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The method of energy-dependent partial-wave analysis of the low-energy two-nucleon scattering data is reviewed. Sonic recent additions to the database are discussed. In particular, the Uppsala np differential cross section at 162 MeV is analyzed. The first steps to improve the partial-wave analysis by implementing constraints from chiral perturbation theory are reviewed. Specifically, the long-range chiral two-pion exchange interaction has been included, and its importance has been demonstrated.

Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle straight phi of the pion relative to the lepton scattering plane was formed for pi(+) electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sinstraight phi moment of the cross section is 0.022+/-0.005+/-0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.

We extend our analysis of transverse single spin asymmetry in electroproduction of J/psi to include the effect of the scale evolution of the transverse momentum dependent (TMD) parton distribution functions and gluon Sivers function. We estimate single spin asymmetry for JLab, HERMES, COMPASS, and eRHIC energies using the color evaporation model of charmonium production, using an analytically obtained approximate solution of TMD evolution equations discussed in the literature. We find that there is a reduction in the asymmetry compared with our predictions for the earlier case considered by us, wherein the Q(2) dependence came only from DGLAP evolution of the unpolarized gluon densities and a different parametrization of the TMD Sivers function was used.

High-quality vector analyzing power data for the $^{1}H\left ( d,pp \right )n$ breakup reaction and elastic scattering at 100MeV beam energy have been measured in a large part of the phase space for these processes. The results are compared to theoretical predictions obtained using the charge-dependent Bonn potential alone or combined with the three-nucleon force TM99 as well as to the results of calculations in the coupled-channel approach, with or without the inclusion of the Coulomb interaction. In the studied observables, effects of the 3NF and the Coulomb force are almost absent. The pairwise NN interactions alone are sufficient to describe the experimental results.

We investigate the polarization parameters in low-energy antiproton-proton elastic ((p) over barp -> (p) over barp) and charge-exchange ((p) over barp -> (n) over barn) scattering. The predictions for unmeasured observables are based on our new energy-dependent partial-wave analysis of all antiproton-proton scattering data below 925 MeV/c antiproton laboratory momentum, which gives an optimal description of the existing database. Sizable and remarkable spin effects are observed, in particular for charge-exchange scattering. These result from the spin dependence of the long- and medium-range one- and two-pion exchange antinucleon-nucleon potential and the state dependence of the parametrized short-range interaction. We study the possibility of polarizing a circulating antiproton beam with a polarized proton target by exploiting the spin dependence of the (p) over barp total cross section. It appears feasible to achieve a significant transverse polarization of an antiproton beam within a reasonable time.

New measurements are reported for the time dependence of the vertical polarization of a 0.97 GeV/c deuteron beam circulating in a storage ring and perturbed by an rf solenoid. The storage ring is the cooler synchrotron (COSY) located at the Forschungszentrum Jülich. The beam polarization was measured continuously using a 1.5 cm thick carbon target located at the edge of the circulating deuteron beam and the scintillators of the EDDA detector. An rf solenoid mounted on the ring was used to generate fields at and near the frequency of the 1-Gγ spin resonance. Measurements were made of the vertical beam polarization as a function of time with the operation of the rf solenoid in either fixed or continuously variable frequency mode. Using rf-solenoid strengths as large as 2.66×10^{-5} revolutions/turn, slow oscillations (∼1 Hz) were observed in the vertical beam polarization. When the circulating beam was continuously electron cooled, these oscillations completely reversed the polarization and showed no sign of diminishing in amplitude. But for the uncooled beam, the oscillation amplitude was damped to nearly zero within a few seconds. A simple spin-tracking model without the details of the COSY ring lattice was successful in reproducing these oscillations and demonstrating the sensitivity of the damping to the magnitude of the synchrotron motion of the beam particles. The model demonstrates that the characteristic features of measurements made in the presence of large synchrotron oscillations are distinct from the features of such measurements when made off resonance. These data were collected in preparation for a study of the spin coherence time, a beam property that needs to become long to enable a search for an electric dipole moment using a storage ring.

Due to the lack of high quality hyperon beams, final state interactions in hyperon production reactions are a compelling tool to study hyperon-nucleon interactions. The COSY-TOF experiment has recently been upgraded in order to reconstruct the pK^+Lambda final state with sufficient precision to determine the spin triplet pLambda scattering length with a polarized proton beam. We find an unexpected behavior of the K^+ analyzing power which prevents the extraction method to be used with the available statistics. A theoretical explanation is pending. Furthermore, the polarized beam together with the self analyzing decay of the Lambda allows us to determine the Lambda depolarization. This is especially sensitive to K^+ and pi exchange in the production mechanism. Our finding verifies, to a large extent, the result from DISTO [2] that has so far been the only measurement close to the production threshold.

