The ${}^{14}$O($\alpha ,p$)${}^{17}$F reaction is an important trigger to the $\alpha p$ process in x-ray bursts. Only limited information is available from direct measurements of the reaction cross section, and the time-inverse ${}^{17}$F($p,\alpha$)${}^{14}$O reaction has been frequently used to constrain the astrophysical reaction rate. These time-inverse measurements must be complemented by inelastic ${}^{17}$F($p,p^{\prime }$)${}^{17}$F${}^{*}$ studies to constrain branches populating the first excited state of ${}^{17}$F. Discrepancies in the literature are examined in relationship to directly measured ${}^{17}$F($p,p^{\prime }$)${}^{17}$F${}^{*}$ data, and it is shown that a resolution is possible. Claims of alternative spin assignments for the 6.15-MeV level are also discussed in relationship to the measured inelastic data.

Using the Coulomb modified Glauber model, we analyze the elastic angular distribution and reaction (${\sigma }_R$) and total (${\sigma }_{\mathrm{tot}}$) cross sections of $K^{+}$-${}^{12}$C at 635, 715, and 800 MeV/$c$, and of $K^{+}$-${}^{40}$Ca at 800 MeV/$c$. The basic (input) $K^{+}N$ amplitude is taken from the phase shift analysis, and for nuclear form factors we use the nucleon density distributions as obtained from the analyses of intermediate energy proton scattering experiments and the relativistic mean field (RMF) calculations. The analysis also considers the nuclear medium effects, and predicts the in-medium behavior of the $K^{+}N$ amplitude. We find that the elastic angular distribution is sensitive to the choice of the nucleon density distributions, whereas the nuclear medium effects are better seen in the study of reaction and total cross sections.

A novel analytically solvable prolate-oblate shape phase transitional description for the SU(3) limit of the interacting boson model is investigated for finite-$N$ as well as in the large-$N$ classical limit. It is shown that the ground state shape phase transition is of first order due to level crossing. Through a comparison of the theoretical predictions with available experimental data for even-even ${}^{180}$Hf, ${}^{182-186}$W, ${}^{188-190}$Os, and ${}^{192-198}$Pt, it is shown that this simple novel description is suitable for a description of the prolate-oblate shape phase transition in these nuclei.

The high spin states in the odd-odd ${}^{194}$Tl nucleus have been studied by populating them using the ${}^{185,187}$Re(${}^{13}\text{C},xn$) reactions at a beam energy of 75 MeV. A $\gamma -\gamma$ coincidence measurement has been performed using the INGA array with a digital data acquisition system to record the time-stamped data. Definite spin-parity assignment of the levels was made from the DCO ratio and the IPDCO ratio measurements. The level scheme of ${}^{194}$Tl has been extended up to 4.1 MeV in excitation energy and includes 19 new $\gamma$-ray transitions. The $\pi h_{9/2}\otimes \nu i_{13/2}$ band, in the neighboring odd-odd Tl isotopes, show very similar properties in both experimental observables and calculated shapes. Two new band structures, with six-quasiparticle configuration, have been observed in ${}^{194}$Tl. One of these bands has the characteristics of a magnetic rotational band. Cranked shell model calculations, using a deformed Woods-Saxon potential, have been performed to obtain the total Routhian surfaces in order to study the shapes of the bands and the band crossing in ${}^{194}$Tl. A semiclassical formalism has been used to describe the magnetic rotational band.

Using the isospin-dependent quantum molecular dynamics model, we study the effect of charge asymmetry and isospin-dependent cross section on different aspects of elliptical flow. Simulations are carried out for the reactions of ${}_{z_1}^{124}{\text{X}}_n{+}_{z_1}^{124}{\text{X}}_n$, where $z_1$ $=$ 47, 50, 53, 57, and 59 and ${}_{z_2}^{40}{\text{Y}}_n{+}_{z_2}^{40}{\text{Y}}_n$, where $z_2$ $=$ 14, 16, 18, 21 and 23. Our study shows that the elliptical flow depends strongly on the nature of the cross section. Transition energy, on the other hand, is unaffected by the neutron content.

