Il Nuovo Cimento (1955-1965)

, Volume 16, Issue 2, pp 342–349 | Cite as

The binding energy of Λ-particles in nuclear matter

  • J. D. Walecka


From an analysis of the existing data on the binding energy of Λ particles in hyperfragments a fairly reliable value of the binding energy of Λ particles in nuclear matter can be obtained. This value isV0≈22 MeV. It is proposed that this number gives an independent check on the validity of potentials deduced from the very light hyper-fragments. Some simple calculations using the techniques ofBrueckneret al. are carried out with the potential of Lichtenberg and Kovacs (which contains a hard core). It is found that if onlys wave interactions are considered one finds good agreement with the above number. If higher partial waves are included one obtains far too much binding energy and it is suggested that the Λ-nucleon interaction may be weakened by an exchange force in these states.


Da un’analisi dei dati esistenti sull’energia di legame delle particelle Λ negli iperframmenti si può ottenere un valore abbastanza attendibile dell’energia delle particelle Λ nella materia nucleare. Questo valore èV0≈22 MeV. Si avanza l’ipotesi che questo valore offra un controllo autonomo sull’attendibilità del valore dei potenziali dedotti da iperframmenti molto leggeri. Alcuni semplici calcoli usando le tecniche diBrueckneret al. vengono eseguiti col potenziale di Lichtenberg e Kovacs (che contiene un « hard core »). Se si considerano solo interazioni dell’ondas si trova un buon accordo con il dato precedente. Se si includono onde parziali superiori si ottiene una energia di legame troppo elevata e si suggerisce quindi che l’interazione Λ-nucleone possa essere indebolita da una forza di scambio fra questi stati.


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  1. (1).
    T. Tati andH. Tati:Nuovo Cimento,3, 1136 (1956).CrossRefGoogle Scholar
  2. (2).
    Proceedings of the Annual International Conference on High Energy Physics at-CERN edited byB. Ferretti, CERN (Geneva, 1958) pag. 182.Google Scholar
  3. (3).
    R. Hofstadter:Rev. Mod. Phys.,28, 214 (1956).ADSCrossRefGoogle Scholar
  4. (*).
    After this work was completed, the author discovered that this value was already known toV. A. Filimonov:Žurn. Ėksp. Teor. Fiz.,36 (9), 1113 (1959), English translation.Google Scholar
  5. (4).
    R. Dalitz andB. Downs:Phys. Rev.,111, 967 (1958).ADSCrossRefGoogle Scholar
  6. (5).
    D. Lichtenberg:Nuovo Cimento,8, 463 (1958).CrossRefGoogle Scholar
  7. (6).
    T. Truong:Effect of a hard core in the Λ-nuclcon potential (preprint).Google Scholar
  8. (7).
    K. Brueckner andJ. Gammel:Phys. Rev.,109, 1023 (1958). (See this paper for earlier ref.).MathSciNetADSCrossRefGoogle Scholar
  9. (8).
    H. Bethe andJ. Goldstone:Proc. Roy. Soc., A238, 551 (1957).MathSciNetADSCrossRefGoogle Scholar
  10. (9).
    L. C. Gomes, J. D. Walecka andV. F. Weisskopf:Ann. Phys.,3, 241 (1958).ADSCrossRefMATHGoogle Scholar
  11. (10).
    J. Kovacs andD. Lichtenberg:Nuovo Cimento,13, 371 (1959).CrossRefGoogle Scholar
  12. (*).
    ν 0 has been reduced by 15% in accordance with the footnote in ref. (10).CrossRefGoogle Scholar
  13. (*).
    For a detailed treatment of the method of calculation see ref. (11).Google Scholar
  14. (11).
    J. D. Walecka:Thesis (Massachussetts Institute of Technology, 1958).Google Scholar
  15. (12).
    L. C. Gomes:Thesis (Massachusetts Institute of Technology, 1958).Google Scholar
  16. (13).
    D. Lichtenberg andM. Ross:Phys. Rev.,109, 2163 (1958).ADSCrossRefGoogle Scholar

Copyright information

© Società Italiana di Fisica 1960

Authors and Affiliations

  • J. D. Walecka
    • 1
  1. 1.Department of PhysicsStanford UniversityStanford

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