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)

Tokai, 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 +LLHe6

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

entum

SKS

K1.8BR

SKS Spectrometer

Q10 Q11

Q12Q13

D4

E19:Penta quark - results 2010 data

No peak of + was observed.

U.L. (90%CL) 0.26mb/sr (2－ 14°) in 1.51－ 1.55GeV/c2

U.L.(90%CL) of G

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

• + 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. Ozawa Missing mass d(π+,K+) [GeV/c2]

Momproton>350MeV/c

coun

ts (/

3M b

eam

・10da

ys )

Expected point by FINUDA, DISTO

N

Z

Nu ~ Nd ~ Ns

High

Den

sity

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

bg<0.5 0.5<bg<1.25 bg<0.5 0.5<bg<1.25

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 100mm 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

E29: f bound state?

31/05/2012 MESON2012, K. Ozawa

ssuud

K+

Λ

Φ

p ud

sus

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 ® w + n+X

gg

p0g

2ppm gpw +

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 6500.01

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 - r/r0) 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 - r/r0) 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 effectsNote:

• similar momentum range• E325 can go lower slightly

31/05/2012 MESON2012, K. Ozawa 33

In addition, background issue is pointed out by CLAS

CLAS KEK

Approved experiments(Co- )Spokespersons Affi l i at i on Ti tl 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 nteract i on process K1. 8 pi + 5 576

E19 M. Naruki KEK Hi gh- resol ut i on Search f or + Pentaquark i n p-p -> K-X Reacti ons K1. 8 yes pi - 5 160

E27 T. Nagae Kyoto U Search f or 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 nteract i 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 f or ω -meson nucl ear bound states i n the π -+AZ -> n+(A-1)(Z-1) ω react i on,and f or 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) react i 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 nteract i on by i n-fl i ght3He(K- , n/p) react i 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)react i 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！