Explore the vast range of titles available.

We study the stability and characteristics of two-dimensional (2D) quasi-isotropic quantum droplets (QDs) of fundamental and vortex types, formed by binary Bose–Einstein condensate with magnetic quadrupole–quadrupole interactions (MQQIs). The magnetic quadrupoles are built as pairs of dipoles and antidipoles polarized along the x -axis. The MQQIs are induced by applying an external magnetic field that varies along the x -axis. The system is modeled by the Gross–Pitaevskii equations including the MQQIs and Lee-Huang-Yang correction to the mean-field approximation. Stable 2D fundamental QDs and quasi-isotropic vortex QDs with topological charges S ⩽ 4 are produced by means of the imaginary-time-integration method for configurations with the quadrupoles polarized parallel to the system’s two-dimensional plane. Effects of the norm and MQQI strength on the QDs are studied in detail. Some results, including an accurate prediction of the effective area, chemical potential, and peak density of QDs, are obtained in an analytical form by means of the Thomas-Fermi approximation. Collisions between moving QDs are studied by means of systematic simulations.

We investigate the low-energy scattering properties of two identical particles interacting via the polarized quadrupolar interaction. It is shown that a series of s - and p -wave resonances appear for identical bosons and fermions, respectively, as the strength of the quadrupolar interaction increases. Interestingly, scattering resonances also appear on the generalized scattering length corresponding to the coupling between the s and d waves. This observation inspires us to propose a new pseudopotential for the quadrupolar interaction. We also explore the bound-state properties of two particles in both free space and harmonic traps.

A bstract Picture yourself in the wave zone of a gravitational scattering event of two massive, spinning compact bodies (black holes, neutron stars or stars). We show that this system of genuine astrophysical interest enjoys a hidden N = 2 supersymmetry, at least to the order of spin-squared (quadrupole) interactions in arbitrary D spacetime dimensions. Using the N = 2 supersymmetric worldline action, augmented by finite-size corrections for the non-Kerr black hole case, we build a quadratic-in-spin extension to the worldline quantum field theory (WQFT) formalism introduced in our previous work, and calculate the two bodies’ deflection and spin kick to sub-leading order in the post-Minkowskian expansion in Newton’s constant G . For spins aligned to the normal vector of the scattering plane we also obtain the scattering angle. All D -dimensional observables are derived from an eikonal phase given as the free energy of the WQFT that is invariant under the N = 2 supersymmetry transformations.

Following the measurements done at MAX-IV [1], we try to exploit for the ESRF-EBS Storage Ring (SR) off-energy response matrix measurement for the optimization of Touschek lifetime. The measurements performed with fast AC steerers on- and off-energy are analyzed and fitted producing an effective model including quadrupole and sextupole errors. Several alternatives to extrapolate sextupoles strengths for correction are compared in terms of lifetime. For the time being none of the corrections could produce better lifetime than the existing empirically optimized set of sextupoles.

The Berry phase provides a modern formulation of electric polarization in crystals. We extend this concept to higher electric multipole moments and determine the necessary conditions and minimal models for which the quadrupole and octupole moments are topologically quantized electromagnetic observables. Such systems exhibit gapped boundaries that are themselves lower-dimensional topological phases. Furthermore, they host topologically protected corner states carrying fractional charge, exhibiting fractionalization at the boundary of the boundary. To characterize these insulating phases of matter, we introduce a paradigm in which “nested” Wilson loops give rise to topological invariants that have been overlooked. We propose three realistic experimental implementations of this topological behavior that can be immediately tested. Our work opens a venue for the expansion of the classification of topological phases of matter.

The reaction between He + and CO forming He + C + + O has been studied at collision energies in the range between 0 and k B ⋅ 25 K. These low collision energies are reached by measuring the reaction within the orbit of a Rydberg electron after merging a beam of He( n ) Rydberg atoms and a supersonic beam of CO molecules with a rotational temperature of 6.5 K. The capture rate of the reaction drops by about 30% at collision energies below k B ⋅ 5 K. This behavior is analyzed in terms of the long-range charge–dipole and charge–quadrupole interactions using an adiabatic-channel capture model. Although the charge–dipole interaction has an effect on the magnitude of the rate coefficients, the effects of the charge–quadrupole interaction determine the main trend of the collision-energy dependence of the rate coefficients at low collision energies. The drop of the capture rate coefficient at low collision energies is attributed to the negative sign of the quadrupole moment of CO ( Q zz = −2.839 D Å) and is caused by the | JM ⟩ = |00⟩ and |1 ± 1⟩ rotational states of CO, which represent about 70% of the CO molecules at the rotational temperature of 6.5 K.

Like physical quantities such as nuclear mass and electric quadrupole moment, the nuclear charge radius is one of the important physical quantities that constitute the essential properties of the atomic nucleus. This paper studies the evolution process of the nuclear charge radius. Based on the local interaction of the atomic nucleus, the original semi-empirical formula for calculating the nuclear charge radius has been improved. The accuracy and reliability of the formula are verified by combining experimental data, with the expectation of providing a reference for the accurate measurement of the nuclear charge radius of nuclides in the future.

In relativistic Astrophysics the I -Love- Q relations refer to approximately EoS-independent relations involving the moment of inertia, Love number, and quadrupole moment through some quantities that are normalised by the mass M 0 of the background configuration of the perturbative scheme. Since M 0 is not an observable quantity, this normalisation hinders the direct applicability of the relations. A common remedy assumes that M 0 coincides with the actual mass of the star M S ; however, this approximation is only adequate for very slow rotation (when the dimensionless spin parameter is χs < 0.1). The more accurate alternative approach, based on the I -Love- Q-δM set of relations, circumvents this limitation by enabling the inference of M 0 . Here we review both approaches and provide numerical comparisons.

This paper investigates the effect of the fringe fields of quadrupole magnets (quads) on the beam optics of a 5 MeV beamline in the Linear IFMIF Prototype Accelerator (LIPAc). IFMIF stands for the International Fusion Materials Irradiation Facility. We optimized the beam optics using a hard-edge (HE) model for all quads to minimize particle losses. However, during beam commissioning, we observed particle losses and differences in the rms beam sizes between measurements and simulations. To address these issues, we incorporated quad field maps into the beam optics simulation and calibrated the conversion coefficients of each quad from magnetic gradients g to excitation currents I (GtoI) using a 5 MeV deuteron beam. This approach enabled us to achieve a matched beam, reducing particle losses and ensuring the successful transport of a 120 mA/5 MeV deuteron beam to the beam dump. We present the difference in the transfer matrices between the HE models and the field maps, along with the calibration method of each GtoI of the quads with the deuteron beam. We also compare the simulated and measured beam sizes.

For Laser WakeField Accelerators with dedicated applications, the role of the transport line is essential, as its mission is to drive the accelerated beam from the plasma exit to the application, where all the requirements on beam quality should be met. This article investigates a two-quadrupole transport line with typical beam parameters at its entrance and exit. Consequences on its capacities and limits are discussed, considering the emittance growth that can be significant.