부산대학교 도서관

The stability of four fermionic particles with unit charge, of which two are positively and two negatively charged, is discussed. Except for using the simplest approximation of a single Gaussian orbital per particle, the problem is exactly solved variationally by varying the masses to simulate molecular di-hydrogen, mono-muonated di-hydrogen, and di-muonated di-hydrogen. We illustrate the celebrated Born-Oppenheimer approximation 2 years after the occasion of its 90th anniversary. It is suggested that this method is valid only for di-hydrogen. Key words: muonated hydrogen, Born-Oppenheimer approximation, [micro]-mesonic molecules, interatomic forces, stability of fermionic particles. Nous examinons la stabilite de particules faites de quatre fermions portantune charge unitaire, deux positives et deux negatives. Excepte pour l'approximation d'une simple orbitale gaussienne par particule, le probleme est solutionne exactement par methode variationnelle et en variant les masses pour simuler les complexes moleculaires de dihydrogene et de dihydrogene a un muon et a deux muons. Ce calcul sert a illustrer la celebre approximation de Born-Oppenheimer, 2 ans apres son [90.sup.e] anniversaire. Nous concluons que cette approximation n'est valide que pour le dihydrogene. [Traduit par la Redaction] Mots-cles : hydrogene muonique, approximation de Born-Oppenheimer, molecule a muon [micro], force interatomique, stabilite de particules faites de fermions.
1. Introduction The understanding of physics and chemistry rests on a hierarchy of approximations, with the one carrying the names of Born and Oppenheimer [1] (BO) being most celebrated. At [...]