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We investigate within a quark-meson coupling (QMC) model, the structure of the bound $\Xi^-$ hypernucleus $^{15}{\!\!\!_{\Xi^-}}$C ($^{14}$N + $\Xi^-$), which has been observed in a recent analysis of the KEK-E373 experiment. In the QMC model, light quarks in nonoverlapping nucleon and $\Xi^-$ bags interact self-consistently with isoscalar-scalar ($\sigma$), isoscalar-vector ($\omega$), and isovector-vector ($\rho$) mesons in the mean field approximation. The parameters of the model (quark-meson coupling constants and masses) are mostly fixed from the nuclear matter saturation properties. The QMC model closely reproduces the separation energies of the two $\Xi^-$ hyperon states in $^{15}{\!\!\!_{\Xi^-}}$C reported in the KEK-E373 analysis, and identifies their quantum numbers. We also make predictions for the cross sections for the production of the $^{15}{\!\!\!_{\Xi^-}}$C hypernuclear specta in the ($K^-, K^+$) reaction on a $^{15}$O target within a covariant effective Lagrangian model using the $\Xi^-$ bound state spinors obtained within the same QMC model., Comment: 17 Pages, 4 figures

We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the $t$-channel $D^0$ and $D^{*0}$ meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus $^{16}_{\Lambda_c^+}$O in the antiproton - $^{16}$O collisions. For antiproton beam momenta of interest to the ${\bar P}ANDA$ experiment, the 0$^\circ$ differential cross sections for the formation of $^{16}_{\Lambda_c^+}$O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few $\mu$b/sr., Comment: 5 pages, 3 figures, Talk presented at the conference "Light-Cone 2017", held at Mumbai India, Sept 18 - 22, 2017. Version as printed in the Journal. arXiv admin note: text overlap with arXiv:1701.02225

We study the productions of charmed baryons ${\bar \Lambda}_c^- \Lambda_c^+$, ${\bar \Lambda}_c^- \Sigma_c^+$, and ${\bar \Sigma}^- \Sigma_c^+$ in the antiproton-proton collisions within an effective Lagrangian model that has only the baryon-meson degrees of freedom and involves the physical hadron masses. The baryon production proceeds via the $t$-channel exchanges of $D^0$ and $D^{*0}$ mesons in the initial collision of the antiproton with the target proton. The distortion effects in the initial and final states are accounted for by using an eikonal approximation-based procedure. We find that the reaction amplitudes of all the production channels are dominated by the $D^{*0}$ meson-exchange diagrams. We discuss the relative roles of tensor and vector components of the $D^{*0}$ coupling in the $D^{*0}$ meson-exchange component of the total production cross sections. The magnitudes of the cross sections are predicted for each final state for the range of beam momenta of relevance to the ${\bar P}ANDA$ experiment., Comment: 16 pages, 5 figures. typos corrected, version accepted for publication in Phys. Rev. D. arXiv admin note: text overlap with arXiv:1406.7071

We use the Coulomb dissociation (CD) method to calculate the rate of the $^{36}$Mg(${n,\gamma}$)$^{37}$Mg radiative capture reaction. The CD cross sections of the $^{37}$Mg nucleus on a $^{208}$Pb target at the beam energy of 244 MeV/nucleon, for which new experimental data have recently become available, were calculated within the framework of a finite range distorted wave Born approximation theory that is extended to include the projectile deformation effects. Invoking the principle of detailed balance, these cross sections are used to determine the excitation function and subsequently the rate of the $^{36}$Mg($n,\gamma$)$^{37}$Mg reaction. We compare these rates to those of the $^{36}$Mg($\alpha,n$)$^{39}$Si reaction calculated within a Hauser-Feshbach model. We find that for $T_9$ as large as up to 1.0 (in units of 10$^9$ K) the $^{36}$Mg($n,\gamma$)$^{37}$Mg reaction is much faster than the $^{36}$Mg($\alpha,n$)$^{39}$Si one. The inclusion of the effects of $^{37}$Mg projectile deformation in the breakup calculations, enhances the ($n,\gamma$) reaction rate even further. Therefore, it is highly unlikely that the $(n,\gamma)$ $\beta$-decay $r$-process flow will be broken at the $^{36}$Mg isotope by the $\alpha$-process., Comment: Published in Physical Review C

We investigate the production of charm-baryon hypernucleus $^{16}_{\Lambda_c^+}$O in the antiproton - $^{16}$O collisions within a fully covariant model that is based on an effective Lagrangian approach. The explicit ${\bar \Lambda}_c^ - \Lambda_c^+$ 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 $\Lambda_c^+$ 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 various vertices are taken to be the same as those used in our previous study of the elementary ${\bar p} + p \to {\bar \Lambda}_c^- + \Lambda_c^+$ reaction. We find that for antiproton beam momenta of interest to the ${\bar P}ANDA$ experiment, the 0$^\circ$ differential cross sections for the formation of $^{16}_{\Lambda_c^+}$O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few $\mu$b/sr., Comment: 17 pages, 5 figures, Journal print version

