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V. B. Kopeliovich

Publications and source records attributed to V. B. Kopeliovich.

At least 19 recordsLinked to original sources
arXiv2020

Charmed and beautiful baryonic systems (hypernuclei) in chiral soliton models

The binding energies of baryonic systems with quantum number charm or beauty and neutron excess (or large isospin) are estimated within the bound state version of the chiral topological soliton model. The procedure of the skyrmion rescaling is applied which is of importance for large enough flavor excitation energies (for heavy flavors). Inclusion of the flavor excitation energies into the minimization of the total mass of the baryonic state naturally leads to its decrease, and this effect increases with increasing flavor mass. Our results concerning the binding energies turned out to be partly negative.

nucl-th↗
arXiv2014

Nuclear Glory Phenomenon

Analytical explanation of the nuclear glory effect, which is similar to the known optical (atmospheric) glory phenomenon, is presented. It is based on the small phase space method for the multiple interaction processes probability estimates and leads to the characteristic angular dependence of the production cross section $dσ\sim 1/ \sqrt {π- θ}$ in the vicinity of the strictly backward direction, for any number of interactions $N\geq 3$, either elastic or inelastic. Rigorous proof of this effect is given for the case of the optimal kinematics, as well as for arbitrary polar scattering angles in the case of the light particle rescattering, but the arguments in favor of the backward azimuthal (axial) focusing are quite general and hold for any kind of the multiple interaction processes. Such behaviour of the cross section near the backward direction agrees qualitatively with available data. In the small interval of final angles including the value $θ=π$ the angular dependence of the cumulative particle production cross section can have the crater-like (or funnel-like) form. Further studies including, probably, certain numerical calculations, are necessary to clear up this point.

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arXiv2013

Baryon Number Violation

This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.

hep-ph↗
arXiv2005

Mass splittings of nuclear isotopes in chiral soliton approach

The differences of the masses of nuclear isotopes with atomic numbers between \~10 and ~30 can be described within the chiral soliton approach in satisfactory agreement with data. Rescaling of the model is necessary for this purpose - decrease of the Skyrme constant by about 30%, providing the "nuclear variant" of the model. The asymmetric term in Weizsaecker-Bethe- Bacher mass formula for nuclei can be obtained as the isospin dependent quantum correction to the nucleus energy. Some predictions for the binding energies of neutron rich nuclides are made in this way, from, e.g. Be-16 and B-19 to Ne-31 and Na-32. Neutron rich nuclides with high values of isospin are unstable relative to strong interactions. The SK4 (Skyrme) variant of the model, as well as SK6 variant (6-th order term in chiral derivatives in the lagrangian as solitons stabilizer) are considered, and the rational map approximation is used to describe multiskyrmions.

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arXiv2005

Mass terms in the Skyrme Model

We consider various forms of the mass term that can be used in the Skyrme model and their implications on the properties of baryonic states. We show that, with an appropriate choice for the mass term, without changing the asymptotic behaviour of the profile functions at large $r$, we can considerably reduce or increase the mass term's contribution to the classical mass of the solitons. We find that multibaryon configurations can be classically bound at large baryon numbers for some choices of this mass term.

hep-th↗
arXiv2004

Flavored exotic multibaryons and hypernuclei in topological soliton models

The energies of baryon states with positive strangeness, or anti-charm (-beauty) are estimated in chiral soliton approach, in the "rigid oscillator" version of the bound state soliton model proposed by Klebanov and Westerberg. Positive strangeness states can appear as relatively narrow nuclear levels (Theta-hypernuclei), the states with heavy anti-flavors can be bound with respect to strong interactions in the original Skyrme variant of the model (SK4 variant). The binding energies of anti-flavored states are estimated also in the variant of the model with 6-th order term in chiral derivatives in the lagrangian as solitons stabilizer (SK6 variant). The latter variant is less attractive, and nuclear states with anti-charm or anti-beauty can be unstable relative to strong interactions. The chances to get bound hypernuclei with heavy antiflavors are greater within "nuclear variant" of the model with rescaled model parameter (Skyrme constant e or e' decreased by ~30%) which is expected to be valid for baryon numbers greater than B ~10. The rational map approximation is used to describe multiskyrmions with baryon number up to ~30 and to calculate the quantities necessary for their quantization (moments of inertia, sigma-term, etc.).

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arXiv2003

Hypernuclei as chiral solitons

The identification of flavored multiskyrmions with the ground states of known hypernuclei is successful for several of them, e.g. for isodoublet H(Lambda) - He(Lambda), A=4, isoscalars He(Lambda) (A=5) and Li(Lambda) (A=7). In other cases agreement is not so good, but the behaviour of the binding energy with increasing baryon number is in qualitative agreement with data. Charmed or beauty hypernuclei within this approach are predicted to be bound stronger than strange hypernuclei. This conclusion is stable against variation of poorly known heavy flavor decay constants.

