Search

A low-energy magnetic dipole $(M1)$ spin-scissors resonance (SSR) located just below the ordinary orbital scissors resonance (OSR) was recently predicted in deformed nuclei within the Wigner Function Moments (WFM) approach. We analyze this prediction using fully self-consistent Skyrme Quasiparticle Random Phase Approximation (QRPA) method. Skyrme forces SkM*, SVbas and SG2 are implemented to explore SSR and OSR in $^{160,162,164}$Dy and $^{232}$Th. Accuracy of the method is justified by a good description of M1 spin-flip giant resonance. The calculations show that isotopes $^{160,162,164}$Dy indeed have at 1.5-2.4 MeV (below OSR) $I^{\pi}K=1^+1$ states with a large $M1$ spin strength ($K$ is the projection of the total nuclear moment to the symmetry z-axis). These states are almost fully exhausted by $pp[411\uparrow, 411\downarrow]$ and $nn[521\uparrow, 521\downarrow]$ spin-flip configurations corresponding to $pp[2d_{3/2}, 2d_{5/2}]$ and $nn[2f_{5/2}, 2f_{7/2}]$ structures in the spherical limit. So the predicted SSR is actually reduced to low-orbital (l=2,3) spin-flip states. Following our analysis and in contradiction with WFM spin-scissors picture, deformation is not the principle origin of the low-energy spin $M1$ states but only a factor affecting their features. The spin and orbital strengths are generally mixed and exhibit the interference: weak destructive in SSR range and strong constructive in OSR range. In $^{232}$Th, the $M1$ spin strength is found very small. Two groups of $I^{\pi}=1^+$ states observed experimentally at 2.4-4 MeV in $^{160,162,164}$Dy and at 2-4 MeV in $^{232}$Th are mainly explained by fragmentation of the orbital strength. Distributions of nuclear currents in QRPA states partly correspond to the isovector orbital-scissors flow but not to spin-scissors one., Comment: 15 pages, 13 figures

In our laboratory, we developed a simple estimation of the wall thickness by the UWB (Ultra Wide-Band) radar system. The described technique measures the wall thickness in the two steps. The first step is a measurement of the wall relative permittivity. The second step is a reflections localisation and estimation of the wall thickness. The borders of the wall could be detected by the envelope of the received signals. The described technique calculates the signal envelope by the Hilbert transform. Moreover, the relative permittivity of the wall is estimated by the technique developed in our department as well. The effective relative permittivity is calculated from the frequency dependency of relative permittivity. This technique was developed for the impulse radar system. The aim of this article is compare the results from impulse radar system with M-sequence radar system which operates in the time domain as well measuring wall relative permittivity and wall thickness estimation.

The $n=2$ and $n=3$ levels for muonic Helium are calculated using a potential that includes all one-loop and recoil effects. Electronic vacuum polarization corrections are calculated using an extension of Kinoshita and Nio method. For $n=2$, the results are $2p_{1/2}-2s_{1/2}=1375.05\pm 1.4$ meV and $2p_{3/2}-2s_{1/2}=1521.65\pm 1.4$ meV, essentially in agreement with the latest summary of the current calculations. The $n=3$ results are summarized in tabular form and give $3p_{1/2}-3s_{1/2}=394.76\pm 0.43$ meV and $3d_{3/2}-3p_{3/2}=111.40$ meV.