Systems composed of a few nucleons are subject of experimental studies for many years with the aim to gain precise information on the interaction between nucleons. Intermediate energies, below the threshold for pion production, deserve special attention: it is a region where comparison with exact theoretical calculations is possible, while the sensitivity to various aspects of interaction, like subtle effects of the dynamics beyond the pairwise nucleon-nucleon force, is significant. In addition to differential cross section, the observables related to nuclear polarization are studied, like vector and tensor analyzing powers, spin-correlation coefficients or polarization transfer coefficients. A brief survey of results of recent studies in few-nucleon systems is given.

Background: There is a renewed experimental interest in antiproton-proton scattering with an intense, possibly polarized antiproton beam. On the theoretical side, significant progress has been made in the understanding of the nuclear force from chiral effective field theory.Purpose: We provide a high-quality model-independent description of the available low-energy antiproton-proton scattering data. Method: We perform a new energy-dependent partial-wave analysis of all antiproton-proton elastic ((p) over barp -> (p) over barp) and charge-exchange ((p) over barp -> (n) over barn) scattering data below 925 MeV/c antiproton laboratory momentum. The Schrodinger equation is solved for the coupled (p) over barp and (n) over barn channels. The relevant long-range parts of the electromagnetic and the one-and two-pion exchange interactions are included exactly. The short-range interactions, including the coupling to the mesonic annihilation channels, are parametrized by a complex boundary condition at a radius of r = 1.2 fm.Results: The updated database, which includes significantly more high-quality charge-exchange data, contains 3749 scattering data. The fit gives chi(2)(min)/N-df = 1.048, where N-df = 3578 is the number of degrees of freedom. We discuss the description of the experimental data and we present the antiproton-proton phase-shift parameters.Conclusions: Chiral effective field theory provides an excellent long-range antinucleon-nucleon interaction. The results of the PWA should serve as the starting point for future theoretical and experimental investigations of low-energy antiproton-proton scattering.

We discuss the possibility of using electroproduction of J/psi as a probe of gluon Sivers function by measuring single spin asymmetry (SSA) in experiments with transversely polarized protons and electron beams. We estimate SSA for JLab, HERMES, COMPASS, and eRHIC energies using the color evaporation model of charmonium production and find asymmetry up to 25% for certain choices of model parameters which have been used earlier for estimating SSA in the SIDIS and Drell-Yan processes.

This review gives a brief introduction to the chiral effective field theory of nuclear forces and atomic nuclei. We discuss the status of the nuclear Hamiltonian derived in this framework and some recent applications in few-nucleon systems. Nuclear lattice simulations as a new tool to address the many-body problem are introduced and some first results based on that method are presented., 39 pages, 13 figures, Commissioned article for Annual Review of Nuclear and Particle Science

A concept for the integration of intermitted trench gates into silicon lateral double-diffused metal-oxide-semiconductor (LDMOS) devices is proposed to achieve a significant reduction in on-resistance. The trench structure can be feasibly integrated into smart-power integrated circuit technology. Using 2-D technology computer aided design (TCAD) simulations, the achievable reduction in $R_{DS, {rm on}}$ from 145 $hbox{m}Omegacdot hbox{mm}{2}$ down to 94 $hbox{m}Omegacdothbox{mm}{2}$ for a 50 V LDMOS device and the negligible impact on the blocking characteristics were demonstrated. Additionally, the device parameters were analyzed with respect to static and dynamic power dissipation. Here, the benefits of trench gate integration became more apparent. Analyzing power losses during high-frequency operation revealed that the increased input capacitance resulting from the trench gate is acceptable for applications where high switching frequencies in the upper megahertz range are not required.

Recent experimental results in three-body systems have unambiguously shown that calculations based only on nucleon-nucleon forces fail to accurately describe many experimental observables and one needs to include effects which are beyond the realm of the two-body potentials. This conclusion owes its significance to the fact that experiments and calculations can both be performed with a high accuracy. In this review, both theoretical and experimental achievements of the past decade will be underlined. Selected results will be presented. The discussion on the effects of the three-nucleon forces is, however, limited to the hadronic sector. It will be shown that despite the major successes in describing these seemingly simple systems, there are still clear discrepancies between data and the state-of-the-art calculations., accepted for publication in Rep. Prog. Phys

