A particle-$\gamma$-coincidence experiment is performed to investigate the role of high $\ell$ values in the production of direct-$\alpha$-emitting channels (associated with incomplete fusion) in ${}^{12}\mathrm{C}+{}^{169}\mathrm{Tm}$ system. Spin distributions of various $\mathit{xn}/\mathit{pxn}/\alpha \mathit{xn}/2\alpha \mathit{xn}$ channels are measured at $E_{\mathrm{lab}}=5.6A$ and $6.5A$ MeV. Entirely different de-excitation patterns are observed in direct-$\alpha$-emitting channels and fusion-evaporation channels. The fusion-evaporation channels are found to be strongly fed over a broad spin range. While narrow range feeding for only high-spin states was observed in the case of direct-$\alpha$-emitting channels, in the present work, incomplete fusion is shown to be a promising tool to populate high-spin states in final reaction products. To have better insight into the associated $\ell$ values in different reaction channels, the present data are compared with similar data obtained in ${}^{16}\mathrm{O}(E_{\mathrm{lab}}\approx 5.6A\hspace{0.5em}\mathrm{MeV})\hspace{0.5em}+\hspace{0.5em}{}^{169}\mathrm{Tm}$ system. The mean driving angular momenta involved in the production of direct-$\alpha$-emitting channels are found to be higher than those involved in the production of fusion-evaporation channels. Direct-$\alpha$ multiplicity in the forward cone increases with driving angular momenta, which indicates the origin of direct-$\alpha$-emitting channels at high $\ell$ values in noncentral interactions.

The hadronic transport model ART is extended to include the production and annihilation of deuterons via the reactions $\mathit{BB}\leftrightarrow \mathit{dM}$, where $B$ and $M$ stand for baryons and mesons, respectively, as well as their elastic scattering with mesons and baryons in the hadronic matter. This new hadronic transport model is used to study the transverse momentum spectrum and elliptic flow of deuterons in relativistic heavy ion collisions, with the initial hadron distributions after hadronization of the produced quark-gluon plasma taken from a blast wave model. The results are compared with those measured by the PHENIX and STAR Collaborations for $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV and also with those obtained from the coalescence model based on freeze-out nucleons in the transport model.

We measured the $\gamma$-ray angular distribution from ${}^{12}\mathrm{C}$$(\alpha ,{\gamma }_0)$${}^{16}\mathrm{O}$ to the ground state of ${}^{16}\mathrm{O}$ using a pulsed $\alpha$ beam at $E_{\mathrm{eff}}=1.6$ and $1.4$ MeV. True events of ${}^{12}\mathrm{C}$$(\alpha ,{\gamma }_0)$${}^{16}\mathrm{O}$ were discriminated from background events with a time-of-flight method because of neutrons from ${}^{13}\mathrm{C}$($\alpha ,n$)${}^{16}\mathrm{O}$. The obtained $\gamma$-ray spectrum with anti-Compton NaI(Tl) spectrometers showed a characteristic line shape from ${}^{12}\mathrm{C}$$(\alpha ,{\gamma }_0)$${}^{16}\mathrm{O}$: the Doppler broadening and energy loss of $\alpha$ particles in ${}^{12}\mathrm{C}$ targets. A Rutherford backscattering spectrum of $\alpha$ particles from enriched ${}^{12}\mathrm{C}$ targets was measured during beam irradiation to obtain the target thickness and incident $\alpha$-beam intensities. The astrophysical $S$ factors for $E1$ and $E2,S_{E1}({\gamma }_0:E_{\mathrm{eff}})$ and $S_{E2}({\gamma }_0:E_{\mathrm{eff}})$, derived from the present cross sections are in excellent agreement with the values derived by $R$-matrix calculation of the $\beta$-delayed $\alpha$ spectrum of ${}^{16}\mathrm{N}$, and by using the asymptotic normalization constant in the $R$-matrix fit.

We have calculated the total nuclear reaction cross sections of exotic nuclei in the framework of the Glauber model, using as inputs the standard relativistic mean field (RMF) densities and the densities obtained from the more recently developed effective-field-theory-motivated RMF (the E-RMF). Both light and heavy nuclei are taken as the representative targets, and the light neutron-rich nuclei as projectiles. We found the total nuclear reaction cross section to increase as a function of the mass number, for both the target and projectile nuclei. The differential nuclear elastic scattering cross sections are evaluated for some selected systems at various incident energies. We found a large dependence of the differential elastic scattering cross section on incident energy. Finally, we have applied the same formalism to calculate both the total nuclear reaction cross section and the differential nuclear elastic scattering cross section for the recently discussed superheavy nucleus with atomic number $Z=122$.

