Inclusive jet spectra from $pp$ and PbPb collisions at a nucleon-nucleon center-of-mass energy of $2.76\text{TeV}$, collected with the CMS detector at the CERN Large Hadron Collider, are presented. Jets are reconstructed with three different distance parameters ($R=0.2$, 0.3, and 0.4) for transverse momentum ($p_{\mathrm{T}}$) greater than $70\mathrm{GeV}/\mathrm{c}$ and pseudorapidity $\left|\eta \right|<2$. Next-to-leading-order quantum chromodynamic calculations with nonperturbative corrections are found to overpredict jet production cross sections in $pp$ for small distance parameters. The jet nuclear modification factors for PbPb compared to $pp$ collisions, show a steady decrease from peripheral to central events, along with a weak dependence on the jet $p_{\mathrm{T}}$. They are found to be independent of the distance parameter in the measured kinematic range.

Fluctuations of conserved quantities, such as baryon, electric charge, and strangeness number, are sensitive observables in heavy-ion collisions to search for the QCD phase transition and critical point. In this paper, we performed a systematical analysis on the various cumulants and cumulant ratios of event-by-event net-strangeness distributions in Au+Au collisions at $\sqrt{s_{\mathit{NN}}}=7.7$, 11.5, 19.6, 27, 39, 62.4, and 200 GeV from an ultrarelativistic quantum molecular dynamics model. We performed a systematical study on the contributions from various strange baryons and mesons to the net-strangeness fluctuations. The results demonstrate that the cumulants and cumulant ratios of net-strangeness distributions extracted from different strange particles show very different centrality and energy-dependence behavior. By comparing with the net-kaon fluctuations, we found that the strange baryons play an important role in the fluctuations of net strangeness. This study can provide useful baselines to study the QCD phase transition and search for the QCD critical point by using the fluctuations of net strangeness in heavy-ion collisions experiment. It can help us to understand noncritical physics contributions to the fluctuations of net strangeness.

Spin-polarization observables of deuteron photodisintegration at low energies are studied in a pionless effective-field theory up to next-to-next-to-leading order (NNLO). The total and differential cross sections, induced neutron polarization $P_{y^{\prime }}$, and tensor analyzing powers $T_{20}$ and $T_{22}$ of the process are calculated at photon energies from the breakup threshold to 20 MeV. We find that the NNLO corrections in the cross sections and $P_{y^{\prime }}$ converge well whereas they turn out to be important contributions in $T_{20}$ and $T_{22}$. We discuss the discrepancy between theory and experiment in $P_{y^{\prime }}$ still persisting as well as an implication of our result to the first measurement of $T_{20}$ at low energies in the High Intensity Gamma-Ray Source facility at Duke University.

Exclusive measurements of high-energy $\gamma$ rays have been performed in ${}^{124}\mathrm{Ba}$ and ${}^{136}\mathrm{Ba}$ at the same excitation energy $(\sim 49\mathrm{MeV})$ to study the properties of the giant dipole resonance (GDR) over a wide $N/Z$ range. The high-energy $\gamma$ rays are measured in coincidence with the multiplicity of low-energy $\gamma$ rays to disentangle the effect of temperature $\left(T\right)$ and angular momentum $\left(J\right)$. The GDR parameters are extracted employing a simulated Monte Carlo statistical model analysis. The observed $\gamma$-ray spectra of ${}^{124}\mathrm{Ba}$ can be explained with prolate deformation, whereas a single-component Lorentzian function which corresponds to a spherical shape could explain the $\gamma$-ray spectra of ${}^{136}\mathrm{Ba}$. The observed GDR width in ${}^{136}\mathrm{Ba}$ is narrower compared to that of ${}^{124}\mathrm{Ba}$. The statistical model best-fit GDR cross sections are found to be in reasonable agreement with the thermal shape fluctuation model (TSFM) calculations. Further, it is shown that the variation of GDR width with $T$ is well reproduced by the TSFM calculations over the temperature range of 1.1–1.7 MeV.

