We investigate two-pion Bose-Einstein correlations of quark-gluon plasma droplet sources in single-event measurements. We find that the distribution of the fluctuation between correlation functions of the single and mixed events provides useful signals to detect the granular structure of the source.

We develop a simple model to study the heavy quarkonium-hadron cross section in the high-energy limit. The hadron is represented by an external electric color field (capacitor) and the heavy quarkonium is represented by a small color dipole. Using high-energy approximations we compute the relevant cross sections, which are then compared with results obtained with other methods.

Angular distributions for production of the ${\Theta }^{+}$ pentaquark are calculated for the collisions of polarized protons with polarized target protons. We compare calculations based on different assumptions concerning spin and parity ($J=1/2^{\pm },3/2^{\pm }$) of the ${\Theta }^{+}$ state. For a wide class of interactions the spin correlation parameters describing the asymmetric angular distributions are calculated up to 250 MeV above production threshold. The deviations from the near-threshold behavior are investigated.

We study the properties of the ${\Theta }^{+}$ in nuclear matter and ${\Theta }^{+}$ hypernuclei within the quark mean-field model, which has been successfully used for the description of ordinary nuclei and Λ hypernuclei. With the assumption that the nonstrange mesons couple only to the u and d quarks inside baryons, a sizable attractive potential of the ${\Theta }^{+}$ in nuclear matter is achieved as a consequence of the cancellation between the attractive scalar potential and the repulsive vector potential. We investigate the ${\Theta }^{+}$ single-particle energies in light, medium, and heavy nuclei. More bound states are obtained in ${\Theta }^{+}$ hypernuclei in comparison with those in Λ hypernuclei.

The ratio of longitudinal to transverse structure functions, ${\sigma }_L/{\sigma }_T$, has been extracted from recent beam-recoil transferred polarization data for the $p(\overrightarrow{e},e^{\text{'}}{K}^{+})\overrightarrow{\Lambda }$ reaction. Results have been obtained for $W=1.72$, 1.84, and 1.98 GeV at an average $Q^2$ of 0.77, 0.69, and 0.61 GeV${}^2$, respectively. Our results indicate a ratio that is systematically slightly smaller than previously published results using a Rosenbluth separation.

The cross sections for the elastic scattering reactions ${}^{112,124}\mathrm{Sn}(\alpha ,\alpha ){}^{112,124}\mathrm{Sn}$ at energies above and below the Coulomb barrier are presented and compared to predictions for global α-nucleus potentials. The high precision of the new data allows a study of the global α-nucleus potentials at both the proton- and neutron-rich sides of an isotopic chain. In addition, local α-nucleus potentials have been extracted for both nuclei and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction ${}^{112}\mathrm{Sn}$($\alpha ,\gamma$)${}^{116}\mathrm{Te}$ at astrophysically relevant energies are presented and compared to experimental data.

Parity- and time-invariance-violating (P,T-odd) atomic electric dipole moments (EDM) are induced by the interaction between atomic electrons and nuclear P,T-odd moments, which are themselves produced by P,T-odd nuclear forces. The nuclear EDM is screened by atomic electrons. The EDM of a nonrelativistic atom with closed electron subshells is induced by the nuclear Schiff moment. For heavy relativistic atoms EDM is induced by the nuclear local dipole moments, which differ by 10–50% from the Schiff moments calculated previously. We calculate the local dipole moments for ${}^{199}\mathrm{Hg}$ and ${}^{205}\mathrm{Tl}$ where the most accurate atomic [Romalis et al., Phys. Rev. Lett. 86, 2505 (2001)] and molecular [Cho et al., Phys. Rev. Lett. 63, 2559 (1989); Phys. Rev. A 44, 2783 (1991)] EDM measurements have been performed.

The Langevin equation was used to describe fusion dynamics in two systems, ${}^{64}\mathrm{Ni}+{}^{100}\mathrm{Mo}$ and ${}^{64}\mathrm{Ni}+{}^{96}\mathrm{Zr}$. The corresponding fusion cross sections were calculated for different energies, and the mean angular momentum and its dependence on energy were also obtained. We were able to reproduce experimental fusion cross sections at high energies with the one-body dissipation mechanism. Attention was focused on the fusion barrier calculated with the Yukawa-plus-exponential method.

