Speaker
Description
Since the prediction of the bound states of a singlet of the color SU(3), the H-dibaryon (uuddss) in 1977[1], discussions regarding the H-dibaryon have persisted. An experimental result on the double-lambda hypernucleus [2] provided a lower limit of H-dibaryon mass very close to the $\Lambda\Lambda$ threshold. However, the possibility of resonant states near the threshold cannot be ruled out at this time.
Recently, an experiment aimed at exploring the H-dibaryon has been conducted at J-PARC (E42 experiment) [3]. This experiment utilized a Hyperon Spectrometer, which consists of a superconducting magnet (HS magnet) and a gas electron multiplier (GEM)-based time projection chamber (HypTPC). This unique system, which incorporates the experimental target and operates even with beam injection, allows for unprecedented detection capabilities, enabling the identification of decay particles over a large acceptance. Consequently, it provides access not only to H-dibaryon exploration but also to various other hadron physics topics. Currently, analyses are simultaneously progressing on the following topics.
- Search for $\Lambda(1405)$ hypernucleus by imposing exclusive conditions to identify decay particles on missing mass distribution of $^{12}$C$(K^{-}, p)$ reaction
- Cross-section measurement $^{12}$C$(K^{-}, K^{+}\Xi^{-})$ and $^{12}$C$(K^{-},K^{+}\Lambda\Lambda)$ to obtain information on $\Xi^{-}$N potential or $\Xi N-\Lambda\Lambda-\Sigma\Sigma$ conversion, which is related to H-dibaryon physics
- Study of possible in-medium (mass) modification due to the ChSB effect by measuring the mass of $K^{＊}(892)$ vector meson via $^{12}$C$(K^{-}, p)$ reaction
- Measurement of the polarization of $\Xi$ via $p(K^{-},K^{+})\Xi$ reaction at sqrt(s)= 2.14 GeV
In this presentation, I will overview the distinguished experiment and also report the recent status of these analyses and preliminary results.
Ref.
[1] R. L. Jaffe, Phys. Rev. Lett. 38, 195 (1977)
[2] H. Takahashi et al., Phys. Rev. Lett. 87, 212502 (2001)
[3] J.K. Ahn et al, the proposal of J-PARC E42 experiment, Search for H-Dibaryon with a Large Acceptance Hyperon Spectrometer
