From our previously obtained shear viscosity to entropy density ratio $(\eta /s)$ in the framework of clustering of color sources (the color string percolation model, CSPM), we calculate the jet quenching parameter $\widehat{q}$ and trace anomaly $\mathrm{\Delta }=(\varepsilon -3\mathit{p})/{\mathit{T}}^{\mathit{4}}$ as a function of temperature. It is shown that the scaled $\widehat{q}/T^3$ is in agreement with the recent JET Collaboration estimates. The inverse of $\eta /s$ is found to represent $\mathrm{\Delta }$. The results for $\mathrm{\Delta }$ are in excellent agreement with lattice quantum chromodynamics (LQCD) simulations. From the trace anomaly and energy density $\epsilon$, the equation of state is obtained as a function of temperature and compared with LQCD simulations. It is possible that there is a direct connection between the $\eta /s$ and $\mathrm{\Delta }$. Thus the estimate of transport coefficient $\eta /s$ provides $\widehat{q}$ and $\mathrm{\Delta }$ as a function of temperature. Both $\mathrm{\Delta }$ and $\eta /s$ describe the transition from a strongly coupled quark-gluon plasma (QGP) to a weakly coupled QGP.

We study the liquid-gas phase transition of stellar matter with the inclusion of the finite-size effect from surface and Coulomb energies. The equilibrium conditions for two coexisting phases are determined by minimizing the total free energy including the surface and Coulomb contributions, which are different from the Gibbs conditions used in the bulk calculations. The finite-size effect can significantly reduce the region of the liquid-gas mixed phase. The influence of the symmetry energy on the liquid-gas phase transition is investigated with the inclusion of finite-size effects. It is found that the slope of the symmetry energy plays an important role in determining the boundary and properties of the mixed phase.

The unbound ${}^{12}\mathrm{O}$ nucleus was studied via the two-neutron transfer $(p,t)$ reaction in inverse kinematics using a radioactive ${}^{14}\mathrm{O}$ beam at 51 MeV/u. Excitation energy spectra and differential cross sections were deduced by the missing mass method using MUST2 telescopes. We achieved much higher statistics compared to the previous experiments of ${}^{12}\mathrm{O}$, which allowed accurate determination of resonance energy and unambiguous spin and parity assignment. The ${}^{12}\mathrm{O}$ resonance previously reported using the same reaction was confirmed at an excitation energy of $1.62\pm 0.03\left(\mathrm{stat}.\right)\pm 0.10\left(\mathrm{syst}.\right)$. MeV and assigned spin and parity of $0^{+}$ from a distorted-wave Born approximation analysis of the differential cross sections. Mirror symmetry of ${}^{12}\mathrm{O}$ with respect to its neutron-rich partner ${}^{12}\mathrm{Be}$ is discussed from the energy difference of the second $0^{+}$ states. In addition, from systematics of known $0^{+}$ states, a distinct correlation is revealed between the mirror energy difference and the binding energy after carrying out a scaling with the mass and the charge. We show that the mirror energy difference of the observed $0^{+}$ state of ${}^{12}\mathrm{O}$ is highly deviated from the systematic trend of deeply bound nuclei and in line with the scaling relation found for weakly bound nuclei with a substantial $2s_{1/2}$ component. The importance of the scaling of mirror asymmetry is discussed in the context of ab initio calculations near the drip lines and universality of few-body quantum systems.

Background: The precise determination of $ft$ values for superallowed mixed transitions between mirror nuclide are gaining attention as they could provide an avenue to test the theoretical corrections used to extract the $V_{ud}$ matrix element from superallowed pure Fermi transitions. The ${}^{17}\mathrm{F}$ decay is particularly interesting as it proceeds completely to the ground state of ${}^{17}\mathrm{O}$, removing the need for branching ratio measurements. The dominant uncertainty on the $ft$ value of the ${}^{17}\mathrm{F}$ mirror transition stems from a number of conflicting half-life measurements.

Purpose: A precision half-life measurement of ${}^{17}\mathrm{F}$ was performed and compared to previous results.