An experiment measuring the analyzing power Ay(θ) for neutron–helium-3 (n-3He) elastic scattering over broad angular distributions for a range of incident neutron energies from 1.60 to 5.54 MeV has been conducted at the Triangle Universities Nuclear Laboratory. These measurements represent an effort to resolve the long-standing discrepancy between experiment and theory in low-energy three-nucleon analyzing powers, through the evaluation of analyzing powers in the four-nucleon systems, which are expected to exhibit sensitivities not accessible with fewer nucleons. The present work is described in terms of the experimental setup and data reduction techniques; a comparison of the results with rigorous calculations using both nucleon-nucleon and, as recently has become available, three-nucleon potential models is presented. While a discrepancy between calculation and measurement was observed, at low energies substantially better agreement was achieved than in related measurements of the proton–helium-3 (p-3He) analyzing power, suggesting a sizeable dependence on isospin in the four-nucleon systems.

In order to establish links between p-wave pion production in nucleon-nucleon collisions and low energy three-nucleon scattering, an extensive programme of experiments on pion production is currently underway at COSY-ANKE. The final proton pair is detected at very low excitation energy, leading to an S-wave diproton, denoted here as {pp}_s. We now report on measurements of the differential cross section and analysing power of the pol{p}p->{pp}_s pi^0$ reaction at 353 MeV. Both observables can be described in terms of s- and d-wave pion production and, by using the phase information from elastic pp scattering, unique solutions can be obtained for the corresponding amplitudes. This information is vital for the partial wave decomposition of the corresponding pn->{pp}_s pi^- reaction and hence for the extraction of the p-wave terms., Comment: The interested reader is advised to study also the paper on pi minus production by S.Dymov et al., which has also been submitted to the arXiv

A partial-wave analysis of all ppBAR scattering data below 925 MeV/c antiproton laboratory momentum is presented. The method used is adapted from the Nijmegen phase-shift analyses of pp and np scattering data. We solve the Schrodinger equation for the coupled ppBAR and nnBAR channels where the long- and intermediate-range interactions are described by a theoretically well-founded potential. This gives the rapid variations of the scattering amplitudes with energy. This potential consists of the Coulomb potential with the main relativistic correction, the magnetic-moment interaction, the one-pion-exchange potential, and the heavy-boson exchanges of the Nijmegen one-boson-exchange potential. Slow variations of the amplitudes due to short-range interactions, including the coupling to mesonic annihilation channels, are parametrized by an energy-dependent, complex boundary condition, specified at a radius of r = 1.3 fm. The Nijmegen 1993 ppBAR database, consisting of 3646 ppBAR scattering data, is presented and discussed. The best fit to this database results in chi(min)2/N(data) = 1.043. This good fit to the data shows that the Nijmegen long- and intermediate-range potential is essentially correct. The pseudovector coupling constant of the charged pion to nucleons is determined to be f(c)2 = 0.0732(11) at the pion pole, where the error is statistical.

This paper presents an approach of analyzing power system voltage stability based on system potential. This framework provides a simple and better way of understanding voltage stability by visualizing the changes in topological structure of the system potential with respect to the change in power system loading. This paper also investigates the effect of random load variation in the power system stability. The stability margin index being studied is the Mean First Passage Time of the power system from the stable operating point to the closest unstable equilibrium point for small magnitude random load perturbations. The variation of MFPT for change in the loading of the system, Intensity and correlation time of the stochastic load are studied initially for an SMIB system. � 2011 Elsevier Ltd. All rights reserved.

Double-differential cross sections of the C-12(n, p) reaction have been measured at 98 MeV in the angular range 0-degrees-33-degrees for excitation energies up to 35 MeV. The spectra have been analysed in terms of multipole components, using peak fitting and decomposition techniques. The data have been compared with cross sections obtained in the distorted-wave Born approximation, using matrix elements from shell-model calculations. The unit cross section and the related strength of the spin-isospin part of the nucleon-nucleon interaction were determined from the extracted Gamow-Teller strength. Cross sections and fractions of strength exhausted by dipole and higher-multipole transitions were extracted and compared with data available in the literature.

In view of the persisting misunderstandings about the determination of the pion-nucleon coupling constants in the Nijmegen multienergy partial-wave analyses of pp, np, and ppBAR scattering data, we present additional information which may clarify several points of discussion. We comment on several recent papers addressing the issue of the pion-nucleon coupling constant and criticizing the Nijmegen analyses.

A global dispersive coupled-channel optical model potential is used to analyze the proton elastic/inelastic analyzing power data and (p,n) data in order to investigate the prediction power of this potential. The numerical calculations show good agreement with available experimental data for proton elastic data and overall agreement for proton inelastic data. The results also showed that present global potential is approximately Lane-consistent, and can predict well the (p,n) cross sections.