A new array of four Deuterated Benzene (${\mathrm{C}}_6{\mathrm{D}}_6$) detectors has been installed at the Gaerttner Linear Accelerator Center at Rensselaer Polytechnic Institute for the purpose of measuring neutron capture cross sections in the keV region. Measurements were performed on samples of ${}^{181}\mathrm{Ta}$ in the unresolved resonance region (URR) using a filtered-beam technique, by which a 30 cm iron filter was placed in a white-spectrum neutron beam to remove all time-dependent $\gamma$-ray background and all neutrons except those transmitted through resonance-potential interference “windows” in the iron. The resulting filtered beam was effectively a quasimonoenergetic neutron source, which was used for performing measurements on isotopes with narrow level spacings in the URR. The capture cross-section results obtained for two thicknesses of tantalum are in agreement with those documented in the JEFF-3.2 library, as are the average resonance parameters obtained via a fit to the data using the sammy-fitacs code.

The fission fragment yield distribution has been measured in the ${}^{239}\mathrm{Pu}\left(n_{\mathrm{th}},f\right)$ reaction in the mass region of $A=126$ to 150 using the Lohengrin recoil-mass spectrometer. Three independent experimental campaigns were performed, allowing a significant reduction of the uncertainties compared to evaluated nuclear data libraries. The long-standing discrepancy of around 10% for the relative yield of $A=134$ reported in JEF-2.2 and JEFF-3.1.1 data libraries is finally solved. Moreover, the measured mass distribution in thermal neutron-induced fission does not show any significant dip around the shell closure ($A=136$) as seen in heavy-ion fission data of ${}^{208}\mathrm{Pb}$(${}^{18}\mathrm{O}$, $f$) and ${}^{238}\mathrm{U}$(${}^{18}\mathrm{O}$, $f$) reactions. Lastly, comparisons between our experimental data and the predictions from Monte Carlo codes (gef and fifrelin) are presented and discussed.

The possibilities of direct production of new isotopes of transfermium nuclei ${}^{261,263,264}\mathrm{No}$, ${}^{263,264}\mathrm{Lr}$, ${}^{263,264,266,268}\mathrm{Rf}$, ${}^{264,265}\mathrm{Db}$, and ${}^{267,268,270,272}\mathrm{Sg}$ are studied in various asymmetric hot fusion-evaporation reactions with radioactive beams. The optimal reaction partners and conditions for the synthesis of new isotopes are suggested. The products of the suggested reactions can fill a gap of unknown isotopes between the isotopes of heaviest nuclei obtained in the $xn$ evaporation channels of the cold and hot complete fusion reactions with the stable beams.

A simple approach based on the separation of wounded nucleons in an $A\text{−}A$ collision in two categories, those suffering single collisions (corona) and the rest (core), estimated within a Glauber Monte Carlo model, explains the centrality dependence of the light flavor hadron production in Pb-Pb collisions at $\sqrt{s_{\mathit{NN}}}=2.76\mathrm{TeV}$. The core contribution does not include any dependence of any process on the fireball shape as a function of the impact parameter. Therefore, the ratios of the $p_T$ distributions to the one corresponding to the minimum-bias $pp$ collisions at the same energy—each of them normalized to the corresponding charged particle density—the $\langle p_T\rangle$ and transverse energy per unit of rapidity are reproduced less accurately by such an approach. The results show that, at energies available at the CERN Large Hadron Collider, the corona contribution still plays an important role, and it has to be considered in order to evidence the centrality dependence of different observables related to the core properties and dynamics.

In order to clarify the nature of hypernuclear low-lying states, we carry out a comprehensive study of the structure of ${}_{\phantom{00000.}\mathrm{\Lambda }}^{145\text{–}155}\mathrm{Sm}$ hypernuclei, which exhibit a transition from vibrational to rotational character as the neutron number increases. To this end, we employ a microscopic particle-core coupling scheme based on a covariant density functional theory. We find that the positive-parity ground-state band in the hypernuclei shares a similar structure to that of the corresponding core nucleus. That is, regardless of whether the core nucleus is spherical or deformed, each hypernuclear state is dominated by the single configuration of the $\mathrm{\Lambda }$ particle in the $s_{1/2}$ state ($\mathrm{\Lambda }{s}_{1/2}$) coupled to one core state of the ground band. In contrast, the low-lying negative-parity states mainly consist of $\mathrm{\Lambda }{p}_{1/2}$ and $\mathrm{\Lambda }{p}_{3/2}$ configurations coupled to plural nuclear core states. We show that, while the mixing amplitude between these configurations is negligibly small in spherical and weakly deformed nuclei, it strongly increases as the core nucleus undergoes a transition to a well deformed shape, which is consistent with the Nilsson wave functions. We demonstrate that the structure of these negative-parity states with spin $I$ can be well understood based on a naive $LS$ coupling scheme, with total orbital angular momentum $L=[I\otimes 1]$ and spin angular momentum $S=1/2$.