Osteoartroza je nejcastějsi kloubni onemocněni dane degeneraci chrupavek s naslednou reakci a transformaci okolnich tkani. U primarni formy je osteoartroza dana starnutim a přibýva s věkem. V sekundarni formě urychluje degeneraci hlavně vliv kongenitalnich změn, urazy a celkove systemove onemocněni řizene řadou zanětlivých mediatorů daneho postiženeho kloubu. Subjektivně se projevuje hlavně bolesti, postupně otoky a omezenim pohyblivosti kloubu. Progrese je větsinou dlouhodoba s různou intenzitou potiži. Nejcastěji postihuje kycelni a kolenni kloub, ale může se vyskytnout na kteremkoliv kloubu vcetně drobných kloubů rukou a nohou. Vedle klinickeho nalezu je zakladnim vysetřenim rentgen, podle ktereho se osteoartroza děli do 4 stupňů. Terapie musi být komplexni. Zakladem je nefarmakologicka lecba, kam patři edukace a motivace pacienta, pravidelne cviceni, u obeznich pacientů redukce hmotnosti, fyzioterapie a podpůrne pomůcky. Z farmakologických prostředků je nejcastějsi uživani nesteroidnich antirevmatik, analgetik, aplikace kortikoidů do kloubů. Tyto ovlivňuji bolest, zanět, bez vlivu na degenerativni změny. Proces degenerace mohou castecně ovlivnit „symptomaticke leky pomalu působici na osteoartrozu“, SYSADOA, uživane celkově i aplikaci do kloubů. Při nelepseni nebo i preventivně je na zvaženi operacni řeseni.

Individual low-energy $E1$ toroidal and compressional states (TS and CS) produced by the convective nuclear current ${\mathbf{j}}_{c}$ were recently predicted for $^{24}\mathrm{Mg}$ in the framework of quasiparticle random-phase approximation (QRPA) with Skyrme forces. In the present QRPA study with Skyrme parametrization SLy6, we explore in more detail properties of these states [toroidal and compressional responses, current distributions, and transitions probabilities $B(E1K,{0}^{+}0\ensuremath{\rightarrow}{1}^{\ensuremath{-}}K),\phantom{\rule{0.28em}{0ex}}B(E3K,{0}^{+}0\ensuremath{\rightarrow}{3}^{\ensuremath{-}}K)$, and $B(M2K,{0}^{+}0\ensuremath{\rightarrow}{2}^{\ensuremath{-}}K)$ with $K=0$ and 1] and analyze the possibility to discriminate and identify TS in inelastic electron scattering to back angles. The interplay of the convective ${\mathbf{j}}_{c}$ and magnetization ${\mathbf{j}}_{m}$ nuclear currents is thoroughly scrutinized. A two-step scheme for identification of TS in $(e,{e}^{\ensuremath{'}})$ reaction is proposed. The key element of the scheme is the strong interference of the orbital and spin contributions, resulting in specific features of $E1$ and $M2$ transversal form factors.

A new automated method has been developed with the aim to correct measured spectra for sudden gain and offset drifts due to temporal instrumentation instabilities. It is based on discrete cross-correlation that alleviates the need for Gaussian-shaped peaks and is capable of correcting spectra that change their shape in time. Potential of this method has been tested on decay and in-beam γ -ray spectroscopy data measured with an array of three n-type coaxial High-Purity Germanium detectors albeit its use is not limited only for γ -ray spectroscopy.

We extend our treatment of the spectroscopy and decays of the charm-strange quarkonium system to include the effect of using the full three-loop QCD correction to the static short distance potential. As before, our potential model consists of the relativistic kinetic energy term, a scalar linear confining term including its relativistic corrections and the perturbative QCD spin-dependent terms. A set of unperturbed wave functions for the various states is obtained using a variational technique that is further constrained by requiring that the wave functions also satisfy the relativistic virial theorem. These are then used in a perturbative treatment of the potential to fit the mass spectrum of the c s ¯ system and calculate the radiative decay widths. Our results accurately describe the D s spectrum and are compatible with the little data that is available for the radiative decays of the D s states.

We suggest a generalized method for elimination of spurious admixtures (SA) from intrinsic nuclear excitations described within the quasiparticle random-phase approximation (QRPA). Various kinds of SA corrections are treated at the same theoretical ground. The known corrections are well reproduced. As relevant cases, we consider subtraction of SA related with (i) violation of the translational invariance (isovector $E1$ and isoscalar toroidal and compression $E1$ modes), (ii) pairing-induced nonconservation of the particle number $(E2(K=0)$ and $E0$ modes), and (iii) rotational invariance $(E2(K=1)$ and $M1(K=1)$ modes). The SA subtraction can be done at the level of QRPA states, electromagnetic responses, and even transition operators. The additional deformation-induced corrections for $E1$ excitations are proposed and shown to be essential for the compression isoscalar mode. The accuracy of the method is demonstrated by Skyrme QRPA calculations for axially deformed $^{154}\mathrm{Sm}$.

