future of hadron physics experiments at j-parc k. ozawa (kek) contents: j-parc & hadron facility...
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Future of Hadron Physics Experiments at J-PARC
K. Ozawa (KEK)
Contents:J-PARC & Hadron FacilitySome topics at J-PARC and related Facility(Future plan of J-PARC & Hadron Facility)Summary
2014/10/25 K. Ozawa, Hadrons in nuclear medium 2
Nara
J-PARCTokyo
KEK
600km
2014/10/25 K. Ozawa, Hadrons in nuclear medium 3
J-PARC (Japan Proton Accelerator Research Complex)
J-PARC (Japan Proton Accelerator Research Complex)
Tokai, JapanTokai, Japan
MR30 GeV Synchrotron
400 MeV LinacRCS
3 GeV Synchrotron
Material and Life Science Facility
Neutrino Experimental Facility
Hadron Hall60m x 56m
Hadron Experimental Facility
30 GeV Accelerator & Hadron Experimental Facility
2014/10/25 K. Ozawa, Hadrons in nuclear medium 4
30GeV proton Accelerator
Branch Point from Acc. to Hadron
Transfer Line from Acc. to Hadron
Hadron Experimental Facility
Current Production target for secondary beams
New Beamline (under construction)
K. Ozawa, Hadrons in nuclear medium 5
Hadron Experimental Facility
K1.8BR
KL
K1.8
K1.1High-p
COMET
Name Species Energy IntensityK1.8 p±, K± < 2.0 GeV/c ~105 Hz for K+
K1.8BR p±, K± < 1.0 GeV/c ~ 104 Hz for K+
K1.1 p±, K± < 1.1 GeV/c ~ 104 Hz for K+
High-pproton 30GeV ~ 1010 Hz
Unseparated < 20GeV/c ~ 108 Hz
2014/10/25
Under Construction
What we know about hadrons?• Colored quarks are confined.• u, d, s quarks are no longer light.• Pseudo-scalar mesons are light. • Flavor SUf(N) symmetry exists
2014/10/25 6
What we naively think? Perturbative region• Current quark• SUL(N) X SUR(N)
Nonperturbative region• Constituent quark• SUV(N)
• Dynamical mass generation• the presence of p, K, h
as NG bosons
SSB
K. Ozawa, Hadrons in nuclear medium
Puzzles in hadron physics• Missing resonances.• States cannot be easily explained by a quark model.
(e.g. Roper, L(1405), …)• Unexpected states. (e.g. narrow resonances at Belle)
2014/10/25 7
What we want to know?• What are inside structures of hadron?
Constituent quark?, Di-quark? Hadron as a constituent of hadron?
• How can hadrons interact with other hadrons ?• How mass is dynamically generated?
K. Ozawa, Hadrons in nuclear medium
Aspects of hadron physics
2014/10/25 K. Ozawa, Hadrons in nuclear medium 8
Inside Structure
QCD Phase Diagram
Hadron-Hadron Interaction
Building blocks? Interaction btw building-blocks in hadron
QCD medium and hadron properties
Interaction btw “color-less” particles
These aspects are strongly related,
especially in interpretations of
experimental results
We should aware of the difference
2014/10/25 K. Ozawa, Hadrons in nuclear medium 9
• Fundamental Reactions– g+N, N+N, p+N, e+N
• Nuclear Target – g+A, N+A, p+A, e+A
• Heavy Ion Collisions
Inside Structure
Hadron-Hadron
Interaction
QCD Phase
Diagram
• When we found an interesting object for our physics, then we should take all data below, because effects of these aspects should be figured out.– Each reaction and energy has a suitable physics explanation.
• If we could have a “standard model” for all reactions, it would be happy. However, it’s difficult, I think.
h’
2014/10/25 K. Ozawa, Hadrons in nuclear medium 10
• Physics:– It is a very interesting object in terms of partial restoration of chiral
symmetry• (I omitted other interesting object, p meson. Sorry.)