Methods: The life-time was determined from the β counting of implanted ${}^{17}\mathrm{F}$ on a Ta foil that was removed from the beam for counting. The ${}^{17}\mathrm{F}$ beam was produced by transfers reaction and separated by the TwinSol facility of the Nuclear Science Laboratory of the University of Notre Dame.

Results: The measured value of $t_{1/2}^{\text{new}}=64.402$(42) s is in agreement with several past measurements and represents one of the most precise measurements to date. In anticipation of future measurements of the correlation parameters for the decay and using the new world average $t_{1/2}^{\text{world}}=64.398$(61) s, we present a new estimate of the mixing ratio $\rho$ for the mixed transition as well as the correlation parameters based on assuming Standard Model validity.

Conclusions: The relative uncertainty on the new world average for the half-life is dominated by the large ${\chi }^2=31$ of the existing measurements. More precision measurements with different systematics are needed to remedy to the situation.

The ${}^9\mathrm{Be}$(${}^{14}\mathrm{C}, \alpha \gamma$) reaction at $E_{Lab}=30$ and 35 MeV was used to study excited states of ${}^{19}\mathrm{O}$. The Florida State University (FSU) $\gamma$ detector array was used to detect $\gamma$ radiation in coincidence with charged particles detected and identified with a silicon $\mathrm{\Delta }E-E$ particle telescope. $\gamma$ decays have been observed for the first time from six states ranging from 368 to 2147 keV above the neutron separation energy ($S_n=3962$ keV) in ${}^{19}\mathrm{O}$. The $\gamma$-decaying states are interspersed among states previously observed to decay by neutron emission. The ability of electromagnetic decay to compete successfully with neutron decay is explained in terms of neutron angular momentum barriers and small spectroscopic factors implying higher spin and complex structure for these intruder states. These results illustrate the need for complementary experimental approaches to best illuminate the complete nuclear structure.

The kinematic constraints on interacting nucleons in Large Hadron Collider (LHC) heavy-ion collisions are investigated in the framework of the Heavy Ion Jet Interaction Generator (HIJING) code incorporated with a collective cascade recipe. The latter is used to implement energy-momentum conservation constraints on both primary and secondary interacting nucleons. It is found that the energy-momentum conservation constraints on the interacting nucleons affect the whole charged-particle pseudorapidity density distribution $\left(\frac{d{N}_{ch}}{d\eta }\right)$, at different centralities [from central (0–5%) to peripheral (70–80%) collisions], in Pb + Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. In particular, the kinematic constraints on the interacting nucleons are shown to reduce $\left(\frac{d{N}_{ch}}{d\eta }\right)$ yield at mid-pseudorapidity $\left(\right|\eta |<2)$ in all centrality intervals, which is consistent with the LHC data. In addition, the model predicts an enhancement of the hadron production at $\left|\eta \right|>8$, which could be checked in the future ALICE Zero Degree Calorimeter. Such an enhancement is found to be mainly due to the interactions of protons at the spectator parts of the collision. This indicates that the kinematic constraints are important for a correct geometrical treatment of Pb + Pb collisions at LHC energies.

Measurements of the fractional momentum loss $\left(S_{\mathrm{loss}}\equiv \delta p_T/p_T\right)$ of high-transverse-momentum-identified hadrons in heavy-ion collisions are presented. Using ${\pi }^0$ in $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{s_{{}_{NN}}}=62.4$ and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in $\mathrm{Pb}+\mathrm{Pb}$ collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of $S_{\mathrm{loss}}$ as a function of a number of variables: the number of participants, $N_{\mathrm{part}}$, the number of quark participants, $N_{\mathrm{qp}}$, the charged-particle density, $d{N}_{\mathrm{ch}}/d\eta$, and the Bjorken energy density times the equilibration time, ${\varepsilon }_{\mathrm{Bj}}{\tau }_0$. We find that the $p_T$, where $S_{\mathrm{loss}}$ has its maximum, varies both with centrality and collision energy. Above the maximum, $S_{\mathrm{loss}}$ tends to follow a power-law function with all four scaling variables. The data at $\sqrt{s_{{}_{NN}}}=200$ GeV and 2.76 TeV, for sufficiently high particle densities, have a common scaling of $S_{\mathrm{loss}}$ with $d{N}_{\mathrm{ch}}/d\eta$ and ${\varepsilon }_{\mathrm{Bj}}{\tau }_0$, lending insight into the physics of parton energy loss.

