hadron spectroscopy with high-momentum hadron beams
TRANSCRIPT
Hadron spectroscopy with high-momentum hadron beams
K. Shirotori for the E50 collaboration
Research Center for Nuclear Physics (RCNP)
Osaka University
The 3rd J-PARC symposium (J-PARC2019)
26th September 2019
Contents
• Motivations of hadron physics• Effective degree of freedom of hadrons
• Hadron property in medium
• J-PARC Facility• J-PARC high-momentum beam line
• Multi-purpose spectrometer system
• K10 beam line and Hadron hall extension
• Summary
2
Motivations of Hadron Physics
Hadron physics investigations
• Excited states
• Effective degree of freedoms
• Constituent quark + Diqaurk correlation & Hadron molecule
⇒ Spectroscopy experiment with heavy quark
• Excites energy, spin and parity, production cross section, decay branching ratio
• Properties in nuclear medium
• Origin of mass
• Spontaneous breaking of chiral symmetry
⇒Measurement on nuclear target
• Change of mass, shape, decay branching ratio, cross section
＊J-PARC: High-intensity Secondary Hadron beams
4
Excited states: Observation of exotic hadrons
＊Excited states: Rich properties
⇒Mass, width, decay branching ratio, spin and parity
from new effective degree of freedoms extended to ordinary constituent quark model
5
Constituentquark
q
q
q
Exotic hadrons q
q
q
Meson Baryon
Hadron molecule Multi-quark
q
q q
Excited states: Observation of exotic hadrons6
Constituentquark
q
q
q
Exotic hadrons q
q
q
Meson Baryon
Hadron molecule
q-q
q
Diquark correlation &
Hadron molecule
Diquark
correlation
Multi-quark
q
q q
Excited states with heavy quark: Diquark7
“Excited mode”: l and r modes in heavy baryon excited states (q-q + Q system)
⇒ Diquark correlation: q-q isolated and developed
Q
q-q
Q
q-q
q
l modeCorrective motion
btw q-q and Q
G.S.
Excited states
by spin-spin
interaction
⇒ Observables
Light quark baryon
r modeExcitation of q-q
Excited states with heavy quark: Diquark8
“Excited mode”: l and r modes in charmed baryon excited states (q-q + system)
⇒ Diquark correlation from Production rate and Decay branching ratio
c
q-q
c
q-q
q
l modeCorrective motion
btw q-q and Q
G.S.
Excited states
by spin-spin
interaction
⇒ Observables
Light quark baryon
r modeExcitation of q-q
Charmed baryon spectroscopy experiment: J-PARC E50
＊p- + p → Yc*+ + D*- reaction @ 20 GeV/c
• High-intensity p- beam: 6.0×107 /spill
• Production rates & Decay branching ratios
Production rates by hadronic reaction9
• p- + p → Yc*+ + D*- reaction: Missing mass method
＊Production rates ⇔ Internal structure of excited states
⇒ Selective production of corrective motion: l mode
＊Angular momentum transfer between
diquark (q-q) and charm quark
Reaction diagram
Lc@
1 n
b
Lc(
25
95)
Lc(
2625)
Sc(
28
00
)
Lc(
29
40
)
Sc(
24
55)
Sc(
25
20)
Lc(
288
0)
Simulation
S.H. Kim, A. Hosaka, H.C. Kim, H. Noumi, K. Shirotori
Prog. Theor. Exp. Phys. 103D01 (2014).
iefff rqiR )exp(2 ~
-
＊Production cross section
⇒ Overlap of wave function
＊charm and q-q (spectator)
1 : 2 3 : 2
Excitation spectrum: q-q + Q10
Strange baryons
0
100
200
300
400
500
600
700
800
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Y* -
YG
.S.[M
eV]
MQ [MeV/c2]
Sc(1/2+)
Lc(1/2+)
Sc(3/2+)
Lc(1/2-, 3/2-)
Lc(1/2-, 3/2-, 5/2-)
l
r
r
L(1/2-, 3/2-, 5/2-)
S(1/2+)
L(1/2+)
S(3/2+)
Charmed baryonsP-wave states
s c
L(1/2-, 3/2-)
L(1/2-, 3/2-)Lc(1/2-, 3/2-)
• Non-rel. QM: H = H0 + Vconf + VSS + VLS + VT
• l-r mixing
(cal. By T. Yoshida, Nucl.Phys. A954 (2016) 341)
＊Heavy quark sector (charm)
⇒ Light quark sectors (u, d, s)
Strange baryon systems
• L* /S* : q-q + Q system
⇒ Systematics with charmed baryon• Production rate: l and r selection• Decay branching ratio
• X* : q + QQ system
⇒ Excitation with two heavy quarks
• W* : QQQ system
⇒ Same weight of three heavy quarks
＊Spectroscopy by high-momentum K- beam• Several GeV/c beam• Poor data of X and W states• Exotic states
⇒ Systematic measurement
11
Q
q-q
q
Q Q
Q
X*
W*
L*/S*
Hadron in nuclear medium
• Properties in finite density
• Origin of hadron mass
⇒ Vector mesons
