontaneous
Chiral Symmetry Breaking
•UA(1) Anomaly Effect
: J p = 0-

Information on P at finite r ~ r0, (T~0)
T
r


Eigen state observation
Quantum number fixed
Invariant Mass Method
Selective information
Umemoto et al., PRC62 (2000)
Ericson-Ericson, Ann. Phys. 36 (66) 323
Seki-Masutani, Phys. Rev. C27(83)2799
with
b1
Observation of Mesic Atoms by x-ray
Kaonic Atom data
4f
3d
S. Hirenzaki, Y. Okumura, H. Toki, E. Oset, A. Ramos,
Phys.Rev.C61:055205,2000.
C.T.A.M. De Laat, et al., Nucl.Phys.A523:453-487,1991.

Theoretical Level Structure – How can we observe?
Observed by
X-ray
Spectroscopy
Toki, Yamazaki(1988), Toki, Hirenzaki, Yamazaki, Hayano (1989)
Toki,
Hirenzaki,
Yamazaki,
Hayano
(1989)
11

Mesons in Nuclei …… seems interesting.

However, x-ray method has limitation, Obviously!

New methods are proposed.
π atom in GSI (1996, 1998, 2002)
Proposals to RIBF and JPARC
Proposed experiments
at JPARC

(http://j-parc.jp/NuclPart/Proposal_e.html)
JPARC Day 1 Experiment at Hadron Hall
*Search for Kaonic Nuclear Bound states
By K. Itahashi, 17-24 Oct. 2010
By H. Ohnishi
By K. Ozawa
By K. Itahashi

ちょっとブレイク ーーー日本の現状ーーー
新しい加速器２台が極最近稼働して、新しい結果が色々
出てくる前夜のような状況です。
＊理化学研究所（埼玉）：RIBF 加速器
宇宙における元素合成、中性子星の内部状態の研究など
に
繋がる成果
＊JPARC 研究所（茨城）：30GeV 加速器
質量の起源、クォーク・ハドロンの性質、ストレンジネスを
持つ原子核の研究。
いろんなテーマで最先端に入る切り口があります。
How can we observe it ?
Missing Mass Spectroscopy
Incident particle
proton -hole
emitted particle
target
In-Medium Dispersion Relation
meson
Medium Effects
look carefully !!
Peaks!!
(K,N)
(d,3He)
* p-atom
- theory (S. Hirenzaki, H. Toki, T. Yamazaki, PRC44(91)2472,…)
- experiment (K. Itahashi et al., PRC62(00)025202,…)
(g,p)
* Kaonic Atoms and Kaonic Nuclei
- J. Yamagata et al., PTP114 (05)301.(Errata:114(05)905)
PRC74(06)014604.
- T. Kishimoto Group
* w-nucleus (Marco, Weise, PLB502(01)59)
(M. Kaskulov, H. Nagahiro, S. Hirenzaki, E. Oset ; nucl-th/0610085)
* p-atom
(Hirenzaki, Oset, PLB527(02)69)
- M. Iwasaki Group
Missing Mass Spectroscopy
look carefully !!
initial
final
N
meson
In-Medium Dispersion Relation
Medium
Effects
Peaks!!
Formation Cross Section by ‘pick-up’ reactions, (d,3He), (g, N), etc.

Effective Number approach
Experimental data



Recoilless
Substitutional States formation
Various activities, (n,p), (d,2He); (n,d), (p,2He); (p,g) …
Good Reaction : d + Nucleus
3He
+ p atom
lower
Outgoing particle energy
higher
Deeply bound p- states in the 208Pb(d,3He) reaction
K. Itahashi et al.
PRC62(00)025202
22
Deeply bound 1s and 2p Pionic States in the 206Pb(d,3He) reaction
Hirenzaki, Toki,
Hirenzaki and Toki, PRC55(97)2719
23
H. Geissel et al,
PRL88(02)122301
Pionic 1s states of Sn nuclei

Deepest 1s states in Pb and Sn : observed
 Nice
spectra were obtained.
 Theoretical
H. Geissel et. al.,
PRL88(02)122301
Potentials are classified
as Rank - A, B, C, D

Information on P at finite r ~ r0, (T~0)
T
r


Eigen state observation
Quantum number fixed
Invariant Mass Method
Selective information
Umemoto et al., PRC62 (2000)
Ericson-Ericson, Ann. Phys. 36 (66) 323
Seki-Masutani, Phys. Rev. C27(83)2799
with
b1
Deeply Bound Pionic Atom by (d,3He)
K. Suzuki et al.
Phys. Rev. Lett. 92(2004) 072302
GOR relation + Tomozawa-Weinberg Relation
27
There have been active discussions

