Status and hadron physics program of JPARC K

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 MESON 2012, K. Ozawa 2

J-PARC Tokai, Japan (Japan Proton Accelerator Research Complex) Material and Biological Science Facility 400 Me. V Linac (350 m) 3 Ge. V Synchrotron (333 m. A) Neutrino Facility World-highest beam intensity : ~1 MW x 10 of BNL-AGS, x 100 of KEK-PS 31/05/2012 MESON 2012, K. Ozawa 50 (30) Ge. V Synchrotron (15 m. A) Hadron Hall 60 m x 56 m 3

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 9 th! 31/05/2012 MESON 2012, K. Ozawa 4

Effects of the earth quake 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. 31/05/2012 MESON 2012, K. Ozawa 5 All damages are fixed.

Magnets are moved – re-aligned! Main Ring 31/05/2012 MESON 2012, K. Ozawa 6

Not only recover, Improvements! SX collimator Solenoid coils to improve duty factor in Slow extraction. SX collimator to localize residual activation 31/05/2012 MESON 2012, K. Ozawa 7

PHYSICS PROGRAM 31/05/2012 MESON 2012, K. Ozawa 8

Nuclear & Hadron Physics at J-PARC Strangen ess Z d Hypernuclei u , X Hypernuclei Pentaquark + 6 He , S Hypernuclei -2 -1 0 s d u N , X SKS hp K 1. 8 BR . 1 B K 1. 1 R Quark am e B Free quarks Ｘray 31/05/2012 et) y t (no K 1 Implantation of Kaon and the nuclear shrinkage on t o Pr Hig KL K meson Ｋ− K 1. 8 Kaonic atom MESON 2012, K. Ozawa Kaonic nucleus Bound quarks Why are bound quarks haevier？ 9 Mass without Mass Puzzle

South side North side KL K 1. 8 BR R K 1. 1 B m entu Mom Hig h SKS

SKS Spectrometer Q 13 Q 12 D 4 Q 10 Q 11

E 19: Penta quark - results 2010 data Search for the Θ+ via the p+π-→K-+X Reaction at 1. 97 Ge. V/c No peak of + was observed. U. L. (90%CL) 0. 26 mb/sr (2－14°) in 1. 51－1. 55 Ge. V/c 2 U. L. (90%CL) of GQ 0. 72 Me. V (1/2+) 3. 1 Me. V (1/2 -) ar. Xiv: 1203. 3604 Submitted to PRL Positive comment, revised version is submitted 31/05/2012 MESON 2012, K. Ozawa 12

Penta quark – additional E 19 2 nd step Rundata at 2. 0 Ge. V/c was completed after n the earthquake. Beam momentum is slightly increased to have larger cross section for penta quark production ØExcept for the beam momentum, experimental setup is the same as the previous run Ø 8. 7× 1010 p- on Liq-H 2 with 1. 7 M/spill beam (7. 8× 1010, 1. 1 M/spill at 1. 92 Ge. V/c in 2010 RUN) Ø • + RUN at 2. 0 Ge. V/c • S+ RUN at 1. 37 Ge. V/c • S- RUN at 1. 45 Ge. V/c 8. 7 × 1010 p 8. 5 × 108 p+ 4. 8 × 109 p 8. 8 × 109 p- DM=1. 87 Me. V/c 2(FWHM) ⇔ 1. 86 Me. V/c 2(FWHM) 1 st step RUN 31/05/2012 MESON 2012, K. Ozawa Sat 1. 37 Ge. V/c 13

E 15: KN Interaction Study by Nuclear Bound-States Physics motivation Experimental scheme Experimental setup 31/05/2012 MESON 2012, K. Ozawa 14 Experiment is ready for beam

Results of the last run (Cont’d) XY plane YZ plane Liquid 4 He inside Target-image together with material around has been reconstructed by the CDS L 31/05/2012 pp- invariant-mass spectra reconstructed by the CDS Charged particles from the target have been successfully identified by the CDS Ø CDS and Liquid Helium target system successfully worked Ø Ready to explore kaonicnuclei @ K 1. 8 BR MESON 2012, K. Ozawa ~10, 000 s have been accumulated 15

