The interacting boson-fermion-fermion model approach to β decay is applied to the decay from the even-even ${}^{124}\mathrm{Ba}$ to the odd-odd ${}^{124}\mathrm{Cs}$ nucleus. The theoretical results for energy levels, electromagnetic properties and β decay rates are compared with experimental data for ${}^{124}\mathrm{Cs}$. The calculated β-decay rates demonstrate that the interacting boson approximation can be applied in the description of β decays from even-even to odd-odd nuclei.

Emission of charged particles from the ${}^7\mathrm{Li}$+${}^6\mathrm{Li}$ reaction at $E$(${}^7\mathrm{Li}$$)=14\text{−}20$ MeV is studied at forward angles. Analysis of the inclusive spectra are performed in terms of the statistical model for compound nuclear process and Serber model for inclusive breakup reactions. Compound nuclear calculations better reproduce the experimental data in comparison to the projectile breakup calculations even at extreme forward angles and above barrier energies.

The energy loss of high $p_T$ partons propagating through a hot and dense medium is regarded as a valuable tool to probe the medium created in ultrarelativistic heavy-ion collisions. The angular correlation pattern of hadrons associated with a hard trigger in the region of $p_T~1\text{−}2$ GeV which exhibits a dip in the expected position of the away side jet has given rise to the idea that energy is lost predominantly to propagating collective modes (‘Mach cones’). Recent measurements by the STAR Collaboration have shown that for a high $p_T>8$ GeV trigger the angular pattern of associate hadrons for $p_T>4$ GeV shows the emergence of the expected away side peak. These dijet events suggest that the away side parton may emerge occasionally without substantial energy loss. Since in such a back-to-back configuration one of the partons may travel through the central region of the fireball, the average in-medium pathlength is substantial and the expected energy loss is not only sensitive to the initial geometry of matter but also to the change of geometry due to expansion. We show that radiative energy loss is able to explain the dijet events provided that the expansion of the medium is taken into account.

The rational map approximation to the solution to the SU(2) Skyrme model with baryon number $B=4$ is canonically quantized. The quantization procedure leads to anomalous breaking of the chiral symmetry, and exponential fall-off of the energy density of the soliton at large distances. The model is extended to SU(2) representations of arbitrary dimension. These soliton solutions capture the double node feature of the empirical α particle charge form factor, but as expected lead to a too compact matter distribution. Comparison to phenomenology indicates a preference for the fundamental representation.

We have measured for the first time the cross section of the ${}^2\mathrm{H}$$(n,\gamma )$${}^3\mathrm{H}$ reaction at an energy relevant to big-bang nucleosynthesis by employing a prompt discrete γ-ray detection method. The outgoing photons have been detected by means of anti-Compton NaI(Tl) spectrometers with a large signal-to-noise ratio. The resulting cross sections are $2.23\pm 0.34,1.99\pm 0.25$, and $3.76\pm 0.41\mu$b at $E_n=30.5,54.2$, and 531 keV, respectively. At $E_n=30.5$ keV the cross section differs from the value reported previously by a factor of 2. Based on the present data the reaction rate has been obtained for temperatures in the range ${10}^7-{10}^{10}$ K. The astrophysical impact of the present result is discussed. The obtained cross sections are compared with a theoretical calculation based on the Faddeev approach, which includes meson exchange currents as well as a three-nucleon force.

Recently, a set of nine nonmagic nuclei with anomalous values of the $B(E2)$ ratio $B_{4/2}\equiv B(E2;4_1^{+}\to 2_1^{+})/B(E2;2_1^{+}\to 0_1^{+})$ < 1 were identified. Such values are outside the range allowed by current collective models. In the present work, the $B(E2;4_1^{+}\to 2_1^{+})$ values for two of these nuclei, ${}^{98}\mathrm{Ru}$ and ${}^{180}\mathrm{Pt}$, were re-measured to determine if the current literature values for these nuclei are correct. ${}^{98}\mathrm{Ru}$ was studied in a ${}^{27}\mathrm{Al}$(${}^{98}\mathrm{Ru}$,${}^{98}\mathrm{Ru}$${}^{*}$) Coulomb excitation experiment in inverse kinematics, while the lifetime of the $4_1^{+}$ state in ${}^{180}\mathrm{Pt}$ was measured in a ${}^{122}\mathrm{Sn}$(${}^{62}\mathrm{Ni}$, $4n$)${}^{180}\mathrm{Pt}$ recoil distance method (RDM) experiment. For both nuclei, the remeasured $B_{4/2}$ values are well above 1, removing the deviations from collective models.

