Unit Of Electric Charge Research Articles

Magnetic dipole moments of the Tcc+ and ZV++ tetraquark states

Inspired by the observation of the doubly charmed state $T_{cc}$ and following theoretical studies on its spectroscopic parameters, we investigate its magnetic dipole moment assigning it the quantum numbers $J^P=1^+$ and both the compact diquark-antidiquark and molecular structures in the framework of the light-cone QCD. We also calculate the magnetic dipole moment of the theoretically predicted singly charmed state, $Z_V^{++}$, with two units of electric charge and the quantum numbers $J^P=1^-$ in diquark-antidiquark picture. The numerical results are obtained as $\mu_{T_{cc}^+-Di} =0.66^{+0.34}_{-0.23}~\mu_N$, $ \mu_{T_{cc}^+-Mol} =0.43^{+0.23}_{-0.22}~\mu_N $ and $\mu_{Z_{V}^{++}} =3.35^{+0.89}_{-0.73} ~\mu_N$. These results may be checked via other phenomenological approaches. The obtained results may be useful in exact determinations of the natures of these states.

Parametric design of multilayered piezoelectric/piezomagnetic transducers with periodic interfacial electrodes based on fracture mechanics analysis

This paper studies the parametric design of multilayered piezoelectric/piezomagnetic (PE/PM) ceramic transducer with periodic interfacial electrodes based on fracture mechanics analysis. The analysis of multilayered PE/PM transducer under electrically actuated mode is carried out by means of solving the magneto-electroelastic problem of a PE/PM bi-layer, where the inner interfacial electrode is electrically charged and periodic conditions are used. Due to the singular stress distributed on the inner side of the electrode ends, cracks are prone to nucleate and propagate along the interfaces. The weight function method and linear superposition are used to find the Stress Intensity Factor (SIF) around the crack tip. Parametric discussion was carried out for the dependence of SIF on the layer thickness ratio as well as the position of the interfacial electrode. Analysis reveals that, under the same electric load, a thicker piezoelectric layer will lead to a lower SIF. This suggests that, for the bonded interfaces with certain fracture toughness in the piezoelectric/piezomagnetic transducer, the design with a thicker piezoelectric layer can sustain a higher threshold electric load and the transducer can accommodate more electric charges under the critical condition. However, concerning with the crack extension rate defined as the crack extension induced by per unit electric charge increase, the design with a thinner piezoelectric layer will find a lower and relative small crack extension rate, while for the case of thicker piezoelectric layer, the crack extension rate enhances significantly as crack propagates, which may lead to fatal destruction of the device.

Electric Area of an Extremely Short Pulse and Moment of Force

The electric area of a radiation pulse, which is defined as a time integral of the electric field strength, is interpreted as a mechanical moment of the Lorentz force acting on a unit electric charge upon its interaction with the radiation pulse. Correspondence between the classical mechanics law of conservation of momentum and the change in the moment of force upon the interaction of a quantum object with an intense extremely short radiation pulse is demonstrated. The high efficiency of acceleration of charged particles with quasi-unipolar radiation pulses is confirmed.

Solid-state Stern-Gerlach spin splitter for magnetic field sensing, spintronics, and quantum computing.

We show conceptually that the edge of a two-dimensional topological insulator can be used to construct a solid-state Stern–Gerlach spin splitter. By threading such a Stern–Gerlach apparatus with a magnetic flux, Aharanov–Bohm-like interference effects are introduced. Using ferromagnetic leads, the setup can be used to both measure magnetic flux and as a spintronics switch. With normal metallic leads a switchable spintronics NOT-gate can be implemented. Furthermore, we show that a sequence of such devices can be used to construct a single-qubit SU(2)-gate, one of the two gates required for a universal quantum computer. The field sensitivity, or switching field, b, is related to the characteristic size of the device, r, through b = h/(2πqr2), with q being the unit of electric charge.

Charged fermions below 100 GeV

How light can a fermion be if it has unit electric charge? We revisit the lore that LEP robustly excludes charged fermions lighter than about 100 GeV. We review LEP chargino searches, and find them to exclude charged fermions lighter than 90 GeV, assuming a higgsino-like cross section. However, if the charged fermion couples to a new scalar, destructive interference among production channels can lower the LEP cross section by a factor of 3. In this case, we find that charged fermions as light as 75 GeV can evade LEP bounds, while remaining consistent with constraints from the LHC. As the LHC collects more data, charged fermions in the 75–100 GeV mass range serve as a target for future monojet and disappearing track searches.

