Advanced Study of New Exotic Hadron Matter at J-PARC

Hyun-Chul Kim1, Makoto Oka2, and Hiroyuki Sako2
1Department of Physics, Inha Univ., Incheon, Korea,
2Advanced Science Research Center, JAEA, Tokai, Japan

Abstract
By utilizing the J-PARC hadron physics facility, we explore new exotic forms of matter inuniverse. We focus on the heavy-flavor hadrons and dense matter produced by heavy-ion
experiments at J-PARC.

1. Research Objectives
The aim of this project is to utilize the J-PARC hadron physics facility to explore new exoticforms of matter in universe. This year we focused on the heavy hadrons, which contain heavyflavor (charm/bottom) quarks, and also dense matter, which can be produced by heavy-ion
collisions on nuclei. J-PARC is a unique experimental facility for producing excited hadron stateswith heavy flavor and also hot and dense hadronic matter with intense hadron beams.

2. Research Contents(A) Studies of exotic and excited heavy-flavor hadrons have been carried out aiming
prospective J-PARC experiments, and (B) development of heavy-ion project at J-PARC isprogressed for physics of high-density hadronic matter.
The former is conducted mainly by(A) M. Oka, K. Tanida, K. Imai, T. Sekihara (JAEA), S. H. Lee (Yonsei Univ., Y. Oh (KyungpookUniv.), A. Hosaka (RCNP, Osaka Univ./JAEA), E. Hiyama (RIKEN/JAEA)
and the latter part is mainly by(B) H. Sako, T. Maruyama, H. Sugimura, Y. Ichikawa (JAEA), K. Oyama (Nakasaki IAS), M.
Kitazawa (Osaka Univ.), H. Harada, P. K. Saha (J-PARC/JAEA).
In order to achieve the final goal, we held three Reimei Workshops:
1. J-PARC Workshop 2016: From Exotic hadrons to QGP, on Jun 7-10, 2016 at Inha Univ.
(Incheon, Korea) with 50 participants,
2. Reimei Workshop: Physics of Heavy-Ion Collisions at J-PARC, on Aug 8-10, 2016 at ASRC
with 50 participants,
3. Reimei Workshop: New exotic hadron matter at J-PARC, on Oct 24-26, 2016 at Inha Univ.
(Incheon, Korea) with 57 participants.

3. Research results
We have established a strong collaboration group in theory between the Korean J-PARC
collaboration and the Hadron-Nuclear Res. Gr. at ASRC and constructed an international
network with other Korean and Japanese groups (Seoul Nat. U, Yonsei U, Tokyo Inst. Tech.,
Osaka U, RIKEN) as well as groups in Italy (ECT*), Germany (GSI, Munchen), China (IHEP,Beijing), Serbia (Belgrade), Spain (IFIC, Valencia) and Russia (JINR, Dubna).
We have carried out studies on heavy-flavor (strange, charm and bottom) hadron- and nuclearphysics with close collaboration with the experimental groups at the J-PARC and KEK. The pionmean field approach is employed to describe heavy baryons [1], and predictions are made for Kpp final states in the 3He(K-, Λp) n reaction [2]. Charmed baryon production and its structure
analysis are proposed to use pionic decay modes of baryons [3]. Mass increase of D meson inmedium was predicted by QCD sum rules [4] and also strangeness in high density matter has
been studied [5].
Design of accelerators and experiments with heavy ions beams at J-PARC and R&D of a fast
data acquisition system for heavy-ion experiments have been developed. The white paper for theJ-PARC heavy-ion project is published in June 2016 and a Letter of Intent of J-PARC-HI wassubmitted to J-PARC PAC in June 2016. A few invited talks were given on this subject atinternational conferences [6].
4. Conclusion
In conclusion, we have achieved theoretical and experimental progress in understanding thestructure and dynamics of heavy flavor hadrons as well as dense hadronic matter, which can beproduced in the forthcoming projects at J-PARC.
5. References[1] G.-S. Yang, H.-C. Kim, M. V. Polyakov, M. Praszalowicz. Phys. Rev. D94 (2016) 071502 (R)[2] T. Sekihara, E. Oset, A. Ramos, PTEP 2016 (2016) 123D03.
[3] A. Hosaka, E. Hiyama, M. Oka, H.-Ch. Kim, et al., Nucl. Phys. A 954 (2016) 341;
H. Nagahiro, S. Yasui, A. Hosaka, M. Oka, H. Noumi, Phys. Rev. D95 (2017) 014023.
[4] Kei Suzuki, Philipp Gubler, M. Oka, Phys. Rev. C 93, 045209-1-11 (2016).
[5] T. Muto, T. Maruyama, T. Tatsumi, JPS Conf. Proc. (NIC-XIV) to be published.
[6] H. Sako, et al, Nucl. Phys. A 956 (2016) 850-853; T. Sakaguchi, H. Sako, et. al, Quark Matter
2017, Chicago, USA; H. Sako, Quarks and Compact Stars 2017, Kyoto, Japan, Feb. 2017.