We discuss results concerning the behavior of hot nuclear sources formed in ${}^{40,48}$Ca+${}^{40,48}$Ca reactions at 25 MeV/nucleon. A correlation between the neutron-to-proton ratio of the total systems and heavy residue production is found. This correlation underlines the strong role played by the neutron-to-proton ratio degree of freedom on the behavior of hot nuclei at intermediate energies. Comparisons of our data with Constrained Molecular Dynamics calculations confirm that a moderately stiff behavior of the symmetry potential must be used to reproduce experimental data. These findings open the way for future investigations with exotic beams at radioactive ion beam facilities.

We discuss a theoretical scheme that accounts for bulk matter, jets, and the interaction between the two. The aim is a complete description of particle production at all transverse momentum ($p_t$) scales. In this picture, the hard initial scatterings result in mainly longitudinal flux tubes, with transversely moving pieces carrying the $p_t$ of the partons from hard scatterings. These flux tubes constitute eventually both bulk matter (which thermalizes and flows) and jets. We introduce a criterion based on parton energy loss to decide whether a given string segment contributes to the bulk or leaves the matter to end up as a jet of hadrons. Essentially low $p_t$ segments from inside the volume will constitute the bulk, high $p_t$ segments (or segments very close to the surface) contribute to the jets. The latter ones appear after the usual flux tube breaking via q-qbar production (Schwinger mechanism). Interesting is the transition region: Intermediate $p_t$ segments produced inside the matter close to the surface but having enough energy to escape, are supposed to pick up q-qbar pairs from the thermal matter rather than creating them via the Schwinger mechanism. This represents a communication between jets and the flowing bulk matter (fluid-jet interaction). Also very important is the interaction between jet hadrons and the soft hadrons from the fluid freeze-out. We employ this picture to investigate Pb-Pb collisions at 2.76 TeV. We discuss the centrality and $p_t$ dependence of particle production and long-range dihadron correlations at small and large $p_t$.

Galactic ${}^{26}$Al is the first radioactive nucleus to be positively identified by $\gamma$-ray astronomy with detection of the 1.809 MeV $\gamma$ ray associated with its decay. This nucleus is destroyed in astrophysical environments in the ${}^{26}$Al($p$,$\gamma$)${}^{27}$Si and inelastic ${}^{26}$Al+$p$ scattering reactions where properties of ${}^{27}$Si levels determine reaction rates. To investigate these properties, elastic and inelastic ${}^{26}$Al+$p$ scattering reactions were measured between $E_{\mathrm{c}.\mathrm{m}.}$ = 0.5–1.5 MeV at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). A candidate for a new resonance in the ${}^{26}$Al($p$,$\gamma$)${}^{27}$Si reaction was identified. Upper limits were also set on the strengths of postulated resonances and on the cross section of the inelastic reaction, but there is little effect on current reaction rate calculations.

We present the results of participant-spectator matter at the energy of vanishing flow for neutron-rich systems. Our study reveals similar behavior of the participant-spectator for neutron-rich systems as had been reported for the stable systems and also points towards nearly mass independent behavior of the participant-spectator matter for neutron-rich systems at the energy of vanishing flow. We also study the thermalization reached in the reactions of neutron-rich systems in terms of anisotropy ratio. A nearly mass independent results are also obtained for the anisotropy ratio.

We study how local fluctuations in the initial states of relativistic heavy-ion collisions manifest in the correlations between different orders of harmonic moments of the density profiles, particularly those involving only odd harmonics that arise purely from initial-state fluctuations. We find the strengths of those correlations are sensitive to the number of hot and cold spots in the initial states. Hydrodynamic evolution of the fireball translates initial-state geometric anisotropies as well as their correlations into final-state momentum anisotropies and correlations. We conclude that the measurement of the correlations between different harmonic moments of final-state azimuthal distribution can be employed to quantify the inhomogeneity of the initial density profiles such as the population of hot and cold spots that are produced in high-energy nuclear collisions.

Neutron evaporation energy spectra have been measured in coincidence with $\gamma$ rays of different multiplicities for ${}^{119}$Sb${}^{*}$ in the excitation energy range of $\sim 31$–43 MeV. The inverse level density parameter ($k$) have been extracted for different angular momentum regions corresponding to different $\gamma$-ray multiplicities by comparing the experimental neutron energy spectra with statistical model prediction. It has been observed that the level density increases with the increase in angular momentum. Possible reasons for this variation have been discussed.