• Past, On-going, and Future Experiments:– Fundamental reactions
• pp @ COSY • gp, gd @ BGOegg – Spring-8• pp @ J-PARC (LOI)
– Nuclear target• p-He results @ COSY• 12C(p,d) reaction @ GSI and Future FAIR• g-C reaction @ BGOegg
– Heavy Ion Collisions• Large mass reduction in AA collisions at sNN = 200 GeV
– T. Csorgo et al., Phys. Rev. Lett. 105 (2010) 182301
K. Ozawa, Hadrons in nuclear medium 11
LOI: Measurements of π-p→η n ′• h’ meson is interesting
– Related to UA(1) anormaly– Large mass reduction is expected in nucleus, theoretically.
• η N interaction is important as a basic information, however, ′current experimental data seems contradictive– weakly interacting?
←COSY-11 (pp→ppη′), |aη N′ |~0.1fm– strongly attractive?
←near-threshold cross section of π-p→η n ′ reaction (against s-wave behavior: σ/p*=const.)
• indicating N* resonance near η N threshold?′
• Precise measurement at J-PARC– with γ detector and neutron counter
2014/10/25
PLB482, 356 (2000)
arXiv: 1109.0394PLB709, 87 (2012)
Nuovo Cimento A75, 163 (1983)
H. Fujioka
h’
2014/10/25 K. Ozawa, Hadrons in nuclear medium 12
• Physics:– It is a very interesting object in terms of partial restoration of chiral
symmetry• (I omitted other interesting object, p meson. Sorry.)
• Past, On-going, and Future Experiments:– Fundamental reactions
• pp @ COSY • gp, gd @ BGOegg – Spring-8• pp @ J-PARC (LOI)
– Nuclear target• p-He results @ COSY• 12C(p,d) reaction @ GSI and Future FAIR• g-C reaction @ BGOegg
– Heavy Ion Collisions• Large mass reduction in AA collisions at sNN = 200 GeV
– T. Csorgo et al., Phys. Rev. Lett. 105 (2010) 182301 • We should keep our collaborations and competitions• Guidance of theorists may must be important
L(1405) and K-pp• Physics:
– Interplay of hadron-hadron interactions and inside structure
• Experiments:– Many many experiments
• At J-PARC, E15 and E31 are on-going.
– Another results from J-PARC • Y. Ichikawa et al., Inclusive spectrum of the d(π+, K+) reaction
at 1.69 GeV/c, Prog. Theor. Exp. Phys. (2014) 101D03– Inclusive spectrum only. Exclusive histogram and ratio will come next.
– Future physics extension• K-K-pp
2014/10/25 K. Ozawa, Hadrons in nuclear medium 13
Future exp: K-K-pp bound states
• K-pp bound states are studied at K1.8/BR (E27/E15). As a physics extension, K-K-pp bound states are also predicted theoretically.
• Produce the system using high momentum (~8GeV/c) proton beam and double L* production.
2014/10/25 K. Ozawa, Hadrons in nuclear medium 14
Experiment
Missing Mass
Invariant Mass
F. Sakuma
Vector Mesons in nucleus • It seems Jido-san said “We don’t need condensates!”. However,
Let’s start with a discussion btw vector mesons and condensates
2014/10/25 K. Ozawa, Hadrons in nuclear medium 15
Relations between mass spectra of V-AV mesons and condensates is developed using a sum rule.
Hatsuda, Koike and Lee, Nucl. Phys. B394 (1993) 221Kapusta and Shuryak, Phys. Rev. D49 (1994) 4694
In free space, there is a good measurement done by ALEPH group.( ALEPH, Phys. Rep. 421(2005) 191 )
However, identifications of Axial-Vector mesons in nucleus and high-temperature matter are difficult due to its large width.