We analyze the relation between isoscalar toroidal modes and so-called pygmy dipole resonance (PDR) which both appear in the same region of low-energy dipole excitations. To this end, we use a theoretical description within the fully self-consistent Skyrme quasiparticle random-phase approximation (QRPA). Test cases are spherical nuclei $^{40,48}$Ca, $^{58,72}$Ni, $^{90,100}$Zr, and $^{100,120,132}$Sn which cover four different elements and for each element at least two isotopes with different neutron excess, one small and another large. The structure of the modes is investigated in terms of strength functions, transition densities (TD) and transition currents (TC). For all considered nuclei, we see that, independently on whether PDR strength exists or not, the flow pattern in the lower part of the "PDR energy region" is basically the isoscalar vortical toroidal motion with a minor irrotational fraction. A one-to-one correspondence between calculated TD and TC can be established. The toroidal flow appears already in the uncoupled two-quasiparticle (2qp) excitations and becomes definitively strong for the QRPA modes. Altogether, we find that low-lying dipole strength often denoted as isoscalar PDR is actually an oversimplified imitation of the basically toroidal motion in nuclei with a sufficient neutron excess., Comment: 12 pages, 14 figures

A flat plate film cooling flow from a multi-exit hole configuration has been numerically simulated using both steady and unsteady Reynolds Averaged Navier Stokes (RANS and URANS) Computational Fluid Dynamics (CFD) formulations. This multi-exit hole concept, the Anti-Vortex Hole (AVH), has been developed and studied by previous research groups and shown to mitigate or counter the vorticity generated by conventional holes resulting in a more attached film cooling layer and higher film cooling effectiveness. The film cooling jets interaction with the free stream flow is a long studied area in gas turbine heat transfer. The present study numerically simulates the jet interaction with the multi-exit hole concept at a high blowing ratio (M = 2.0) and density ratio (DR = 2.0) in order to provide a more detailed, graphical explanation of the improvement in film cooling effectiveness. This paper presents a numerical study of the flow visualization of the interaction of film cooling jets with a subsonic crossflow. The contour plots of adiabatic cooling effectiveness were used to compare the multi-exit hole and conventional single hole configurations. The vortex structures in the flow were analyzed by URANS formulations and the effect of these vortices on the cooling effectiveness was investigated together with the coolant jet lift-off predictions. Quasi-Instantaneous Temperature Isosurface plots are used in the investigations of the effect of turbulence intensity on the cooling effectiveness and coolant jet coverage. The effect of varying turbulence intensity was investigated when analyzing the jets’ interaction with the cross flow and the corresponding temperatures at the wall. The results show that as the turbulence intensity is increased, the cooling flow will stay more attached to the wall and have more pronounced lateral spreading far downstream of the cooling holes.

The existence of individual low-energy E1 toroidal and compression states (TS and CS) in $^{24}$Mg was predicted recently in the framework of quasiparticle random-phase-approximation (QRPA) model with Skyrme forces. It was shown that the strong axial deformation of $^{24}$Mg is crucial to downshift the toroidal strength to the low-energy region and thus make the TS the lowest E1(K=1) dipole state. In this study, we explain this result by simple mean-field arguments. Comparing TS in two strongly axial nuclei, $^{24}$Mg and $^{20}$Ne, we show that the lowest TS is not not a universal phenomenon but rather a peculiarity of $^{24}$Mg. The spectroscopy of TS and CS is analyzed and some additional interpretation of these states is suggested., 6 pages, 8 figures, 2 tables. Submitted to proceedings of International Conference on Nuclear Structure and Related Topics - NSRT18 (Bulgaria, Bourgas, June 3-9, 2018). The paper was resubmitted to enlarge the reference list

