1 Heavy-Ion Physics at J-PARC Shoji Nagamiya RIKEN / KEK / JAEA January 20, 2016 Tokai 1) Motivation 2) J-PARC vs. FAIR

2 First E T Data from AGS and SPS E T Spectra from an early days of AGS E T Spectra from an early days of SPS The nucleus seems black at the AGS energy

3 Possibility for High Density Formation

4 Neutron star STAR’s BES FAIR NICA? J-PARC? RHIC LHC Temperature vs. Baryon Density

5 |S| > 3 Hypernuclei –Full intensity beam of /s is ~10 MHz central collisions –10 -5 for 10 6 events means dN/dy = = 0.3 events/hour Very marginal but not impossible FAIR or J-PARC S=-1 Hypernuclei S=-2 Hypernuclei |S| > 3 Hypernuclei Multi-Strangeness Hypernuclei? A. Andronic, PLB697 (2011) 203 Pb + Pb Central collision _ _

6 Mystery of neutron star matter n p   Strange Hadronic Matter High density nuclear matter with hyperons (strange quarks) ? ?? n Neutron Matter Superfluid Final form of matter evolution in the universe Produced by supernova explosion, Observed as X-ray pulsars Highest density matter in the universe M = 1~2 M, R ~ 10~20 km => Density of the core = 3~10  0 （ 1 ～ 3 Btons/cm 3 ）  0 : nuclear density Various forms of matter made of almost only quarks Quark Matter Deconfined quarks Color superconductivity Nuclear “Pasta” Nuclear + Neutron Matter Slide from H. Tamura High density formation may help multi-strangeness production

7 Possible Ideas for Fixed Target Primary Beam Lepton pairs Search for lepton pairs + many other ideas …. Primary Beam Primary Neutrons Primary Beam Very strong magnet Primary Protons Detector for stable object Search of strangeness related objects Normal magnet  p

8 Existing Recent Scheme by the Accelerator Team ~ /s

9 Nuclear Transmutation (Phase 2) Joint Project between KEK and JAEA Materials and Life Science Experimental Facility Hadron Beam Facility ５００ｍ Linac (330m) Neutrino to Kamiokande J-PARC Facility 3 GeV Synchrotron (25 Hz, 1MW) 50 GeV Synchrotron (0.75 MW) J-PARC = Japan Proton Accelerator Research Complex

10 J-PARC vs. FAIR FAIR –FAIR has good support by over 1000 people, but may fail its funding. Surely, it is delayed. In addition, synchrotron??? J-PARC –Only front-end (linac + booster) addition is needed. –It already has high-intensity capability at both RCS and MR. –In addition, even two facilities (J-PARC and FAIR) exist, we have strong experimental and theoretical teams in Japan. –J-PARC-HI requires, however, multi processes: ① J-PARC → ② Japanese Nuclear Physics Committee → ③ Science Council of Japan → ④ MEXT+Funding –In each process, there are serious competitions (In October no processes existed, but in January process ① started and the process ② will also start). Let us to proceed to further stages for J-PARC ASAP.