QCD sum rule is developed to connect vector meson mass spectrum only and condensates under some assumptions
T. Hatsuda and S.H. Lee, PRC 46 (1992) R34I’m interested in measurements of vector mesons
w meson• Physics:
– Condensates in nucleus– Interplay of w-N interactions and nuclear matter effects
• Experiments– gN @ FOREST-ELPH
• Near threshold w meson photo production, R. Hashimoto et al., Few-Body Syst. (2013) 54:1135
– gA @ CB-ELSA TAPS• No mass modification (Phys. Rev. C 82 (2010) 035209)• Large width of w meson in nucleus is suggested by measurements of A-dependence
of production cross section. (Phys. Rev. Lett. 100 (2008) 192302)• Recently, they also report a depth of real part potential (Phys. Lett. B736 (2014) 26)
– Heavy Ions• As far as I know, no significant results for w mesons• HADES collaboration reports mass modification of r even in pp and AA reactions and
they study effects of N* (Phys. Rev. C84 (2011) 014902, Eur. Phys. J. A48(2012) 64)
– pA @ J-PARC• Good opportunity to study BOTH nuclear matter effects and w-N interactions,
simultaneously. 2014/10/25 K. Ozawa, Hadrons in nuclear medium 16
w in nucleus and w-N Interaction(E26)
• Measurements of w meson in nucleus using p0 g decays using an exclusive reaction
– Focus on low momentum w meson and clear mass spectrum in nucleus
– Missing mass spectroscopy and detection of an exclusive production process using the forward
• Beam Momentum is 2.0 GeV/c. – To generate w meson at rest– K1.8 or High-p
K. Ozawa, Hadrons in nuclear medium 17
g g
gp
w p0
n
p-A + n+X
p0g
2ppm
g detector around the target
Neutron counter at the forward direction
• Detectors– High precision g detector
• DE/E = ~ 1% @ Eg = 1 GeV
– Neutron counter• DTOF ~ 80ps
2014/10/25
f meson• Physics:
– Condensates of strangeness in nucleus
• Experiments:– gA @ LEPS
• Large Width (Phys. Lett. B608 (2005) 215)
– gA @ CLAS• Large Width (Phys. Rev. Lett. 105 (2010) 112301)
– Heavy Ions• Strangeness has less absorption in high temperature matter
– For example, see Journal of Physics: Conference Series 509 (2014) 012002
– pA @ KEK-PS & J-PARC• Di-electron mass spectrum• Experimentally, only hadron beam can measure mass spectra of f mesons
clearly.
2014/10/25 K. Ozawa, Hadrons in nuclear medium 18
Measurements of f meson
2014/10/25 K. Ozawa, Hadrons in nuclear medium 19
R. Muto et al., PRL 98(2007) 042581
Indication of mass modification!
Cu
bg<1.25 (Slow)
e+e- invariant mass
Decays inside nucleusDecays outside nucleus
fmeson has mass modification
Modification is shown as an Excess
fmeson has NO mass modification
Blue line shows expected line shape including all experimental effectswo mass modification
New Goal
2014/10/25 20
Pb
Proton
A clear shifted peak needs to be identified to establish QCD-originated effects
Momentum Dependence w large statistics
E325 resultsExtrapolate
K. Ozawa, Hadrons in nuclear medium
Experimental set up
2014/10/25 21
Cope with 1010 per spill beam intensity (x10)Extended acceptance (90 in vertical) (x5)Increase cross section (x2)
K. Ozawa, Hadrons in nuclear medium
Construct a new beam line and new spectrometer
Deliver 1010 per spill proton beam Primary proton (30GeV) beam
New high momentum beam line
29: E f bound state?
2014/10/25 K. Ozawa, Hadrons in nuclear medium
ssuud
K+
Λ
Φ
p ud
s
us
fp -> K+L
pp -> ff
22
Mass shift of f in nucleus can produce a bound state?
Production
Detection
J. Yamagata-Sekihara, D. Cabrera, M. J. Vicednte-Vacas, S. Hirenzaki; 'Formation of Φ mesic nuclei'; Progress of Theoretical Physics 124, 147-162 (2010).