The ($e,e^{\prime }{p}_0$) cross section of ${}^{12}\mathrm{C}$ has been measured at an energy transfer of 60 MeV and a momentum transfer of $104.4$ MeV/$c$ using a $197.5$ MeV continuous electron beam. The cross section at missing momenta between $181.5$ and $304.8$ MeV/$c$ obtained from the experiment is compared with theoretical calculations based on the relativistic distorted-wave impulse approximation with and without meson-exchange currents (MEC). The contribution of MEC due to the seagull current is large in the high-missing-momentum region, in particular for the longitudinal component. The cross sections calculated using three different current-conserving operators (cc1, cc2, and cc3) are similar, in contrast to the $(\gamma ,p)$ reaction, where the operators give very different results. The shape of the measured cross section is well described by the calculations, whereas its magnitude is slightly smaller than that described by the calculations.

In this work, we examine the effect of bulk viscosity on elliptic flow, taking into account the critical behavior of the equation of state and transport coefficients near the QCD phase transition. We found that the $p_T$ dependence of $v_2$ is quantitatively changed by the presence of the QCD phase transition. Within reasonable values of the transport coefficients, $v_2$ decreases by a factor of $15\%$ at small $p_T$ values ($<1$ GeV). However, for larger values of $p_T$ ($>2$ GeV), the interplay between the velocity of sound and transport coefficient near the QCD phase transition enhances $v_2$. We point out that Grad’s 14-moment approximation cannot be applied for the calculation of the one-particle distribution function at the freeze-out.

Spin-polarized states in neutron matter in strong magnetic fields up to ${10}^{18}$ G are considered in the model with the Skyrme effective interaction. By analyzing the self-consistent equations at zero temperature, it is shown that a thermodynamically stable branch of solutions for the spin-polarization parameter as a function of density corresponds to the negative spin polarization when the majority of neutron spins are oriented opposite to the direction of the magnetic field. Besides, beginning from some threshold density dependent on magnetic field strength, the self-consistent equations also have two other branches of solutions for the spin-polarization parameter with the positive spin polarization. The free energy corresponding to one of these branches turns out to be very close to that of the thermodynamically preferable branch. As a consequence, in a strong magnetic field, the state with the positive spin polarization can be realized as a metastable state in the high-density region in neutron matter, which, under decreasing density, at some threshold density changes to a thermodynamically stable state with the negative spin polarization.

Differential cross sections for $\eta$ photoproduction from protons have been measured at $E_{\gamma }=1.6–2.4\hspace{0.5em}\mathrm{GeV}$ in the backward direction. A bump structure has been observed above $2.0$ GeV in the total energy. No such bump is observed in ${\eta }^{\text{'}},\omega$, and ${\pi }^0$ photoproductions. It is inferred that this unique structure in $\eta$ photoproduction is due to a baryon resonance with a large $s\overline{s}$ component that is strongly coupled to the $\eta N$ channel.

Using the chiral anomaly, we discuss the pair creation of massless fermions under the effect of a magnetic field $\overrightarrow{B}$ when an electric flux tube $\overrightarrow{E}$ parallel to $\overrightarrow{B}$ is switched on. The tube is axially symmetric and infinitely long. For the constraint $B\gg E$, we can analytically obtain the spatial and temporal behaviors of the number density of the fermions, the azimuthal magnetic field generated by the fermions, and so on. We find that the lifetime $t_c$ of the electric field becomes shorter as the width of the tube becomes narrower. Applying it to the glasma in high-energy heavy-ion collisions, we find that the color electric field decays quickly such that $t_c\simeq Q_s^{-1}$, in which $Q_s$ is the saturation momentum.

Properties of symmetric nuclear matter and neutron-rich matter predicted by effective field based relativistic mean field parameter sets are compared to those presented in a recent analysis of nuclear giant monopole resonance and isospin diffusion data and a study of the neutron skin of finite nuclei, as well as some selected observational data of neutron stars. Motivated by the fact that none of the published parameter sets of this model is simultaneously consistent with all previously mentioned constraints, an improvement not only in the isovector sector but also in isoscalar sector of this model is proposed. The properties of symmetric nuclear matter and neutron-rich matter, as well as some basic properties of static neutron stars predicted by the proposed parameter set ($\mathrm{G}{2}^{**}$), are discussed.