A sizable contribution to heavy-quark production in high-energy hadronic and nuclear collisions comes from heavy quark-antiquark pair production from gluon splitting during the parton shower evolution. We investigate the effect of gluon-medium interaction on open heavy flavor spectra in ultrarelativistic heavy-ion collisions. The interaction of hard gluons and heavy quarks with the hot QCD medium is simulated by utilizing a Langevin transport model that simultaneously incorporates contributions from collisional and radiative processes. It is found that, while the gluon splitting channel has quite an important contribution to the single $D$-meson production cross section, its influence on the final heavy-meson nuclear modification turns out to be quite modest because the average lifetime of hard gluons is short before splitting into heavy-quark-antiquark pairs during the evolution and propagation of the parton shower.

We analyze the spectrum of harmonic flow, $v_n\left(p_T\right)$ for $n=0–5$, in event-by-event hydrodynamic simulations of Pb+Pb collisions at the CERN Large Hadron Collider ($\sqrt{s_{NN}}=2.76\mathrm{TeV}$) with principal component analysis (PCA). The PCA procedure finds two dominant contributions to the two-particle correlation function. The leading component is identified with the event plane $v_n\left(p_T\right)$, while the subleading component is responsible for factorization breaking in hydrodynamics. For $v_0, v_1$, and $v_3$ the subleading flow is a response to the radial excitation of the corresponding eccentricity. By contrast, for $v_2$ the subleading flow in peripheral collisions is dominated by the nonlinear mixing between the leading elliptic flow and radial flow fluctuations. In the $v_2$ case, the sub-sub-leading mode more closely reflects the response to the radial excitation of ${\varepsilon }_2$. A consequence of this picture is that the elliptic flow fluctuations and factorization breaking change rapidly with centrality, and in central collisions (where the leading $v_2$ is small and nonlinear effects can be neglected) the sub-sub-leading mode becomes important. Radial flow fluctuations and nonlinear mixing also play a significant role in the factorization breaking of $v_4$ and $v_5$. We construct good geometric predictors for the orientation and magnitudes of the leading and subleading flows based on a linear response to the geometry, and a quadratic mixing between the leading principal components. Finally, we suggest a set of measurements involving three point correlations which can experimentally corroborate the nonlinear mixing of radial and elliptic flow and its important contribution to factorization breaking as a function of centrality.

The $\gamma$-ray production cross section for the 477.6-keV $1/2^{-}\to 3/2_{g.s.}^{-}$ transition in ${}^7\text{Li}$ following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other $\gamma$-ray production cross-section measurements. The experiment was conducted at the GELINA pulsed white neutron source with the GAINS spectrometer consisting of 12 high-purity germanium detectors. The time-of-flight method was used for neutron energy determination. The sample was an optical-quality lithium fluoride disk and the neutron flux was monitored using a ${}^{235}\text{U}$ fission chamber. Previous measurements of this cross section are reviewed and compared with our results. Recently, the examined cross section has been calculated using the continuum-discretized coupled-channels method. The results are found to be in reasonable agreement with the experimental data.

We study the effect of temperature ($T$) and baryon density ($\mu$) dependent hadron masses on the thermodynamics of hadronic matter. We use linear scaling rule in terms of constituent quark masses for all hadrons except for light mesons. $T$- and $\mu$-dependent constituent quark masses and the light meson masses are computed using $2+1$ flavor Nambu-Jona-Lasinio (NJL) model. We compute the thermodynamical quantities of hadronic matter within excluded volume hadron resonance gas model (EHRG) with these $T$- and $\mu$-dependent hadron masses. We confront the thermodynamical quantities with the lattice quantum chromodynamics (LQCD) at $\mu =0\mathrm{GeV}$. Further, we comment on the effect of $T$- and $\mu$-dependent hadron masses on the transport properties near the transition temperature ($T_c$).