K. Suzuki et al., Phys. Rev. Lett. 92(2004)072302

Kolomeitsev, Kaiser, Weise, Phys. Rev. Lett. 90(2003)092501
observation
in two-loop chiral perturbation


Energy dependent of P

Gauge coupling of Vc

Phenomenological pieces (Br2, p-wave terms)
Daisuke Jido, Tetsuo Hatsuda, Teiji Kunihro, Phys.Lett.B670:109-113,2008.
‘In-medium Pion and Partial Restoration of Chiral Symmetry’
---------
Garcia-Recio, Nieves, Oset, Phys. Lett. B 541(2002)64


Discussion on rn (n>1) ?
M. Doring, E. Oset, arXiv:0705.3027 [nucl-th]

s-wave pion-nucleus optical potential in chiral unitary model

E. Friedman and A. Gal, Phys. Lett. B578 (2004)85

G. Chanfray, M. Ericson, M. Oertel, Phys. Lett. B563(2003)61
Hadron Physics at finite density
Fundamental theory (QCD)
Effective theory
Hadron property at finite r
Infinite System
Finite System
Mesic Atoms and Mesic Nuclei
seems to be interesting and possible.
However, ……not so simple…
Many researches !!
さて研究室の状況
１、この分野に関しては、世界的な業績を上げています。
（おおげさでも誇張でもありません。）
２、研究室の学生は、国際的な業績を普通にあげられます。
（４回生が終わった時点で物理学会発表、
M1でハワイの国際会議発表（旅費は研究室から）等、
十分できます。）
３、あんまり今まで勉強が出来なかった人も、
これからのやる気で大丈夫！
（勉強と研究は違うし、ちゃんと教えるから）
１−３に関しては、次で詳しく
やる気のある人には理想的な研究室なんですよ。。。。
１、この分野に関しては、世界的な業績を上げています。
＝＝＝たとえば、あちこちでの講演。。
これで今年の分だけです。HP 見て下さい。
２、研究室の学生は、国際的な業績を普通にあげられます。
（４回生が終わった時点で物理学会発表、
M1でハワイの国際会議発表（旅費は研究室から）等、
十分できます。）ーー例：池野さん
（４回生：卒研テーマで）
（以下M1）
うちでは、これぐらいは、やる気があれば十分出来るのです。。。。
研究室から補助貰って海外の国際会議に行ってキャリアアップもいいのでは？
＊国際会議発表（旅費は研究室から）ですが。。。。。。
２国間共同研究
日本代表：比連崎
うちの研究室は予
算あります。でも
研究室人数少な
い。
私は外部の人たち
より奈良女の学
生に補助を出し
て、どんどん国
内外で活躍して
もらいたい！
３、あんまり今まで勉強が出来なかった人も、
これからのやる気で大丈夫！（勉強と研究は違うし、ちゃんと教えるから）
勉強と研究： 研究は「教科書に無い新しい発想」。
現存するものの理解とは違う。
「ちゃんと教える」人数が少ない方が圧倒的に
先生の指導を独占できる（有利！）と思いませんか？
私は東京理科大（私学）出身です。一人の先生に
多くの学生がついて、緻密な指導が可能かどうかは
疑問があります。当時、国立大の「学生/教員」の比は、
ものすごくうらやましかった。
もちろん基礎的な勉強も必要ですが、、
＝＞次ページの図
永廣さんの図
やる気のある人には理想的な研究室なんですよ。。。。
また、学生を教える事に、大変意欲を持っています。
それから。。。。。
＊就職希望の人も、もちろん welcome! いままでの研究室出身
者のほとんどは就職してます。研究室在籍する間に、一生懸
命やってくれれば良い。
＊卒研のテーマも相談に乗ります。（詳しくはHP 見て下さい。）
＊就職担当をしていた時の経験から、企業の担当者は、
＝ちゃんと専門（物理）の能力を備えているか
＝卒研をきっちり指導されているか 等も見ています。
推薦した学生に対して「物理がこんなに出来なくては。。」と
言われた事もあります。
＊物理出身を「うり」にして生きて行くのに、物理を修得するの
は、まぁ必須でしょうね。
さて閑話休題
この後は、先週の国際会議（招待講演）で発表した
最新の話題。
ちょっと難しいかもしれません。
3. Recent Topics
Structure and Formation of
Meson Nucleus Systems
S. Hirenzaki (Nara Women’s Univ.)
International conference BARYONS’10
Dec. 7-11, 2010, Osaka, Japan
Introduction and Motivation

