status and hadron physics program of j-parc k. ozawa (kek)
Post on 18-Dec-2015
217 Views
Preview:
TRANSCRIPT
Status and hadron physics program of J-PARC
K. Ozawa (KEK)
Contents
• Status of J-PARC– Effects of the earth quake
• Physics program– Penta-quark search – KN & KNN bound state– Meson mass in nucleus
31/05/2012 2MESON2012, K. Ozawa
J-PARC (Japan Proton Accelerator Research Complex)
J-PARC (Japan Proton Accelerator Research Complex)
Tokai, JapanTokai, Japan
50 (30) GeV Synchrotron (15 mA)
400 MeV Linac (350m)
3 GeV Synchrotron (333 mA)
Material and Biological Science Facility
World-highest beam intensity : ~1 MW x10 of BNL-AGS, x100 of KEK-PS
Neutrino Facility
Hadron Hall60m x 56m
31/05/2012 3MESON2012, K. Ozawa
Status of J-PARC
• All components are back by the last December– The first beam after the earthquake is delivered to
Neutrino on Dec 24.
• Physics data are collected in February– Penta quark search with a different beam energy
• Next Physics run will start on June 9th!
31/05/2012 4MESON2012, K. Ozawa
Effects of the earth quake
31/05/2012 5MESON2012, K. Ozawa
Building itself is almost OK, since it is fixed to a solid rock under the ground using piles. However, ground level has large effects like these photos.
All damages are fixed.
Magnets are moved – re-aligned!
31/05/2012 6MESON2012, K. Ozawa
Main Ring
Not only recover, Improvements!
SX collimator to localize residual activation
Solenoid coils to improve duty factor in Slow extraction.
SX collimator
31/05/2012 7MESON2012, K. Ozawa
PHYSICS PROGRAM
31/05/2012 8MESON2012, K. Ozawa
Nuclear & Hadron Physics at J-PARC
,L X N
ZL, S Hypernuclei
LL, X Hypernuclei
Stra
ngen
ess
0
Hypernuclei
-1
-2
Proton Beam
K1.8
KL
K1.1BR
High p (not yet)SKS
K1.8BRK1.1
d
uu
d
s
Pentaquark +He6
Free quarks Boundquarks
Why are bound quarks haevier ?
Quark
Mass without Mass PuzzleKaonic nucleusKaonic atom
X ray
K−
Implantation ofKaon and the
nuclear shrinkage
K meson
31/05/2012 9MESON2012, K. Ozawa
KL
K1.1BR
North side
South sideH
igh
Mom
en
tum
SKS
K1.8BR
SKS Spectrometer
Q10 Q11
Q12
Q13
D4
E19:Penta quark - results 2010 data
No peak of Q+ was observed.
U.L. (90%CL) 0.26mb/sr (2- 14°) in 1.51- 1.55GeV/c2
U.L.(90%CL) of GQ
0.72 MeV (1/2+) 3.1 MeV (1/2-)
Search for the Θ+ via the p+π-→K-+X Reaction at 1.97GeV/c
arXiv:1203.3604
Submitted to PRLPositive comment, revised version is submitted
31/05/2012 12MESON2012, K. Ozawa
• Q+ RUN at 2.0 GeV/c 8.7 ×1010 p-
• S+ RUN at 1.37 GeV/c 8.5 ×108 p+
• S- RUN at 1.37 GeV/c 4.8 ×109 p-
• S- RUN at 1.45 GeV/c 8.8 ×109 p-
S- at 1.37GeV/c
DM=1.87MeV/c2(FWHM) ⇔ 1.86MeV/c2(FWHM) 1st step RUN
13
Penta quark – additional data E19 2nd step Run at 2.0 GeV/c was completed after
the earthquake. Beam momentum is slightly increased to have larger cross
section for penta quark production Except for the beam momentum, experimental setup is the
same as the previous run 8.7×1010 p- on Liq-H2 with 1.7M/spill beam
(7.8×1010, 1.1M/spill at 1.92GeV/c in 2010 RUN)
31/05/2012 MESON2012, K. Ozawa
E15:KN Interaction Study by Nuclear Bound-States
