Evidence of existence of the nn hypernucleus with the ALICE detector

Author(s)

Caio Laganá Fernandes

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2017-05-30

Examining board members

Alexandre Alarcon do Passo Suaide; Airton Deppman; Eduardo de Moraes Gregores; Renato Higa; Sergio Ferraz Novaes

• Advisor: Alexandre Alarcon do Passo Suaide

Abstract

The study of nuclear isotopes with strangeness is a wide area of reserach, encompassing hadronic interaction theories, stellar models and hypernuclear structure. Although fixed-target experiments represent the main technology to produce hypernuclei, heavy-ion collisions have been shown to be a fruitful alternative when considering light isotopes, particularly due to the capability of creating antimatter partners. We propose to investigate the existence of the hypernucleus composed by nn with the ALICE detector. The study of this particular state have raised special interest in the community in view of the current dilemma between a measurement reported by the HypHI Collaboration, which observed an excess compatible with the nn, and the statement by some theoreticians that the existence of such isotope is inconsistent with the current understanding of hadronic interactions, that well predicts properties of other bound systems. An independent endorsement on the existence, or not, of this state is thus of fundamental importance. The results obtained with ALICE indicates an excess of significance 4.55 in the 3H+ channel at a mass of 2.993(1) GeV/c2. Although this excess is observed in the current data, the new LHC run, with at least 10 times more collisions than the current one, will put a definitive answer in this question. (AU)

• FAPESP's process: 12/20730-0 - Search for light (anti)hypernuclei with the ALICE detector at the LHC
• Grantee: Caio Laganá Fernandes
• Support Opportunities: Scholarships in Brazil - Doctorate