E 27: Search for “K-pp” bound state in the d(p+, K+)X reaction • “K-pp” is produced through * doorway in the d(p+, K+) reaction π+ n p K+ Λ* K-pp d • Semi-exclusive measurement by Range Counter Array (RCA) in order to suppress quasi-free B. G. p- • Beam: 3 M/spill beam – 3. 6 x 104 * /day Assuming 1% trapping probability – 360 bound states/day ( inclusive ) – ~45 events/10 days (exclusive) 31/05/2012 with e. RCA ~14% for two protons MESON 2012, K. Ozawa counts (/3 M beam・ 10 days ) – p 1 , p 2 – K-pp S 0 p 1, S 0 ( g) p 2 p- g – p+d * K+ p 1 s, * S p, S+ p 2 p 0 K-pp K+ p RCA Momproton>350 Me. V/c Expected point by FINUDA, DISTO 16 Missing mass d(π+, K+) [Ge. V/c 2]

Next: Strangeness Nuclear Physics 3 D nuclear chart →High density matter, Generalized nuclear force … Nu ~ Nd ~ Ns →First step toinunderstand matter Strangeness neutron starsstrangeness ( r > 3 - 4 r 0 nuclear ) “stable“ High Density Strangeness Strange hadronic matter (A → ∞) , X ハイパー核 (K-, K+)、E 03, E 05, E 07 Z -2 -1 31/05/2012 0 , S Hypernuclei (p-, K+)、E 10、(K-, p-)、 E 13 N As increasing of intensity, K beam experiment becomes feasible. MESON 2012, K. Ozawa 17 Many experiments are already approved.

Vector Meson mass in nucleus Many measurements are already done • High energy heavy ion collisions – SPS-NA 60 (PRL 96 (2006) 162302) • Modification of r meson due to hadronic effects – RHIC-PHENIX (PRC 81(2010) 034911) • Origin of the enhancement is under discussion • Nuclear targets – CBELSA/TAPS (Phys. Rev. C 82 (2010) 035209) • Modification of w is not observed – J-LAB CLAS G 7 (PRL 99 (2007) 262302) • Mass broadening of r due to hadronic effects – KEK-PS E 325 (PRL 96 (2006) 092301) • Peak shift and width broadening of r/w Large uncertainty in background subtraction method Clear measurements are required to clarify it. 2012/3/16 18 Pionic atom is a good example and see Prof. Itahashi’s talk tomorrow.

Measurements of f meson at KEK-PS. The only one measurement on medium modification of f meson. b <1. 25 (Slow) Decays outside nucleus R. Muto et al. , PRL 98(2007) 042581 Decays inside nucleus Cu fmeson has NO mass modification fmeson has mass modification Blue line shows expected line shape including all experimental effects wo mass modification Modification is shown as an Excess e+e- invariant mass Indication of mass modification! 2012/3/16 19

Target/Momentum dep. b <1. 25 (Slow) 1. 25<b <1. 75 Two nuclear targets: Carbon & Copper Inside-decay increases in large nucleus Momentum bin Slowly moving f mesons have larger chance to decay inside nucleus Excess Same as previous slide Only one momentum bin shows a mass modification under the current statistics. To see clear mass modification, significantly larger statistics are required. 31/05/2012 e+e- invariant mass. MESON 2012, K. Ozawa 20

Next Goal A clear shifted peak needs to be identified to establish QCD-originated effects Momentum Dependence Pb E 325 results 31/05/2012 Proton Extrapolate MESON 2012, K. Ozawa statistics are required. 100 times larger 21

Calc. with other models bg<0. 5 E 325 Dm : 35 Me. V (28 ~ 41) G : 15 Me. V (10~23) cf. Hatsuda, Lee (PRC 46, 34) Dm : 12~44 Me. V G : not estimated --Dm : 35 Me. V G : 50 Me. V 0. 5<bg<1. 25 Cu bg<0. 5<bg<1. 25 Oset, Ramos (NPA 679, 616) Dm : 10 Me. V G : 15 Me. V Hadronic model Pb Cu Klingle, Waas, Weise (PLB 431, 254) Dm : 10 Me. V G : 50 Me. V Hadronic model Pb blue: decays inside nuclei red: decays outside nuclei MESON 2012, K. Ozawa 22 At 31/05/2012 J-PARC, clear mass spectra in nucleus will be obtained to compare with models.

