Production yields of single-$Λ$ hypernuclei from simulated peripheral annihilations of antiprotons after capture on various target nuclei are reported. The initial annihilation process and the production of excited hypernuclei are estimated within the GiBUU transport framework, while their deexcitation process is treated with the ABLA++ code. The yield of excited hypernuclei range from $\sim$ 0.3% for $^{16}$O to $\sim$ 1.2% for $^{132}$Xe per annihilation, consistent with previous measurements at LEAR, CERN. The yield of specific ground state hypernuclei after deexcitation reaches up to a few 10$^{-4}$ per annihilation. The hypernuclei are produced in strangeness exchange reactions occuring between a nucleon of the target and the kaons originating from the annihilation in $\sim$ 80% of the cases, while the strangeness pair production in secondary pion-nucleon collision contributes to the remaining $\sim$ 20%. The simulations indicate that antiproton annihilations at rest on different nuclei could populate a wide range of so-far unexplored hypernuclei.
We investigate for the first time the influence of hyperon-nucleon (YN) interaction models on the strangeness dynamics of antiproton- and $Ξ$-nucleus interactions. Of particular interest is the formation of bound multi-strangeness hypermatter in reactions relevant for \panda. The main features of two well-established microscopic approaches for YN-scattering are first discussed and their results are then analysed such that they can be applied in transport-theoretical simulations. The transport calculations for reactions induced by antiproton beams on a primary target including also the secondar…
We investigate the production of charm-baryon hypernucleus $^{16}_{Λ_c^+}$O in the antiproton - $^{16}$O collisions within a fully covariant model that is based on an effective Lagrangian approach. The explicit ${\bar Λ}_c^ - Λ_c^+$ production vertex is described by the $t$-channel $D^0$ and $D^{*0}$ meson-exchanges in the initial collision of the incident antiproton with one of the protons of the target nucleus. The $Λ_c^+$ bound state spinors as well as the self-energies of the exchanged mesons employed in our calculations are derived from the quark-meson coupling model. The parameters of va…
We study the properties of double-$Λ$ hypernuclei in the relativistic mean-field theory, which has been successfully used for the description of stable and unstable nuclei. With the meson-hyperon couplings determined by the experimental binding energies of single-$Λ$ hypernuclei, we present a self-consistent calculation of double-$Λ$ hypernuclei in the relativistic mean-field theory, and discuss the influence of hyperons on the nuclear core. The contribution of two mesons with dominant strange quark components (scalar $σ^*$ and vector $ϕ$) to the $ΛΛ$ binding energy of double-$Λ$ hypernuclei i…
Several aspects about $Λ$-hypernuclei in the relativistic mean field theory, including the effective $Λ$-nucleon coupling strengths based on the successful effective nucleon-nucleon interaction PK1, hypernuclear magnetic moment and $\barΛ$-hypernuclei, have been presented. The effect of tensor coupling in $Λ$-hypernuclei and the impurity effect of $\barΛ$ to nuclear structure have been discussed in detail.
Hypernuclei have been studied within the framework of Relativistic Mean Field theory. The force FSU Gold has been extended to include hyperons. The effective hyperon-nucleon and nucleon-nucleon interactions have been obtained by fitting experimental energies in a number of hypernuclei over a wide range of mass. Calculations successfully describe various features including hyperon separation energy and single particle spectra of single-Λhypernuclei throughout the periodic table. We also extend this formalism to double-Λhypernuclei.
Single--particle spectra of $Λ$ and $Σ$ hypernuclei are calculated within a relativistic mean--field theory. The hyperon couplings used are compatible with the $Λ$ binding in saturated nuclear matter, neutron-star masses and experimental data on $Λ$ levels in hypernuclei. Special attention is devoted to the spin-orbit potential for the hyperons and the influence of the $ρ$-meson field (isospin dependent interaction).