The existence of the permanent electric dipole moment of a fundamental particle implies violation of time reversal invariance. The electric dipole moment of a diamagnetic neutral atom is mainly induced by the nuclear Schiff moment. In this study the Schiff moments induced by the interaction which violates parity and time reversal invariance are calculated for various Xe isotopes using the shell-model wave functions. The contributions to the Schiff moment from one-particle and one-hole excitations turn out to be very different from orbital to orbital. It is also found that the contributions from the core excitations are larger than other particle-hole contributions.

A new precision half-life measurement of ${}^{25}\mathrm{Al}$ was conducted using the TwinSol $\beta$-counting station at the University of Notre Dame. The new measured value of $t_{1/2}^{\mathrm{new}}=7.1657\left(24\right)$ s is in good agreement with the most recent measurement, while being 3 times more precise. Using these new measurements, an evaluation of the ${}^{25}\mathrm{Al}$ half-life has been performed, leading to an average half-life of $t_{1/2}^{\mathrm{world}}=7.1665\left(26\right)$ s, which is 5 times more precise than it's predecessor and has a more satisfactory Birge ratio of 1.1. To aid in future measurements of correlation parameters, a new Fermi to Gamow-Teller mixing ratio $\rho$ and correlation parameters for this mixed transition have been calculated assuming the standard model validity using the new world half-life.

The magnetic dipole moment and mean-square charge radius of ${}^{199g}\mathrm{Pt}$ $(I^{\pi }=$ $5/2^{-},t_{1/2}=30.8$ min) ground state and ${}^{199m}\mathrm{Pt}$ $(E_{\mathrm{ex}}=424$ keV, $I^{\pi }=$ (13/2)${}^{+},t_{1/2}=13.6$ s) isomeric state are evaluated for the first time from investigations of the hyperfine splitting of the ${\lambda }_1=248.792$ nm transition by in-gas-cell laser ionization spectroscopy. Ground and isomeric states of neutron-rich ${}^{199}\mathrm{Pt}$ nucleus were produced by a multinucleon transfer reaction at the KEK Isotope Separation System (KISS), designed for the study of nuclear spectroscopy in the vicinity of $N=126$. The measured magnetic dipole moments $+0.75$(8)${\mu }_{\mathrm{N}}$ and $-0.57$(5)${\mu }_{\mathrm{N}}$ are consistent with the systematics of those of nuclei with $I^{\pi }=$ $5/2^{-}$ and $I^{\pi }=$ $13/2^{+}$, respectively.

The cosmogenic neutron yield $Y_n$ characterizes the ability of matter to produce neutrons under the effect of cosmic ray muons with spectrum and average energy corresponding to an observation depth. The yield is the basic characteristic of cosmogenic neutrons. The neutron production rate and neutron flux both are derivatives of the yield. The constancy of the exponents $\alpha$ and $\beta$ in the known dependencies of the yield on energy $Y_n\propto E_{\mu }^{\alpha }$ and the atomic weight $Y_n\propto A^{\beta }$ allows one to combine these dependencies in a single formula and to connect the yield with muon energy loss in matter. As a result, the phenomenological formulas for the yields of muon-induced charged pions and neutrons can be obtained. These expressions both are associated with nuclear loss of the ultrarelativistic muons, which provides the main contribution to the total neutron yield. The total yield can be described by a universal formula, which is the best fit of the experimental data.

Neutron multiplicity prior to scission and evaluation of mass distribution of fission fragments with the fission time scale for neutron induced fission of plutonium isotopes are investigated using a dynamical Langevin approach. Also, mass yield of fragments and prompt neutron multiplicity in different time scales of the fission process are compared with experimental data. Reasonable agreement is achieved between calculated and available experimental data.