H. Ohnishi
Charm
• Physics:– Understand internal structure and interactions of “light” hadrons through Heavy
flavor hadrons
• Reactions:– (We should find a suitable reaction. Generated charm have a large momentum
due to a kinematics. Two step interactions should be considered)• DN interaction, Charmed Deuteron• Heavy Flavor in nucleus
– High Energy, High Luminosity ee collisions• Several new states are found
– Heavy Ion Collisions • Charm quarks are also thermalized in high-temperature hadronic matter. Production can
be affected by quark interactions.– Example: Lc/D0 ratio increasment, S.H. Lee et al., PRL 100 (2008)222301 – Exotic Hadrons in HI, S. Cho et al.(ExHIC Col.), PRC84(2011) 064910
– Charmed Baryon Spectroscopy • Di-quark correlation
2014/10/25 K. Ozawa, Hadrons in nuclear medium 23
Di-quark correlation• One of possible strong effects is a quark-quark (Di-quark)
correlationColor-Magnetic Interaction of two quarks
VCMI ~ [as/(mimj)]*(li,lj)(si,sj)
“Good Diquark”: Strong Attraction
VCMI(1S0, 3c) = 1/2*VCMI(1S0, 1c)
[qq] [ qq]
• Diquarks are emerged due to the color magnetic interaction between two quarks.
• The so-called “good diquark” has a color anti-symmetric 3bar and spin singlet configuration. It’s strong enough.
• One expects that a “good diquark” may be formed in a baryon.2014/10/25 K. Ozawa, Hadrons in nuclear medium 24
Emergent DiquarksBaryons as well as Mesons seem to be well described by a
Rotating String Configuration with a universal string tension.
“diquark”in low-lying modes
2014/10/25 K. Ozawa, Hadrons in nuclear medium 25
qA diquark-quark picture of baryons seems valid in low-lying modesHowever, it is difficult to study strength of a di-quark correlation only using light quarks, because all combination of qq contribute and interfere.
Charmed baryon spectroscopy (E50)• Missing mass spectroscopy of excited charmed baryon using pp
-> D*X reactions to study a di-quark correlation in a baryon
K. Ozawa, 20/May/2014 26
Level structure of Charmed BaryonExperiment
Expected results
Current design of the spectrometer
Physics is approvedDetector R&D is just started.
Physics extension w the same technique• The charm baryon experiment introduces new experimental
techniques– Multi-particle measurements in the forward region– Missing mass measurements in relatively high momentum region
• K/p separation up to 10 GeV/c
– High precision measurements
2014/10/25 27
p
virtual p, K
N*, D*, Y* (slow)
high-p π r, K* (fast)
• Such new features open new experiments also in light quark .• Production of Baryon
resonance is well controlled.• Study further dependences
on momentum and reaction. K. Ozawa, Hadrons in nuclear medium
T. Ishikawa
Summary• Hadron Experimental Facility at J-PARC has following
beams
• Several experiments are on-going and planned. • Please make our facility (and related facilities) productive
as much as possible!
2014/10/25 K. Ozawa, Hadrons in nuclear medium 28
Name Species Energy IntensityK1.8 p±, K± < 2.0 GeV/c ~105 Hz for K+
K1.8BR p±, K± < 1.0 GeV/c ~ 104 Hz for K+
K1.1 p±, K± < 1.1 GeV/c ~ 104 Hz for K+
High-pproton 30GeV ~ 1010 Hz
Unseparated < 20GeV/c ~ 108 Hz
FUTURE UPGRADE OF THE FACILITY
2014/10/25 K. Ozawa, Hadrons in nuclear medium 29
2014/10/25 K. Ozawa, Hadrons in nuclear medium 30
2014/10/25 K. Ozawa, Hadrons in nuclear medium 31
+
Summary of Beam line
K10 (π,K 4 GeV/c p,pbar 10 GeV/c)HRHI (π < 2GeV/c)K1.1 (π,K,p < 1.1 GeV/c )
After Hall extractionK1.8 (π,K,p < 1.8 GeV/c)K1.8BR (π,K,p < 1.1 GeV/c)High-p ( 30 GeV proton,
< 20 GeV/c unseparated )
Existing
Physics with High-p Kaon• Ξc Spectroscopy
– Investigate Strangeness and Charm sector– K- + p -> Ξc + D- (Production Threshold: 10 GeV/c)– Use the same spectrometer with charm baryon
spectroscopy. Experimental issues, such as yield, background, resolutions, are being evaluated.
