We study a cylindrical helical magnetic flux rope subject to the requirement that its electromagnetic field retain the same local two-plane structure as it evolves. On the nondegenerate branch considered here, , equivalently , the Maxwell tensor splits canonically into two decomposable parts spanning mutually orthogonal two-planes; we require the magnetic-type part to keep a fixed radial leg and a helical direction, with a prescribed longitudinal profile. Imposing the source-free Maxwell equations on the total field then yields a convex scalar conservation law for the field-line pitch variable , whose ratio to r is the tangent of the local field-line pitch angle. Smooth compressive pitch profiles therefore steepen, and the radial characteristic map loses invertibility after a finite accumulated drive while the pitch and the field amplitudes can remain finite. Provided an explicitly computable prefactor does not vanish, the Amp & egrave;re current required to support the rope diverges at that point. We call this endpoint a current-sheet precursor, because the analysis does not show that a self-consistent plasma reaches it, nor which layer resistive, Hall, or kinetic physics would select. The focusing survives the addition of radial magnetic through-flux. An exact homologous family shows that pitch-gradient blow-up is not the essential feature: The characteristic Jacobian vanishes and the rotation rate of the unit helical direction diverges while . Since , no four-velocity satisfies and no frame removes the electric field-an algebraic property that fixes no resistivity, dissipation rate, or reconnection model.
By performing a field redefinition via a cohomomorphism on the Maurer-Cartan action of the $A_\infty$ algebra, we construct an action that reproduces the characteristic structure of boundary string field theory (BSFT), which we refer to as the BSFT-like action. We show that the form and several properties of this BSFT-like action closely resemble those of BSFT. Our results suggest that this approach provides a systematic framework to derive the BSFT action from the open string field theory based on $A_\infty$ algebras.
Abstract We study a planar Dirac oscillator in a uniform gauge background with an Abelian magnetic component and two non-Abelian amplitudes. The noncommuting spatial potentials generate a chromomagnetic curvature along T3 = τ3/2, while the temporal potential generates chromoelectric components proportional to their product. We derive the second-order stationary identity without discarding the isospin–orbit, diamagnetic, or scalar-potential terms. The first-order Hamiltonian, with minimal coupling, a Pauli interaction, or both, admits a conserved oscillator–spin–isospin operator and reduces to finite blocks. We obtain the exact secular equations, the exceptional lowest signed levels, and the leading avoided-crossing gaps. Minimal coupling produces transverse mixing already when the scalar amplitude vanishes; a gap proportional to the product of the amplitudes instead occurs at resonance in the pure Pauli model. We also solve a separately defined field-strength comparison operator. Its spin-dependent backbone does not commute with the transverse internal coupling, so its spectrum is not obtained by adding the isolated internal eigenvalues to the backbone energies. The mixed branches have quadratic weak-coupling shifts away from degeneracy. We distinguish gauge invariants from internal-basis labels and give conditional, spectrally resolved parameter examples, without claiming demonstrated graphene or atomic realizations.
Abstract Liquid scintillators for neutrino and particle detection commonly use organic fluor and wavelength-shifter chains to control the final emission spectrum. Here we investigate a 1,4-bis (2-methylstyryl)benzene (bis-MSB)-free toluene/2,5-diphenyloxazole (PPO) formulation containing all-inorganic CsPbBr3 perovskite quantum dots (PQDs) as a spectrally distinct semiconductor emissive component. Ligand-passivated CsPbBr3 PQDs were synthesized by ambient ligand-assisted reprecipitation and characterized by X-ray diffraction, transmission electron microscopy, and first-principles calculations. The optical spectra identify a green CsPbBr3 band-edge emission component near 510 nm and spectral overlap between PPO emission and CsPbBr3 absorption. Matched 137Cs component-control measurements show that the PPO/toluene control produces the principal broad pulse-height response. Adding the CsPbBr3-containing component shifts the integrated-charge distribution toward lower charge, whereas the PPO-free PQD formulation exhibits a photomultiplier-tube response mainly at low integrated charge. These controls characterize changes in the overall formulation response without separating the PPO and PQD emission contributions within the mixture. In a separate future optimization scenario assuming unchanged effective photon yield ($\xi =1$), shifting the modeled emission from 510 to 440 nm increases the projected photoelectron yield by a factor of 1.63 and reduces the photostatistical energy-resolution term by about 22% relative to the modeled 510-nm reference.
Abstract Starting from an isospin-symmetric microscopic interaction of Shin et al. [Phys. Rev. C 110, 034306 (2024)], we developed two isospin symmetry breaking (ISB) shell-model interactions by adding Coulomb interaction, as well as charge-symmetry breaking (CSB) and charge-independence breaking (CIB) components from the Argonne v18 (Av18) interaction at two different radial cutoffs, rc = 0.55 and 0.70 fm. With additional modifications to the proton single-particle energies, we then employed these interactions to calculate the Coulomb displacement energies (CDEs) and triplet displacement energies (TDEs) of the isobaric multiplet masses for nuclei with |Tz| = 1/2 and T = 1 across the sd-shell to test their validity and applicability, and compared with the USDCm interaction. We found that both ISB interactions show important roles of the CSB and CIB components in the CDEs and TDEs. In addition, we investigated mirror energy differences (MEDs) in the low-energy spectra of nuclei around A = 20, and triplet energy differences (TEDs) in the A = 18 and 22 systems. They are generally well described by the ISB interactions, although some discrepancies remain. Furthermore, the calculated E2 transition strengths obtained with the ISB interactions are shown to be in good agreement with experimental data, indicating small ISB effects in these transitions. Overall, both the ISB interactions provide a consistent and physically motivated framework for describing ISB effects, while the phenomenological USDCm interaction achieves closer agreement with experiment due to a larger number of adjustable parameters.