We have reinvestigated the $\beta$ decay of the three isomers of ${}^{116}\mathrm{Ag}$ at the Holifield Radioactive Ion Beam Facility (HRIBF). Through the use of half-life information, we have been able to construct individual decay schemes for each isomer and correct what was a puzzling inconsistency with the published data, namely the $\beta$ feeding of $2^{+}$ states by a $5^{+}$ isomer. Our results indicate that the feeding of these levels arises from a $3^{+}$ isomer in ${}^{116}\mathrm{Ag}$. A total of $271\gamma$-ray transitions ($159$ new) were assigned to $148$ levels ($94$ new) from the $\beta$ decay of ${}^{116}\mathrm{Ag}$${}^{m1,m2,\mathrm{gs}}$. Significant deviations are observed from IBM-2 calculations for the decay of the $0^{+}$ and $2^{+}$ members of the previously assigned three-phonon quintuplet. Candidate states for the quadrupole-octupole quintuplet states and $\pi g_{9/2}–\pi p_{1/2}$, $\pi g_{9/2}–\pi p_{3/2}$, $\nu h_{11/2}–\nu s_{1/2}$, $\nu h_{11/2}–\nu d_{3/2}$, and $\nu h_{11/2}–\nu d_{5/2}$ broken-pair states are assigned.

High spin states in ${}^{178}\mathrm{Os}$ were studied by means of ${}^{165}\mathrm{Ho}$(${}^{20}\mathrm{Ne}$,$p6n$)${}^{178}\mathrm{Os}$ fusion evaporation reaction at a beam energy of 150 MeV, using a clover detector array. Several new transitions belonging to ${}^{178}\mathrm{Os}$ were placed in a level scheme and a new aligned rotational band was observed in addition to earlier known bands. Spin-parity assignments for most of the proposed levels were made using the deduced directional correlation orientation and polarization measurements for the de-exciting transitions. Experimental results are compared with the projected angular momentum deformed Hartree-Fock model calculations and cranked Woods-Saxon model calculations. This nucleus is predicted to be prolate deformed in the ground state but the $\gamma$-softness at higher excitation is revealed by the cranked Woods-Saxon model and the geometrical asymmetric model calculations.

The level scheme of ${}^{212}\mathrm{Rn}$ has recently been expanded and extended to spins of $~39\hslash$ and excitation energies of about 13 MeV using the ${}^{204}\mathrm{Hg}$(${}^{13}\mathrm{C}$,$5n$)${}^{212}\mathrm{Rn}$ reaction and $\gamma$-ray spectroscopy. Time-correlated techniques were used to obtain channel selectivity and improved sensitivity. New $\gamma$-ray branches from states associated with valence proton configurations as well as a number of new states below the ${22}^{+}$ isomer have been identified. The excitation energy of the ${22}^{+}$ core excited isomer itself has been established through the observation of several branches parallel to the main decay, implying a transition energy of $7.6$ keV for the previously unobserved decay to the ${20}_2^{+}$ state. The level scheme above the ${22}^{+}$ isomer includes two new isomers with $\tau =25(2)$ ns and $\tau =12(2)$ ns placed at $12,211$ and $12,548$ keV, respectively. These are attributed to configurations involving triple neutron core excitations coupled to the aligned valence protons. The results are compared to semiempirical shell-model calculations, which can account for many of the states observed, with considerable precision for the valence proton configurations but with significant energy discrepancies for some core excited configurations. Calculations within the deformed independent particle model (DIPM) have also been carried out for the main core excited configurations at high spin and compared with both experiment and the empirical shell-model approach. The possible sources of discrepancies in both approaches are discussed, and it is suggested that anomalously low excitation energies are predicted for specific configurations in the DIPM.