The density dependent relativistic hadron field theory is used to describe single particle properties of Lambda hypernuclei. The discussion focuses on the spin-orbit systematics in the relativistic mean-field formalism by discussing general effects of the Lambda continuum threshold and the delocalization of the Lambda wave function. Theoretical predictions for the hypernuclear Auger effect are presented.
We have investigated the properties of $Θ^{+}$ in nuclei within the framework of relativistic mean field. The coupling constants are educed with quark meson coupling model. There is strong attractive interaction for $Θ^{+}$-nucleus and $Θ^{+}$ can be bind in nuclei. The depth of optical potential for $Θ^{+}$ in nuclear matter is estimated.
A self-consistent description for hot $Λ$ hypernuclei in hypothetical big boxes is developed within the relativistic Thomas-Fermi approximation in order to investigate directly the liquid-gas phase coexistence in strangeness finite nuclear systems. We use the relativistic mean-field model for nuclear interactions. The temperature dependence of $Λ$ hyperon density, $Λ$ hyperon radius, excitation energies, specific heat, and the binding energies of $Λ$ hypernuclei from $^{16}_Λ$O to $^{208}_Λ$Pb in phase transition region are calculated by using the subtraction procedure in order to separate the…
We develop a chiral SU(3) symmetric relativistic mean field (RMF) model with a logarithmic potential of scalar condensates. Experimental and empirical data of symmetric nuclear matter saturation properties, bulk properties of normal nuclei, and separation energies of single- and double-$Λ$ hypernuclei are well explained. The nuclear matter equation of state (EOS) is found to be softened by $σζ$ mixing which comes from determinant interaction. The neutron star matter EOS is further softened by $Λ$ hyperons.
In this work, we conduct a study on the properties of single-Λ hypernuclei in the relativistic mean-field theory with the parameter set FSU, where the isoscalar-isovector coupling has been included to soften the symmetry energy. In our model, a tensor coupling between ω and Λ is employed, which is found to be essential in obtaining the small spin-orbit interaction in single-Λ hypernuclei. Our calculated values of Λ single-particle energies are in good agreement with the known experimental data. As a comparison to other existing parameter sets, calculations are also carried out by using paramet…
The Relativistic Hartree Bogoliubov model in coordinate space, with finite range pairing interaction, is applied to the description of $Λ$-hypernuclei with a large neutron excess. The addition of the $Λ$ hyperon to Ne isotopes with neutron halo can shift the neutron drip by stabilizing an otherwise unbound core nucleus. The additional binding of the halo neutrons to the core originates from the increase in magnitude of the spin-orbit term. Although the $Λ$ produces only a fractional change in the central mean-field potential, through a purely relativistic effect it increases the spin-orbit ter…
New effective $ΛN$ interactions are proposed for the density dependent relativistic mean field model. The multidimensionally constrained relativistic mean field model is used to calculate ground state properties of eleven known $Λ$ hypernuclei with $A\ge 12$ and the corresponding core nuclei. Based on effective $NN$ interactions DD-ME2 and PKDD, the ratios $R_σ$ and $R_ω$ of scalar and vector coupling constants between $ΛN$ and $NN$ interactions are determined by fitting calculated $Λ$ separation energies to experimental values. We propose six new effective interactions for $Λ$ hypernuclei: DD…
Deformed multi-$Λ$ hypernuclei are studied within a relativistic mean-field model. In this paper, we take some $N=Z$ "hyper isotope" chains, i.e., $^{8+n}_{\ \ nΛ}{\rm Be}$, $^{20+n}_{\ \ \ nΛ}{\rm Ne}$, and $^{28+n}_{\ \ \ nΛ}{\rm Si}$ systems where $n = 2$, $4$ for Be, and $n = 2$, $8$ for Ne and Si. A sign of two-$^6_{2Λ}$He cluster structure is observed in the two-body correlation in $^{12}_{4Λ}$Be. In the Ne hyper isotopes, the deformation is slightly reduced by addition of $Λ$ hyperons whereas it is significantly reduced or even disappears in the Si hyper isotopes.
