The $\beta$ decays of ${}^{12}\mathrm{N}$ and ${}^{12}\mathrm{B}$ have been studied at KVI and JYFL to resolve the composition of the broad and interfering $0^{+}$ and $2^{+}$ strengths in the triple-$\alpha$ continuum. For the first time a complete treatment of $3\alpha$ decay is presented including all major breakup channels. A multilevel, many-channel $R$-matrix formalism has been developed for the complete description of the breakup in combination with the recently published separate analysis of angular correlations. We find that, in addition to the Hoyle state at 7.65 MeV, more than one $0^{+}$ and $2^{+}$ state is needed to reproduce the spectra. Broad $0_3^{+}$ and $2_2^{+}$ states are found between 10.5 and 12 MeV in this work. The presence of $\beta$ strength up to the ${}^{12}\mathrm{N}$ $Q$-value window suggests the presence of additional $0^{+}$ and $2^{+}$ components in the ${}^{12}\mathrm{C}$ structure at energies above 12.7 MeV.

A thermal-model analysis of particle production of $p$-$p$ collisions at $\sqrt{s}=17$ GeV using the latest available data is presented. The sensitivity of model parameters on data selections and model assumptions is studied. The system-size dependence of thermal parameters and recent differences in the statistical model analysis of $p$-$p$ collisions at the super proton synchrotron are discussed. It is shown that the chemical freeze-out temperature and strangeness undersaturation factor depend strongly on kaon yields, which, at present, are still not well known experimentally. Excluding the $\varphi$ meson and using data that are in agreement with the overall trend, it is rather unlikely that the chemical decoupling temperature in $p$-$p$ collisions exceeds significantly that extracted from central heavy-ion collisions.

We renormalize the two-nucleon interaction at leading order (LO) in chiral perturbation theory using the scheme proposed by Nogga, Timmermans, and van Kolck—also known as modified Weinberg counting. With this interaction, we calculate the energy per nucleon of symmetric nuclear matter in the Brueckner pair approximation and obtain a converged, cutoff-independent result that shows saturation, but also substantial underbinding. We find that the renormalized LO interaction is characterized by an extraordinarily strong tensor force (from one-pion exchange), which is the major cause for the lack of binding. The huge tensor force also leads to the unusually large wound integral of $40\%$ in nuclear matter, which implies a very slow convergence of the hole-line or coupled-cluster expansion, rendering this interaction impractical for many-body calculations. In view of the unusual properties of the renormalized LO interaction and in view of the poor convergence of the nuclear many-body problem with this interaction, there is doubt that this interaction and its predictions can serve as a reasonable and efficient starting point that is improved by perturbative corrections.

New parameter sets of Michigan three-range Yukawa-type semirealistic nucleon-nucleon interaction are obtained by taking into account the whole contribution of the interaction to the pairing. The interactions are applicable to nuclear structure studies via mean-field calculations and their extensions. Implementing self-consistent mean-field calculations for the spherical nuclei, the author confirms that the results do not change significantly from previous results, in which the parameters were determined by partly discarding the influence of the density-dependent repulsion on the pairing.

In this article, we examine the methodology for extracting the Knudsen number ($K$) and the ratio of shear viscosity to entropy density ($\eta /s$) developed by Drescher et al. [1]. The final result for $\eta /s$ turns out to be quite sensitive to Glauber parameters, particularly the parameter $x$, which controls the balance between $N_{\mathrm{part}}$ and $N_{\mathrm{coll}}$. We also explore how alternative formulations of the functional relation between the elliptic flow and Knudsen number ($K=\lambda /\mathrm{R̄}$) impacts the physics conclusions, based on Padé approximants. Finally, we extend the calculation to include a limiting minimum value on the mean free path proportional to the DeBroglie wavelength. These results emphasize the importance of clarifying the initial state used in different calculations as well as the ambiguities inherent in using a transport approach in a strongly coupled regime.