The method proposed by Kinoshita and Nio to compute higher order vacuum polarization contributions to the Coulomb potential in muonic hydrogen is generalized to obtain relativistic corrections to their results., Comment: 4 pages

The low-energy dipole excitations in ^{24}Mg are investigated within the Skyrme quasiparticle random phase approximation for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest I^{π}K=1^{-}1 excitation (E=7.92 MeV) in ^{24}Mg is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of the well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an individual TS which can be much more easily discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in ^{24}Mg. The result persists for different Skyrme parametrizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of ^{24}Mg. Similar TSs could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.

We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations,$\gamma$-vibrational $K^{\pi}=2^+$ states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random-phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the $K^{\pi}=0^+$ states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch $K^{\pi}=1^-$ is shown to dominate over $K^{\pi}=0^-$ one in the range of excitation energy $E, Comment: 12 pages, 12 figures

The phenomenological consequences of the residual Z 2 s and Z ¯ 2 s symmetries are explored in detail. With a precisely measured value of the reactor angle, these two residual symmetries predict distinct distributions for the Dirac CP phase and the atmospheric angle, which lead to the possibility of identifying them at future neutrino experiments. For both symmetries, it is possible to resolve the neutrino mass hierarchy in most of the parameter space, and they can be distinguished from one another if the true residual symmetry is Z 2 s and the atmospheric angle is non-maximal. These results are obtained using an equally split schedule: a 1.5-year run of neutrinos and a 1.5-year run of antineutrinos at NO ν A together with a 2.5-year run of neutrinos and a 2.5-year run of antineutrinos at T2K. This schedule can significantly increase and stabilize the sensitivities to the mass hierarchy and the octant of the atmospheric angle with only a moderate compromise to the sensitivity of distinguishing Z 2 s and Z ¯ 2 s .

Different Skyrme functional parametrizations were tested for Te, Xe, Ba and Ce isotopes for N > 82. For the SVsym34 parametrization, which best fits the experimental binding energy, potential energy curves obtained from constrained beta(2), beta(3) and beta(4) Hartree-Fock+BCS calculations were investigated. Positions of the lowest quadrupole and octupole vibrational states and the lowest 2(+) rotational states in deformed nuclei were obtained within the Skyrme QRPA and compared to existing experimental data. Web of Science 50 3 560 555

Electron scattering is a tool that can provide relatively clean view of the nuclear structure in both ground and excited states, as it depends on the well-known electromagnetic interaction. But since the common expressions for its cross section were derived with certain assumptions, in this paper we describe several nontrivial steps necessary for a proper theoretical calculation within the current density-functional framework, namely with Skyrme QRPA for axial nuclei, with aim to enable comparison of the theoretically predicted low-lying $1^-$ toroidal modes with future (e,e') experiments., 10 pages, 5 figures, to be published in the proceedings of XXV Nuclear Physics Workshop (25-30 September 2018), Kazimierz Dolny, Poland; now slightly improved wording in introduction

An advanced, high-effectiveness film cooling design, the antivortex hole (AVH) has been investigated by several research groups and shown to mitigate or counter the vorticity generated by conventional holes and increase film effectiveness at high blowing ratios and low freestream turbulence levels. The effects of increased turbulence on an AVH geometry were previously investigated in a preliminary steady computational fluid dynamics (CFD) study by Hunley et al. on the film effectiveness and net heat flux reduction (NHFR) at high blowing ratio. The current paper presents the results of an extended numerical parametric study, which attempts to separate the effects of turbulence intensity and length scale on film cooling performance of the AVH concept at high blowing ratio (2.0) and density ratio (2.0). In this extended study, steady Reynolds-averaged Navier–Stokes (RANS) analysis was performed with turbulence intensities of 5, 10, and 20% and length scales based on cooling hole diameter of Λx/dm = 1, 3, and 6. Increasing turbulence intensity was shown to increase the centerline, span-averaged, and area-averaged adiabatic film cooling effectiveness and NHFR. Larger turbulent length scales in the steady RANS analysis were shown to have little to no effect on the centerline, span-averaged, and area-averaged adiabatic film cooling effectiveness and NHFR at lower turbulence levels, but moderate effect at the highest turbulence levels investigated. Heat transfer results were in good agreement with the findings from adiabatic cases from previous work. Unsteady RANS results also provided supplementary flow visualization for the AVH film cooling flow under varying turbulence levels.