14
Physics motivation
Experimental setup
Experimental scheme
Experiment is ready for beam31/05/2012 MESON2012, K. Ozawa
Results of the last run (Cont’d)
CDS and Liquid Helium target system successfully worked
Ready to explore kaonic-nuclei @ K1.8BR
XY plane YZ plane
Liquid 4He insideTarget-image together with material around
has been reconstructed by the CDSCharged particles from the target have been successfully identified by the CDS
15
pp- invariant-mass spectra reconstructed
by the CDSL
~10,000 Ls have been accumulated31/05/2012 MESON2012, K. Ozawa
16
E27: Search for “K-pp” bound state in the d(p+,K+)X reaction• “K-pp” is produced through L* doorway in the d(p+,K+) reaction
• Semi-exclusive measurement by Range Counter Array (RCA) in order to suppress quasi-free B.G.– K-pp ® L p1, L ® p2 p-
– K-pp ® S0 p1, S0 ® (Lg) ® p2 p- g
– p+d ® L* K+ p1s, L* ® S p, S+ ® p2 p0
• Beam: 3M/spill beam– 3.6x104 L* /dayAssuming 1% trapping probability– 360 bound states/day ( inclusive )– ~45 events/10 days (exclusive)
with eRCA ~14% for two protons
np K-ppd
Λ*π+ K+
RCA
K+
p
31/05/2012 MESON2012, K. OzawaMissing mass d(π+,K+) [GeV/c2]
Momproton>350MeV/c
coun
ts (/
3M b
eam
・10d
ays
)
Expected point by FINUDA, DISTO
N
Z
Nu ~ Nd ~ Ns
Hig
h D
ensi
ty
Strangeness in neutron stars ( r > 3 - 4 r0 )
Strange hadronic matter (A → ∞)
L, S Hypernuclei
LL, X ハイパー核
Stra
ngen
ess
0
-1
-2
“stable“
3D nuclear chartNext: Strangeness Nuclear Physics
(K-,K+) 、 E03,E05,E07
(p-,K+) 、 E10 、(K-,p-) 、 E13
→High density matter, Generalized nuclear force …
→First step to understand strangeness nuclear matter
As increasing of intensity,K beam experiment becomes feasible.Many experiments are already approved.31/05/2012 17MESON2012, K. Ozawa
Vector Meson mass in nucleus
• 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
2012/3/16 18
Clear measurements are required to clarify it.
Many measurements are already done
Large uncertainty in background subtraction method
Pionic atom is a good example and see Prof. Itahashi’s talk tomorrow.
Measurements of f meson at KEK-PS.
2012/3/16 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
The only one measurement on medium modification of f meson.
2031/05/2012
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
MESON2012, K. Ozawa
Next Goal
31/05/2012 21
Pb
Proton
A clear shifted peak needs to be identified to establish QCD-originated effects
Momentum Dependence
E325 results Extrapolate
MESON2012, K. Ozawa100 times larger statistics are required.
Calc. with other models
31/05/2012 22
<0.5 0.5< <1.25 <0.5 bg bg bg 0.5< <1.25bg
Cu
Pb
Pb
Cu
E325 Dm : 35 MeV(28 ~ 41) G : 15 MeV(10~23)
Oset, Ramos(NPA 679, 616)Dm : 10 MeV G : 15 MeV
Klingle, Waas, Weise (PLB431,254)Dm : 10 MeV G : 50 MeV
---Dm : 35 MeV G : 50 MeV
cf. Hatsuda, Lee (PRC46, 34)Dm : 12~44 MeV G : not estimated
blue: decays inside nuclei red: decays outside nuclei
Hadronic model
Hadronic model
MESON2012, K. OzawaAt J-PARC, clear mass spectra in nucleus will be obtained to compare with models.
