Study of effects of few-body physics in light few-atomic and molecular low-energy collisions and in three-charge-particle systems involving muons and antiprotons

• Grant number: 18/17439-9
• Support type: Research Grants - Visiting Researcher Grant - International
• Duration: December 09, 2019 - January 08, 2020
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal researcher: Sadhan Kumar Adhikari
• Grantee: Sadhan Kumar Adhikari
• Visiting researcher: Renat Anasovich Sultanov
• Visiting researcher institution: Odessa College, United States
• Home Institution: Instituto de Física Teórica (IFT). Universidade Estadual Paulista (UNESP). Campus de São Paulo. São Paulo , SP, Brazil

Abstract

Few-atomic and three-charge-particle systems are the main subjects of the current research proposal to FAPESP. Within the first part of the project it is planed to carry out a new investigation of certain few-body effects in various three-charge-particle systems involving antiprotons, muons and/or electrons. (a) Specifically we will continue our previous Faddeev calculations of the protonium, Pn = (pbar p), formation three-body reaction, i.e. pbar + (p-mu) -- (pbar-p)_nl + mu- . (b) It is also planned to carry out new computation for the following three-body reaction with participation of deuterium, i.e. pbar + (D mu) -- (pbar D)-nl + mu-. Here and above: pbar, p, D and mu are antiproton, proton, deuteron and a muon respectively. The main goal of this part of the project is to study an interplay between Coulomb and nuclear forces and annihilation channels in P n (it is also named as an anti-protonic hydrogen) and in (pbar D) and (pbar T) atoms. (c) Additionally, it is planned to start a very new calculation of the muonic antihydrogen atom formation, H_mu = (pbar mu+), reaction in the following three-body collision: pbar + Mu -- H_mu + e- , where Mu is a light muonium atom, i.e. Mu=(mu+e-). A Faddeev-type detailed few-body approach will be applied to all systems mentioned above. In the the second part of this proposal we plan to deal with light few-atomic molecular systems. Specifically, the H_2 +H_2 and HD+H_2 rotational energy transfer collisions will be computed. Here: H is hydrogen and D is deuterated hydrogen atoms. These non-reactive inelastic scatterings are of significant interest in astrophysical applications. If time permits it is planed to carry out new three-atomicH+H_2 /HD inelastic scattering collisions too. Recently published H_2 -H_2 and H-H_2 potential energy surfaces (PESs) will be used. The new results will be compared with older data to check the sensitivity the results to different PESs. This is one of the main goals of this part of the project. A specific interest represent the hydrogen systems with participation of D. For example, in the case of the HD molecule the center of mass of HD is shifted relative to H 2 . It is planned to obtain new results for the HD molecule collision cross sections and thermal rates. (AU)