• Quark condensation: <qqbar>
＊Different mesons:
Different aspect on QCD vacuum
• Experimental signals on nuclear target
• Mass spectrum: Shift & Shape change
• Decay branching ratio
• Production cross section
• A-dependence
• Quark configuration: Light and heavy quarks
12
h/h’
f/w/r
＊Mass shift in medium
Chiral origin ~ Constituent mass
UA(1) anomaly
+ SBCS
＊Spontaneous breaking
of chiral symmetry
Experimental approaches
• DDbar production at threshold region• c/cbar: No effect• q/qbar: Change of mass⇒ Cross section in medium
• pbar + p → D + Dbar
⇔ pbar + A → D + Dbar + X
＊Effects to q/qbar w/o other light quarks
• Charmonium states
⇒Access to gluon condensation• Mass shape (Production cross section)• Decay branching ratio⇒ Suppression of decay modes
• pbar + A → M(ccbar) + X
• Ex. M(ccbar) → DDbar mode forbidden
＊High-momentum pbar beam on nuclear target• Several GeV/c beam• Fixed target experiment
13
T [GeV]
Gy. Wolf at al., PLB 780, 25-28, 2018
D ≠ Dbar
Mass reduction Mass gain
Question to hadron/nuclear physics
• Neutron star: High-density nuclear matter• Quark・Gluon → Hadron → Hadron interaction → Nucleus → Neutron Start
＊Hadron properties: Effective degree of freedom, origin of mass• Roles of light quarks (u, d, s) from studies of heavy quark (charm) @ J-PARC
14
NucleusNeutron star
104 m 10-14 m
Quark・Gluon
q
Hadron
Effective degree of freedom
and origin of mass
J-PARC Facility
High-momentum beam line
Hadron hall extension: K10 beam line
High-momentum beam line for 2ndary beam
• High-intensity beam: > 1.0×107 Hz p (< 20 GeV/c)• Unseparated beam: p/K/pbar
• High-resolution beam: Dp/p ~ 0.1%(rms)• Momentum dispersive optics method
16
Collimator
Production Target
(SM)
Exp. Target (FF)
Focal Point (IF)
High-momentum beam line for 2ndary beam
• High-intensity beam: > 1.0×107 Hz p (< 20 GeV/c)• Unseparated beam: p/K/pbar
• High-resolution beam: Dp/p ~ 0.1%(rms)• Momentum dispersive optics method
17
• Size: 100 mm×100 mm
• 1 MHz / 1 mm
• 6.0×107 /spill (30 MHz)
@ 20GeV/c
1.0E+04
1.0E+05
1.0E+06
1.0E+07
1.0E+08
1.0E+09
0 2 4 6 8 10 12 14 16 18 20
[GeV/c]
Design Intensity [/spill (5.2 sec)]
p+
K+
p-
K-
pbar
pSeveral 107 /spill
Several 105 /spill
@ 15 kW loss
~100 mm
Charmed baryon spectrometer18
2m
LH2-target
Beam p-
p-
K+
ps- Ring Image
Cherenkov
Counter
DC
TOF wall
PID counter
Fiber tracker
T0
Pole face
detector
Internal DC
Internal TOF
Fiber wall
p-
p+
Charmed baryon spectrometer19
2m
LH2-target
Beam p-
p-
K+
ps- Ring Image
Cherenkov
Counter
DC
TOF wall
PID counter
Fiber tracker
T0
Pole face
detector
Internal DC
Internal TOF
Fiber wall
p-
p+Large Acceptance Multi-Purpose Spectrometer
+ Trigger–less DAQ system
Charmed baryon spectrometer
⇒ New platform for Hadron experiment
Beam intensity for K and pbar experiment
• Several GeV/c beam for X*/W*, DDbar and charmonium
• > 1 MHz K/pbar beam ⇔ > 100 MHz p beam
• Beam measurement is bottleneck. ⇒ Dedicated K/pbar beam line
20
1.0E+04
1.0E+05
1.0E+06
1.0E+07
1.0E+08
1.0E+09
0 2 4 6 8 10 12 14 16 18 20
[GeV/c]
Design Intensity [Hz] in spill (2.0 sec)
p-
K-
pbar
@ 15 kW loss
0.E+00
5.E-03
1.E-02
2.E-02
2.E-02
0 2 4 6 8 10 12 14 16 18 20
[GeV/c]
K/p & pbar/p ratio
K-/p-
pbar/p-
2%
MHz K beam
Hadron hall extension 21
Hadron hall extension 22
K10 beam line
• Separated K/pbar beams up to 10 GeV/c • RF separator
⇒ ~107 /spill beam
＊High intensity, purity and momentum hadron beams
23Conceptual design of Di-muon spectrometer
Summary
• Motivations of hadron physics • Effective degree of freedom of hadrons
• Spectroscopy of excited states
• Properties in finite density• Measurement of hadron properties in nuclear medium
• Experimental approaches to understand hadrons• Spectroscopy of hadrons with heavy quarks
• Charmed baryon, X* and W*
• Meson in nuclei• Vector meson(f), DDbar, Charmonium
• J-PARC facility: High-intensity
& High-momentum hadrons beams• High-momentum beam line
• Unseparated beam• Multi-propose spectrometer
• K10 beam line in extended hadron hall• Separated K/pbar beams
24
Q
q-q
＊Key: Hadron with heavy quark
Q
q_