Mesons in nuclei and main interest (and my collaborators)

Pionic Atom … fpi at finite density (Toki, Yamazaki, Hayano, Itahashi, K.
Suzuki,,,)

K-atom & nuclei … deeply bound nuclear state ? (Yamagata-Sekihara, Jido)

h-mesic nuclei … N*(1535) in medium (Nagahiro, Jido,,,)

h’(958)-mesic nuclei … UA(1) anomaly in medium (Nagahiro, Takizawa)

Φ –mesic nuclei … mass shift, OZI rule (Yamagata-Sekihara, Cabrera,
Vicente-Vacas)

w-mesic nuclei ... bound state ? mass shift ? (Kaskulov, Nagahiro, Oset)

s-mesic nuclei … ms ~ 2mp enhancement ? (Nagahiro, Hatsuda,
Kunihiro)
41

--------

Q+ in medium … S=+1 hypernuclei [(K+,p+)] (Nagahiro, Oset, Vicente-Vacas)
Formation of mesic
nucleus
at JPARC and COSY
With H. Nagahiro, D. Jido
Introduction of h-mesic
nuclei
Motivation and our aim
» h-N system … strongly couples to the N*(1535) resonance
h-mesic nuculei … doorway to in-medium N*(1535)
» N*(1535) … a candidate of the chiral partner of nucleon
chiral symmetry for baryons
Many works for h mesic nuclei from 1980’s
 Theor.
 Exp.
43
Liu, Haider, PRC34(1986)1845
Kohno, Tanabe, PLB231(1989)219; NPA519(1990)755
Garcia-Recio, Nieves, Inoue, Oset PLB550(02)47
C. Wilkin, T. Ueda, S. Wycech, ……
Chrien et al., PRL60(1988)2595
TAPS@MAMI (g + 3He  p0 + p + X)
COSY-GEM (p + Al  3He + Mg-h)
WASA-at-COSY (d + d  3He + p + p)
JPARC, 
Chiral model for N and N*
Chiral doublet model
DeTar, Kunihiro, PRD39 (89)2805
Jido, Oka, Hosaka, Nemoto, PTP106(01)873
Jido, Hatsuda, Kunirhiro, NPA671(00)471
Chiral unitary model
Kaiser, Siegel, Weise, PLB362(95)23
Waas, Weise, NPA625(97)287
Garcia-Recio, Nieves, Inoue, Oset, PLB550(02)47
Inoue, Oset, NPA710(02) 354
* In this study, we directly take the eta-self-energy in the ref.NPA710(02)354
A coupled channel Bethe-Salpeter eq.
Lagrangian
Physical fields
N* : chiral partner of nucleon
Mass difference
* C~0.2 :the strength of the Chiral restoration
at the nuclear saturation density
44
* reduction
of mass difference
* the N* is introduced as a resonance
generated dynamically from meson-baryon scattering.
* No mass shift of N* is expected
in the nuclear medium.
h self-energy
h-nucleus interaction : potential descriptions
optical potential
+ (crossed term)
potential nature at h threshold
repulsive core
60
attractive
energy w
mN*-mN
Re [Vopt] [MeV]
repulsive
Chiral doublet model
C=0.2
40
medium effect
20
0
attractive pocket
-20
Chiral Unitary model
-40
(Inoue, Oset, NPA710(02)354)
mh
-60
t-r approximation (CDM : C=0.0)
-80
0
45
r/r0
1
2
3
r [fm]
4
5
6
•D.Jido, H.Nagahiro and S.Hirenzaki, PRC66(02)045202

momentum transfer
spectra : experiment at Brookhaven
500
400
Chrien et al., PRL60(1988)2595
pp = 800 MeV/c : proton angle : 15 deg. (Lab.)
 search for predicted narrow bound state
by Liu, Haider, PRC34(86)1845
 negative results (bound state peak was not observed)

[MeV]
(p+,p)
15 deg.
300
200
100
0 deg.
0
0.4
0.6
0.8
1
1.2
1.4
pp [GeV/c]
Chrienatatal.,
al.,PRL60(88)2595,
PRL60(88)2595,Fig.1
Fig.1
Chrien
80
Li
0 deg.
Li
chiral doublet
0 deg.
chiral unitary
40
C
C
0
30
O
15 deg.
O
15 deg.
20
Al
46
Al
10
0
-100
-50
0
50
Eex – E0 [MeV]
100
-100
-50
0
50
Eex – E0 [MeV]
100
(p+,p) spectra : experiment at Brookhaven
momentum transfer