Experiment Construct a new beam line and new spectrometer 1010 Deliver per spill proton beam Primary proton (30 Ge. V) beam Cope with 1010 per spill beam intensity (x 10) Extended acceptance (90 in vertical) (x 5) Increase cross section (x 2) New high momentum beam line 31/05/2012 MESON 2012, K. Ozawa 23

Detector components HBD (Hadron-Blind Cherenkov detector ) GEM Tracker 100 x 100 200 x 200 300 x 300 Position resolution of 100 m is achieved Key Technology: Cs. I evaporated GEM as a photo cathode Q. E. of 40% is achieved 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. 31/05/2012 MESON 2012, K. Ozawa 24

E 29: f bound state? Mass shift of f in nucleus can produce a bound state? Production pp -> ff Detection fp -> K+ s s u p u d Φ 31/05/2012 MESON 2012, K. Ozawa s K+ u s u d Λ 25

E 26: Omega in nucleus p n p 0 Measurements of w meson in nucleus Production of w is also measured Focus on low momentum meson H. Nagahiro et al, Calculation for 12 C(p-, n)11 Bw p-A + n+X p 0 Construct Neutron counter Gamma Detector Beam Momentum is 2. 0 Ge. V/c It can be done at K 1. 8 and also at new high momentum beam line 31/05/2012 Missing Mass (Bound state? ) Invariant Mass MESON 2012, K. Ozawa 26

Experiment for h 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. Simulation In addition, measurements of invariant mass of N* decay 2008/3/6 NP 08@Mito, K. Ozawa

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-bar. N boundstates, mesons in nucleus, and more. 31/05/2012 MESON 2012, K. Ozawa 28

BACK UP 31/05/2012 MESON 2012, K. Ozawa 29

Results of the last run (Feb. 2012) Run time: 19 -22 Feb Beam PW: 3. 3 kw ~ 6 x 108 K- on Target ~25 M events recorded beam-line commissioning for 1 Ge. V/c K- was completed Yield/TM 100 K- 10 p 1 0, 01 450 31/05/2012 CM (A) 550 0, 8 K- yield 0, 1 350 ESS=± 250 k. V 20000 650 [ /spill ] 3. 3 k. W 10 k. W 0, 6 beam intensity 100 k 300 k 10000 0, 4 Kyield 33 k 100 k 5000 0, 2 E 15 trig. rate 700 2. 1 k 0 0, 0 K/π ratio 15000 0, 8 1 1, 2 1, 4 K/π ratio p- Beam/TM Proton/TM Pion/TM Electron/TM Kaon/TM K yield /1 k. W/spill 1000 1, 6 1, 8 2 IF-V, MS (W)K. Ozawa MESON 2012, Parameters for Kaon tune have been produced 2, 2 expected Ready to receive more than 10 k. W beam-power 30

Mass spectra measurements KEK E 325, r/w e+e. Induce 12 Ge. V protons to Carbon and Cupper target, generate vector mesons, and detect e+e- decays with large acceptance spectrometer. M. Naruki et al. , PRL 96 (2006) 092301 Cu e+e- / /f e+e- The excess over the known hadronic sources on the low mass side of w peak has been observed. m = m 0 (1 - / 0) for = 0. 09 31/05/2012 MESON 2012, K. Ozawa 31

CLAS g 7 a @ J-Lab 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 / /f No peak shift of r Only broadening is observed 31/05/2012 MESON 2012, K. Ozawa m = m 0 (1 - / 0) for = 0. 02 ± 0. 02 32

Contradiction? • Difference is significant • What can cause the difference? CLAS KEK – Different production process – Peak shift caused by phase space effects in p. A? • Need spectral function of r without nuclear matter effects Note: • similar momentum range • E 325 can go lower slightly In addition, background issue is pointed out by CLAS 31/05/2012 MESON 2012, K. Ozawa 33

Approved experiments K 1. 8 BR Stage 1 Stage 2 Running