Experiment
31/05/2012 23
Cope with 1010 per spill beam intensity (x10)Extended acceptance (90 in vertical) (x5)Increase cross section (x2)
MESON2012, K. Ozawa
Construct a new beam line and new spectrometer
Deliver 1010 per spill proton beam Primary proton (30GeV) beam
New high momentum beam line
Detector components
31/05/2012 24
100x100 200x200 300x300
Position resolution of 100m is achieved
GEM Tracker
HBD (Hadron-Blind Cherenkov detector )
Developments of detectors are almost done. Remaining issue is photo-electrons HBD (half of an expectation).
Read out electronics are being developed. Basically, combination of existing components.
The first production will be done by the next March.
Key Technology:CsI evaporated GEM as a photo cathodeQ.E. of 40% is achieved
MESON2012, K. Ozawa
29: E f bound state?
31/05/2012 MESON2012, K. Ozawa
ssuud
K+
Λ
Φ
p ud
s
us
fp -> K+L
pp -> ff
25
Mass shift of f in nucleus can produce a bound state?
Production
Detection
E26: Omega in nucleus
31/05/2012 26
g g
gp
w p0
n
p-A + n+X
p0g
2ppm
Measurements of w meson in nucleusProduction of w is also measuredFocus on low momentum w meson
ConstructNeutron counterGamma Detector
Beam Momentum is 2.0 GeV/cIt can be done at K1.8 and also at new high momentum beam line
MESON2012, K. Ozawa
H. Nagahiro et al, Calculation for 12C(p-, n)11Bw
Missing Mass(Bound state?)
Invariant Mass
Experiment for h
2008/3/6 NP08@Mito, K. Ozawa
LOI by K. Itahashi et. al Calc. by H. Nagahiro, D. Jido, S. Hirenzaki et. al
Forward neutron is detected.missing mass distribution is measured.
In addition, measurements of invariant mass of N* decay
Simulation
Summary
• J-PARC is recovered from damages of the earth quake. – Thanks for your helps and efforts.
• New data for penta quark search is already collected.
• An experiment for K bound state search is ready and will take data in this year.
• Many experiments will be done in few years including hyper nuclear physics, K-barN boundstates, mesons in nucleus, and more.
31/05/2012 28MESON2012, K. Ozawa
BACK UP
31/05/2012 29MESON2012, K. Ozawa
Run time: 19-22 Feb Beam PW: 3.3kw~ 6x108 K- on Target~25M events recorded
Results of the last run (Feb. 2012)
0.8 1 1.2 1.4 1.6 1.8 2 2.20
5000
10000
15000
20000
0.0
0.2
0.4
0.6
0.8
K- yield
K/π ratio
IF-V, MS (W)
K yi
eld
/1kW
/spi
ll
K/π
ratio
Ready to receive more than 10kW beam-powerParameters for Kaon tune have been produced
[ /spill ] 3.3kW 10kWbeam
intensity 100k 300k
K-
yield 33k 100k
E15 trig. rate 700 2.1k
expected350 400 450 500 550 600 650
0.01
0.1
1
10
100
1000 Beam/TMProton/TMPion/TMElectron/TMKaon/TMK-
p
p-
CM (A)
Yiel
d/TM
30
ESS=±250kV
beam-line commissioning for 1GeV/c K- was completed
31/05/2012 MESON2012, K. Ozawa
Mass spectra measurements
mr = m0 (1 - /0) for = 0.0931/05/2012 MESON2012, K. Ozawa 31
Induce 12 GeV protons to Carbon and Cupper target, generate vector mesons, and detect e+e- decays with large acceptance spectrometer.
Cu we+e-
re+e-
w/ /r f
The excess over the known hadronic sources on the low mass side of w peak has been observed.
M. Naruki et al., PRL 96 (2006) 092301
KEK E325, / r w e+e-
CLAS g7a @ J-Lab
31/05/2012 MESON2012, K. Ozawa 32
Induce photons to Liquid dueterium, Carbon, Titanium and Iron targets, generate vector mesons, and detect e+e- decays with large acceptance spectrometer.