Having in mind its future extension for theoretical investigations related to charmed nuclei, we develop a relativistic formalism for the nonmesonic weak decay of single-$Λ$ hypernuclei in the framework of the independent-particle shell model and with the dynamics represented by the $(π,K)$ one-meson-exchange model. Numerical results for the one-nucleon-induced transition rates of ${}^{12}_Λ\textrm{C}$ are presented and compared with those obtained in the analogous nonrelativistic calculation. There is satisfactory agreement between the two approaches, and the most noteworthy difference is tha…
Neutron and proton driplines of single-$Λ$ and double-$Λ$ hypernuclei, $Ξ^{-}$ hypernuclei as well as normal nuclei are studied within a relativistic mean field approach using an extended form of the FSU Gold Lagrangian density. Hyperons are found to produce bound nuclei beyond the normal nuclear driplines. Radii are found to decrease in hypernuclei near the driplines, in line with observations in light $Λ$ hypernuclei near the stability valley, The inclusion of a $Ξ^{-}$ introduces a much larger change in radii than one or more $Λ$'s.
We review the relativistic mean-field approach to various aspects of hypernuclei. It was Brockmann and Weise who first applied this approach to hypernuclei. At that time, it had been already observed experimentally that the spin-orbit splittings in hypernuclei are significantly smaller than that in ordinary nuclei. The relativistic approach was suitable for a discussion of spin-orbit splittings in hypernuclei, as the spin-orbit interaction is naturally emerged with the relativistic framework. Since this seminal work, many developments have been done and the relativistic approach has been appli…
Based on relativistic mean field (RMF) models, we study finite $Λ$-hypernuclei and massive neutron stars. The effective $N$-$N$ interactions PK1 and TM1 are adopted, while the $N$-$Λ$ interactions are constrained by reproducing the binding energy of $Λ$-hyperon at $1s$ orbit of $^{40}_Λ$Ca. It is found that the $Λ$-meson couplings follow a simple relation, indicating a fixed $Λ$ potential well for symmetric nuclear matter at saturation densities, i.e., around $V_Λ = -29.786$ MeV. With those interactions, a large mass range of $Λ$-hypernuclei can be well described. Furthermore, the masses of PS…
This research article is a follow up of earlier work by M. Ikram et al., reported in International Journal of Modern Physics E {\bf{25}}, 1650103 (2016) wherein we searched for $Λ$ magic numbers in experimentally confirmed doubly magic nucleonic cores in light to heavy mass region (ie.$^{16}O - ^{208}Pb$) by injecting $Λ$'s into them. In present manuscript, working within the state-of-art relativistic mean field theory with inclusion of $ΛN$ and $ΛΛ$ interaction in hypernuclei using the predicted doubly magic nucleonic cores ie. $^{292}$120, $^{304}$120, $^{360}$132, $^{370}$132, $^{336}$138, …
The density dependent relativistic hadron field theory is extended to also describe strange systems. It is seen that the application to hypernuclei works extremely well. Important spin orbit effects in lambda hypernuclei are studied and their experimental relevance is pointed out.