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arXiv2003

Exotic baryon states in topological soliton models

The novel observation of an exotic strangeness S=+1 baryon state at 1.54 GeV will trigger an intensified search for this and other baryons with exotic quantum numbers. This state was predicted long ago in topological soliton models. We use this approach together with the new datum in order to investigate its implications for the baryon spectrum. In particular we estimate the positions of other pentaquark and septuquark states with exotic and with non-exotic quantum numbers.

hep-ph↗
arXiv2003

Energy-Charge Dependence for Q-Balls

We show that many numerically established properties of Q-balls can be understood in terms of analytic approximations for a certain type of potential. In particular, we derive an explicit formula between the energy and the charge of the Q-ball valid for a wide range of the charge Q.

hep-th↗
arXiv2002

Approximate analytical solutions of the baby Skyrme model

In present paper we show that many properties of the baby skyrmions, which have been determined numerically, can be understood in terms of an analytic approximation. In particular, we show that this approximation captures properties of the multiskyrmion solutions (derived numerically) such as their stability towards decay into various channels, and that it is more accurate for the "new baby Skyrme model" which describes anisotropic physical systems in terms of multiskyrmion fields with axial symmetry. Some universal characteristics of configurations of this kind are demonstrated, which do not depend on their topological number.

hep-th↗
arXiv2000

Skyrmions from SU(3) harmonic maps and their quantization

Static properties of SU(3) multiskyrmions with baryon number up to 6 (classical masses and momenta of inertia) are estimated. The calculations are based on the recently suggested generalization of the SU(2) rational map ansaetze applied to the SU(3) model. Both SU(2) embedded skyrmions and genuine SU(3) solutions are considered, and it is shown that although, at the classical level, the energy of embeddings is lower, the quantum corrections can alter this conclusion. This correction to the energy of lowest state, bilinear in the Wess-Zumino (WZ) term, is presented for the most general case as a convolution of the inverse tensor of inertia and the components of the WZ-term.

hep-th↗
arXiv1999

Multibaryons with strangeness, charm and bottom

Static properties of multiskyrmions with baryon numbers up to 8 are calculated, including momenta of inertia and sigma-term. The calculations are based on the recently suggested SU(2) rational map ansaetze. Minimization with the help of SU(3) variational minimization program shows that these configurations become local minima in SU(3) configuration space. The B-number dependence of the so called flavour moment of inertia of multiskyrmions playing an important role in the quantization procedure is close to the linear one. The spectra of baryonic systems with strangeness, charm and bottom are considered within a "rigid oscillator" version of the bound state soliton model. The binding energies estimates are made for the states with largest isospin which can appear as negatively charged nuclear fragments, as well as for states with zero isospin - light fragments of "flavoured" nuclear matter. Our results confirm the previously made observation that baryonic systems with charm or bottom quantum numbers have more chance to be stable with respect to strong interactions than strange baryonic systems.

hep-ph↗
arXiv1999

Flavoured multiskyrmions

Static properties of multiskyrmions with baryon numbers up to 8 are calculated starting from recently given rational map ansaetze. The spectra of baryonic systems with strangeness, charm and bottom are estimated within a "rigid oscillator" version of the bound state soliton model. It is suggested that the recently observed negatively charged nuclear fragment can be considered as quantized strange multiskyrmion with baryon number 6 or 7 and large value of strangeness. In agreement with previous observation, it is argued that baryonic systems with charm or bottom quantum numbers have more chances to be bound with respect to strong interactions than strange baryonic systems.

hep-ph↗
arXiv1998

Strangeness, charm and bottom in a chiral quark-meson model

In this paper we investigate an SU(3) extension of the chiral quark-meson model. The spectra of baryons with strangeness, charm and bottom are considered within a "rigid oscillator" version of this model. The similarity between the quark part of the Lagrangian in the model and the Wess-Zumino term in the Skyrme model is noted. The binding energies of baryonic systems with baryon number B=2 and 3 possessing strangeness or heavy flavor are estimated. The results obtained are in good qualitative agreement with those obtained previously in the topological soliton (Skyrme) model.

hep-ph↗
arXiv1998

Baryonic systems with charm and bottom in the bound state soliton model

The binding energies of baryonic systems (BS) with baryon number $B=2, 3$ and 4 possessing heavy flavor, charm and bottom, are estimated within the rigid oscillator version of the bound state approach to chiral soliton models. Two tendencies are noted: the binding energy increases with increasing mass of the flavor and with increasing $B$. Therefore, the charmed or bottomed baryonic systems have more chances to be bound than strange baryonic systems discussed previously. The flavor symmetry breaking in decay constants $F$ is considered which is especially important for baryonic systems with bottom quantum numbers. Generally, for heavy flavors the scale of the binding energies of BS depends on the scale of flavor symmetry violation in $r_F=F_F/F_π$.

hep-ph↗
arXiv1997

Semiclassical quantization of SU(3) skyrmions

Semiclassical quantization of the SU(3)-skyrmions is performed by means of the collective coordinate method. The quantization condition known for the SU(2)-solitons quantized with SU(3) collective coordinates is generalized for the SU(3) skyrmions with strangeness content different from zero. Quantization of the dipole-type configuration with large strangeness content found recently is considered as an example, the spectrum and the mass splitting of the quantized states are estimated. The energy and baryon number density of SU(3) skyrmions are presented in the form emphasizing their symmetry in different SU(2) subgroups of SU(3), and the lower boundary for the static energy of SU(3) skyrmions is derived.

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