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 31/05/20122MESON2012, K. Ozawa

J-PARC (Japan Proton Accelerator Research Complex) Tokai, Japan 50 (30) GeV Synchrotron (15  A) 400 MeV Linac (350m) 3 GeV Synchrotron (333  A) Material and Biological Science Facility World-highest beam intensity : ~1 MW x10 of BNL-AGS, x100 of KEK-PS Neutrino Facility Hadron Hall 60m x 56m 31/05/20123MESON2012, 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 9 th ! 31/05/20124MESON2012, K. Ozawa

Effects of the earth quake 31/05/20125MESON2012, 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! 31/05/20126MESON2012, 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 31/05/20127MESON2012, K. Ozawa

PHYSICS PROGRAM 31/05/20128MESON2012, K. Ozawa

Nuclear & Hadron Physics at J-PARC  N Z ,  Hypernuclei ,  Hypernuclei Strangen ess 0 Hypernuclei -2 Proton Beam K1.8 KL K1.1BR High p (not yet) SKS K1.8BR K1.1 d u u d s Pentaquark  +  He 6 Free quarks Bound quarks Why are bound quarks haevier ？ Quark Mass without Mass Puzzle Kaonic nucleus Kaonic atom Ｘ ray Ｋ−Ｋ− Implantation of Kaon and the nuclear shrinkage K meson 31/05/20129MESON2012, K. Ozawa

KL K1.1BR North side South side High Momentum SKS K1.8BR

SKS Spectrometer Q10 Q11 Q12 Q13 D4

E19:Penta quark - results 2010 data No peak of   was observed. U.L. (90%CL) 0.26  b/sr (2 － 14°) in 1.51 － 1.55GeV/c 2 U.L.(90%CL) of     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: Submitted to PRL Positive comment, revised version is submitted 31/05/201212MESON2012, K. Ozawa

  RUN at 2.0 GeV/c 8.7      RUN at 1.37 GeV/c8.5  10 8     RUN at 1.37 GeV/c4.8  10 9     RUN at 1.45 GeV/c8.8  10 9     at 1.37GeV/c  M=1.87MeV/c 2 (FWHM) ⇔ 1.86MeV/c 2 (FWHM) 1 st step RUN 13 Penta quark – additional data E19 2 nd 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  8.7×10 10   on Liq-H 2 with 1.7M/spill beam (7.8×10 10, 1.1M/spill at 1.92GeV/c in 2010 RUN) 31/05/2012MESON2012, K. Ozawa

E15:KN Interaction Study by Nuclear Bound-States 14 Physics motivation Experimental setup Experimental scheme Experiment is ready for beam 31/05/2012MESON2012, K. Ozawa

Results of the last run (Cont’d)  CDS and Liquid Helium target system successfully worked  Ready to explore kaonic- K1.8BR XY planeYZ plane Liquid 4 He inside Target-image together with material around has been reconstructed by the CDS Charged particles from the target have been successfully identified by the CDS 15 p  - invariant-mass spectra reconstructed by the CDS  ~10,000  s have been accumulated 31/05/2012MESON2012, K. Ozawa

16 E27: Search for “K  pp” bound state in the d(  ,K  )X reaction “K  pp” is produced through  * doorway in the d(  ,K + ) reaction Semi-exclusive measurement by Range Counter Array (RCA) in order to suppress quasi-free B.G. – K  pp   p 1,   p 2   – K  pp   p 1,    (  )  p 2    –   d   * K + p 1s,  *   ,    p 2   Beam: 3M/spill beam – 3.6x10 4  * /day Assuming 1% trapping probability – 360 bound states/day ( inclusive ) –  45 events/10 days (exclusive) with  RCA  14% for two protons n p K - pp d Λ* π+π+ K+K+ RCA K+K+ p 31/05/2012MESON2012, K. Ozawa Missing mass d(π +,K + ) [GeV/c 2 ] Mom proton >350MeV/c counts (/3M beam ・ 10days ) Expected point by FINUDA, DISTO

N Z N u ~ N d ~ N s High Density Strangeness in neutron stars (  >  0 ) Strange hadronic matter (A → ∞) ,  Hypernuclei ,  ハイパー核 Strangeness 0 -2 “stable“ 3D nuclear chart Next: Strangeness Nuclear Physics (K -,K + ) 、 E03,E05,E07 (  -,K + ) 、 E10 、 (K -,  - ) 、 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. 31/05/201217MESON2012, K. Ozawa