We study the binding energies, radii, single-particle energies, spin-orbit potential and density profile for multi-strange hypernuclei in the range of light mass to superheavy region within the relativistic mean field (RMF) theory. The stability of multi-strange hypernuclei as a function of introduced hyperons ($Λ$ and $Σ$) is investigated. The neutron, lambda and sigma mean potentials are presented for light to superheavy hypernuclei. The inclusion of hyperons affects the nucleon, lambda and sigma spin-orbit potentials significantly. The bubble structure of nuclei and corresponding hypernucle…
Stored antiprotons beams in the GeV range represent a unparalleled factory for hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of strange hadronic systems with unprecedented precision. The behavior of hyperons and -- for the first time -- of antihyperons in nuclear systems can be studied under well controlled conditions. The exclusive production of $Λ\barΛ$ and $Σ^-\barΛ$ pairs in antiproton-nucleus interactions probe the neutron and proton distribution in the nuclear periphery and will help…
We extend the relativistic Hartree-Fock (RHF) theory to study the structure of single-$Λ$ hypernuclei. The density dependence is taken in both meson-nucleon and meson-hyperon coupling strengths, and the induced $Λ$-nucleon ($ΛN$) effective interactions are determined by fitting $Λ$ separation energies to the experimental data for several single-$Λ$ hypernuclei. The equilibrium of nuclear dynamics described by the RHF model in normal atomic nuclei, namely, the balance between nuclear attractive and repulsive interactions, is then found to be drastically changed in single-$Λ$ hypernuclei, reveal…
We generalized our approach to the hypernuclei with $A=B=3$ containing one charm or one bottom quark. We derive the relativistic nine-quark equations using the dispersion relation technique. The hypernuclei as the system of interacting quarks and gluons are considered. The relativistic nine-quark amplitudes of hypernuclei, including the constituent quarks with the charm or bottom are calculated. The approximate solutions of these equations are obtained using a method based on the extraction of leading singularities of the amplitudes. The poles of the multiquark amplitudes allow us to determine…
We report the recent progress in relativistic mean-field (RMF) and beyond approaches for the low-energy structure of deformed hypernuclei. We show that the $Λ$ hyperon with orbital angular momentum $\ell=0$ (or $\ell>1$) generally reduces (enhances) nuclear quadrupole collectivity. The beyond mean-field studies of hypernuclear low-lying states demonstrate that there is generally a large configuration mixing between the two components $[^{A-1}Z (I^+) \otimes Λp_{1/2}]^J$ and $[^{A-1}Z (I\pm2 ^+) \otimes Λp_{3/2}]^J$ in the hypernuclear $1/2^-_1, 3/2^-_1$ states. The mixing weight increases as t…
The density dependent relativistic hadron (DDRH) theory is introduced as an effective field theory for nuclei and hypernuclei. A Dirac-Brueckner approach to in-medium nucleon-hyperon interactions is presented. Density dependent meson-baryon vertices are determined from DBHF self-energies in infinite matter. Scaling laws for hyperon vertices are derived from a diagrammatic analysis of self-energies. In a local density approximation the DB vertices are applied in relativistic DDRH Hartree calculations to finite hypernuclei. Lambda single particle spectra and spin-orbit splittings are described r…
The relativistic mean-field theory with Green's function method is extended to study $Λ$ hypernuclei. Taking hypernucleus $^{61}_Λ$Ca as an example, the single-particle resonant states for $Λ$ hyperons are investigated by analyzing density of states and the corresponding energies and widths are given. Different behaviors are observed for the resonant states, i.e., the distributions of the very narrow $1f_{5/2}$ and $1f_{7/2}$ states are very similar as bound states while that of the wide $1g_{7/2}$ and $1g_{9/2}$ states are like scattering states. Besides, the impurity effect of $Λ$ hyperons o…
We study the superdeformed (SD) states and corresponding SD hypernuclei of Ar isotopes with the multidimensionally-constrained relativistic mean field (MDC-RMF) models which can accommodate various shape degree of freedom. %The hyperon-nucleon $σ$-$Λ$ and $ω$-$Λ$ interactions are introduced %in the same covariant framework. We found that the density profiles of SD states in Ar isotopes show a strong localization with a ring structure near the surface, while the central part of the density is dilute showing a hole structure. This localization of SD density induces an appreciable deformation in …
We extend the relativistic point coupling model to single-$Λ$ hypernuclei. For this purpose, we add $N$-$Λ$ effective contact couplings to the model Lagrangian, and determine the parameters by fitting to the experimental data for $Λ$ binding energies. Our model well reproduces the data over a wide range of mass region although some of our interactions yield the reverse ordering of the spin-orbit partners from that of nucleons for heavy hypernuclei. The consistency of the interaction with the quark model predictions is also discussed.
