449 research outputs found
Nuclear fragmentation by tunneling
Fragmentation of nuclear system by tunneling is discussed in a molecular
dynamics simulation coupled with imaginary time method. In this way we obtain
informations on the fragmenting systems at low densities and temperatures.
These conditions cannot be reached normally (i.e. above the barrier) in
nucleus-nucleus or nucleon-nucleus collisions. The price to pay is the small
probability of fragmentation by tunneling but we obtain observables which can
be a clear signature of such phenomena.Comment: Phys.Rev.C (submitted
The many facets of the (non relativistic) Nuclear Equation of State
A nucleus is a quantum many body system made of strongly interacting
Fermions, protons and neutrons (nucleons). This produces a rich Nuclear
Equation of State whose knowledge is crucial to our understanding of the
composition and evolution of celestial objects. The nuclear equation of state
displays many different features; first neutrons and protons might be treated
as identical particles or nucleons, but when the differences between protons
and neutrons are spelled out, we can have completely different scenarios, just
by changing slightly their interactions. At zero temperature and for neutron
rich matter, a quantum liquid gas phase transition at low densities or a
quark-gluon plasma at high densities might occur. Furthermore, the large
binding energy of the particle, a Boson, might also open the
possibility of studying a system made of a mixture of Bosons and Fermions,
which adds to the open problems of the nuclear equation of state.Comment: 71 pages, 30 figures, accepted by Prog. Part. Nucl. Phys. and in
pres
Higher Order Corrections to Density and Temperature of Fermions from Quantum Fluctuations
A novel method to determine the density and temperature of a system based on
quantum Fermionic fluctuations is generalized to the limit where the reached
temperature T is large compared to the Fermi energy {\epsilon}f . Quadrupole
and particle multiplicity fluctuations relations are derived in terms of T .
The relevant Fermi integrals are numerically solved for any values of T and
compared to the analytical approximations. The classical limit is obtained, as
expected, in the limit of large temperatures and small densities. We propose
simple analytical formulas which reproduce the numerical results, valid for all
values of T . The entropy can also be easily derived from quantum fluctuations
and give important insight for the behavior of the system near a phase
transition. A comparison of the quantum entropy to the entropy derived from the
ratio of the number of deuterons to neutrons gives a very good agreement
especially when the density of the system is very low
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