Vector Meson mass in nucleus High energy heavy ion collisions – SPS-NA60 (PRL 96 (2006) ) Modification of  meson due to hadronic effects – RHIC-PHENIX (PRC81(2010) ) Origin of the enhancement is under discussion Nuclear targets – CBELSA/TAPS (Phys.Rev. C82 (2010) ) Modification of  is not observed – J-LAB CLAS G7 (PRL 99 (2007) ) Mass broadening of  due to hadronic effects – KEK-PS E325 (PRL 96 (2006) ) Peak shift and width broadening of  2012/3/1618 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  meson at KEK-PS. 2012/3/1619 R. Muto et al., PRL 98(2007) Indication of mass modification! Cu  <1.25 (Slow) e + e - invariant mass Decays inside nucleus Decays outside nucleus  meson has mass modification Modification is shown as an Excess  meson has NO mass modification Blue line shows expected line shape including all experimental effects wo mass modification The only one measurement on medium modification of  meson.

2031/05/2012 Target/Momentum dep.  <1.25 (Slow) 1.25<  <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 & Copper Inside-decay increases in large nucleus Momentum bin Slowly moving  mesons have larger chance to decay inside nucleus Same as previous slide Excess MESON2012, K. Ozawa

Next Goal 31/05/ Pb Proton A clear shifted peak needs to be identified to establish QCD-originated effects Momentum Dependence E325 results Extrapolate MESON2012, K. Ozawa 100 times larger statistics are required.

Calc. with other models 31/05/  Cu Pb Cu E325  m : 35 MeV (28 ~ 41)  : 15 MeV (10~23) Oset, Ramos (NPA 679, 616)  m : 10 MeV  : 15 MeV Klingle, Waas, Weise (PLB431,254)  m : 10 MeV  : 50 MeV ---  m : 35 MeV  : 50 MeV cf. Hatsuda, Lee (PRC46, 34)  m : 12~44 MeV  : not estimated blue: decays inside nuclei red: decays outside nuclei Hadronic model MESON2012, K. Ozawa At J-PARC, clear mass spectra in nucleus will be obtained to compare with models.

Experiment 31/05/ Cope with 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 per spill proton beam Primary proton (30GeV) beam New high momentum beam line

Detector components 31/05/ x x x300 Position resolution of 100  m 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 cathode Q.E. of 40% is achieved MESON2012, K. Ozawa

 bound state? 31/05/2012 MESON2012, K. Ozawa s s u u d K+ Λ Φ p u d s u s  p -> K +  pp ->  25 Mass shift of  in nucleus can produce a bound state? Production Detection

E26: Omega in nucleus 31/05/       n   A   + n+X  00 Measurements of  meson in nucleus Production of  is also measured Focus on low momentum  meson Construct Neutron counter Gamma Detector Beam Momentum is 2.0 GeV/c It can be done at K1.8 and also at new high momentum beam line MESON2012, K. Ozawa H. Nagahiro et al, Calculation for 12 C(  , n) 11 B  Missing Mass (Bound state?) Invariant Mass

Experiment for  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. 31/05/201228MESON2012, K. Ozawa

BACK UP 31/05/201229MESON2012, K. Ozawa

Run time: Feb Beam PW: 3.3kw ~ 6x10 8 K - on Target ~25M events recorded Results of the last run (Feb. 2012) Ready to receive more than 10kW beam-power Parameters for Kaon tune have been produced [ /spill ] 3.3kW10kW beam intensity 100k300k K - yield 33k100k E15 trig. rate k expected K-K- p -- CM (A) Yield/TM 30 ESS=±250kV beam-line commissioning for 1GeV/c K - was completed 31/05/2012MESON2012, K. Ozawa

Mass spectra measurements m  = m 0 (1 -   /  0 ) for  = /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 e+e-e+e- e+e-e+e-  /  The excess over the known hadronic sources on the low mass side of  peak has been observed. M. Naruki et al., PRL 96 (2006) KEK E325,  e + e -

CLAS 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) m  = m 0 (1 -   /  0 ) for  = 0.02 ± 0.02 No peak shift of  Only broadening is observed   / 

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  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 CLAS KEK

Approved experiments Stage 1Stage 2Running K1.8 K1.8 BR

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！