Within the framework of generalized factorization of higher-twist contributions to semi-inclusive cross sections of deeply inelastic scattering (DIS) off a large nucleus, multiple parton scattering leads to an effective medium-modified fragmentation function and the corresponding medium-modified DGLAP evolution equations. We extend the study to include gluon multiple scattering and induced quark-antiquark production via gluon fusion. We numerically solve these medium-modified DGLAP (mDGLAP) evolution equations and study the scale ($Q^2$), energy ($E$), length ($L$), and jet transport parameter ($\mathrm{q̂}$) dependence of the modified fragmentation functions for a jet propagating in a uniform medium with finite length (a “brick” problem). We also discuss the concept of parton energy loss within such mDGLAP evolution equations and its connection to the modified fragmentation functions. With a realistic Wood-Saxon nuclear geometry, we calculate the modified fragmentation functions and compare them to experimental data on DIS off large nuclei. The extracted jet transport parameter at the center of a large nucleus is found to be ${\mathrm{q̂}}_0=0.024\pm 0.008$ GeV${}^2$/fm.

The cross section and the transverse-longitudinal asymmetry $A_{\mathrm{TL}}$ of the three-body breakup process ${}^3\mathrm{He}(e,e^{\text{'}}p)\mathit{pn}$ have been calculated by a parameter-free approach based upon realistic few-body wave functions corresponding to the AV18 interaction, treating the rescattering of the struck nucleon within the unfactorized generalized eikonal approximation. The results of calculations exhibit a good agreement with recent JLab experimental data and show the dominant role played by the final state interaction, which, however, in the region of missing momentum, $300\lesssim p_m\lesssim 600$ MeV/$c$, and removal energy corresponding to the two-body kinematic peak and higher, $E_m\gtrsim p_m^2/4m_N$, is dominated by single-nucleon rescattering, providing evidence that the final state interaction is mainly due to the one between the struck nucleon and a nearby correlated one.

Model-independent formulas are derived for the polarizations and spin correlations of protons in the final state of $\mathit{pp}\to \mathit{pp}\omega$, taking into consideration all six threshold partial wave amplitudes, $f_1,\dots ,f_6$, covering the $\mathit{Ss},\mathit{Sp}$, and $\mathit{Ps}$ channels. It is shown that these measurements of the final state spin observables, employing only an unpolarized beam and an unpolarized target, can be utilized to complement measurements at the double-differential level suggested earlier [J. Balasubramanyam, Venkataraya, and G. Ramachandran, Phys. Rev. C 78, 012201(R) (2008)] so that all six partial wave amplitudes can be determined empirically.

The $g$ factor of the $15/2^{-}$ state in ${}^{137}\mathrm{Xe}$ was measured for the first time by using a newly developed technique for measuring angular correlations with Gammasphere. Spins and parities were assigned to several levels in the $N=83$ isotones ${}^{135}\mathrm{Te}$, ${}^{136}\mathrm{I}$, ${}^{137}\mathrm{Xe}$, and ${}^{138}\mathrm{Cs}$. The calculated $g$ factor in the shell-model frame is in good agreement with the measured one in the present work. Shell-model calculations also support our spin-parity assignments.

Evidence is presented showing that for the ${}^6\mathrm{He}+{}^{209}\mathrm{Bi}$ system, the reaction cross sections can be entirely accounted for by interactions of the halo state of ${}^6\mathrm{He}$ plus reactions that occur with the ${}^4\mathrm{He}$ core. These and similar conclusions about core-halo decoupling reported earlier for ${}^8\mathrm{B}+{}^{58}\mathrm{Ni}$ are further supported by proving that no such decoupling occurs for reactions with ${}^{17}\mathrm{O}$, whose valence neutron is rather weakly bound but does not form a halo. The preceding conclusions are based on comparisons with purely experimental data, using a quite reasonable scaling. Thus such a decoupling seems to stand out as a characteristic feature of true halo systems.

The electromagnetic form factors of the three-nucleon bound states were calculated in complete impulse approximation in the framework of the Covariant Spectator Theory for the new high-precision two-nucleon interaction models WJC-1 and WJC-2. The calculations use an approximation for the three-nucleon vertex functions with two nucleons off mass shell. The form factors with WJC-2 are close to the ones obtained with the older model W16 and to nonrelativistic potential calculations with lowest-order relativistic corrections, while the form factors with the most precise two-nucleon model WJC-1 exhibit larger differences. These results can be understood when the effect of the different types of pion-nucleon coupling used in the various models is examined.