• Charmed exotic baryons– Qcs can be searched using a similar reaction.
– K- + p -> Qcs + D+
2014/10/25 K. Ozawa, Hadrons in nuclear medium 32
Future: Heavy Ion Beam
2014/10/25 K. Ozawa, Hadrons in nuclear medium 33
f in nucleus using Inverse Kinematics• Beam & Target
– 1010 ions per second 10A GeV– 40 cm H2 target ( 5% Interaction Length)
• cf. KEK-PS E325 case, 12 Gev 3 x 108 protons per sec. on 0.2 % interaction length target (Cu)
• If we assume a similar production cross section, ~1000 times larger statistics can be expected
• Production of vector meson– Maximum momentum of produced vector mesons is 9.5 GeV/c– Velocity (b) at the nuclear rest frame is 0.013
• Small enough
• Decay Measurements– Muon
• Enough momentum to identify muon due to a Lorentz boost– Acceptance is in Forward region
• 0.035 < θ < 0.14 radian, 100% particle ID• 30 % of f mesons are detected
342014/10/25 K. Ozawa, Hadrons in nuclear medium
BACK UP
2014/10/25 K. Ozawa, Hadrons in nuclear medium 35
New Beam Line is under construction
Construction of New Beam Line is on-going. Multi Purpose beam line for following beams
Primary Proton Beam (30GeV), 1010-12 per spillHigh Momentum un-separated secondary beam (20GeV/c), 108 per spillPrimary Proton Beam (8GeV) for COMET
PhysicsHadrons in nucleusHadron spectroscopy mu-e conversion (COMET)
2014/10/25 36K. Ozawa, Hadrons in nuclear medium
In this lecture, I will introduce new experiments using a new beam line.
KL
K1.1BR
North side
South sideH
igh
Mom
en
tum
SKS
K1.8BR
2014/10/25 K. Ozawa, Hadrons in nuclear medium 37
Observables
2014/10/25 K. Ozawa, Hadrons in nuclear medium 38
However, the quark condensate is not an observable and one need to find observables which are related to the quark condensate.
We need to find out observables related to quark condensates.Relations between mass spectra of V-AV mesons and condensates is developed using a sum rule.
Hatsuda, Koike and Lee, Nucl. Phys. B394 (1993) 221Kapusta and Shuryak, Phys. Rev. D49 (1994) 4694
In free space, there is a good measurement done by ALEPH group.( ALEPH, Phys. Rep. 421(2005) 191 ) See the next slide.
Condensates and spectra
2014/10/25 K. Ozawa, Hadrons in nuclear medium 39
ALEPH, Phys. Rep. 421(2005) 191
QCD Sum rule
2014/10/25 K. Ozawa, Hadrons in nuclear medium 40
q
q
Vacuum Vacuum
QCD sum rule
Average of Imaginary part of P(w2)
vector meson spectral function
T.Hatsuda and S.H. Lee,PRC 46 (1992) R34
03.0;10
*
B
V
V
m
m
Prediction
Spectrum
mV
Theoretical Assumption
Example:
Measurements of axial vector mesons in a medium is difficult.Different type of sum rule is proposed.
Measurements of vector mesons can be done in nucleus and high energy collisions.