Low-lying hypernuclei $ ^3_ΛH$, $ ^3_ΣH$, $ ^3_ΛHe$, $ ^3_ΣHe$ are described by the relativistic nine-quark equations 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 nine-quark amplitudes of hypernuclei, including the quarks of three flavors ($u$, $d$, $s$) are calculated. The poles of these amplitudes determine the masses of hypernuclei. The mass of state $ ^3_ΛH$ with the isospin I=0 and the spin-parity $J^P=\frac{1}{2}^+$ is e…
Within a dynamical and statistical approach we study the main regularities in production of hypernuclei coming from projectile and target residues in relativistic ion collisions. We demonstrate that yields of hypernuclei increase considerably above the energy threshold for Lambda hyperons, and there is a saturation for yields of single hypernuclei with increasing the beam energy up to few TeV. Production of specific hypernuclei depend very much on the isotopic composition of the projectile, and this gives a chance to obtain exotic hypernuclei that may be difficult to reach in traditional hyper…
We present, using the statistical model, an analysis of the production of light nuclei, hypernuclei and their antiparticles in central collisions of heavy nuclei. Based on these studies we provide predictions for the production yields of multiply-strange light nuclei.
Hypernuclei $ ^4_Y He$, $ ^4_Y H$, $ ^4_{YY} He$, $ ^4_{YY} H$, where $Y=Λ$, $Σ_0$, $Σ_+$, $Σ_-$, A=4 are considered using the relativistic twelve-quark equations in the framework of the dispersion relation technique. Hypernuclei as the systems of interacting quarks and gluons are considered. The relativistic twelve-quark amplitudes of hypernuclei, including $u$, $d$, $s$ quarks are constructed. The approximate solutions of these equations are obtained using a method based on the extraction of leading singularities of the amplitudes. The poles of the multiquark amplitudes allow us to determine…
The production of strangeness on the nucleon and hyperon and hypernuclear production in heavy ion collisions at relativistic energies and in antiproton annihilation on nuclei is discussed. The reaction process is described by transport theory with focus on $S=-2$ channels and a comparison of different model interactions. The interactions of hyperons in nuclear matter is investigated in a novel SU(3) approach. An outlook to the $S=-3$ sector and $Ω^-$ physics is given.
The production of antiprotons in proton-nucleus and nucleus-nucleus reactions is calculated within the relativistic BUU approach employing proper selfenergies for the baryons and antiprotons and treating the p-bar annihilation nonperturbatively. The differential cross section for the antiprotons is found to be very sensitive to the p-bar selfenergy adopted. A detailed comparison with the available experimental data for p-nucleus and nucleus-nucleus reactions shows that the antiproton feels a moderately attractive mean-field at normal nuclear matter density which is in line with a dispersive po…
The Giessen Boltzmann-Uehling-Uhlenbeck transport model with relativistic mean fields is used to simulate $\bar p$-nucleus collisions. Antiproton absorption cross sections and momentum distributions of annihilation products are calculated by varying the $\bar p$ coupling strength to the mean meson fields. Parameters of the antiproton-nucleus optical potential are extracted from the comparison of the model calculations with experimental data.
We investigate the formation of fragments with strangeness degrees of freedom in proton- and heavy-ion-induced reactions at high relativistic energies. The model used is a combination of a dynamical transport model and a statistical approach of fragment formation. We discuss in detail the applicability and limitations of such a hybrid model by comparing data on spectator fragmentation at relativistic $SIS/GSI$-energies. The theoretical results are analyzed in terms of spectator fragmentation with strangeness degrees of freedom such as the production of single-$Λ-{}^{3,4,5}He$ hypernuclei. We p…
Shapes of light normal nuclei and $Λ$-hypernuclei are investigated using relativistic mean field approach. The FSUGold parametrization is used for this purpose. The addition of a $Λ$ is found to change the shape of the energy surface towards prolate. The deformation in a $Λ$-hypernucleus, when the hyperon is in the first excited state, is also discussed. The effect of the inclusion of the hyperon on the nuclear radius is generally small with one exception.