We perform a fully relativistic calculation of the ${}^2\mathrm{H}$$(e,e^{\text{'}}\mathrm{p⃗})n$ reaction in the impulse approximation employing the Gross equation to describe the deuteron ground state, and we use the SAID parametrization of the full $\mathit{NN}$ scattering amplitude to describe the final state interactions (FSIs). The formalism for treating the ejectile polarization with a spin projection on an arbitrary axes is discussed. We show results for the six relevant asymmetries and discuss the role of spin-dependent FSI contributions.

In-gas-cell laser spectroscopy of the isotopes ${}^{57,58,59,63,65}\mathrm{Cu}$ has been performed at the LISOL facility using the $244.164$-nm optical transition from the atomic ground state of copper. A detailed discussion on the hyperfine structure of ${}^{63}\mathrm{Cu}$ is presented. The magnetic dipole moments of the isotopes ${}^{57,58,59,65}\mathrm{Cu}$ are extracted based on that of ${}^{63}\mathrm{Cu}$. The new value $\mu =+0.479(13){\mu }_N$ is proposed for ${}^{58}\mathrm{Cu}$, consistent with that of a $\pi p_{3/2}\otimes \nu p_{3/2}$ ground-state configuration. Spin assignments for the radioactive isotopes ${}^{57,58,59}\mathrm{Cu}$ are confirmed. The isotope shifts between the different isotopes are also given and discussed.

Theoretical matrix elements, for the ground-state to ground-state two-neutrino double-$\beta$-decay mode ($2\nu {\beta }^{-}{\beta }^{-}\mathrm{gs}\to \mathrm{gs}$) of ${}^{128,130}\mathrm{Te}$ isotopes, are calculated within a formalism that describes interactions between neutrons in a superfluid phase and protons in a normal phase. The elementary degrees of freedom of the model are proton-pair modes and pairs of protons and quasineutrons. The calculation is basically a parameter-free one, because all relevant parameters are fixed from the phenomenology. A comparison with the available experimental data is presented.

Multiparticle correlation techniques are frequently used to study jet shapes and yields in hadronic and nuclear collisions. To date, a standard assumption applied in such analyses is that the observed correlations arise from either jets and associated hard scattering phenomena, or from a background component due to combinatorial pairs connected only through whole event correlations. Within this assumption of two essentially independent sources, a fundamental problem centers around determining the relative contributions of each component. We discuss the methods commonly used to establish the background yield in jet correlation analyses, with a full explanation of the absolute background normalization technique which establishes the background yield without assumptions about the shape of jet correlations. This is especially important in relativistic heavy ion collisions where the jet shapes are significantly distorted from the well separated back-to-back dijets observed in proton-proton collisions.

Excited states of ${}^{118}\mathrm{Sn}$ have been populated in the ${}^{116}\mathrm{Cd}$(${}^7\mathrm{Li}$,$1p4n$) reaction with a beam energy of $50$ MeV. The previously known level scheme is extended in the low-spin region as well as to higher spins. The systematic behavior of the intruder deformed bands in the Sn isotopes is discussed. Total Routhian surface calculations and configuration-fixed constrained triaxial relativistic mean-field approaches are employed for analysis of the nuclear structure of ${}^{118}\mathrm{Sn}$.

Using a Langevin model, we explore the role of fissility in probing presaddle nuclear dissipation by calculating the excess of the evaporation residue cross section over its standard statistical-model value as a function of nuclear dissipation strength for nuclei ${}^{190}\mathrm{Os}$ and ${}^{210}\mathrm{Po}$, which are taken as two representatives that have the same neutron-to-proton ratio ($N/Z$) but have a difference in fissility. We find that a large fissility not only amplifies the dissipation effects on the excess of evaporation residues, but also significantly increases the sensitivity of this excess to nuclear dissipation. The results suggest that in experiments, to obtain a more accurate information of nuclear dissipation inside the saddle point by measuring evaporation residue cross sections, it is best to populate among the various compound systems with equal $N/Z$ those with high fissility.