We present the first large-acceptance measurement of event-wise mean transverse momentum $\langle p_t\rangle$ fluctuations for Au-Au collisions at nucleon-nucleon center-of-momentum collision energy $\sqrt{s_{\mathit{NN}}}$ = 130 GeV. The observed nonstatistical $\langle p_t\rangle$ fluctuations substantially exceed in magnitude fluctuations expected from the finite number of particles produced in a typical collision. The r.m.s. fractional width excess of the event-wise $\langle p_t\rangle$ distribution is $13.7\pm 0.1$(stat) $\pm 1.3$(syst)% relative to a statistical reference, for the 15% most-central collisions and for charged hadrons within pseudorapidity range $\left|\eta \right|<1,2\pi$ azimuth, and $0.15\le p_t\le 2$ GeV/c. The width excess varies smoothly but nonmonotonically with collision centrality and does not display rapid changes with centrality which might indicate the presence of critical fluctuations. The reported $\langle p_t\rangle$ fluctuation excess is qualitatively larger than those observed at lower energies and differs markedly from theoretical expectations. Contributions to $\langle p_t\rangle$ fluctuations from semihard parton scattering in the initial state and dissipation in the bulk colored medium are discussed.

The standard definition of the electromagnetic radius of a charged particle (in particular the proton) is ambiguous once electromagnetic corrections are considered. We argue that a natural definition can be given within an effective field theory framework in terms of a matching coefficient. The definition of the neutron radius is also discussed. We elaborate on the effective field theory relevant for hydrogen and muonic hydrogen, especially for the latter. We compute the hadronic corrections to the Lamb shift (for the polarizability effects only with logarithmic accuracy) within heavy-baryon effective theory. We find that they diverge in the inverse of the pion mass in the chiral limit.

The question, whether the high-quality nucleon-nucleon potentials can successfully describe the three-nucleon system, and to what extent three-nucleon forces (3NFs) play a role, has become very important in nuclear few-body physics. One kinematic region where effects because of 3NFs show up is in the minimum of the differential cross section of elastic nucleon-deuteron scattering. Another observable, which could give an indication about the contribution of the spin to 3NFs, is the vector analyzing power. To investigate the importance of 3NFs systematically over a broad range of intermediate energies, both observables of elastic proton-deuteron scattering have been measured at proton bombarding energies of 108, 120, 135, 150, 170, and 190 MeV, covering an angular range in the center-of-mass system between ${30}^{°}$ and ${170}^{°}$. The results show unambiguously the shortcomings of calculations employing only two-body forces and the necessity of the inclusion of 3NFs. They also show the limitations of the results of the present day models for few-nucleon systems at backward angles, especially at higher beam energies. New calculations based on chiral perturbation theory are also presented and compared with the data at the lowest energy.

Experimentally determined level densities of the transitional isotopes ${}^{148,149,150,152}\mathrm{Sm}$ at excitation energies below and around the neutron binding energy are compared with microcanonical calculations based on a Monte Carlo approach to noncollective level densities, folded with a collective enhancement estimated in the frame of the interacting boson model (IBM). The IBM parameters are adjusted so as to reproduce the low-lying discrete levels of both parities, with the exception of the odd-mass nucleus, ${}^{149}\mathrm{Sm}$, where complete decoupling of the unpaired neutron from the core is assumed.

The level structure of odd-odd ${}^{134}\mathrm{Sb}$ has been studied at CERN/ISOLDE following the ${\beta }^{-}$ decay of ${}^{134}\mathrm{Sn}$ and the β-delayed neutron decay of ${}^{135}\mathrm{Sn}$. Elemental and isobaric separation were accomplished by use of a resonance ionization laser ion source and an on-line mass separator, respectively. Both γ-ray singles and $\gamma \text{−}\gamma$ coincidence data were taken as a function of time. New levels at 279, 441, 555, 617, and 1385 keV have been identified and given proposed spin and parity assignments of $7^{-}$, $5^{-}$, $6^{-}$, $4^{-}$, and $5^{-}$, respectively, following β-delayed neutron decay of $7/2^{-}$ ${}^{135}\mathrm{Sn}$. New $1^{-}$ levels have been identified at 1900, 2170, and 2430 keV following the ${\beta }^{-}$ decay of $0^{+}$ ${}^{134}\mathrm{Sn}$. The resulting level structures are compared to shell-model calculations using the CD Bonn interaction and scaled and unscaled Kuo-Herling interactions developed for the ${}^{208}\mathrm{Pb}$ region. Remarkably enough, the unscaled Kuo-Herling interaction provides the best fit for the levels below 1 MeV.

Results of reaction cross-section measurements on ${}^{12}\mathrm{C},{}^{40}\mathrm{Ca},{}^{90}\mathrm{Zr}$, and ${}^{208}\mathrm{Pb}$ at incident proton energies between 80 and 180 MeV and for ${}^{58}\mathrm{Ni}$ at 81 MeV are presented. The experimental procedure is described, and the results are compared with earlier measurements and predictions using macroscopic and microscopic models.