The excitation functions (EFs) for different fragments produced in the ${}^{27}\mathrm{Al}$+${}^{27}\mathrm{Al}$ dissipative collisions have been measured in steps of 250 keV in the incident energy range 122–132 MeV. Deep inelastic processes have been selected by integrating events on a total kinetic energy loss window of 12 MeV between 20 and 32 MeV. Large fluctuations are observed in all the studied EFs. Large-channel cross-correlation coefficients confirm the nonstatistical origin of these fluctuations. The energy autocorrelation function (EAF) shows damped oscillation structure as expected when a dinuclear system with a lifetime [$\tau =(5.1\pm 2.1)·{10}^{-21}$s], similar with its revolution period ($T=4.9·{10}^{-21}$sec), is formed. From the periodicity of the EAF oscillations, information on the deformation of the ${}^{27}\mathrm{Al}$+${}^{27}\mathrm{Al}$ dinucleus is inferred.

The strengths of resonances located at center-of-mass energies of $E_{c.m.}=189$, 304, 374, and 418 keV for the ${}^{25}\mathrm{Mg}$($p$,$\gamma )$ reaction have been measured for the first time with an off-line method: Mg targets were firstly activated with protons at the resonance energies and the produced ${}^{26}\mathrm{Al}$${}^g$ nuclei were counted by means of highly sensitive accelerator mass spectrometry (AMS). Thus, the production of ${}^{26}\mathrm{Al}$ in its ground state is determined independently from the γ-decay branching ratio. While the 304, 374, and 418 keV resonances show fair agreement with previous measurements, the 189 keV resonance yield a significantly less strength. In addition, an experimental upper limit for the $E_{c.m.}=92$ keV resonance was determined.

We apply the recently developed $\log N$–$\log S$ test of compact star cooling theories for the first time to hybrid stars with a color superconducting quark matter core. Although there is not yet a microscopically founded superconducting quark matter phase that would fulfill constraints from cooling phenomenology, we explore the hypothetical $2\mathrm{SC}+X$ phase and show that the magnitude and density dependence of the X-gap can be chosen to satisfy a set of tests: temperature-age ($T$–$t$), the brightness constraint, $\log N$–$\log S$, and the mass spectrum constraint. The latter test appears as a new conjecture from the present investigation.

We investigate the role of odd-odd (with respect to time inversion) couplings in the Skyrme force on collisions of light nuclei, employing a fully three-dimensional numerical treatment without any symmetry restrictions and with modern Skyrme functionals. We demonstrate the necessity of these couplings to suppress spurious spin excitations owing to the spin-orbit force in free translational motion of a nucleus but show that in a collision situation there is a strong spin excitation even in spin-saturated systems which persists in the departing fragments. The energy loss is considerably increased by the odd-odd terms.

The charged-particle pseudorapidity density for Au+Au collisions at $\sqrt{s_{\mathit{NN}}}=62.4$ GeV has been measured over a wide range of impact parameters and compared to results obtained at other energies. As a function of collision energy, the pseudorapidity distribution grows systematically both in height and width. The midrapidity density is found to grow approximately logarithmically between BNL Alternating Gradient Synchrotron (AGS) energies and the top BNL Relativistic Heavy Ion Collider (RHIC) energy. There is also an approximate factorization of the centrality and energy dependence of the midrapidity yields. The new results at $\sqrt{s_{\mathit{NN}}}=62.4$ GeV confirm the previously observed phenomenon of “extended longitudinal scaling” in the pseudorapidity distributions when viewed in the rest frame of one of the colliding nuclei. It is also found that the evolution of the shape of the distribution with centrality is energy independent, when viewed in this reference frame. As a function of centrality, the total charged particle multiplicity scales linearly with the number of participant pairs as it was observed at other energies.