To gain some sense about the likelihood of measuring the Higgs boson quartic coupling, we calculate the contribution to the triple Higgs production cross section from the subprocesses $q\bar{q}\to ZHHH$ and $q\bar{q}'\to WHHH$. Our results illustrate that determining this coupling, or even providing experimental evidence that it exists, will be very difficult.

This paper describes a simple method for the relative permittivity estimation of the wall by an UWB (ultra wideband) impulse radar system. It is non-invasive reflected free space method for data gathering just from the single side of the wall. There is just one condition also by which we can achieve the best possible accuracy. It is a short time window of monitored signal, while there is an undesired reflection from the other side of the wall. Frequency dependence of the relative permittivity is then obtained from the reflection coefficient of the transmitted TEM (transverse electromagnetic) wave. The paper describes two demonstrative measurements and verification of the measured data by the transmission method.

The lowest quadrupole $\ensuremath{\gamma}$-vibrational ${K}^{\ensuremath{\pi}}={2}^{+}$ states in axially deformed rare-earth (Nd, Sm, Gd, Dy, Er, Yb, Hf, W) and actinide (U) nuclei are systematically investigated within the separable random-phase-approximation (SRPA) based on the Skyrme functional. The energies ${E}_{\ensuremath{\gamma}}$ and reduced transition probabilities $B(E2)$ of ${2}_{\ensuremath{\gamma}}^{+}$ states are calculated with the Skyrme forces SV-bas and ${\mathrm{SkM}}^{*}$. The energies of two-quasiparticle configurations forming the SRPA basis are corrected by using the pairing blocking effect. This results in a systematic downshift of ${E}_{\ensuremath{\gamma}}$ by 0.3--0.5 MeV and thus in a better agreement with the experiment, especially in Sm, Gd, Dy, Hf, and W regions. For other isotopic chains, a noticeable overestimation of ${E}_{\ensuremath{\gamma}}$ and too weak collectivity of ${2}_{\ensuremath{\gamma}}^{+}$ states still persist. It is shown that domains of nuclei with low and high ${2}_{\ensuremath{\gamma}}^{+}$ collectivity are related to the structure of the lowest two-quasiparticle states and conservation of the Nilsson selection rules. The description of ${2}_{\ensuremath{\gamma}}^{+}$ states with SV-bas and ${\mathrm{SkM}}^{*}$ is similar in light rare-earth nuclei but deviates in heavier nuclei. However SV-bas much better reproduces the quadrupole deformation and energy of the isoscalar giant quadrupole resonance. The accuracy of SRPA is justified by comparison with exact RPA. The calculations suggest that a further development of the self-consistent calculation schemes is needed for a systematic satisfactory description of the ${2}_{\ensuremath{\gamma}}^{+}$ states.

The low-lying $M1$-strength of the open-shell nucleus $^{50}$Cr has been studied with the method of nuclear resonance fluorescence up to 9.7 MeV, using bremsstrahlung at the superconducting Darmstadt linear electron accelerator S-DALINAC and Compton backscattered photons at the High Intensity $\gamma$-ray Source (HI$\gamma$S) facility between 6 and 9.7 MeV of the initial photon energy. Fifteen $1^{+}$ states have been observed between 3.6 and 9.7 MeV. Following our analysis, the lowest $1^{+}$ state at 3.6 MeV can be considered as an isovector orbital mode with some spin admixture. The obtained results generally match the estimations and trends typical for the scissors-like mode. Detailed calculations within the Skyrme Quasiparticle Random-Phase-Approximation method and the Large-Scale Shell Model justify our conclusions. The calculated distributions of the orbital current for the lowest $1^{+}$-state suggest the schematic view of Lipparini and Stringari (isovector rotation-like oscillations inside the rigid surface) rather than the scissors-like picture of Lo Iudice and Palumbo. The spin M1 resonance is shown to be mainly generated by spin-flip transitions between the orbitals of the $fp$-shell.

