J-PARC E16 experiment

Measurements of spectral change of vector mesons in nuclei

In order to explore the chiral symmetry in nuclear matter, we measure the mass modification of vector mesons in nuclei systematically. We construct a large acceptance di-electron spectrometer at the high-momentum beam line in the J-PARC hadron facility.

Current status(2023/June)

After the completion of high-momentum beam line in June 2020, commissioing runs of E16 spectrometer were performed in June 2020-June 2021, with limited number of detectors.
Data analysis and construction of additional detectors for physics run is on-going. TDR is submitted and reviewed in Jun.-Aug. 2022.
Based on the TDR, beam time 230 h for the beam line- and trigger- studies was approved. Beam time for the studies is started in June 2023 with the eight detector modules, with new SSD (STS, develped in cooperation with the CBM-STS group in GSI). Unfortunately just 21 hours of beam time were performed in June due to the machine troubles in J-PARC. Next beam time is expected within JFY 2023.
Physics run will be performed in 2024, after an approval by PAC is obtained.

Just after the first comissioning run (Run-0a), 2020/June/22

Publications and presentations

Proposal pdf(2006/6)

Run0(Commissioning Run) Proposal pdf(2017/6)

Schematic view of the proposed spectrometer

Spectromter magnet at the J-PARC hadron facility(2015).

Spectrometer, from the upstream (2020).

Proposed spectromter Photo of the spectromter magnet
(2015/Oct, after reassemble) Photo of the spectromter 2020

Prototype of GEM chambers

production type of GEM chambers

Assembled single module of GEM Traker

Prototype of a hadron blind Cherenkov detector

1st production type of HBD

A HBD gas vessel (for two modules) to be installed

preamp for GEM Tracker using APV25

prototype FEM for the lead-glass EMcal

Trigger-signal merging module[taken from IEEE TNS 66(2019)2022]

24ch-ASD for the trigger signal from GTR

9ch-ASD for the trigger signal from HBD (with two CERN APV hyblid preamp card )

SSD borrowed from the J-PARC E10/E03 group, operated 2020-21

SSD located inside the GTR

new SSD ("STS") developed with the CBM-STS group, operated in 2023


アウトリーチ活動(OUTREACH, in Japanese)

Collaboration (2023/June)

S. Yokkaichi*, H. En'yo, F. Sakuma (RIKEN Nishina Center)
K. Aoki, R. Honda, K. Kanno, Y. Morino, R. Muto, W. Nakai, K. Ozawa, S. Sawada, M. Sekimoto, H. Sugimura (KEK)
T. N. Murakami, J. Kakunaga (University of Tokyo)
H. Murakami(CNS, University of Tokyo)
M. Ichikawa, S. Nagafusa, S. Nakasuga, M. Naruki, S. Ochiai (Kyoto University)
H. Noumi, K. Shirotori, T. N. Takahashi, S. Ashikaga (RCNP, Osaka Univ.)
H. Hamagaki (NiAS)
K. Shigaki, R. Ejima, R. Yamada, Y.L.Yamaguchi (Hiroshima University)
A. Kiyomichi (JASRI)
T. Sakaguchi (BNL)
H. Sako, S. Sato (JAEA)
T. Chujo, S. Esumi, T. Nonaka (Tomonaga Center, University of Tsukuba)
S. Kajikawa (Tohoku University)
W.-C. Chang, C.-H Lin, P.-H. Wang(Academia Sinica)
J. Heuser, A.R.Rodriguez, M.Teklishyn (GSI)
A. Toia, D.R.Garces (Goethe University/GSI)

* : Spokesperson
This project is supported by RIKEN, KEK,
and Ministry of Science and Technology of Taiwan, Grant number: .


Last modified: Sat Jul 22 21:30:07 2023