Current status of experiments
• High energy heavy ion collisions– SPS-NA60 (PRL 96 (2006) 162302)
• Modification of r meson due to hadronic effects– RHIC-PHENIX (PRC81(2010) 034911)
• Origin of the enhancement is under discussion
• Nuclear targets– CBELSA/TAPS (Phys.Rev. C82 (2010) 035209)
• Modification of w is not observed– J-LAB CLAS G7 (PRL 99 (2007) 262302)
• Mass broadening of r due to hadronic effects– KEK-PS E325 (PRL 96 (2006) 092301)
• Peak shift and width broadening of /r w
2014/10/25 41
Most measurements are done for /r w mesons
Large uncertainty in background subtraction method
K. Ozawa, Hadrons in nuclear medium
Several hadronic and experimental effects cause difficulties in /r w measurements.
How about f meson?• /r w
– Dynamical mass contribution is dominantMp ~ 130 MeV/c2 Mr ~ 770 MeV/c2
– Large hadronic effects and background issues are large• f
– Still, dynamical mass contribution is dominantMh ~ 550 MeV/c2 Mf ~ 1020 MeV/c2
– Narrow width ( 4.3 MeV/c2)• Small background issue
– Small effects of hadron-hadron interactions• e.g. Binding energy of fN is 1.8 MeV (Phys. Rev. C 63(2001) 022201R)
2014/10/25 42
To see QCD-originated effects, f meson is the most promising probe.
K. Ozawa, Hadrons in nuclear medium
KEK-PS E325 Experiment• Finite density matter• Stable system• Saturated density
Measure Vector meson spectrum
43432014/10/25 K. Ozawa, Hadrons in nuclear medium
Use Nucleus
Generate vector mesons using proton beamMeson mass spectrum in nucleus can be measured using decays and compared to the prediction.Leptonic (e+e-) decay is suitable, since
lepton doesn’t have final state interaction.
T.Hatsuda and S. Lee,PRC 46 (1992) R34
03.0;10
*
B
V
V
m
m
Prediction
Experimental Setup
2014/10/25 K. Ozawa, Hadrons in nuclear medium 44
12 GeV proton induced. p+A f + X
Electrons from f decays are detected.
KEK E325
E325 Spectrometer
2014/10/25 K. Ozawa, Hadrons in nuclear medium 45
2014/10/25 K. Ozawa, Hadrons in nuclear medium 46
Target/Momentum dep.bg<1.25 (Slow) 1.25<bg<1.75
Only one momentum bin shows a mass modification under the current statistics.
To see clear mass modification, significantly larger statistics are required.
e+e- invariant mass
Two nuclear targets:Carbon & CopperInside-decay increases in large nucleus
Momentum binSlowly moving f mesons have larger chance to decay inside nucleus
Same as previous slide
Excess
What can be achieved?
2014/10/25 K. Ozawa, Hadrons in nuclear medium 47
Pb
fModified f
[GeV/c2]
f from Proton
Invariant mass in medium
ff
ff
ff
ff
p dep.
High resolution
Dispersion relation
Next step
2014/10/25 K. Ozawa, Hadrons in nuclear medium 48
Then, calculate quark condensate using QCD sum rule.
Experimental requirements
1. High statics2. Good mass resolution
Average of Imaginary part of P(w2)
Assumed Spectrum
Evaluate quark condensate directly.
Replace by average of measured spectra
p
Detector components
2014/10/25 K. Ozawa, Hadrons in nuclear medium 49
Tracker~Position resolution 100μmHigh Rate(5kHz/mm2)Small radiation length(~0.1% per 1 chamber)
Electron identificationLarge acceptanceHigh pion rejection @ 90% e-eff.