The symmetries of the standard model dictate that for very low energies, where nucleon dynamics can be described in terms of a pionless effective field theory $(\text{EFT}\left(\pi /\right))$, the leading-order parity-violating nucleon-nucleon Lagrangian contains five independent unknown low-energy constants (LECs). We find that imposing the approximate symmetry of QCD that appears when the number of colors $N_c$ becomes large reduces the number of independent LECs to two at leading order in the combined $\text{EFT}\left(\pi /\right)$ and large-$N_c$ expansions. We also find a relation between the two isoscalar LECs in the large-$N_c$ limit. This has important implications for the number of experiments and/or lattice calculations necessary to confirm this description of physics. In particular, we find that a future measurement of the parity-violating asymmetry in $\vec{\gamma }d\to np$ together with the existing result for parity-violating $\vec{p}p$ scattering would constrain all leading-order (in the combined expansion) LECs. This is a considerable improvement on the previous understanding of the system.

We have measured the proton decay probabilities of the ${}^{56}\mathrm{Fe}^{*}$ and ${}^{47}\mathrm{Ti}^{*}$ compound systems which are populated by the transfer reactions ${}^{52}\mathrm{Cr}({}^6\mathrm{Li},d){}^{56}\mathrm{Fe}^{*}$ (surrogate of $n+{}^{55}\mathrm{Fe}\to {}^{56}\mathrm{Fe}^{*}\to p+{}^{55}\mathrm{Mn})$ and ${}^{45}\mathrm{Sc}({}^6\mathrm{Li},\alpha ){}^{47}\mathrm{Ti}^{*}$ (surrogate of $n+{}^{46}\mathrm{Ti}{\to }^{47}{\mathrm{Ti}}^{*}\to p+{}^{46}\mathrm{Sc})$ reactions, respectively. The ${}^{55}\mathrm{Fe}(n,p)$ cross sections were then obtained in the equivalent neutron energy range of 7.9 to 20.1 MeV within the framework of the surrogate-reaction method. The measured results were compared with predictions of the empire-3.2.3 statistical model code and various recent evaluated data libraries. The experimental cross-section data on ${}^{55}\mathrm{Fe}(n,p)$ are in reasonable agreement with EAF-2010, while the TENDL-2014 and ROSFOND-2010 data show some discrepancies. This study demonstrates the possibility of determining neutron-induced charged particle emission cross sections for unstable radionuclides relevant to fusion technology applications by the surrogate-reaction method.

The low-spin structure of odd-odd ${}^{88}\mathrm{Y}$ has been studied via ($p,d\gamma$) reactions on an ${}^{89}\mathrm{Y}$ target. The K150 Cyclotron at the Texas A&M University Cyclotron Institute was employed to provide a 28.5-MeV proton beam, and particle-$\gamma$ and particle-$\gamma -\gamma$ coincidence data were collected with the STARLiTeR array. A number of new levels and $\gamma$ rays have been observed below 2.5 MeV, while level and $\gamma$-ray energies as well as spin-parity assignments have been re-evaluated.

Kaon photoproduction on the proton is studied in the resonance region using an isobar model. The higher-spin nucleon (3/2 and 5/2) and hyperon (3/2) resonances were included in the model utilizing the consistent formalism by Pascalutsa, and they were found to play an important role in data description. The spin-1/2 and spin-3/2 hyperon resonances in combination with the Born terms contribute significantly to the background part of the amplitude. Various forms of the hadron form factor were considered in the construction, and the dipole and multidipole forms were selected as those most suitable for the data description. Model parameters were fitted to new experimental data from CLAS, LEPS, and GRAAL collaborations, and two versions of the model, BS1 and BS2, were chosen. Both models provide a good overall description of the data for the center-of-mass energies from the threshold up to 2.4 GeV. Predicted cross sections of the models at very small kaon angles being consistent with results of the Saclay-Lyon model indicate that the models could be also successful in predicting the hypernucleus production cross sections. Although kaon photoproduction takes place in the third-resonance region with many resonant states, the total number of included resonances, 15 and 16, is quite moderate, and it is comparable with numbers of resonances in other models. The set of chosen nucleon resonances overlaps well with the set of the most probable contributing states determined in the Bayesian analysis with the Regge-plus-resonance model. Particularly, we confirm that the missing resonances $P_{13}\left(1900\right)$ and $D_{13}\left(1875\right)$ do play an important role in the description of data. However, the spin-1/2 state $P_{11}\left(1880\right)$ included in the Bayesian analysis was replaced in our analysis with the near-mass spin-5/2 state $N^{*}\left(1860\right)$, recently considered by the Particle Data Group.

