Cluster misti 3He/4He : stati e strutture

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Cluster misti 3He/4He stati e strutture
Universita degli Studi dellInsubria
Dario Bressanini Gabriele Morosi
Gabriele.Morosi_at_uninsubria.ithttp//scienze-como.
uninsubria.it/morosi
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4Hen Clusters Stability
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3Hem Clusters Stability
3Hem
m ? 20 lt m lt 35 critically bound

• What is the smallest 3Hem stable cluster ?

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3Hen / 4Hem Clusters Stability

• Even less is known for mixed clusters.
• Is 3Hem4Hen stable ?

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The Simulations

• Potential sum of two-body TTY

• Both VMC and DMC simulations

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3He4Hen Clusters Stability
3He4He2 E -0.00984(5) cm-1
4He3 E -0.08784(7) cm-1
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3He24Hen Clusters Stability

• Now put two 3He. Singlet state. Y is positive
  everywhere

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Why excited states ?
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Distribution Functions in 3He4Hen
c.o.m. center of mass
r(4He-c.o.m.)
r(3He-c.o.m.)
Similar to pure clusters
Fermion is pushed away
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3D harmonic oscillator levels
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Rigid rotor levels
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3He4He14

• l 2 -12.304(5)
• ?E 0.353(6)
• l 1 -12.657(3)
• ?E 0.270(4)
• l 0 -12.927(3)

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3Hem4Hen
m2 m3 m4 m8
R.Guardiola, J.Navarro, Few-Body Syst. Suppl. 14,
223 (2003)
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Rigid rotor levels

• Aufbau principle
• Pauli exclusion principle
• Hunds rule

• A wealth of possible states

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3Hem 4Hen Clusters

• ENERGETICS

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3He4Hen energies
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3He4Hen excitation energies
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3He24Hen energies

• Energy relative to 4Hen energy

l 1 ______ l 0 ______
l 1 ______ l 0 ______
l 0 ______
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3He34Hem energies
l 1 ______ l 0 ______
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Evidence of 3He3 4He4Kalinin, Kornilov and
Toennies
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3Hem4Hen stability chart
4Hen
3Hem
0 1 2 3 4 5 6 7 8 9
10 11
Bound L0
0 1 2 3 4 5
Unbound
Unknown
L1 S1/2
L1 S1
GuardiolaNavarro
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3He34He8 L0 S1/2
3He24He2 L0 S0
3He34He4 L1 S1/2
3He24He4 L1 S1
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3Hen / 4Hem Clusters

• STRUCTURE

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Average values
must be sampled
DMC samples
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3He34He22

• 3He-c.o.m. distribution

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3He34He22

• 3He-c.o.m. distribution

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3He4Hen
3He com rdf
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3He4He7 L 1 state
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3He4He9 L 2 state
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3He24He17

• 3He c.o.m. - 3He cosine distribution

c.o.m
???? L0 (s2) ???? L1 (sp) singlet ????
triplet
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3He24He14

• 3He c.o.m. - 3He angle distribution

c.o.m
????? L0 (s2) ????? L1 (sp) singlet ????
triplet
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3He34He22 L 1
Distribution with respect to the center of mass
r(He-c.o.m.)
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3He34He22 L 1

• 3He c.o.m. - 3He cosine distribution

a-a
c.o.m
a(s)-b(s)
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Dario Bressanini Silvia Tarasco Matteo
Bardin Sara Marelli