The Density Dependent Relativistic Hadron Field (DDRH) theory, previously introduced and applied to isospin nuclei, is extended to hypernuclei by including the octet hyperons. Infinite matter Dirac-Brueckner theory for octet baryons and the derivation of in-medium DDRH baryon-meson vertices is discussed. From the properties of Dirac-Brueckner interactions it is found that hyperon and nucleon self-energies and vertices are related by the ratios of free space coupling constants. This leads to simple scaling laws for the in-medium hyperon and nucleon vertices. The model is applied in relativistic…
We present a new fit to the LEAR data on antiproton-proton -> pi^- pi^+ differential cross sections and analyzing powers motivated by relativistic considerations. Within a quark model describing this annihilation we argue, since the pions are highly energetic, that relativistic effects cannot be neglected. The intrinsic pion wave functions are Lorentz transformed to the center of mass frame. This change in quark geometry gives rise to additional angular dependence in the transition operators and results in a relative enhancement of higher J \ge 2 partial wave amplitudes. The fit to the data is…
In peripheral collisions of relativistic heavy ions highly excited spectators containing Lambda-hyperons can be produced. Such strange spectator matter may undergo a break-up into many fragments (multifragmentation) as it is well established for ordinary nuclear systems. We generalize the statistical multifragmentation model, previously successfully used for the description of experimental data, for the case of hypernuclear systems. We predict relative yields of hypernuclei and the main characteristics of such a break-up. We point at a connection of this phenomenon with a liquid-gas phase tran…
We study the deformation property of $Λ$ hypernuclei using the relativistic mean field (RMF) method. We find that $^{29}_Λ$Si and $^{13}_Λ$C hypernuclei have spherical shape as a consequence of the additional $Λ$ particle, whereas the corresponding core nuclei, $^{28}$Si and $^{12}$C, are oblately deformed. Most of other hypernuclei have a similar deformation parameter to the core nucleus, in accordance with the previous study with the non-relativistic Skyrme-Hartree-Fock method. We discuss the sensitivity of our results to the choice of pairing interaction and to the parameter set of the RMF …
The impurity effect of hyperon on atomic nuclei has received a renewed interest in nuclear physics since the first experimental observation of appreciable reduction of $E2$ transition strength in low-lying states of hypernucleus $^{7}_Λ$Li. Many more data on low-lying states of $Λ$ hypernuclei will be measured soon for $sd$-shell nuclei, providing good opportunities to study the $Λ$ impurity effect on nuclear low-energy excitations. We carry out a quantitative analysis of $Λ$ hyperon impurity effect on the low-lying states of $sd$-shell nuclei at the beyond-mean-field level based on a relativi…
The relativistic nucleus-nucleus collisions can produce hypernuclei and low-temperature hyper-matter as a result of hyperon capture by nuclear residues and free nucleons. We use the transport, coalescence and statistical models to describe the whole process, and point at the important advantages of such reactions: A broad variety of formed hypernuclei in masses and isospin allows for investigating properties of exotic hypernuclei, as well as the hypermatter both at high and low temperatures. The abundant production of multi-strange nuclei that can give an access to multi-hyperon systems and st…
The shapes of light normal nuclei and $Λ$ hypernuclei are investigated in the $(β, γ)$ deformation plane by using a newly developed constrained relativistic mean field (RMF) model. As examples, the results of some C, Mg, and Si nuclei are presented and discussed in details. We found that for normal nuclei the present RMF calculations and previous Skyrme-Hartree-Fock models predict similar trends of the shape evolution with the neutron number increasing. But some quantitative aspects from these two approaches, such as the depth of the minimum and the softness in the $γ$ direction, differ a lot …
Within a combined approach we investigate the main features of the production of hyper-fragments in relativistic heavy-ion collisions. The formation of hyperons is modelled within the UrQMD and HSD transport codes. To describe the hyperon capture by nucleons and nuclear residues a coalescence of baryons (CB) model was developed. We demonstrate that the origin of hypernuclei of various masses can be explained by typical baryon interactions, and that it is similar to processes leading to the production of conventional nuclei. At high beam energies we predict a saturation of the yields of all hyp…
We study the structure of antiproton spectra at extreme subthreshold bombarding energies using a thermodynamic picture. Antiproton production processes and final state interactions are discussed in detail in order to find out what can be learned about these processes from the observed spectra.
