72
6 Three-Body Approach to Structural Properties …
Fig. 6.2 Plot of the
spectator function, G(p c ) (in
arb. Units) versus p 1 —the
halo neutron momentum in
the laboratory frame
expressed in terms of σ varies between 18 and 2 MeV/c. The present results are at
least in broad agreement with the conclusions drawn from the experimental findings
[68].
From our ‘master’ three-body Eq. (4.25), we can also make some estimates of
the correlation between two halo neutrons or between a halo neutron and
9 Li core
within the
11 Li nucleus. In fact, the term
φ nn = D
−1
p 12 ,
P 3 ; E
g( p 12 ),
(6.1)
which is just the coefficient of F(P 3 ), can be interpreted as describing the correlation
between the two neutrons in momentum space. Similarly, the function
φ nc = D
−1
p 12 ,
P
3 E
f (
p 23 )
(6.2)
gives an estimate of the correlation between neutron and
9 Li core in the presence of
other neutrons.
Experimentally, kinematically complete measurements for Coulomb dissociation
of
11 Li into
9 Li + 2n were made [69] at 28 MeV/nucleon. The data for the correlation
function deduced from the relative momentum spectrum between two neutrons in
coincidence with
9 Li fragment are shown in Fig. 6.3, wherein we also depict a plot
of the function φ nm versus p 12 . While the nature of the correlation between two
neutrons is yet to be clearly understood, the agreement with the data shows that the