Speaker
Mr
Yuichi Toyama
(Tohoku University)
Description
In 2010s, it is reported that lifetime of hypertriton was about 20\% shorter than $\Lambda$ particle by heavy-ion collision experiment groups.
On the other hand, binding energy of $\Lambda$ particle($B_\Lambda$) of hypertriton measured by emulsion experiment is very small($ = 0.13 \pm 0.05$ MeV).
It is difficult to understand shallow bound state and short lifetime of hypertriton simultaneously.
This problem is known as "hypertriton puzzle".
Precise measurement of lifetime of hypertriton is necessary to solve hypertriton puzzle.
We plan to perform a new experiment to measure the lifetime with a precision of 10 ps using tagged photon beam at ELPH(Research center for ELectron PHoton science).
hypertriton will be produced from He3 via (gamma, K+) reaction and lifetime of hypertriton will be directly deduced by measuring produced time of pi- meson from hypertriton to X + pi- decay in the new experiment.
We are developing a detector system for decay pions, including a timing counter with a good time resolution (<100\ ps) by using SiPM and plastic scintillator for this experiment.
Lifetime of hypernuclei can be directly deduced by measuring timings of incident photon and decay pi-.
In my presentation, I will report about motivation of hypertriton lifetime measurements, and status of detector development.
Primary author
Mr
Yuichi Toyama
(Tohoku University)