Statistics of the single-particle levels in a deformed axially symmetric Woods-Saxon potential is analyzed in terms of the Poisson and Wigner nearest-neighbor spacing distributions for several deformations and multipolarities of the surface distortions. We found the significant differences of all the distributions with a fixed value of the angular momentum projection of the particle on the symmetry axis, more closely to the Wigner distribution, in contrast to the full spectra with Poisson-like behavior. The shell effects in the nearest-neighbor spacing distributions, for both small and large deformations of the surface are analyzed.

We report measurements of cross sections and analyzing powers for reaction angles of ${\theta }_{\mathrm{lab}}={0.0}^{\circ }$–${10.0}^{\circ }$ and complete sets of polarization transfer observables and induced polarizations at ${\theta }_{\mathrm{lab}}={0.0}^{\circ }$–${7.0}^{\circ }$ for the ${}^{208}\mathrm{Pb}(\vec{p},\vec{n})$ reaction at a bombarding energy of $T_p=296$ MeV. A multipole decomposition technique was applied to the data to extract the Gamow-Teller (GT) and spin-dipole (SD) components from the continuum. The polarization observables were also used, for the first time, to separate the SD components into different spin-parity transfer ($\Delta J^{\pi }=0^{-}$, $1^{-}$, and $2^{-}$) contributions. A significant strength with $\Delta J^{\pi }=1^{+}$ is identified in the continuum beyond the GT giant resonance, which is due to configuration mixing effects and the isovector spin monopole (IVSM) contribution. The SD strength distributions were clearly dependent on $\Delta J^{\pi }$, which is reasonably reproduced by Hartree-Fock (HF) plus random phase approximation (RPA) calculations that include the Skyrme interaction with tensor components [Phys. Rev. C 83, 054316 (2011)].

Inclusive energy spectra of the complex fragments (3 $\le$ Z $\le$ 5) emitted in the reactions ${}^{12}$C (77 MeV)+ ${}^{28}$Si, ${}^{11}$B (64 MeV)+ ${}^{28}$Si, and ${}^{12}$C (73 MeV)+ ${}^{27}$Al (all having the same excitation energy of $\sim$67 MeV), have been measured in the angular range of 10${}^{\circ }$ $\lesssim {\theta }_{\mathrm{lab}}\lesssim$ 60${}^{\circ }$. The fully energy-damped (fusion-fission) and the partially energy-damped (deep inelastic) components of the fragment energy spectra have been extracted. It has been found that the yields of the fully energy-damped fragments for all the above reactions are in conformity with the respective statistical model predictions. The time scales of various deep inelastic fragment emissions have been extracted from the angular distribution data. The angular momentum dissipation in deep inelastic collisions has been estimated from the data and it has been found to be close to the corresponding sticking limit value.

The particle ratio fluctuations of $K/\pi$, $(p+\overline{p})/\pi$, $K^{+}/p$, and $K/(p+\overline{p})$ are calculated with the statistical model and compared with the experimental measurements. The statistical model calculated $K/\pi$ ratio fluctuations are consistent with the NA49 measurements fairly well, but overestimate the STAR measurements. The model calculated $(p+\overline{p})/\pi$ fluctuations are consistent with the NA49 measurements at the low CERN Super Proton Synchrotron (SPS) energies, but larger than the measurements at the higher SPS energies. The model calculated dynamical fluctuations of $K^{+}/p$ and $K/(p+\overline{p})$ cannot reproduce the energy dependence of the NA49 measurements. Introduction of excluded volume corrections does not entail better data-model agreement with respect to the ideal gas picture.

The NA60 Collaboration has extracted the inverse slope parameters, $T_{\mathrm{eff}}$ of the di-muon spectra originating from the In + In collisions at $\sqrt{s_{NN}}=17.3$ GeV for various invariant mass regions. They have observed that the inverse slope parameter as a function of invariant mass of the lepton pair drops beyond the $\rho$ peak. In the present work, first we reproduce the observed invariant mass and transverse momentum spectra of the muon pairs by taking into account the medium effects on the hadronic spectral function. Then we show that the slope parameters extracted from the transverse momentum distributions for various invariant mass windows can be explained by assuming the formation of a partonic phase initially which reverts to the hadronic phase through a weak first-order phase transition at a temperature $T_c\sim 175$ MeV. It is observed that a scenario without the formation of a partonic phase does not reproduce the nonmonotonic behavior of the inverse slope parameter nontypical of radial flow.