An efficient model for the frictional contact between two multiferroic bodies

This paper presents a semi-analytical model (SAM) for three-dimensional frictional magnetoelectroelastic (MEE) contact of two multiferroic bodies, together with a set of effective solution methods. The frequency response functions (FRFs) for the MEE fields in a multiferroic half-space are analytically derived with respect to a unit concentrated normal force, a unit concentrated tangential force, a unit electric charge, and/or a unit magnetic charge, which are then converted into the results of continuous Fourier transforms of the influence coefficients (ICs), followed by the discrete Fourier transforms with a proper aliasing treatment. The conjugate gradient method (CGM) is used to obtain the unknown distributed pressure. Furthermore, the discrete convolution-fast Fourier transform (DC-FFT) algorithm is implemented to calculate the in-plane electric/magnetic potentials and subsurface stresses. The model is implemented to analyze the frictional sliding contact between a half-space and a sphere, and to study the coupled effects of surface electric/magnetic charges and friction on contact behaviors, including pressure, stresses, and electric/magnetic potentials. A sensitivity analysis is also conducted to evaluate the influences of friction and material properties on the contact-induced multifield coupling behaviors. A number of case studies are committed, and the results indicate that electric/magnetic charge densities and the friction coefficient strongly influence the contact pressure, stress, and electric potential.

Quantum physics: Destruction of discrete charge.

Electric charge is quantized in units of the electron's charge. An experiment explores the suppression of charge quantization caused by quantum fluctuations and supports a long-standing theory that explains this behaviour. See Letter p.58 The charge of a single electron or proton defines the fundamental unit of electric charge. But in nanoelectronic devices, where quantum fluctuations are in play, the discreteness of this elementary charge is eroded with increasing connection strengths between conducting elements. Fundamental predictions have been difficult to verify, but now Frederic Pierre and colleagues have constructed a device, consisting of a micrometre-scale metallic island connected to electrodes via fully controllable semiconducting channels, where the complete evolution of charge quantization can be measured. The work confirms long-standing theory and opens up a platform for testing charge quantization in challenging scenarios involving correlated electrons and topological quasiparticles.

Constructing symmetric topological phases of bosons in three dimensions via fermionic projective construction and dyon condensation

Recently, there is a considerable study on gapped symmetric phases of bosons that do not break any symmetry. Even without symmetry breaking, the bosons can still be in many exotic new states of matter, such as symmetry-protected topological (SPT) phases, which are short-range entangled and symmetry-enriched topological (SET) phases, which are long-range entangled. It is well known that noninteracting fermionic topological insulators are SPT states protected by time-reversal symmetry and U(1) fermion number conservation symmetry. In this paper, we construct three-dimensional exotic phases of bosons with time-reversal symmetry and boson number conservation U(1) symmetry by means of fermionic projective construction. We first construct an algebraic bosonic insulator, which is a symmetric bosonic state with an emergent U(1) gapless gauge field. We then obtain many gapped bosonic states that do not break the time-reversal symmetry and boson number conservation via proper dyon condensations. We identify the constructed states by calculating the allowed electric and magnetic charges of their excitations, as well as the statistics and the symmetric transformation properties of those excitations. This allows us to show that our constructed states can be trivial SPT states (i.e., trivial Mott insulators of bosons with symmetry), nontrivial SPT states (i.e., bosonic topological insulators), and SET states (i.e., fractional bosonic topological insulators). In nontrivial SPT states, the elementary monopole (carrying zero electric charge but unit magnetic charge) and elementary dyon (carrying both unit electric charge and unit magnetic charge) are fermionic and bosonic, respectively. In SET states, intrinsic excitations may carry fractional charge.

Vector-bilepton contribution to four lepton production at the LHC

Some extensions of the standard model predict the existence of particles having two units of leptonic charge, known as bileptons. One such model is based on the $SU(3{)}_{c}\ifmmode\times\else\texttimes\fi{}SU(3{)}_{L}\ifmmode\times\else\texttimes\fi{}U(1{)}_{X}$ symmetry group (3-3-1 model, for short). Our search uses the minimal version of the 3-3-1 model, which has exotic charges for the quarks and new gauge bosons. This model predicts the existence of bileptons as vector particles having one (${V}^{\ifmmode\pm\else\textpm\fi{}}$) and two (${Y}^{\ifmmode\pm\else\textpm\fi{}\ifmmode\pm\else\textpm\fi{}}$) units of electric charge. We study the signatures for the production of four leptons by considering the contribution of a pair of bileptons in $pp$ collisions for three energy and luminosity regimes at the Large Hadron Collider (LHC). We present invariant mass and transverse momentum distributions, the total cross section, and we determine the expected number of events for each bilepton type. Finally, we analyze the LHC potential for discovering single and double charged vector bileptons at 95% C.L. We conclude that the LHC collider can show a clear signature for the existence of bileptons as a signal of new physics.