We report angular distribution measurements of the cross section, analyzing power, induced polarization, and all polarization transfer coefficients for the natural parity transitions in ${}^{10}\mathrm{B}$($\overrightarrow{p},{\overrightarrow{p}}^{\text{'}}){}^{10}$B at 197 MeV. All of the transitions closely follow the pattern for spin-1/2 scattering from spin-0, namely $A=P,D_{{\mathit{SS}}^{\text{'}}}=D_{{\mathit{LL}}^{\text{'}}}$, and $D_{{\mathit{SL}}^{\text{'}}}=-D_{{\mathit{LS}}^{\text{'}}}$. Small deviations from $D_{{\mathit{NN}}^{\text{'}}}=1$ reflect spin-flip contributions to these transitions. Distorted wave impulse approximation calculations were generally successful, supporting the use of an empirical effective nucleon-nucleon interaction, the inclusion of channel-coupling in the ground state and the $3^{+}\leftrightarrow 4^{+}$ transition, and the procedure of increasing the $L=2$ strength of shell-model particle-hole matrix elements to match the collective contribution to these transitions.

The effects of core deformation and of its dynamical reorientation and rotational excitation on the inclusive single-neutron knockout reaction cross sections on light spherical target nuclei are examined. The projectile nuclei are modeled within the framework of a weak-coupling, quadrupole-deformed core-plus-neutron two-body model. We formulate the inclusion of this non-spectator-core degree of freedom within the nonperturbative eikonal model and calculate the elastic and inelastic breakup (or stripping) neutron-removal cross sections. We apply the methods to model the single-neutron removal reactions induced by ${}^{11}\mathrm{Be}$ and ${}^{17}\mathrm{C}$ secondary fragmentation beams incident on a ${}^9\mathrm{Be}$ target. Our calculations indicate that dynamical deformation effects on the elastic breakup component of the knockout cross section can be significant. This is the largest effect. The more geometrical stripping cross section is found to be hardly changed by the inclusion of the deformed core degree of freedom.

When a matrix is reduced to Lanczos tridiagonal form, its matrix elements can be divided into an analytic smooth mean value and a fluctuating part. The next-neighbor spacing distribution $P(s)$ and the spectral rigidity ${\Delta }_3$ are shown to be universal functions of the average value of the fluctuating part. It is explained why the behavior of these quantities suggested by random matrix theory is valid in far more general cases.

A systematic investigation of the rotating $N=Z$ even-even nuclei in the mass $A=68\text{−}80$ region has been performed within the frameworks of the cranked relativistic mean field, cranked relativistic Hartree-Bogoliubov theories, and cranked Nilsson-Strutinsky approach. Most of the experimental data are well accounted for in the calculations. The present study suggests the presence of strong isovector np pair field at low spin, whose strength is defined by the isospin symmetry. At high spin, the isovector pair field is destroyed and the data are well described by the calculations assuming zero pairing. No clear evidence for the existence of the isoscalar $t=0$ np pairing has been obtained in the present investigation performed at the mean field level.

Nuclear moments of odd-A neon isotopes in the range $17\le A\le 25$ have been determined from optical hyperfine structures measured by collinear fast-beam laser spectroscopy. The magnetic dipole moments of ${}^{17}\mathrm{Ne}$, ${}^{23}\mathrm{Ne}$, and ${}^{25}\mathrm{Ne}$, as well as the electric quadrupole moment of ${}^{23}\mathrm{Ne}$, are either reported for the first time or improved considerably. The measurements also decide for a $1/2^{+}$ ground state of ${}^{25}\mathrm{Ne}$. The behavior of the magnetic moments of the proton drip-line nucleus ${}^{17}\mathrm{Ne}$ and its mirror partner ${}^{17}\mathrm{N}$ suggests isospin symmetry. Thus, no clear indication of an anomalous nuclear structure is found for ${}^{17}\mathrm{Ne}$. The magnetic moments of the investigated nuclei are discussed in a shell-model approach.

Owing to the smallness of the electromagnetic coupling, photons escape from the hot and dense matter created in a heavy-ion collision at all times, in contrast to hadrons, which are predominantly emitted in the final freeze-out phase of the evolving system. Thus, the thermal photon yield carries an imprint from the early evolution. We suggest how this fact can be used to gain information on where the actual evolution can be found between the two limiting cases of Bjørken (boost-invariant expansion) and Landau (complete initial stopping and re-expansion) hydrodynamics. We argue that both the rapidity dependence of the photon yield and photonic two-particle correlation radii are capable of answering this question.