With the discovery of massive neutron stars such as PSR J1614-2230, the question has arisen of whether exotic matter such as hyperons can exist in the neutron star core. We examine the conditions under which hyperons can exist in massive neutron stars. We consistently investigate the vector baryon-meson coupling, going from the SU(6) quark model to a broader SU(3) symmetry. We propose that the maximum neutron star mass decreases linearly with the strangeness content $f_s$ of the neutron star core as $M_{\text{max}}\left(f_s\right)=M_{\text{max}}\left(0\right)-0.6M_{\odot }(f_s/0.1)$, which seems to be independent of the underlying nuclear equation of state and the vector baryon-meson coupling scheme. Thus, pulsar mass measurements can be used to constrain the hyperon fraction in neutron stars.

The equation of state and composition of the inner crust of neutron stars at zero temperature are calculated, using the $T$ $=$ 0 version of the temperature-dependent extended Thomas-Fermi plus Strutinsky integral method, for each of a family of three functionals based on Skyrme-type forces BSk19, BSk20, and BSk21, which are characterized by different degrees of symmetry-energy stiffness, and also for the SLy4 functional. We also solve the Tolman-Oppenheimer-Volkoff equations to calculate the distribution of mass within the inner crust. Qualitatively similar results are found for all four functionals, and in particular the number of protons per Wigner-Seitz cell is in all cases equal to 40 throughout the inner crust.

We compute the nonequilibrium stress tensor induced by a heavy quark moving through weakly coupled QCD plasma at the speed of light and compare the result to $\mathcal{N}=4$ super-Yang-Mills theory at strong coupling. The QCD Boltzmann equation is reformulated as a Fokker-Planck equation in a leading logarithmic approximation, which is used to compute the induced stress. The transition from nonequilibrium at short distances to equilibrium at long distances is analyzed with first- and second-order hydrodynamics. Even after accounting for the obvious differences in shear lengths, the strongly coupled theory is significantly better described by hydrodynamics at subasymptotic distances. We argue that this difference between the kinetic and the anti-de Sitter space/conformal field theories is related to the second-order hydrodynamic coefficient ${\tau }_{\pi }$. ${\tau }_{\pi }$ is numerically large in units of the shear length for theories based on the Boltzmann equation.

Meson-charmonium dissociation reactions governed by the quark interchange are studied with temperature-dependent quark potentials. Quark-antiquark relative-motion wave functions and masses of charmonia and charmed mesons are determined by the central spin-independent part of the potentials or by the central spin-independent part and a smeared spin-spin interaction. The prominent temperature dependence of the masses is found. Based on the potentials, the wave functions, and the meson masses, we obtain temperature-dependent cross sections for the fifteen dissociation reactions: $\pi J/\psi \to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, $\pi J/\psi \to {\overline{D}}^{*}{D}^{*}$, $\pi {\psi }^{\prime }\to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, $\pi {\psi }^{\prime }\to {\overline{D}}^{*}{D}^{*}$, $\pi {\chi }_c\to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, $\pi {\chi }_c\to {\overline{D}}^{*}{D}^{*}$, $\rho J/\psi \to \overline{D}D$, $\rho J/\psi \to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, $\rho J/\psi \to {\overline{D}}^{*}{D}^{*}$, $\rho {\psi }^{\prime }\to \overline{D}D$, $\rho {\psi }^{\prime }\to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, $\rho {\psi }^{\prime }\to {\overline{D}}^{*}{D}^{*}$, $\rho {\chi }_c\to \overline{D}D$, $\rho {\chi }_c\to {\overline{D}}^{*}D$ or $\overline{D}{D}^{*}$, and $\rho {\chi }_c\to {\overline{D}}^{*}{D}^{*}$. The numerical cross sections are parametrized for future applications in hadronic matter. The particular temperature dependence of the $J/\psi$ bound state leads to unusual behavior of the cross sections for endothermic $J/\psi$ dissociation reactions. The quantum numbers of ${\psi }^{\prime }$ and ${\chi }_c$ cannot make their difference in mass in the temperature region $0.6T_{\mathrm{c}}⩽T<T_{\mathrm{c}}$ but can make the ${\psi }^{\prime }$ dissociation different from the ${\chi }_c$ dissociation.