Stationary configurations of two extreme black holes obtainable from the Kinnersley-Chitre solution

Stationary axisymmetric systems of two extreme Kerr sources separated by a massless strut, which arise as subfamilies of the well-known Kinnersley-Chitre solution, are studied. We present explicit analytical formulas for the individual masses and angular momenta of the constituents and establish the range of the parameters for which such systems can be regarded as describing black holes. The mass-angular momentum relations and the interaction force in the black-hole configurations are also analyzed. Furthermore, we construct a charging generalization of the Kinnersley-Chitre metric and, as applications of the general formulas obtained, discuss two special cases describing a pair of identical co- and counter-rotating extreme Kerr-Newman black holes kept apart by a conical singularity. From our analysis it follows, in particular, that the equality ${m}^{2}\ensuremath{-}{a}^{2}\ensuremath{-}{e}^{2}=0$ relating the mass, angular momentum per unit mass and electric charge of a single Kerr-Newman extreme black hole is no longer verified by the analogous extreme black-hole constituents in binary configurations.

Muons and frustrated magnetism in NiGa2S4 and Pr2Ir2O7

Geometrically frustrated magnets are of interest because of the novel phenomena that arise from their exotic ground states and low-lying excitations. Muon spin rotation and relaxation (μSR) is a sensitive probe of magnetism on the local (atomic) distance scale, and is an attractive tool for the study of frustrated magnets. The muon carries a unit electric charge, however, which can have an appreciable effect on local properties. We discuss two cases where such an effect might be involved. In the 2D triangular antiferromagnet NiGa2S4 the 'magnetic' specific heat is field-independent up to 7 T, suggesting nonmagnetic excitations, but μSR experiments reveal Ni spin freezing below ~9 K and strong magnetic fluctuations down to 25 mK. Comparison with Ga nuclear quadrupole resonance data suggests, however, that the muon charge does not cause this discrepancy. In the pyrochlore iridate Pr2Ir2O7 muon spin relaxation due to a distribution of quasistatic fields is observed over a wide temperature range. The data strongly suggest hyperfine-enhanced 141Pr nuclear magnetism, which requires a nonmagnetic Pr3+ ground state. This may be due to lifting of the Pr3+ non-Kramers degeneracy by the muon electric field or, at least in part, a property of a spin-liquid-like many-body ground state.

New self-dual solutions ofSU(2)Yang-Mills theory in Euclidean Schwarzschild space

We present a systematic study of spherically symmetric self-dual solutions of SU(2) Yang-Mills theory on Euclidean Schwarzschild space. All the previously known solutions are recovered and a new one-parameter family of instantons is obtained. The newly found solutions have continuous actions and interpolate between the classic Charap and Duff instantons. We examine the physical properties of this family and show that it consists of dyons of unit (magnetic and electric) charge.

Integrated Aeroservoelastic Analysis of Induced Strain Rotor Blades

This paper presents an application of an original formulation for the characterization of generally anisotropic, non-homogeneous beam sections including induced-strain devices (in this case piezo-electric patches) to the aeroservoelastic analysis and optimization of actively twisted helicopter rotor blades. The induced-strain inclusions can have arbitrary shape and orthotropy. The beam section characterization is based on a semi-analytical approach to the analysis of the beam, where the section is modeled as a 2-D FE model. The linear and angular strains of the beam, the free warping of the section and the electric potential are solved in terms of unit internal forces, moments and electric charge density on the electrodes under appropriate boundary conditions to provide the elastic and electro-static solution of the compliance problem. This solution yields the 6 × 6 generalized elastic and inertia properties, the 6 × N generalized piezo-electric properties and the N × N dielectric properties of a piezo-electric beam section characterized by N independent piezo-electric patches. These properties, and detailed information about the strain and stress state inside the beam section for each span-wise location are used to synthesize noteworthy geometric, mechanical, aeroelastic and piezo-electric properties to be used in the definition of the objective function and the constraints of an aeroservoelastic optimization problem. The piezo-electric blade section characterization is detailed; the optimization procedure is illustrated, and relevant results are presented and discussed in view of indications arising from simplified models based on the monocoque theory.

Are magnetic monopoles hadrons?

The charges of magnetic monopoles are constrained to a multiple of 2 π times the inverse of the elementary unit electric charge. In the standard model, quarks have fractional charge, raising the question of whether the basic magnetic monople unit is a multiple of 2 π / e or three times that. A simple lattice construction shows how a magnetic monopole of the lower strength is possible if it interacts with gluonic fields as well. Such a monopole is thus a hadron. This is consistent with the construction of magnetic monopoles in grand unified theories.

