Potential experimental evidence of an Efimov state in 12C and its influence on astrophysical carbon creation

Giuseppe Cardella; Aldo Bonasera; Nunzia, Simona Martorana; Luis Acosta; Enrico De Filippo; Elena Geraci; Brunilde Gnoffo; Chiara Guazzoni; Concettina Maiolino; Angelo Pagano; Emanuele, Vincenzo Pagano; Massimo Papa; Sara Pirrone; Giuseppe Politi; Fabio Risitano; Francesca Rizzo; Paolo Russotto; Marina Trimarchi

doi:10.1051/epjconf/202327903001

Proceedings

Open Access

EPJ Web of Conferences 279, 03001 (2023)
https://doi.org/10.1051/epjconf/202327903001

Potential experimental evidence of an Efimov state in ¹²C and its influence on astrophysical carbon creation

Giuseppe Cardella¹^*, Aldo Bonasera²^,3, Nunzia, Simona Martorana⁴^,2, Luis Acosta⁶^,7, Enrico De Filippo¹, Elena Geraci⁴^,1, Brunilde Gnoffo⁴^,1, Chiara Guazzoni⁶, Concettina Maiolino², Angelo Pagano¹, Emanuele, Vincenzo Pagano², Massimo Papa¹, Sara Pirrone¹, Giuseppe Politi⁴^,1, Fabio Risitano⁵^,1, Francesca Rizzo⁴^,2, Paolo Russotto² and Marina Trimarchi⁵^,1

¹ INFN Sezione di Catania, Italy
² INFNLaboratori Nazionali del Sud, Catania, Italy
³ Cyclotron Institute Texas AM University college station, USA
⁴ Dip. di Fisica e Astr. “Ettore Majorana”, Università degli Studi di Catania, Italy
⁵ DSMISFT Università di Messina, Italy
⁶ DEIB Politecnico Milano and INFN Sez. Milano, Italy
⁷ Instituto de Física, Universidad Nacional Autónoma de México

^* e-mail: cardella@ct.infn.it

Published online: 22 March 2023

Abstract

We describe the search of the Efimov state in ¹²C performed by analysing a large set of 3-α particles coincidence data measured at the LNS laboratories with the CHIMERA detector. The data are compatible with the presence of an Efimov state at the excitation energy of 7.485 MeV, with an excitation probability smaller than 0.3% of the population probability of the Hoyle state. The Efimov state gamma decay probability should be around 30%, much larger than the one of the Hoyle state. The population of this level is compatible with the Suda limit for the 3-α reaction rate in stars because its population should be possible only through direct 3-α reaction. More investigations improving the detector angular resolution are needed to confirm these preliminary observations.

© The Authors, published by EDP Sciences, 2023

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