Chiral Anomaly and Schwinger Effect in Non-Abelian Gauge Theories

We study the production of chiral fermions in a background of a strong non-abelian gauge field with a non-vanishing Chern-Pontryagin density. We discuss both pair production analogous to the Schwinger effect as well as asymmetric production through the chiral anomaly, sourced by the Chern-Pontryagin density. In abelian gauge theories one may nicely understand these processes by considering that the fermion dispersion relation forms discrete Landau levels. Here we extend this analysis to a non-abelian gauge theory, considering an intrinsically non-abelian isotropic and homogeneous SU(2) gauge field background with a non-vanishing Chern-Pontryagin density. We show that the asymmetric fermion production, together with a non-trivial vacuum contribution, correctly reproduces the chiral anomaly. This indicates that the usual vacuum subtraction scheme, imposing normal ordering, fails in this case. As a concrete example of this gauge field background, we consider chromo-natural inflation. Applying our analysis to this particular model, we compute the backreaction of the generated fermions on the gauge field background. This backreaction receives contributions both from the vacuum through a Coleman-Weinberg-type correction and from the fermion excitations through an induced current.Comment: 27 pages + appendices, 2 figures; v2: published versio

Neutrino experiments probe hadrophilic light dark matter

We use Super-K data to place new strong limits on interactions of sub-GeV Dark Matter (DM) with nuclei, that rely on the DM flux inevitably induced by cosmic-ray upscatterings. We derive analogous sensitivities at Hyper-K and DUNE and compare them with others, e.g. at JUNO. Using simplified models, we find that our proposal tests genuinely new parameter space, allowed both by theoretical consistency and by other direct detection experiments, cosmology, meson decays and our recast of monojet. Our results thus motivate and shape a new physics case for any large volume detector sensitive to nuclear recoils.Comment: 22 pages, 5 figures, submission to SciPos

Benzyl­tributyl­ammonium 6-hydroxy­naphthalene-2-sulfonate

The title compound, C19H34N+·C10H7O4S−, is a charge-control agent for toners used in electrophotography. Inter­moleclar O—H⋯O hydrogen bonding between the OH group of one anion and the sulfonate O atom of a neighboring anion leads to the formation of one-dimensional chains along the b axis. In addition, C—H⋯O hydrogen bonds are observed. One of the n-butyl chains of the cation is disordered over two sites in a 0.88:0.12 ratio

Diacetonitrile­tetra­kis{μ2-3-anilinocarbonyl-1-[(5-chloro-2-oxidophen­yl)diazen­yl]-2-naphtholato}tetra­aqua­diiron(III)disodium(I) dihydrate

The title compound, [Fe2Na2(C23H14ClN3O3)4(C2H3N)2(H2O)4]·2H2O, is a hydrated Fe–azo complex dimer that is used as a charge-control agent in electrophotography. The mol­ecule is a centrosymmetric dimer with two octa­hedral FeIII units linked by two bridging five-coordinate NaI cations. Each FeIII atom is chelated by the N and two O atoms from two 3-anilinocarbonyl-1-[(5-chloro-2-oxidophen­yl)diazen­yl]-2-naph­tholate ligands. The Na+ cation is coordinated by a carbonyl O atom from the two ligands of each octa­hedral FeIII unit, two water mol­ecules and the N atom of an acetonitrile mol­ecule. Two solvent water mol­ecules complete the structure. In the crystal structure, the dimeric mol­ecules are bridged by a pair of discrete inter­molecular O—H⋯O hydrogen bonds, one of which involves a sodium-bound water mol­ecule and a hydrate water, and the other a 5-chloro­phenolate O atom and a water molecule to form an extended chain along b

Diacetonitrile­tetra­kis{μ2-3-anilinocarbonyl-1-[(5-chloro-2-oxidophen­yl)diazen­yl]-2-naphtholato}tetra­aqua­diiron(III)disodium(I) dihydrate. Corrigendum

Corrigendum to Acta Cryst. (2008), E64, m240–m241

Dominant Model-Parameter Determination for the Analysis of Current Imbalance Across Paralleled Power Transistors

In this article, we propose a new sensitivity-based analytical equation, the nn -devices forward propagation of variance (NFPV). Using the proposed NFPV equation, the dominant device model parameters— essential for accurate analysis of energy-loss variation due to the current imbalance across paralleled power transistors from statistical parameter variations—are efficiently determined. The proposed method with the NFPV equation is faster than conventional methods that use Monte Carlo simulation. We conducted experimental validation using the measured current–voltage characteristics of commercially available 100 silicon mosfet s and 300 silicon carbide mosfet s. The results show that the proposed NFPV-based method efficiently finds the dominant device model parameters, which are sufficient and necessary to reproduce the energy-loss variation, regardless of the number of parallel transistors. The results also show that the determined dominant device model parameters are valid under practical situations, such as uneven parasitic inductances and device temperature imbalance among paralleled transistors. The proposed method determines the dominant device model parameters 9.33× faster than the conventional method while maintaining the same accuracy. Additionally, we demonstrate that, compared with the conventional method, an increase in the number of candidate statistical model parameters increases the efficiency of the proposed method