R. Nasseripour et al., PRL 99 (2007) 262302
mr = m0 (1 - /0) for = 0.02 ± 0.02
No peak shift of r
Only broadening is observed
g w/ /r f
Contradiction?
• Difference is significant
• What can cause the difference?– Different production process– Peak shift caused by phase
space effects in pA?• Need spectral function of r
without nuclear matter effects
Note: • similar momentum range• E325 can go lower slightly
31/05/2012 MESON2012, K. Ozawa 33
In addition, background issue is pointed out by CLAS
CLASKEK
Approved experiments(Co- )Spokespersons Affi l i ati on Ti t l e of the experi ment at Hadron Experi mental Hal l BeamL. Day1 Beam MR Power
[kW] [hours]
E03 K. Tani da SNU Measurement of X rays f rom X- Atom K1. 8 K- 270 800
E05 T. Nagae Kyoto U Spectroscopi c Study of X-Hypernucl eus, 12XBe, vi a the 12C(K- , K+) Reacti on K1. 8 yes K- 270 672
E07 K. I mai , K. Nakazawa,H. Tamura
J AEA, Gi fu U,Tohoku U
Systemati c Study of Doubl e Strangeness System wi th an Emul si on-counter Hybri dMethod K1. 8 K- >50 600
E10 A. Sakaguchi ,T. Fukuda Osaka U Producti on of Nuetron-Ri ch Λ -Hypernucl ei wi th the Doubl e Charge-Exchange
Reacti ons K1. 8 pi - 5 1008
E13 H. Tamura Tohoku U Gamma-ray spectroscopy of l i ght hypernucl ei K1. 8 yes K- 270 1000
E18 H. Bhang, H. Outa,H. Park
SNU, RI KEN,KRI SS
Coi nci dence Measurement of the Weak Decay of 12LC and the three-body weak
i nteracti on processK1. 8 pi + 5 576
E19 M. Naruki KEK Hi gh- resol uti on Search for Q+ Pentaquark i n -p -> K-X Reacti ons K1. 8 yes pi - 5 160
E27 T. Nagae Kyoto U Search for a nucl ear Kbar bound state K-pp i n the d(π +, K+) reacti on K1. 8 pi + 5 960
E08 A. Krutenkova I TEP Pi on doubl e charge exchange on oxygen at J -PARC K1. 8 pi + 5 240
E22 S. Aj i mura,A. Sakaguchi Osaka U Excl usi ve Study on the Lambda-N Weak I nteracti on i n A=4 Lambda-Hypernucl ei
(Revi sed f rom I ni t i al P10) K1. 8 pi + 5 672
E26 K. Ozawa KEK Search for ω -meson nucl ear bound states i n the π -+AZ -> n+(A-1)(Z-1) ω reacti on,and for ω mass modi fi cati on i n the i n-medi um ω ->π 0γ decay.
K1. 8 pi - 10 1600
E40 K. Mi wa Tohoku U Measurement of the cross secti ons of Σ p scatteri ngs K1. 8 pi -&+ 10 1056
E15 M. I wasaki , T. Nagae RI KEN, KyotoU A Search for deepl y-bound kaoni c nucl ear states by i n-fl i ght 3He(K- , n) reacti on K1. 8BR yes K- 270 924
E17 R. Hayano, H. Outa U Tokyo,RI KEN Preci si on spectroscopy of Kaoni c 3He 3d->2p X- rays K1. 8BR yes K- 5 840
P28 H. Fuj i oka Kyoto U Study of i sospi n dependence of kaon-nucl eus i nteracti on by i n-fl i ght3He(K- , n/ p) reacti ons K1. 8BR
E31 H. Noumi RCNP, Osaka U Spectroscopi c study of hyperon resonances bel ow KN threshol d vi a the (K- , n)reacti on on Deuteron
K1. 8BR K- 27 960
Stage 1 Stage 2 Running
K1.8
K1.8BR
As increasing the beam intensity,
ニュートリノとビームタイムを分け合って実験を行う。
加速器部と協力してビーム強度を増強する!
これからが新たな成果が出てくる時期!
top related