A Stueckelberg extension of the Standard Model

An extension of the standard model of electro-weak interactions by an extra abelian gauge boson is given, in which the extra gauge boson and the hypercharge gauge boson both couple to an axionic scalar in a form that leads to a Stueckelberg mass term. The theory leads to a massive Z′ whose couplings to fermions are uniquely determined and suppressed by small mixing angles. Such a Z′ could have a low mass and appear in e+e− collisions as a sharp resonance. The branching ratios into ff̄ species, and the forward–backward asymmetry are found to have distinctive features. The model also predicts a new unit of electric charge e′=Q′e, where Q′ is, in general, irrational, in the coupling of the photon with hidden matter that is neutral under SU(2)L×U(1)Y.

Ion-migration Polarity Change and 3D Shape Evaluation in the WDT Method

In this paper, protection resistance was measured as a parameter for the 3D shape of the dendrite, which was produced on the copper, printed wired board by the WDT method. The measurement was occurred using the 3D shape measurement system. We measured the 3D shape of a dendrite in a nonuniform electric field with a changing polarity. Moreover, the polar effect of ion-migration was examined by the 3D shape electric field analysis using ANSYS. Consequently, the height of the accumulation things at anode was higher than the negative pole side under round shaped cathode condition. Similarly, the quantity of the accumulation thing is also found larger at anode. On the other hand, the dispersal of the accumulation thing is observed between the anode and the negative pole under a round shaped anode conditions. And it turns out that there is also smaller accumulation thing at the tip part of a round shaped electrode. Moreover, for a same protection resistance, the amounts of generating of the accumulation objects per unit electric charge were larger for round shaped anode conditions comparing to the cathode. It is seen from 3d shape electric field analysis, that horizontal part of the electric field vector at anode is greater than the cathode. At the same time, the field intensity at anode is also larger than cathode. For a round shaped anode in 3D shape electric field analysis, the strongest electric field vector was found between a round shape electrode tip part and flat electrode. Although in the round shape cathode, the electric field vector had become the strongest between the flat electrode and the round shape electrode tip part. The electric field intensity of a nearby flat electrode was strong for a round shape electrode facing the field. Since the action states of the accumulation thing after a short circuit is different depending on the polarity of electrode for a nonuniform electric field conditions, it appears that it will not take much time to occur a failure

Dynamic Ionic Strength Effects in Fast Bimolecular Electron Transfer between a Redox Metalloprotein of High Electrostatic Charge and an Inorganic Reaction Partner

The ionic strength dependence of the bimolecular electron transfer (ET) reaction between Clostridium pasteurianum rubredoxin(III) and photochemically generated [Ru(bpy)3]+ has been investigated. The reaction is fast and close to the diffusion-controlled limit. Dynamic ionic strength effects on all kinetics parameters (work terms, driving force, and reorganization free energy) have been incorporated in the data analysis; the effects on the intermolecular work terms are large and dominate in the driving force region close to the activationless limit. The variation in ET rate constant over the 0.005−2.0 M ionic strength range is quantitatively consistent with the high negative charge (−9e where e is the unit electric charge) and size (crystallographic radius ≈ 12 Å) of rubredoxin(III). If low ionic strength (0.005−0.01 M) data are omitted, the variation in rates suggests a somewhat smaller charge on the protein (−4e to −5e).

The Leptons After 100 Years

Over the course of a century, six leptons have been discovered in the universe of elementary particles. Three—the electron, muon and tau—each have one unit of electric charge; the other three—the neutrinos—have no charge.

The strong-coupling spectrum of the Seiberg-Witten theory

We carefully study the global structure of the solution of the N = 2 supersymmetric pure Yang-Mills theory with gauge group SU(2) obtained by Seiberg and Witten. We exploit itsZsymmetry and describe the curve in moduli space where BPS states can become unstable, separating the strong-coupling from the weak-coupling region. This allows us to obtain the spectrum of stable BPS states in the strong-coupling region: we prove that only the two particles responsible for the singularities of the solution (the magnetic monopole and the dyon of unit electric charge) are present in this region. Our method also permits us to very easily obtain the weak-coupling spectrum, without using semiclassical methods. We discuss how the BPS states disintegrate when crossing the border from the weak- to the strong-coupling region.

Elementary vorton instability in a Yang-Mills model

A model consisting of anSO(3) gauge field coupled to a single Higgs isovector is considered. An Abelian gauge symmetry, identified with the electromagneticU(1) gauge symmetry, survives the spontaneous symmetry breaking. The model admits solutions which can describe either neutral gauge strings or strings which carry charge and current. Circular-loop configurations of the charged strings form the vortons of the model, provided that there exists a large-distance cut-off corresponding to the loop radius. It is found that if elementary vortons which carry a single unit of electric charge exist, then they are quantum-mechanically unstable against decay.