Energy Spectra of 9ΛBe

  • E. Cravo
  • A. C. Fonseca
  • Y. Koike
Conference paper
Part of the Few-Body Systems book series (FEWBODY, volume 15)


The hypernucleus Λ 9 Be is investigated using the α + Λ + α cluster model. The corresponding Faddeev equations are solved for different α- α and Λ- α interactions that describe both 8Be and Λ 5 He energy spectra. For the ground state Inline Equation
$${J^\pi } = {\frac{1}{2}^ + }$$
and excited states Inline Equation
$${\frac{3}{2}^ + }and{\frac{5}{2}^ + }$$
we include the Coulomb repulsion between the a’s and calculate, in addition to the energy eigenvalues, the a¡ª and A¡ªparticle mean radius, the rms charge radius, the electric quadrupole moment (Q), as well as the magnetic dipole. Structural differences between 9Be and Λ 9 Be lead to values of Q and,u that have opposite sign. Unlike previous theoretical work we find only two degenerate negative parity resonances Inline Equation
$${\tfrac{1}{2}^ - }({\tfrac{3}{2}^ - })$$
but, in addition, we get two degenerate positive parity resonances with Inline Equation
$${J^\pi } = {\frac{7}{2}^ + }\left( {{{\frac{9}{2}}^ + }} \right)$$
at higher energy which, together with the bound states, complete the positive parity rotational band.


Quadrupole Moment Coulomb Repulsion Negative Parity Faddeev Equation Electric Quadrupole Moment 
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  1. 1.
    H. Feshbach:In: Proc. of the Summer Study Meeting on Kaon Physics and Facilities, ed. by H. Palevsky, p. 185 (BNL 18335) 1973Google Scholar
  2. 2.
    E. Gravo, A.C. Fonseca, Y. Koike:Phys. Rev. C66 014001 (2002)ADSGoogle Scholar
  3. 3.
    A.C. Fonseca, M.T. Peña:Nucl. Phys. A487, 92 (1988)ADSCrossRefGoogle Scholar
  4. 4.
    E. Cravo:Phys. Rev. C54, 523 (1996)ADSGoogle Scholar
  5. 5.
    S. Oryu et al.:Few-Body Systems 28, 103 (2000)ADSCrossRefGoogle Scholar
  6. 6.
    Y. Sunami, H. Narumi:Prog. Theor. Phys. 66, 355 (1981)ADSCrossRefGoogle Scholar
  7. 7.
    L.D. Faddeev: JETP 12, 1014 (1961)MathSciNetGoogle Scholar
  8. 8.
    D.R. Lehman et al.:Phys. Rev. C29, 1450 (1984)ADSGoogle Scholar
  9. 9.
    Y. Koike:Phys. Rev. C42, R2286 (1990)ADSMathSciNetGoogle Scholar
  10. 10.
    M. Juric et al.:Nucl. Phys. B52, 1 (1973)ADSCrossRefGoogle Scholar
  11. 11.
    H. Akikawa et al.:Phys. Rev. Lett. 88, 082501 (2002)ADSCrossRefGoogle Scholar
  12. 12.
    F. Ajzenberg-Selove:Nucl. Phys. A490, 1 (1988)ADSCrossRefGoogle Scholar
  13. 13.
    T. Yamada et al.: Phys. Rev. C38, 854 (1988) and references thereinGoogle Scholar
  14. 14.
    R.H. Dalitz, A. Gal: Phys. Rev. Lett. 36, 362 (1976)ADSCrossRefGoogle Scholar
  15. 15.
    W. Brueckner et al.: Phys. Lett. 55B, 107 (1975); 79B, 157 (1978)CrossRefGoogle Scholar
  16. 16.
    S. Ajimura et al.: Nucl. Phys. A639, 93C (1998)Google Scholar
  17. 17.
    B.F. Gibson, E.V. Hungerford III: Phys. Rep. 257, 349 (1995)ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • E. Cravo
    • 1
  • A. C. Fonseca
    • 1
  • Y. Koike
    • 2
  1. 1.Centro de Física NuclearUniversity of LisbonLisbonPortugal
  2. 2.Science Research CenterHosei UniversityTokyo 102Japan

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