Speaker
Mr
Kosuke Itabashi
(Tohoku University)
Description
The $\Lambda$-hypernuclear spectroscopy is a basic tool to investigate
the interaction between a $\Lambda$ and nucleon ($N$).
We developed a spectroscopic method of $\Lambda$ hypernuclei
with the $(e,e^{\prime}K^{+})$ reaction at the Thomas Jefferson National Accelerator Facility (JLab)~.
The last $(e,e^{\prime}K^{+})$ experiment
resulted in the best energy resolution and accuracy in the reaction spectroscopy
of $\Lambda$ hypernuclei.
The next experiment will measure $^{40}_{\Lambda}$K and $^{48}_{\Lambda}$K hypernuclei with
a new spectrometer system, HRS $+$ HKS, at JLab Hall A (Experiment E12-15-008).
The spectrometer system is now being designed.
We will measure the $\Lambda$-binding energy [$B_{\Lambda}$ ($^{40,48}_{\Lambda}$K)] with a precision
of $\Delta B_{\Lambda} \leq 100$~keV to investigate the isospin dependence of the $\Lambda NN$ interaction
that would be an important factor particularly in high-density nuclear matters such as neutron stars.
In the E12-15-008 experiment, we will use isotopically enriched targets
of $^{40}$Ca and $^{48}$Ca with a thickness of about 0.1~g/cm$^{2}$
for the $^{40,48}_{\Lambda}$K production as well as other solid targets
for an energy calibration.
The targets will be exposed to a 50-$\mu$A electron beam
with the energy of $E_{e}=4.5$~GeV in a vacuum environment
and will expose high radiation around target system aria.
The radiation level around the targets will be high.
Therefore, the targets need a cooling system that allows us to use
such a high current of the continuous electron beam
and remote control system that can chenge a target without hall access.
In the presentation,
I will introduce an overview and a preparation status
of the spectrometers and detectors of the E12-15-008 experiment.
The design of the target system will be presented in detail.
Primary author
Mr
Kosuke Itabashi
(Tohoku University)
Co-authors
Dr
Franco Garibaldi
(INFN Rome)
Dr
Guido Urciuoli
(Istituto Nazionale di Fisica Nucleare)
Prof.
Kazushike Maeda
(Tohoku University)
Mr
Keita Uehara
(Tohoku University)
Prof.
Liguang Tang
(Hampton University/JLab)
Dr
Masaki Kaneta
(Tohoku University)
Prof.
Pete Markowitz
(Florida International University)
Prof.
Satoshi Nakamura
(Tohoku University)
Dr
Sho Nagao
(Tohoku University)
Mr
Takeshi Uematu
(Tohoku University)
Dr
Toshiyuki Gogami
(Tohoku University)
Mr
Yoshihiro Konishi
(Tohoku University)
Mr
Yuichi Toyama
(Tohoku University)
Mr
Yuta Muroi
(Tohoku University)
Dr
Yuu Fujii
(Tohoku Medical and Pharmaceutical University)