The deformation-induced splitting of isoscalar giant monopole resonance (ISGMR) is systematically analyzed in a wide range of masses covering medium, rare-earth, actinide, and superheavy axial deformed nuclei. The study is performed within the fully self-consistent quasiparticle random-phase-approximation (QRPA) method based on the Skyrme functional. Two Skyrme forces, one with a large (SV-bas) and one with a small (SkP) nuclear incompressibility, are considered. The calculations confirm earlier results that, due to the deformation-induced E0-E2 coupling, the isoscalar E0 resonance attains a double-peak structure and significant energy upshift. Our results are compared with available analytic estimations. Unlike earlier studies, we get a smaller energy difference between the lower and upper peaks and thus a stronger E0-E2 coupling. This in turn results in more pumping of E0 strength into the lower peak and more pronounced splitting of ISGMR. We also discuss widths of the peaks and their negligible correlation with deformation., Comment: 11 pages, 10 figures

We review a recent progress in investigation of the isoscalar toroidal dipole resonance (TDR). A possible relation of the TDR and low-energy dipole strength (also called a pygmy resonance) is analyzed. It is shown that the dipole strength in the pygmy region can by understood as a local manifestation of the collective vortical toroidal motion at the nuclear surface. Application of the TDR as a measure of the nuclear dipole vorticity is discussed. Finally, an anomalous splitting of the TDR in deformed nuclei is scrutinized., Comment: 8 pages, 5 figures, submitted to "Physics of Atomic Nuclei"

The lowest γ -vibrational states with Kπ = 2+ γ in well-deformed Dy, Er and Yb isotopes are investigated within the self-consistent separable quasiparticle random-phase-approximation (QRPA) approach based on the Skyrme functional. The energies Eγ and reduced transition probabilities B(E2) γ of the states are calculated with the Skyrme force SV-mas10. We demonstrate the strong effect of the pairing blocking on the energies of γ -vibrational states. It is also shown that collectivity of γ -vibrational states is strictly determined by keeping the Nilsson selection rules in the corresponding lowest 2qp configurations.

Model-independent consequences of applying a generalized hidden horizontal Z_2 symmetry to the neutrino mass matrix are explored. The Dirac CP phase delta_D can be expressed in terms of the three mixing angles as 4 c_a s_a c_s s_s s_x cos delta_D = (s^2_s - c^2_s s^2_x) (c^2_a - s^2_a) where the s_i, c_i are sines and cosines of the atmospheric, solar, and reactor angles. This relation is independent of neutrino masses and whether neutrinos are Dirac- or Majorana-type. Given the present constraints on the angles, delta_D is constrained to be almost maximal, a result which can be explored in experiments such as NOvA and T2K. The Majorana CP phases do not receive any constraint and are thus model-dependent. Also a distribution of theta_x with a lower limit is obtained without specifying delta_D., 5 pages, 4 figures; Condensed version or PLB with references added; for more details see the previous version

Results for the one-loop calculation of the decay width Γ(H→ggZ) in the standard model with Higgs boson masses in the range 115 GeV

We show that the dominant channel proposed for the determination of the Higgs boson trilinear coupling, $pp\to HH+X$ via gluon fusion, exhibits an interference structure that is independent of the collider energy for collider energies in the range $8\,{\rm TeV}\leq \sqrt{s}\leq 100\,{\rm TeV}$ and is almost maximally destructive. This insensitivity to the collider energy remains approximately true for a variety of other two Higgs production mechanisms although the magnitude of the interference varies widely., Comment: 8 pages, 4 figures, additional references,publication version