The results of the microscopic transport calculations of $\bar p$-nucleus interactions within a GiBUU model are presented. The dominating mechanism of hyperon production is the strangeness exchange processes $\bar K N \to Y π$ and $\bar K N \to ΞK$. The calculated rapidity spectra of $Ξ$ hyperons are significantly shifted to forward rapidities with respect to the spectra of $S=-1$ hyperons. We argue that this shift should be a sensitive test for the possible exotic mechanisms of $\bar p$-nucleus annihilation. The production of the double $Λ$-hypernuclei by $Ξ^-$ interaction with a secondary ta…
We develop both relativistic mean field and beyond approaches for hypernuclei with possible quadrupole-octupole deformation or pear-like shapes based on relativistic point-coupling energy density functionals. The symmetries broken in the mean-field states are recovered with parity, particle-number, and angular momentum projections. We take $^{21}_Λ$Ne as an example to illustrate the method, where the $Λ$ hyperon is put on one of the two lowest-energy orbits (labeled as $Λ_s, Λ_p$), respectively. We find that the $Λ$ hyperon in both cases disfavors the formation of a reflection-asymmetric molec…
We present a new algorithm to identify fragments in computer simulations of relativistic heavy ion collisions. It is based on the simulated annealing technique and can be applied to n-body transport models like the Quantum Molecular Dynamics. This new approach is able to predict isotope yields as well as hyper-nucleus production. In order to illustrate its predicting power, we confront this new method to experimental data, and show the sensitivity on the parameters which govern the cluster formation.
We present the novel microscopic n-body dynamical transport approach PHQMD(Parton-Hadron-Quantum-Molecular-Dynamics) for the description of particle production and cluster formation in heavy-ion reactions at relativistic energies. The PHQMD extends the established PHSD (Parton-Hadron-String-Dynamics) transport approach by replacing the mean field by density dependent two body interactions in a similar way as in the Quantum Molecular Dynamics (QMD) models. This allows for the calculation of the time evolution of the n-body Wigner density and therefore for a dynamical description of clusters and…
Assuming a~simple spherical relativistic mean field model of the nucleus, we estimate the width of the antiproton--neutron annihilation ($Γ_n$) and the width of antiproton--proton ($Γ_p$) annihilation, in an antiprotonic atom system. This allows us to determine the halo factor $f$, which is then discussed in the context of experimental data obtained in measurements recently done on LEAR utility at CERN. Another quantity which characterizes the deviation of the average nuclear densities ratio from the corresponding ratio of the homogeneous densities is introduced too. It was shown that it is al…
[Background] The hyperon impurity effect in nuclei has been extensively studied in different mean-field models. Recently, there is a controversy about whether the $Λ$ hyperon is more tightly bound in the normal deformed (ND) states than that in the superdeformed (SD) states.[Purpose] This article is aimed to provide a beyond-mean-field study of the low-lying states of hypernuclei with shape coexistence and to shed some light on the controversy.[Method] The models of relativistic mean-field and beyond based on a relativistic point-coupling energy functional are adopted to study the low-lying st…
