99 research outputs found
Negative parity tetraquarks with the open charm
The relativistic four-quark equations are found in the framework of
coupled-channel formalism. The dynamical mixing of the meson-meson states with
the four-quark states is considered. The four-quark amplitudes of the negative
parity tetraquarks including the quarks of three flavors (u, d, s) and the
charmed quark are constructed. The poles of these amplitudes determine the
masses of tetraquarks. The mass values of low-lying tetraquarks with the
spin-parity JP=0-,1-,2-,3- are calculated.Comment: 18 pages, pd
S-wave bottom tetraquarks
The relativistic four-quark equations are found in the framework of
coupled-channel formalism. The dynamical mixing of the meson-meson states with
the four-quark states is considered. The four-quark amplitudes of the
tetraquarks, including , , and bottom quarks, are constructed. The
poles of these amplitudes determine the masses and widths of -wave bottom
tetraquarks.Comment: 8 pages, late
Relativistic five-quark equations and u, d- pentaquark spectroscopy
The relativistic five-quark equations are found in the framework of the
dispersion relation technique. The five-quark amplitudes for the low-lying
pentaquarks including u, d quarks are calculated. The poles of the five-quark
amplitudes determine the masses of the lowest pentaquarks. The calculation of
pentaquark amplitudes estimates the contributions of four subamplitudes. The
main contributions to the pentaquark amplitude are determined by the
subamplitudes, which include the meson states M.Comment: 21 pages, pd
Relativistic five-quark equations and negative parity pentaquarks
The relativistic five-quark equations are found in the framework of the
dispersion relation technique. The solutions of these equations using the
method based on the extraction of the leading singularities of the amplitudes
are obtained. The five-quark amplitudes for the low-lying pentaquarks including
the u, d, s- quarks are calculated. The poles of these amplitudes determine the
masses of the negative parity pentaquarks with I = 0, 1 and spin 3/2-, 5/2-.
The mass of the lowest pentaquark with I = 0 and spin 3/2- is equal to 1514
MeV.Comment: 18 pages, pdf, published versio
Binding and structure of tetramers in the scaling limit
The momentum-space structure of the Faddeev-Yakubovsky (FY)components of
weakly-bound tetramers is investigated at the unitary limit using a
renormalized zero-range two-body interaction. The results, obtained by
considering a given trimer level with binding energy , provide further
support to a universal scaling function relating the binding energies of two
successive tetramer states. The correlated scaling between the tetramer
energies comes from the sensitivity of the four-boson system to a short-range
four-body scale. Each excited th tetramer energy moves as the
short-range four-body scale changes, while the trimer properties are kept
fixed, with the next excited tetramer emerging from the
atom-trimer threshold for a universal ratio , which does not depend on . We show that both
channels of the FY decomposition [atom-trimer (type) and dimer-dimer
(type)] present high momentum tails, which reflect the short-range
four-body scale. We also found that the channel is favored over channel
at low momentum when the four-body momentum scale largely overcomes the
three-body one.Comment: To appear in PR
Relativistic quark model and pentaquark spectroscopy
The relativistic five-quark equations are found in the framework of the
dispersion relation technique. The solutions of these equations using the
method based on the extraction of leading singularities of the amplitudes are
obtained. The five-quark amplitudes for the low-lying pentaquarks are
calculated under the condition that flavor SU(3) symmetry holds. The poles of
five-quark amplitudes determine the masses of the lowest pentaquarks. The mass
spectra of pentaquarks which contain only light quarks are calculated. The
calculation of pentaquark amplitudes estimates the contributions of three
subamplitudes. The main contributions to the pentaquark amplitude are
determined by the subamplitudes, which include the meson states.Comment: 22 pages, pd
Low energy n-\nuc{3}{H} scattering : a novel testground for nuclear interaction
The low energy n-\nuc{3}{H} elastic cross sections near the resonance peak
are calculated by solving the 4-nucleon problem with realistic NN interactions.
Three different methods -- Alt, Grassberger and Shandas (AGS), Hyperspherical
Harmonics and Faddeev-Yakubovsky -- have been used and their respective results
are compared. We conclude on a failure of the existing NN forces to reproduce
the n-\nuc{3}{H} total cross section.Comment: To be published in Phys. Rev.
Hexaquarks in the coupled-channel formalism
The relativistic six-quark equations are found in the framework of the
dispersion relation technique. The approximate solutions of these equations
using the method based on the extraction of leading singularities of the
amplitudes are obtained. The relativistic six-quark amplitudes of hexaquarks
including the quarks of three flavors (, , ) are calculated. The poles
of these amplitudes determine the masses of six-quark systems.Comment: 24 pages, late
Benchmark calculation of n-3H and p-3He scattering
The n-3H and p-3He elastic phase-shifts below the trinucleon disintegration
thresholds are calculated by solving the 4-nucleon problem with three different
realistic nucleon-nucleon interactions (the I-N3LO model by Entem and
Machleidt, the Argonne v18 potential model, and a low-k model derived from the
CD-Bonn potential). Three different methods -- Alt, Grassberger and Sandhas,
Hyperspherical Harmonics, and Faddeev-Yakubovsky -- have been used and their
respective results are compared. For both n-3H and p-3He we observe a rather
good agreement between the three different theoretical methods. We also compare
the theoretical predictions with the available experimental data, confirming
the large underprediction of the p-3He analyzing power.Comment: 18 pages, 9 figure
Low-lying exotic mesons in the coupled-channel formalism
The relativistic four-quark equations are found in the framework of the
dispersion relation technique. The dynamical mixing of the four-quark
amplitudes and the glueball amplitudes is considered. The approximate solutions
of these equations using the method based on the extraction of leading
singularities of the amplitudes are obtained. The four-quark amplitudes of
exotic mesons including the quarks of three flavors (u, d, s) are calculated.
The poles of these amplitudes determine the masses of the exotic mesons.Comment: 15 pages, pd
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