The strong deformation splitting of the isoscalar giant monopole resonance (ISGMR), recently observed in ($\alpha,\alpha'$) reaction in prolate $^{24}$Mg, is analyzed in the framework of the Skyrme quasiparticle random-phase-approximation (QRPA) approach with the Skyrme forces SkM*, SVbas and SkP$^{\delta}$. The calculations with these forces give close results and confirm that the low-energy E0-peak is caused by the deformation-induced coupling of ISGMR with the K=0 branch of the isoscalar giant quadrupole resonance., Comment: 3 pages, 1 figure, to be published in EPJ Web of Conferences (Proceedings of the International Conference NSRT15, Dubna, Russia, 2015)

Results from a study of a transportable electric field strength standard are presented. A measurement formula for the standard in the form of a product of three functions, an amplitude function, a frequency function, and a correction function, is obtained. The limits of the working range of measurement of the electric field strength with respect to amplitude and frequency are determined. The random measurement error of the electric field strength is experimentally estimated.

The motion of charged particles in magnetic fields whose magnitude varies as a power of one of the coordinates in the plane of the motion is investigated. For interesting power laws, the parametric equations for the trajectory are expressible in terms of Jacobi elliptic functions. These represent a rather natural generalization of the elementary trigonometric solutions that are encountered in the case of a constant magnetic field.

A possible relation of the low-lying E1 (pygmy resonance) and toroidal strengths is analyzed by using Skyrme-RPA results for the strength functions, transition densities and current fields in $^{208}$Pb. It is shown that the irrotational pygmy motion can appear as a local manifestation of the collective vortical toroidal dipole resonance (TDR) at the nuclear surface. The RPA results are compared to unperturbed (1ph) ones., 3 pages, 5 figures, to be submitted to EPJ Web of Conferences [Proceedings of 15th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15), Dresden, Germany, August 24-29, 2014]

The Dalitz decay $H\ensuremath{\rightarrow}f\overline{f}\ensuremath{\gamma}$ is calculated for very small $f\overline{f}$ invariant masses where the $f\overline{f}$ pair could be mistaken for a photon in the analysis of $H\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ decays. Using the ATLAS cuts and the full Dalitz decay amplitude, we estimate this fraction to be 7.06%.

Two basic concepts of nuclear vorticity, hydrodynamical (HD) and Rawenthall-Wambach (RW), are critically inspected. As a test case, we consider the interplay of irrotational and vortical motion in isoscalar electric dipole $E1(T=0)$ modes in ${}^{208}\mathrm{Pb}$, namely the toroidal and compression modes. The modes are described in a self-consistent random-phase approximation (RPA) with the Skyrme force SLy6. They are examined in terms of strength functions, transition densities, current fields, and form factors. It is shown that the RW conception (suggesting the upper component of the nuclear current as the vorticity indicator) is not robust. The HD vorticity is not easily applicable either because the definition of a velocity field is too involved in nuclear systems. Instead, the vorticity is better characterized by the toroidal strength which closely corresponds to HD treatment and is approximately decoupled from the continuity equation.

A precise comparison is made between the Dalitz decay $H\to\ell\bar{\ell}\gamma$ and the two body decay $H\to\gamma Z,Z\to\ell\bar{\ell}$ for electrons and for muons including experimental cuts appropriate for the ATLAS detector. The widths for these two processes differ by 8% for electrons and 3% for muons. Given that there remain QCD radiative corrections of this order that are not included, this suggests that the isolation of the Dalitz decay will be challenging.

The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The exact RPA and its separable version (SRPA) are used for spherical and deformed nuclei, respectively. The quadrupole deformation is shown to yield two effects: the GMR broadens and attains a two-peak structure due to the coupling with the quadrupole giant resonance., Comment: 6 pages, 4 figures, proceedings of 11th Intern. Spring Seminar on Nuclear Physics (Ischia, Italy, May 12-16, 2014)

We study the production of neutral scalar (CP even) Higgs bosons in the process $e\gamma\to e h$ by including supersymmetric corrections to the dominant $t$-channel photon exchange amplitude. In addition to the standard model $W^{\pm}$ and fermion loops, there are substantial contributions from chargino loops. For some cases, these contributions can exceed those of the $W$'s and ordinary fermions. The cross sections in this channel are generally one or two orders of magnitude larger than those in the related channel $e\bar{e}\to\gamma h$.

