108 research outputs found
Benchmark calculations for elastic fermion-dimer scattering
We present continuum and lattice calculations for elastic scattering between
a fermion and a bound dimer in the shallow binding limit. For the continuum
calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to
determine the scattering length and effective range parameter to high
precision. For the lattice calculation we use the finite-volume method of
L\"uscher. We take into account topological finite-volume corrections to the
dimer binding energy which depend on the momentum of the dimer. After
subtracting these effects, we find from the lattice calculation kappa a_fd =
1.174(9) and kappa r_fd = -0.029(13). These results agree well with the
continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained
from the STM equation. We discuss applications to cold atomic Fermi gases,
deuteron-neutron scattering in the spin-quartet channel, and lattice
calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure
Hard-core Radius of Nucleons within the Induced Surface Tension Approach
In this work we discuss a novel approach to model the hadronic and nuclear
matter equations of state using the induced surface tension concept. Since the
obtained equations of state, classical and quantum, are among the most
successful ones in describing the properties of low density phases of strongly
interacting matter, they set strong restrictions on the possible value of the
hard-core radius of nucleons. Therefore, we perform a detailed analysis of its
value which follows from hadronic and nuclear matter properties and find the
most trustworthy range of its values: the hard-core radius of nucleons is
0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies
that the hard-core radius of nucleons has to be temperature and density
dependent.Comment: 12 pages, 4 figures, references added, typos correcte
Second virial coefficients of light nuclear clusters and their chemical freeze-out in nuclear collisions
Here we develop a new strategy to analyze the chemical freeze-out of light
(anti)nuclei produced in high energy collisions of heavy atomic nuclei within
an advanced version of the hadron resonance gas model. It is based on two
different, but complementary approaches to model the hard-core repulsion
between the light nuclei and hadrons. The first approach is based on an
approximate treatment of the equivalent hard-core radius of a roomy nuclear
cluster and pions, while the second approach is rigorously derived here using a
self-consistent treatment of classical excluded volumes of light (anti)nuclei
and hadrons. By construction, in a hadronic medium dominated by pions, both
approaches should give the same results. Employing this strategy to the
analysis of hadronic and light (anti)nuclei multiplicities measured by ALICE at
TeV and by STAR at GeV, we got rid
of the existing ambiguity in the description of light (anti)nuclei data and
determined the chemical freeze-out parameters of nuclei with high accuracy and
confidence. At ALICE energy the nuclei are frozen prior to the hadrons at the
temperature MeV, while at STAR energy there is a
single freeze-out of hadrons and nuclei at the temperature
MeV. We argue that the found chemical freeze-out volumes of nuclei can be
considered as the volumes of quark-gluon bags that produce the nuclei at the
moment of hadronization.Comment: 15 pages, 4 figures, 3 table
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