$J/\psi$ observables of $p+p$ collisions at $\sqrt{s}=200\mathrm{GeV}$ and 2.76 TeV are calculated using the pythia event generator for the production of $c$ and $\overline{c}$ and the Wigner density formalism. The charm quark momentum from pythia is tuned in such a way that the transverse momentum and rapidity distribution correspond to the fixed-order next-to-leading logarithm calculations and hence to the experimental data for open charm mesons. Using the Wigner density of the charmonium wave function we calculate for each charm quark pair the probability to form a charmonium. As a result, the experimental data on the total $J/\psi$ yield, its rapidity and transverse momentum distribution as well as the fractions of feed-down from excited states of charmonium are reproduced. Applying the same approach to relativistic heavy-ion collisions, we find, if quark gluon plasma (QGP) effects are ignored, a considerable enhancement of the primordial $J/\psi$'s.

We report the independent experimental confirmation of an isomeric state in the proton drip-line nucleus ${}^{26}\mathrm{P}$. The $\gamma$-ray energy and half-life determined are $164.4\pm 0.3\left(\text{sys}\right)\pm 0.2\left(\text{stat}\right)$ keV and $104\pm 14$ ns, respectively, which are in agreement with the previously reported values. These values are used to set a semiempirical limit on the proton separation energy of ${}^{26}\mathrm{P}$, with the conclusion that it can be bound or unbound.

We report measurements of cross sections and analyzing powers for nucleon-knockout $(\vec{p},np)$ reactions of ${}^2\mathrm{H}, {}^6\mathrm{Li}$, and ${}^{12}\mathrm{C}$ at 296 MeV using the RCNP NPOL3 neutron detector and large acceptance spectrometer. The $1s$ and $1p$ knockout reactions were successfully separated with a separation-energy resolution of approximately 6 MeV. The resulting data were compared with plane-wave and distorted-wave impulse approximation calculations employing the nucleon-nucleon $t$ matrix in free space. No significant differences were identified in the case of the present analyzing power data, in contrast to the significant reductions observed in $(\vec{p},2p)$ values. The conventional Pauli blocking and nuclear binding effects with the $g$ matrix and the relativistic effect of nucleon mass reduction in the nuclei are also discussed.

We investigate pseudorapidity correlations of the average transverse flow of particles emitted in relativistic heavy-ion collisions. We employ $3+1$-dimensional viscous relativistic hydrodynamics with initial conditions from the quark Glauber Monte Carlo model to confront the recent measurements on the pseudorapidity correlations of the average transverse momentum in Pb+Pb collisions at $\sqrt{s_{NN}}=2760$ GeV. We find good agreement between the model predictions and data. Further, we study two other observables build with the covariance of the average transverse momentum in different rapidity bins. These observables have better stability under various systematics, thus allowing for a robust comparison between data and model. The transverse flow-transverse flow correlation coefficient is directly related to correlations of the underlying collective flow at different pseudorapidities. The three-bin measure of $p_T$ factorization breaking in pseudorapidity gives an estimate of possible decorrelation of the average transverse flow in the longitudinal direction.

The Coulomb-breakup method to extract the cross section for neutron radiative capture at astrophysical energies is analyzed in detail. In particular, its sensitivity to the description of the neutron-core continuum is ascertained. We consider the case of ${}^{14}\mathrm{C}(n,\gamma ){}^{15}\mathrm{C}$ for which both the radiative capture at low energy and the Coulomb breakup of ${}^{15}\mathrm{C}$ into ${}^{14}\mathrm{C}+n$ on Pb at 68 MeV/nucleon have been measured with accuracy. We confirm the direct proportionality of the cross section for both reactions to the square of the asymptotic normalization constant of ${}^{15}\mathrm{C}$ observed by Summers and Nunes [Phys. Rev. C 78, 011601(R) (2008)], but we also show that the ${}^{14}\mathrm{C}-n$ continuum plays a significant role in the calculations. Fortunately, the method proposed by Summers and Nunes can be improved to absorb that continuum dependence. We show that a more precise radiative-capture cross section can be extracted selecting the breakup data at forward angles and low ${}^{14}\mathrm{C}-n$ relative energies.