500
Chrien et al., PRL60(1988)2595
pp = 800 MeV/c : proton angle : 15 deg. (Lab.)
 search for predicted narrow bound state
by Liu, Haider, PRC34(86)1845
 negative results (bound state peak was not observed)

[MeV/c]
400
15 deg.
300
200
100
0 deg.
Chrien at al., PRL60(88)2595, Fig.1
0
0.4
0.6
15 deg.
Li
0.8
1
1.2
1.4
pp [GeV/c]
30
doublet
20
C
unitary
10
O
0
Al
• wider energy range
-100
• proton
angle = 0 degree
47
• S/N ~ 1/10  need background reduction
H.Nagahiro, D.Jido, S.Hirenzaki, PRC80(09)025205
-50
0
50
Eex – E0 [MeV]
100
150
A Simple Theoretical Model for
Some remarks
(COSY Proposal)
(P.Moskal, arXiv:nucl-ex/09093979)
• Momentum transfer
pd = 1.025 GeV/c, pa = ph= 0 at threshold in C.M.
• Data of d d  4He h
• Simple spectral structure for light systems
• System consists of
2 Nucleon + 2 Nucleon  4 Nucleon + 1 meson
48
A Simple Theoretical Model for
Some remarks
• Transition (h-production) part
h
High q transfer at each propagator
Parameterize this part. Fix by h production data
49
A Simple Theoretical Model for
Schematic picture
d
h
d
a
s
Green function method
with h-a optical potential
s
total
s(dd4Heh) data
escape
conversion
threshold
50
Etot
threshold
Etot
Numerical Results
stot [nb]
8
25
20
15
7
10
5
0
Arbitrary unit
6
5
(V0,W0) = (−100, −10) MeV
p0 = 500 MeV/c
4
3
2
1
51
0
−20
−15
−10
−5
0
5
Eh − mh [MeV]
10
15
Numerical Results
6
stot [nb]
25
20
15
Arbitrary unit
5
10
5
0
4
(V0,W0) = (−100, −20) MeV
p0 = 500 MeV/c
3
2
~
0
52
−20
~
−15
−10
−5
0
5
Eh − mh [MeV]
10
15
’(958) –mesic nucleus
h’(958) mesic nuclei formation
H.Nagahiro., S. H, PRL94(05)232503
H. Nagahiro, M. Takizawa and S. H, PRC74(06)045203

h’(958) meson … close connection to the UA(1) anomaly

many theoretical works
 in
PLB206(88)385
vacuum / at finite temperature / at Kunihiro,
finiteHatsuda,
density








poor experimental information at finite density
effect in vacuum
UA(1) anomaly in medium from the viewpoint of “mesic Anomaly
nuclei”


R. D. Pisarski, R. Wilczek, PRD29(84)338
T. Kunihiro, T. Hatsuda, PLB206(88)385 / T. Kunihiro, PLB219(89)363
V. Bernard, R.L.Jaffe and U.-G.Meissner, NPB308(1988)753
Y. Kohyama, K.Kubodera and M.Takizawa, PLB208(1988)165
K. Fukushima, K.Onishi, K.Ohta, PRC63(01)045203
P. Costa et al.,PLB560(03)171, PRC70(04)025204, etc …
the h’ properties, especially mass shift, at finite density
Nambu-Jona-Lasinio model with the KMT interaction
54
explicit breaking the UA(1) sym.
Kobayashi, Maskawa Prog.Theor.Phys.44, 1422 (70), G. ’t Hooft, Phys.Rev.D14,3432 (76)
h’ mass shift in medium

we consider the SU(2) sym. matter as the sym. nuclear matter.
anomaly term
effect
meson mass [MeV]
1000
parameters (in vacuum)
800 steep
600
flat
h’
h
400
200
0
P. Costa et al.,PLB560(03)171, PRC70(04)025204, etc …
flat
p
P. Rehberg, et al., PRC53(96)410.
L
= 602.3 [MeV]
gS L2 = 3.67
gDL5 = -12.36
mu,d = 5.5 [MeV]
ms = 140.7 [MeV]
Mu,d
= 367.6 [MeV]
Ms
= 549.5 [MeV]
〈uu〉1/3 = -241.9 [MeV]
〈ss〉1/3 = -257.7 [MeV]
mh’ = 958 [MeV]
mh = 514 [MeV]
mp = 135 [MeV]
h and h’ mass shifts @ r0
Dmh’ ~ -150 MeV @ r0
Dmh ~ +20 MeV @ r0
We can see the large medium effect even at normal nuclear density.
55
h’(958) mesic nuclei by (p,N) reaction

