Multiple parton scatterings in high-energy $p+A$ collisions involve multiparton correlation inside the projectile and color coherence of multiple jets, which will lead to nuclear modification of final hadron spectra relative to that in $p+p$ collisions. Such modifications of final hadron spectra in $p+A$ collisions are studied within the hijing 2.1 model. Besides parton shadowing and transverse momentum broadening, which influence final hadron spectra at intermediate $p_T$, modification of parton flavor composition due to multiple scattering and hadronization of many-parton jets system are shown to lead to suppression of final hadrons at large $p_T$ in $p+A$ collisions at the CERN Large Hadron Collider.

Background: Symmetry restoration and configuration mixing in the spirit of the generator coordinate method based on energy density functionals have become widely used techniques in low-energy nuclear structure physics. Recently, it has been pointed out that these techniques are ill defined for standard Skyrme functionals, and a regularization procedure has been proposed to remove the resulting spuriosities from such calculations. This procedure imposes an integer power of the density for the density-dependent terms of the functional. At present, only dated parametrizations of the Skyrme interaction fulfill this condition.

Purpose: To construct a set of parametrizations of the Skyrme energy density functional for multireference energy density functional calculations with regularization using the state-of-the-art fitting protocols.

Method: The parametrizations were adjusted to reproduce ground-state properties of a selected set of doubly magic nuclei and properties of nuclear matter. Subsequently, these parameter sets were validated against properties of spherical and deformed nuclei.

Results: Our parameter sets successfully reproduce the experimental binding energies and charge radii for a wide range of singly magic nuclei. Compared to the widely used SLy5 and to the SIII parametrization that has integer powers of the density, a significant improvement of the reproduction of the data is observed. Similarly, a good description of the deformation properties at $A\sim 80$ was obtained.

Conclusions: We have constructed new Skyrme parametrizations with integer powers of the density and validated them against a broad set of experimental data for spherical and deformed nuclei. These parametrizations are tailor-made for regularized multireference energy density functional calculations and can be used to study correlations beyond the mean field in atomic nuclei.

High-spin states in the odd-odd ${}^{194}$Au nucleus have been investigated using the ${}^{192}$Os(${}^7\text{Li},5n$) reaction at a beam energy of 44 MeV. The previously known structures built on the $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-1}$ and $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-2}\nu j$ configurations are extended to high-spin states, and a new $I^{\pi }=$ (20${}^{+}$) state associated with the $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-2}\nu h_{9/2}^{-1}$ configuration is identified. Importantly, the $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-1}$ band is found to exhibit normal signature splitting. The experimental results are compared with predictions from total Routhian surface and cranked shell-model calculations. Nonaxial shapes for the $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-1}$ and $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-2}\nu h_{9/2}^{-1}$ configurations are proposed. Possible reasons for the absence of signature inversion in the $\pi h_{11/2}^{-1}\otimes \nu i_{13/2}^{-1}$ band in ${}^{194}$Au are discussed.

The tensor properties of the algebra generators are determined with respect to the reduction chain $\mathrm{Sp}(12,R)\supset \mathrm{U}(3,3)\supset {\mathrm{U}}_p\left(3\right)\otimes \overline{{\mathrm{U}}_n\left(3\right)}\supset {\mathrm{U}}^{*}\left(3\right)\supset \mathrm{O}\left(3\right)$, which defines one of the dynamical symmetry limits of the interacting vector boson model. The symplectic basis according to the considered chain is thus constructed and the action of the $\mathrm{Sp}(12,R)$ generators as transition operators between the basis states is illustrated. The matrix elements of the $\mathrm{U}(3,3)$ ladder operators in the so obtained symmetry-adapted basis are given. The $\mathrm{U}(3,3)$ limit of the model is further tested on the more complicated and complex problem of reproducing the $B\left(E2\right)$ transition probabilities between the collective states of the ground band in ${}^{104}\mathrm{Ru}$, ${}^{192}\mathrm{Os}$, ${}^{192}\mathrm{Pt}$, and ${}^{194}\mathrm{Pt}$ isotopes, considered by many authors to be axially asymmetric. Additionally, the excitation energies of the ground and $\gamma$ bands in ${}^{104}\mathrm{Ru}$ are calculated. The theoretical predictions are compared with the experimental data and some other collective models which accommodate the $\gamma -$rigid or $\gamma -$soft structures. The obtained results reveal the applicability of the model for the description of the collective properties of nuclei exhibiting axially asymmetric features.

Recently, we reported a theoretical study on the $K^{-}p\to \eta \Lambda$ reaction near threshold by using an effective Lagrangian approach. It was found that the description of angular distribution data measured by the Crystal Ball Collaboration needs a $D_{03}$ resonance with mass $M=1668.5\pm 0.5$ MeV and total decay width $\Gamma =1.5\pm 0.5$ MeV, which is not the conventional $\Lambda$(1690) or other $\Lambda$ state listed in the Particle Data Group book. In the present work, we study the $\Lambda$ polarization in the $K^{-}p\to \eta \Lambda$ reaction within the same framework. The results show that the existence of this narrow $D_{03}$ state is also compatible with current $\Lambda$ polarization data and that the more accurate $\Lambda$ polarization data at $P_{K^{-}}=735$ MeV can offer further evidence for the existence of this resonance. Furthermore, the role of the $\Lambda \left(1690\right)$ resonance in this reaction is also discussed.

