Oct 20 – 23, 2026
RIKEN
Asia/Tokyo timezone
Registration deadline is October 12!!

Probing proton upscattering of the $^{12}$C Hoyle State with the AToM-X active-target TPC

Oct 21, 2026, 6:00 PM
3h
Headquarters Building 2F (RIKEN)

Headquarters Building 2F

RIKEN

2-1, Hirosawa, Wako, Saitama 351-0198, Japan
Poster Presentation Poster Session

Speaker

Dr Jung Woo Lee (Center for Exotic Nuclear Studies, Institutes for Basic Science)

Description

Proton-induced inelastic scattering to the $^{12}$C Hoyle state (7.654 MeV), which de-excites $^{12}$C to its ground state by carrying away the excitation energy — a process known as "upscattering" — may enhance the stellar triple-alpha process by up to orders of magnitude. The triple-alpha enhancement was predicted using previous measurements of the time-reversed reaction $^{12}$C($p$,$p'$)$^{12}$C$^*$(HS) covering proton energies up to ~2.3 MeV above the Hoyle-state threshold, while the cross section in the higher-energy region relied on Hauser-Feshbach calculations. Using AToM-X, the active-target TPC developed at the Center for Exotic Nuclear Studies (CENS), with 8–18 MeV proton beams, we plan to extend the $^{12}$C($p$,$p'$)3$\alpha$ cross-section measurement up to ~10 MeV above the Hoyle-state threshold and determine the resulting triple-alpha enhancement. A main challenge in this experiment lies in reconstructing the three-alpha events and distinguishing them from background reactions. To address this, we present an analysis using Geant4 simulations to identify the three-alpha tracks.

Category Experiment

Author

Dr Jung Woo Lee (Center for Exotic Nuclear Studies, Institutes for Basic Science)

Co-authors

Dr Aram Kim (CENuM, Korea University) Chaeyeon Park (IRIS/IBS) Kevin Hahn (Center for Exotic Nuclear Studies, IBS) Dr Minju Kim (Center for Exotic Nuclear Studies) Dr Soomi Cha (Center for Exotic Nuclear Studies, Institute for Basic Science) Dr Sunghan Bae (IRIS, IBS) Sunghoon (Tony) Ahn (Institute for Basic Science)

Presentation materials

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