In Au+Au collisions at $2<p_T<6$ GeV/$c$ baryon production is enhanced compared to $p+p$ collisions. Since charm baryon decays produce electrons less frequently than charm meson decays, the nonphotonic electron spectrum is sensitive to the ${\Lambda }_c/D$ ratio. In this report we study the dependence of the nonphotonic electron spectrum on the baryon-to-meson ratio for charm hadrons. As an example, we take the ${\Lambda }_c/D$ ratio to have the same form as the $\Lambda /K_S^0$ ratio. In this case, even if the total charm quark yield in Au+Au collisions scales with the number of binary nucleon-nucleon collisions ($N_{\mathrm{bin}}$), the electron spectrum at $2<p_T<5$ GeV/$c$ is suppressed by as much as 20% relative to $N_{\mathrm{bin}}$ scaled $p+p$ collisions.

We have measured the half-life of ${}^{120}\mathrm{Xe}$ using a high-purity germanium (HPGe) detector to monitor the 176, 178, and 762 keV γ rays from ${}^{120}\mathrm{Xe}$ ${\beta }^{+}$ decay. The result, 46±0.6 min, differs significantly from the value 40±1 min reported by Andersson et al. [Ark. Fys. 28, 37 (1964)]. We have also measured the half-lives of ${}^{120}\mathrm{Cs}$ and ${}^{120}\mathrm{I}$ to be 60±0.7 s and 82.1±0.6 min, respectively, both of which are consistent with previous measurements.

In the interaction of two electric quadrupoles, there is at short range a contact term proportional to the second derivative of a δ function. This contact term contributes to the hyperfine splitting of bound states of two particles with spin one or higher — for example, the bound state of ${\Omega }^{-}$ and a nucleus with spin one. The contact hyperfine splitting occurs in states with orbital angular momentum unity ($P$ wave), in contrast to the Fermi contact interaction, which is in $S$ states. We find that these contact splittings will be observable with ${\Omega }^{-}$ atoms and help measure the quadrupole moment and charge radius of the hyperon.

We study the systematics of neutron star cooling curves with three representative masses from the most populated interval of the estimated mass distribution for compact objects. The cooling simulations are made in the framework of the nuclear medium cooling scenario using different combinations of possible nucleon-nucleon pairing gaps. Possible heating or enhanced cooling mechanisms in the crust are not considered. We define a constraint on the highest possible temperatures for a given age of young neutron stars and show that this limits the freedom of modeling pairing gaps and crust properties.

We study charge fluctuations within the statistical hadronization model. Considering both the particle yield ratios and the charge fluctuations we show that it is possible to differentiate between chemical equilibrium and non-equilibrium freeze-out conditions. As an example of the procedure we show quantitatively how the relative yield ratio $\Lambda /K^{-}$ together with the normalized net charge fluctuation $v(Q)=\langle (\Delta Q){}^2\rangle /\langle N_{\mathrm{ch}}\rangle$ constrain the chemical conditions at freeze-out. We also discuss the influence of the limited detector acceptance on fluctuation measurements, and show how this can be accounted for within a quantitative analysis.

We investigate the evolution of one-particle spectroscopic intensities as a possible signature of shape phase transitions. The study describes the odd systems in terms of the interacting boson–fermion model. We consider the particular case of an odd $j=3/2$ particle coupled to an even-even boson core that undergoes a phase transition from spherical U(5) to γ-unstable O(6) situation. At the critical point, our findings are compared with the one-particle spectroscopic intensities that can be obtained within the E(5/4) model proposed by[F. Iachello, Phys. Rev. Lett. 95, 052503 (2005); F. Iachello, in Symmetries and Low-Energy Phase Transitions in Nuclear Structure Physics, edited by G. Lo Bianco (University of Camerino Press, Camerino, Italy, in press)].

The inclusive production of ω and ϕ mesons is studied in the backward region of the interaction of 12 GeV protons with polyethylene, carbon, and copper targets. The mesons are measured in $e^{+}{e}^{-}$ decay channels. The production cross sections of the mesons are presented as functions of rapidity $y$ and transverse momentum $p_T$. The nuclear mass number dependences ($A$ dependences) are found to be $A^{0.710\pm 0.021(\text{stat})\pm 0.037(\text{syst})}$ for ω mesons and $A^{0.937\pm 0.049(\text{stat})\pm 0.018(\text{syst})}$ for ϕ mesons in the region of $0.9<y<1.7$ and $p_T<0.75$ GeV/$c$.