100 @ Gas Cherenkov25 @ EMCal
R&D Items
2014/10/25 K. Ozawa, Hadrons in nuclear medium 50
Develop 1 detector unit and make 26 units.① GEM foil
③ Hadron Blind detectorGas Cherenkov for electron-ID
② GEM Tracker
Ionization (Drift gap)+ Multiplication (GEM)
High rate capability + 2D strip readout
CsI + GEMphoto-cathode
50cm gas(CF4) radiator~ 32 p.e. expected
CF4 also for multiplication in GEM
Beam test results of prototype detectors (2012)
100x100 200x200 300x300
10 p.e.
QE upto 40%
Required position
resolution (~100m) is
achieved
UV Cherenkov
photons are
detected with
CsI-evaporated
LCP-GEM
and CF4 gas
● Large size (300x300mm) PI- and LCP-GEM are successfully worked for a electron beam– Stability and response for a pion beam should be checked at J-PARC.
● GEM Tracker is successfully worked. ● Improvement of the photo-detection efficiency of HBD is on going.
GEM Tracker
HBD (Hadron-Blind Cherenkov detector )
2014/10/25 K. Ozawa, Hadrons in nuclear medium 51
GEM Tracker : first prod. type is testedislands for Y-strip(Ni plated)
X-strip(Ni plated)
Y-strip
200mm
125mm
x
Y
island
100mm
Y.Komatsu, NIM A 732(2013)241
BVH type 2D R/O PCB2014/10/25 K. Ozawa, Hadrons in nuclear medium 52
53
HBD @ J-PARC
2014/10/25 K. Ozawa, Hadrons in nuclear mediumCerenkov blob, f ~34mm
Electron
HBD (Hadron Blind Detector) ● Test @ J-PARC K1.1BR in 2013/Jan (T47)
● pion rejection is improved with a higher gain of new PI-GEM and smaller-size readout pad
– measure the distributed charge: selecting 3 fired pads or more• → pion rejection factor 100 with e-efficiency 70% achieved, same level as
PHENIX, in spite of the less #p.e.
e-eff. 70%
rejection>100
2014/10/25 K. Ozawa, Hadrons in nuclear medium 54
Emergent DiquarksBaryons as well as Mesons seem to be well described by a
Rotating String Configuration with a universal string tension.
M2~ *W LA distance of [qq]-q/ q-q increases as L increases.
q
q
2014/10/25 K. Ozawa, Hadrons in nuclear medium 55
q
L L
Emergent Diquarks
0 1 2 3 4 5 6 70
1
2
3
4
5
6
7
8
9
10
NDeltaLambdaSigmaXi
0 1 2 3 4 5 6 70
1
2
3
4
5
6
7
8
9
10
rho/aomega/fphi/fK*
Baryons Mesons
LL
M2 (
GeV
2 ) M2 1.1∝ L M2 1.1∝ L
Baryons as well as Mesons seem to be well described by a Rotating String Configuration with a universal string tension.
2014/10/25 56K. Ozawa, Hadrons in nuclear medium
Experiment• Observable is a production cross section of vector meson as a
function of t.• Charmed baryon spectrometer will be used also for this
experiment. There is enough acceptance. Missing mass resolution of 10 MeV/c2 can be achieved.
2014/10/25 K. Ozawa, Hadrons in nuclear medium 57
Measurements of K* production are also under discussions to investigate strange
quark sector.
By T. Ishikawa
Muon decays of f mesons• Simple calculation for the easiest
case– f mesons are produced in the beam
direction with a momentum of 9.5 GeV/c
– f mesons are decayed into muon pairs isotropically at the f rest frame
• Momentum and emitted angle of muons are calculated– Momentum distribution is almost
flat • Large fraction has enough momentum
– Muons are generated in the forward region
• Acceptance is calculated– 0.035 < θ < 0.14 radian, 100%
particle ID– 30 % of f mesons are detected
2014/10/25 K. Ozawa, Hadrons in nuclear medium 58
Momentum distribution of muons from f decays
50 10 [GeV/c]
A.U
.
0.50 1 [rad]
A.U
.
Angle distribution of muons from f decays