We investigate the evolution of the net-proton kurtosis and the kurtosis of the chiral order parameter near the critical point in the model of nonequilibrium chiral fluid dynamics. The order parameter is propagated explicitly and coupled to an expanding fluid of quarks and gluons in order to describe the dynamical situation in a heavy-ion collision. We study the critical region near the critical point on the crossover side. There are two sources of fluctuations: noncritical initial event-by-event fluctuations and critical fluctuations. These fluctuations can be distinguished by comparing a mean-field evolution of averaged thermodynamic quantities with the inclusion of fluctuations at the phase transition. We find that while the initial state fluctuations give rise to flat deviations from statistical fluctuations, critical fluctuations reveal a clear structure of the phase transition. The signals of the critical point in the net-proton and $\sigma$-field kurtosis are affected by the nonequilibrium dynamics and the inhomogeneity of the space-time evolution but they develop clearly.

The model-dependent uncertainties in the nuclear transition matrix elements for the Majoron-accompanied neutrinoless double-$\beta$ decay $\left(0^{+}\to 0^{+}\text{transition}\right)$ of ${}^{94,96}\mathrm{Zr}, {}^{100}\mathrm{Mo}, {}^{128,130}\mathrm{Te}$, and ${}^{150}\mathrm{Nd}$ isotopes are calculated by employing the projected-Hartree-Fock-Bogoliubov formalism with four different parametrizations of the pairing plus multipolar two-body interactions and three different parametrizations of the Jastrow short-range correlations. Uncertainties in the nuclear transition matrix elements turn out to be less than 15% and 21% for decays involving the emission of single and double Majorons, respectively.

The multiplicities of scission neutrons ${\nu }_{sc}$ are calculated for series of U, Pu, Cm, and Cf isotopes assuming a sudden transition between two different nuclear configurations (${\alpha }_i\to {\alpha }_f$): one just before the neck rupture and one immediately after the disappearance of the neck. This calculation requires only the knowledge of the corresponding two sets of neutron eigenstates. The nuclear shapes around the scission point are described in terms of Cassinian ovals with only two parameters: $\alpha$ (that positions the shape with respect to the zero-neck shape) and ${\alpha }_1$ (that defines the mass asymmetry). Based on these shapes, a neutron mean field of the Woods-Saxon type is constructed using two prescriptions to calculate the distance to the nuclear surface. The accent in the present work is put on the dependence of ${\nu }_{sc}$ on the neutron number $N_f$ of the fissioning nucleus and on the mass asymmetry ${\mathrm{A}}_L/{\mathrm{A}}_H$ of the primary fission fragments. The relative dependence of these multiplicities, averaged over the mass yields, $\langle {\nu }_{sc}\rangle$, are finally compared with existing experimental data on prompt fission neutrons $\langle {\nu }_p\rangle$.

There is no generally accepted view of the structure of the light-quark nonstrange scalar mesons. A variety of models has been proposed that encompass $qq\overline{q}\overline{q}$, molecular, $q\overline{q}$, and glueball states in various combinations. Previously we considered scalar-meson photoproduction in a simple Regge-pole model and showed that it was experimentally viable. Recent data on the photoproduction of $a_0\left(980\right)$ and $f_0\left(980\right)$ confirm this. We extend our model to incorporate Regge cuts, based on our knowledge of ${\pi }^0$ photoproduction. The theoretical predictions are compared to the $a_0\left(980\right)$ and $f_0\left(980\right)$ photoproduction data.