We use the behavior of the photon-photon scattering for photon energies $\omega$ less than the electron mass, $m_e$, to examine the implications of treating the Euler-Heisenberg Lagrangian as an effective field theory. Specifically, we determine the $\omega^2/m_e^2$ behavior of the scattering amplitude predicted by including one-loop corrections to the Euler-Heisenberg effective Lagrangian together with the counterterms required by renomalizability. This behavior is compared with the energy dependence obtained by expanding the exact QED photon-photon scattering amplitude. If the introduction of counterterms in the effective field theory is restricted to those determined by renormalizability, the $\omega^2/m_e^2$ dependences of the two expansions differ., Comment: 10 pages, ReVTeX, 2 postscript figures included

We present cross sections for the reaction {mu}{bar {mu}}{r_arrow}H{gamma} over a range of {mu}{bar {mu}} collider energies. The amplitudes for this process receive tree level contributions and one-loop contributions, which are of comparable magnitude. The tree level amplitudes are dominated by helicity non-flip terms and the one-loop amplitudes are dominated by helicity flip terms. As a consequence, the interference terms between the tree level and one-loop contributions are negligible. For a 500 GeV {mu}{bar {mu}} collider, the cross section for H{gamma} associated production approaches 0.1 fb. {copyright} {ital 1997} {ital The American Physical Society}

Higgs boson radiative decays of the form H{r_arrow}f{bar f}{gamma} are calculated in the standard model using the complete one-loop expressions for the decay amplitudes. Contributions to the radiative width from leptons and light quarks are given. We also present e{bar e}-invariant mass distributions for H{r_arrow}e{bar e}{gamma}, which illustrate the importance of the photon pole contribution and the effects of the box diagrams. {copyright} {ital 1997} {ital The American Physical Society}

We revisit an earlier calculation of the decay $H\ensuremath{\rightarrow}e\overline{e}\ensuremath{\gamma}$ using the recently reported mass value of the Higgs boson candidate observed in the ATLAS and CMS experiments together with cuts that are appropriate for experimental analyses.

The nature of $E1$ low-energy strength (LES), often denoted as a ``pygmy dipole resonance'', is analyzed within the random-phase approximation (RPA) in ${}^{208}$Pb using Skyrme forces in a fully self-consistent manner. A first overview is given by the strength functions for the dipole, compressional, and toroidal operators. More detailed insight is gained by averaged transition densities and currents where the latter provide a very illustrative flow pattern. The analysis reveals clear isoscalar toroidal flow in the low-energy bin 6.0--8.8 MeV of the LES and a mixed isoscalar/isovector toroidal/compression flow in the higher bin 8.8--10.5 MeV. Thus the modes covered by LES embrace both vortical and irrotational motion. The simple collective picture of the LES as a ``pygmy'' mode (oscillations of the neutron excess against the nuclear core) is not confirmed.

We have extended our earlier treatment of the gauge-boson scattering with radiative corrections in the standard model at supercollider energies, and computed the rates for gauge-boson scattering modes in {ital pp} collisions leading to the final states {ital W}{sup +}{ital W}{sup {minus}}, {ital ZZ}(4{ital l}), {ital ZZ}(2{ital l}2{nu}), {ital W}{sup {plus_minus}}{ital Z}, and {ital W}{sup {plus_minus}}{ital W}{sup {plus_minus}}. Our results at the CERN LHC energy of {radical}{ital s}=14 TeV for {ital m}{sub {ital H}}=1000 GeV are compared with those recently obtained by Bagger {ital et} {ital al}. These results will be useful in the search for the Higgs bosons at supercollider energies as well as for experimentally distinguishing the standard model from nonminimal Higgs models. {copyright} {ital 1996 The American Physical Society.}