The classical and quantal features of a quadrupole coherent state and its projections over angular momentum and boson number are quantitatively analyzed in terms of the departure of the Heisenberg uncertainty relations from the classical limit. This study is performed alternatively for two choices of pairs of conjugate coordinates. The role of deformation as mediator of classical and quantal behaviors is also commented upon. Although restoring the rotational and gauge symmetries makes the quantal features manifest dominantly for small deformation, these are blurred by increasing the deformation, which pushes the system toward a classical limit.

Excited levels of ${}^{128}$Te to 3.3 in MeV excitation have been studied using $\gamma$-ray spectroscopy following inelastic scattering of accelerator-produced neutrons. Spectroscopic information, including transition energies, level spins, $E$2/$M$1 multipole-mixing ratios, and $\gamma$-ray branching ratios, was determined from $\gamma$-ray excitation functions measured from $E_n=2.15$–3.33 MeV in 90-keV increments, $\gamma$-ray angular distributions measured at $E_n=2.2$, 2.8, and 3.3 MeV, and $\gamma$$\gamma$ coincidences measured at $E_n=3.6$ MeV. Lifetimes of levels in ${}^{128}$Te were deduced using Doppler-shift attenuation techniques. Absolute transition probabilities were determined for many levels and compared to interacting boson model and particle-core coupling model calculations to identify few particle and collective structures; states exhibiting the decay characteristics expected for two-phonon, mixed-symmetry, and quadrupole-octupole coupled states are identified.

The dilepton invariant mass spectrum measured in heavy-ion collisions includes contributions from important quark-gluon plasma (QGP) probes such as thermal radiation and the quarkonium ($J/\psi$, ${\psi }^{\prime }$, and ${\rm Y}$) states. Dileptons coming from hard $q\overline{q}$ scattering, the Drell-Yan process, contribute in all mass regions. In heavy-ion colliders, such as the Large Hadron Collider (LHC), semileptonic decays of heavy flavor hadrons provide a substantial contribution to the dilepton continuum. Because the dilepton continuum can provide quantitative information on heavy quark yields and their medium modifications, it is important to identify which dilepton sources populate different parts of the continuum. In the present study, we calculate $c\overline{c}$ and $b\overline{b}$ production and determine their contributions to the dilepton continuum in Pb+Pb collisions at $\sqrt{s_{{}_{NN}}}=2.76$ TeV with and without including heavy quark energy loss. We also calculate the rates for Drell-Yan and thermal dilepton production. The contributions to the continuum from these dilepton sources are studied in the kinematic ranges relevant for the LHC detectors. The relatively high $p_T$ cutoff for single leptons excludes most dileptons produced by the thermal medium. Heavy flavors are the dominant source of dilepton production in all the kinematic regimes except at forward rapidities where Drell-Yan dileptons become dominant for masses greater than 10 GeV/$c^2$.

A systematic study is presented for centrality, transverse momentum ($p_T$), and pseudorapidity ($\eta$) dependence of the inclusive charged hadron elliptic flow ($v_2$) at midrapidity ($\left|\eta \right|<1.0$) in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=7.7$, 11.5, 19.6, 27, and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and four-particle cumulants ($v_2\left\{4\right\}$), are presented to investigate nonflow correlations and $v_2$ fluctuations. We observe that the difference between $v_2\left\{2\right\}$ and $v_2\left\{4\right\}$ is smaller at the lower collision energies. Values of $v_2$, scaled by the initial coordinate space eccentricity, $v_2/\varepsilon$, as a function of $p_T$ are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider ($\sqrt{s_{NN}}=62.4$ and 200 GeV) and at the Large Hadron Collider ($\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=2.76$ TeV). The $v_2\left(p_T\right)$ values for fixed $p_T$ rise with increasing collision energy within the $p_T$ range studied ($<$$2\mathrm{GeV}/c$). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of $v_2\left(p_T\right)$. We also compare the $v_2$ results to UrQMD and AMPT transport model calculations, and physics implications on the dominance of partonic versus hadronic phases in the system created at beam energy scan energies are discussed.

In the present measurements a ${}^{12}$C target was bombarded by a ${}^4$He beam with energies from 14 to 21 MeV and the excitation function measurements for the reactions of the ${}^{12}$C$({}^4$He, ${}^8$Be)${}^8$Be, ${}^{12}$C(${}^4$He, ${}^{12}$C$[7.65,0^{+}]$)${}^4$He, and ${}^{12}$C(${}^4$He, ${}^{12}$C$[9.64,3^{-}]$)${}^4$He were obtained using an array of 6 double-sided silicon strip detectors. The excitation functions are used to gain an insight into possible $\alpha$-cluster structures in ${}^{16}$O.