Potential description
Real Part V0 … evaluated by possible h’ mass shift at r0
Imaginary part W0 … unknown  20 MeV, for example
elementary cross section p+ n h’p
Momentum transfer q [MeV/c]
momentum transfer
500
mh’
400
s(p+nh’p) ~ 100
mb
300
mh’ – 50 MeV
200
100
56
0
mh’ – 100 MeV
1
2
pp [GeV/c]
3
4
R.K.Rader et al., PRD6(72)3059
h’-mesic nuclei formation spectra : 12C target
• pp = 1.8 GeV/c
: (p+,p) reaction
By H. Nagahiro
• proton angle = 0 deg.
case
with no mass reduction
2.5
V0 = −(0, 20i) MeV
with 150 MeV reduction @ r0
V0 = −(150, 20i) MeV
2.0
1.5
1.0
0.5
0
-150
57
-100
-50
0
Eex – E0 MeV
50
-150
-100
-50
0
Eex – E0 MeV
50
100
Suppose we have nice data (spectra) ….
1, Mass reduction will be equivalent to attractive V in Eq. of Motion..
2, But “ Attractive  Mass reduction ’’ is wrong. Ex.) Coulomb case.
Origin of the attraction is important.
3, Both NJL and Optical potential are approximations,
describing a (different) part of truth. Then, if the one of them is
dominant, the interpretation of data could be relatively easier.
4, η(958)-proton scattering length 〜0.1fm =>V(0) ~ 10MeV Weak!
P. Moskal et al., Phys. Lett. B 482, 356 (2000) [arXiv:nucl-ex/0004006]
And Oset-Ramos theoretical results, Nanova talk this morning..
5, η(958) seems interesting.
With Jido, Nagahiro
h’-mesic nuclei formation spectra : 12C target
• pp = 1.8 GeV/c
: (p+,p) reaction
case
• proton angle = 0 deg.
with no mass reduction
2.5
V0 = −(0, 20i) MeV
By H. Nagahiro
with 150 MeV reduction @ r0
V0 = −(150, 20i) MeV
2.0
1.5
1.0
0.5
0
-150
59
-100
-50
0
Eex – E0 MeV
50
-150
-100
-50
0
Eex – E0 MeV
50
100
Pionic atoms at
RIBF
Deeply Bound Pionic Atom by (d,3He) –
Data at GSI
K. Suzuki et al.
Phys. Rev. Lett. 92(2004) 072302
GOR relation + Tomozawa-Weinberg Relation
T. Yamazaki,
S. Hirenzaki
PLB557(03)20
Density Probed by pion – Too much stable…..
pdensity
Peak positions of the overlapping
density are almost same for all states.
Nuclear density
The effective nuclear density re is
almost same, re~ 1/2r0 for all states.
re
Rovpeak
Overlappin
g
N
p
Overlapping density
π atom at RIBF

Exp. plan by Ito, Itahashi (RIBF-027)

2 ~ 3 times better energy resolution  1s and 2s
observation

better determination of p-A interactions

Various ρ probe ?

In future, pionic atom in unstable nuclei
- Hirenzaki, Kajino, Kubo, Toki, Tanihata, PLB(87)
- Umemoto, Hirenzaki, Kume, Toki, Tanihata, NPA(01)
- Fujita, Hirenzaki, Kume, PRC(03)
- Kienle, Yamazaki, Toki, ‘ Inverse kinematics idea’ 91~92
EXPERIENCE at GSI
FWHM394kev
THEORY
FWHM394kev
THEORY
FWHM150kev！
２ｓpeak
will be seen.
By R. Kimura, N. Ikeno
5. Summary
Mesic Atoms and Mesic Nuclei


Nucleus as Finite Density Laboratory
Exotic Nuclei with Meson impurities
We are interested in …
= how to connect to the fundamental theory
= how to get reliable experimental information
η (958) -Nucleus System
 η-Nucleus System at JPARC and COSY
 π-Atom at RIBF
Study of meson-nucleus bound states is interesting !!
＊いつでも研究室に話しを聞きに来て下さい。
一緒に国際的な場に出られる仕事をしませんか？比連崎、永廣
（あと、研究で充実しているときの宴会（学会打ち上げとか）は楽しいもので
すよ（笑））