The structure of the $T=1$ isotriplet hypernuclei, ${}_{\Lambda }^7\mathrm{He}$, ${}_{\Lambda }^7\mathrm{Li}$, and ${}_{\Lambda }^7\mathrm{Be}$ within the framework of an $\alpha +\Lambda +N+N$ four-body cluster model is studied. Interactions between the constituent subunits are determined so as to reproduce reasonably well the observed low-energy properties of the $\alpha N$, $\alpha \Lambda$, $\alpha \mathit{NN}$, and $\alpha \Lambda N$ subsystems. Furthermore, the two-body $\Lambda N$ interaction is adjusted so as to reproduce the $0^{+}–1^{+}$ splitting of ${}_{\Lambda }^4\mathrm{H}$. Also, a phenomenological $\Lambda N$ charge symmetry breaking (CSB) interaction is introduced. The $\Lambda$ binding energy of the ground state in ${}_{\Lambda }^7\mathrm{He}$ is predicted to be $5.16(5.36)$ MeV with (without) the CSB interaction. The calculated energy splittings of the $3/2^{+}–5/2^{+}$ states in ${}_{\Lambda }^7\mathrm{He}$ and ${}_{\Lambda }^7\mathrm{Li}$ are around 0.1 MeV. We point out that there is a three-layer structure of the matter distribution, $\alpha$ particle, $\Lambda$ skin, and proton or neutron halo, in the ${}_{\Lambda }^7\mathrm{He}(J=5/2^{+})$, ${}_{\Lambda }^7\mathrm{Li}(J=5/2^{+})$, and ${}_{\Lambda }^7\mathrm{Be}(J=1/2^{+})$ states.

A detailed $\alpha$-decay study of the neutron-deficient isotope ${}^{181}\mathrm{Pb}$ has been performed in the complete fusion reaction ${}^{40}\mathrm{Ca}$$+$${}^{144}\mathrm{Sm}$$\to$${}^{184}\mathrm{Pb}$${}^{*}$ at the velocity filter SHIP (GSI, Darmstadt). In comparison with the literature, more precise data have been deduced for the $I^{\pi }=(9/2^{-})$ ground state in this nucleus, which is presumably based on the neutron $\nu h_{9/2}$ spherical orbital. Improved $\alpha$-decay data were also measured for ${}^{180}\mathrm{Pb}$.

The stationary internal density functional theory (DFT) formalism and Kohn-Sham scheme are generalized to the time-dependent case. It is proven that, in the time-dependent case, the internal properties of a self-bound system (such as an atomic nucleus or a helium droplet) are all defined by the internal one-body density and the initial state. A time-dependent internal Kohn-Sham scheme is set up as a practical way to compute the internal density. The main difference from the traditional DFT formalism and Kohn-Sham scheme is the inclusion of the center-of-mass correlations in the functional.

We develop an approach to calculating the pure cross section of the ground state of artificial radioactive nuclides that subtracts the effect of an excited state on the ground state. We apply a formalism to obtaining pure cross sections by subtracting the effect of excited states in the reactions ${}^{122}\mathrm{Te}$($n,2n$)${}^{121}\mathrm{Te}$${}^g$ and ${}^{128}\mathrm{Te}$($n,2n$)${}^{127}\mathrm{Te}$${}^g$, induced by neutrons of about $14$ MeV. The cross sections are measured by an activation relative to the ${}^{93}\mathrm{Nb}$($n,2n$)${}^{92}\mathrm{Nb}$${}^m$ reaction and are compared with results that take into account the effect of the excited state. Measurements are carried out by $\gamma$ detection using a coaxial high-purity germanium (HPGe) detector. As samples, spectroscopically pure Te powder is used. The fast neutrons are produced by the ${}^3\mathrm{H}$($d,n$)${}^4\mathrm{He}$ reaction. The neutron energies in these measurements are determined using the method of cross-section ratios between the ${}^{90}\mathrm{Zr}$($n,2n$)${}^{89}\mathrm{Zr}$${}^{m+g}$ and ${}^{93}\mathrm{Nb}$($n,2n$)${}^{92}\mathrm{Nb}$${}^m$ reactions.

In this article, I provide a pedagogical discussion of the GSI anomaly. Using two different formulations, namely the intuitive quantum-field-theory language of the second quantized picture as well as the language of amplitudes, I clear up the analogies and differences between the GSI anomaly and other processes (the double-slit experiment using photons, $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ scattering, and charged-pion decay). In both formulations, the conclusion is reached that the decay rate measured at GSI cannot oscillate if only standard model physics is involved and the initial hydrogen-like ion is no coherent superposition of more than one state (in case there is no new, yet unknown, mechanism at work). Furthermore, a discussion of the quantum beat phenomenon will be given, which is often assumed to be able to cause the observed oscillations. This is, however, not possible for a splitting in the final state only.

The presence of baryonic matter leads to the mixing between transverse $\rho$ and $a_1$ mesons through a set of $\omega \rho a_1$-type interactions, which results in modification of the dispersion relation. We show that a clear enhancement of the vector spectral function appears below $\sqrt{s}=m_{\rho }$ for small three-momenta of the $\rho$ meson, and thus the vector spectrum exhibits broadening. We also discuss its relevance to dilepton measurements.