We study the hadron yield correlation in the combination models in high-energy heavy-ion collisions. We derive the relationship between the average yields of different hadrons produced in the combination of a system consisting of equal numbers of quarks and antiquarks. We present the results for the directly produced hadrons as well as those for the final hadrons including the strong and electromagnetic decay contributions. We also study the net quark influence by considering the case when the number of quarks is larger than that of antiquarks. We make comparison with the data wherever possible.

We use the holographic principle to study quark jets using trailing strings in an expanding plasma with asymptotic Bjorken hydrodynamics. We make use of the fact that the trailing string is the locus of the light delay in bulk to obtain the explicit form for quark jets in the expanding plasma. From the trailing string solution we calculate the drag coefficient of a heavy quark in the strongly coupled expanding plasma. The energy scaling of the maximum penetration length of an ultrarelativistic light quark jet using light rays in bulk is estimated.

The $2_1^{+}$ energies and $B(E2;0_1^{+}\to 2_1^{+})$ values of even-even Sn nuclei with mass numbers between 102 and 130 have been calculated within the framework of the $SD$-pair approximation of the nuclear shell model. We employ monopole and quadrupole pairing plus quadrupole-quadrupole interaction with optimized parameters. Good agreement is obtained between the calculated results and experimental data. The robustness of our calculated $2_1^{+}$ level and $E2$ transition rates with respect to different sets of effective charge and different forms of the Hamiltonian is studied.

Background: Nuclei in the $A\approx 190$ mass region show gradual shape changes from prolate through nonaxial deformed shapes and ultimately towards spherical shapes as the Pb region is approached. Exploring how this shape evolution occurs will help us understand the evolution of collectivity in this region.

Purpose: The level scheme of the ${}^{192}$Au nucleus in $A\approx 190$ region was studied in order to deduce its deformations.

Methods: High-spin states of ${}^{192}$Au have been populated in the ${}^{186}$W(${}^{11}$B, 5$n$) reaction at a beam energy of 68 MeV and their $\gamma$ decay was studied using the YRAST Ball detector array at the Wright Nuclear Structure Laboratory (WNSL), Yale University.

Results: Based on double and triple $\gamma$-ray coincidence data the level scheme of ${}^{192}$Au has been extended up to $I^{\pi }={32}^{+}$ at an excitation energy of $\sim$6 MeV.

Conclusion: The results are discussed in the framework of pairing and deformation self-consistent total Routhian surface (TRS) and cranked shell model (CSM) calculations. The comparison of the experimental observations with the calculations indicates that this nucleus takes a nonaxial shape similar to other Au nuclei in this region.

Spectroscopic observables such as electromagnetic transition strengths can be related to the properties of the intrinsic mean-field wave function when the latter are strongly deformed, but the standard rotational formulas break down when the deformation decreases. Nevertheless there is a well-defined, nonzero, spherical limit that can be evaluated in terms of overlaps of mean-field intrinsic deformed wave functions. We examine the transition between the spherical limit and the strongly deformed limit for a range of nuclei, comparing the two limiting formulas with exact projection results. We find a simple criterion for the validity of the rotational formula depending on $\langle \Delta {\vec{J}}^2\rangle$, the mean square fluctuation in the angular momentum of the intrinsic state. We also propose an interpolation formula which describes the transition strengths over the entire range of deformations, reducing to the two simple expressions in the appropriate limits.

High-$p_T$ hadrons produced in hard collisions and detected inclusively bear peculiar features: (i) they originate from jets whose initial virtuality and energy are of the same order and (ii) such jets are rare and have a very biased energy sharing among the particles, namely the detected hadron carries the main fraction of the jet energy. The former feature leads to an extremely intensive gluon radiation and energy dissipation at the early stage of hadronization, either in vacuum or in a medium. As a result, a leading hadron must be produced on a short length scale. Evaluation within a model of perturbative fragmentation confirms the shortness of the production length. This result is at variance with the unjustified assumption of long production length, made within the popular energy-loss scenario. Thus, we conclude that the main reason of suppression of high-$p_T$ hadrons in heavy-ion collisions is the controlled-by-color-transparency attenuation of a high-$p_T$ dipole propagating through the hot medium. Adjusting a single parameter, the transport coefficient, we describe quite well the data from the Large Hadron Collider and the Relativistic Heavy Ion Collider for the suppression factor $R_{AA}$ as function of $p_T$, collision energy, and centrality. We observe that the complementary effect of the initial-state interaction causes a flattening and even fall of $R_{AA}$ at large $p_T$. The azimuthal anisotropy of hadron production, calculated with no further adjustment, also agrees well with data at different energies and centralities.

We present a detailed report of a measurement of the neutron $\beta$-asymmetry parameter $A_0$, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T $2\times 2\pi$ solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages located on both ends of the spectrometer. From an analysis of data acquired during runs in 2008 and 2009, we report $A_0=-0.11966\pm 0.{00089}_{-0.00140}^{+0.00123}$, from which we extract a value for the ratio of the weak axial-vector and vector coupling constants of the nucleon, $\lambda =g_A/g_V=-1.27590\pm 0.{00239}_{-0.00377}^{+0.00331}$. Complete details of the analysis are presented.