We study the $\bar D D$ (${\bar D}^0 D^0$ and $D^-D^+$) charm meson pair production in antiproton (${\bar p}$) induced reactions on nuclei at beam energies ranging from threshold to several GeV. Our model is based on an effective Lagrangian approach that has only the baryon-meson degrees of freedom and involves the physical hadron masses. The reaction proceeds via the $t$-channel exchanges of $\Lambda_c^+$, $\Sigma_c^+$, and $\Sigma_c^{++}$ baryons in the initial collision of the antiproton with one of the protons of the target nucleus. The medium effects on the exchanged baryons are included by incorporating in the corresponding propagators, the effective charm baryon masses calculated within a quark-meson coupling (QMC) model. The wave functions of the bound proton have been determined within the QMC model as well as in a phenomenological model where they are obtained by solving the Dirac equation with appropriate scalar and vector potentials. The initial- and final-state distortion effects have been approximated by using an eikonal approximation-based procedure. Detailed numerical results are presented for total and double differential cross sections for the ${\bar D}^0 D^0$ and $D^-D^+$ production reactions on $^{16}$O and $^{90}$Zr targets. It is noticed that at ${\bar p}$ beam momenta of interest to the ${\bar P}ANDA$ experiment, medium effects lead to noticeable enhancements in the charm meson production cross sections., Comment: 23 pages, 8 figures, Journal print version

We study the breakup of $^{37}$Mg on Pb at 244MeV/u with the recently developed extended theory of Coulomb breakup within the post-form finite range distorted wave Born approximation that includes deformation of the projectile. Comparing our calculated cross section with the available Coulomb breakup data we determine the possible ground state configuration of $^{37}$Mg., Comment: 6 pages, 2 figures, Proceedings of the 12th International conference on Nucleus-Nucleus collisions (NN2015), June 21-26, Catania, Italy

We study the charmed meson pair (${\bar D}^0 D^0$ and $D^- D^+$) production in ${\bar p}p$ annihilation within an effective Lagrangian model that has only the baryon-meson degrees of freedom and involves the physical hadron masses. The reaction amplitudes include terms corresponding to the t-channel $\Lambda_c^+$, $\Sigma_c^+$ and $\Sigma_c^{++}$ baryon exchanges and the s-channel excitation, propagation and decay of the $\Psi$(3770) resonance into the charmed mesons. The initial- and final-state distortion effects have been accounted for by using a simple eikonal approximation-based procedure in the same way as was done in our previous study of the ${\bar p}p \to {\bar \Lambda}_c^-\Lambda_c^+$ reaction within a similar model. The ${\bar D}^0 D^0$ production reaction is dominated by the $\Lambda_c^+$ baryon exchange process, and the corresponding total cross sections are predicted to be in the range of 0.18 - 0.7 $\mu$b for antiproton beam momenta varying between threshold and 20 $GeV/c$. The $\Psi$(3770) resonance contributions have a large influence on the differential cross sections of the $D^- D^+$ production reaction., Comment: 23 pages, 10 figures, Journal Print version

We calculate Coulomb breakup of the neutron rich nucleus $^{37}$Mg on a Pb target at the beam energy of 244 MeV/nucleon within the framework of a finite range distorted wave Born approximation theory that is extended to include the effects of projectile deformation. In this theory, the breakup amplitude involves the full wave function of the projectile ground state. Calculations have been carried out for the total one-neutron removal cross section $(\sigma_{-1n})$, the neutron-core relative energy spectrum, the parallel momentum distribution of the core fragment, the valence neutron angular, and energy-angular distributions. The calculated $\sigma_{-1n}$ has been compared with the recently measured data to put constraints on the spin parity, and the one-neutron separation energy ($S_n$) of the $^{37}$Mg ground state ($^{37}$Mg$_{gs}$). The dependence of $\sigma_{-1n}$ on the deformation of this state has also been investigated. While a spin parity assignment of $7/2^-$ for the $^{37}$Mg$_{gs}$ is ruled out by our study, neither of the $3/2^-$ and $1/2^+$ assignments can be clearly excluded. Using the spectroscopic factor of one for both the $3/2^-$ and $1/2^+$ configurations and ignoring the projectile deformation effects, the $S_n$ values of $0.35 \pm 0.06$ MeV and $0.50 \pm 0.07$ MeV, respectively, are extracted for the two configurations. However, the extracted $S_n$ is strongly dependent on the spectroscopic factor and the deformation effects of the respective configuration. The narrow parallel momentum distribution of the core fragment and the strong forward peaking of the valence neutron angular distribution suggest a one-neutron halo configuration in either of the $2p_{3/2}$ and $2s_{1/2}$ configurations of the $^{37}$Mg ground state., Comment: 11 figures, 32 pages, version to be published in Nucl. Phys. A