Neutrino mass patterns, R-parity violating supersymmetry and associated phenomenology

Motivated by the recent super-Kamiokande results on atmospheric neutrinos, we incorporate massive neutrinos, with large angle oscillation between the second and third generations, in a theory with R-parity violating supersymmetry. The general features of such a theory are briefly reviewed. We emphasize its testability through the observation of comparable numbers of muons and taus, produced together with the W-boson, in decays of the lightest neutralino. A distinctly measurable decay gap is another remarkable feature of such a scenario.     

Working group report: Collider and B physics

The activities of the working group including some of the seminars are summarized. The written reports received are included.     

Cyano-, nitro-, and alkoxycarbonyl-activated observable stable enols of carboxylic acid amides

A search for the enol structures of several amides YY'CHCONHPh with Y,Y' = electron-withdrawing groups (EWGs) was conducted. When Y = CN, Y' = CO(2)Me the solid structure is that of the enol (8b) MeO(2)CC(CN)=C(OH)NHPh, whereas in solution the NMR spectrum indicate the presence of both the amide MeO(2)CCH(CN)CONHPh (8a) and 8b. When Y = NO(2), Y' = CO(2)Et the main compound in CDCl(3) is the amide, but <10% of enol(s), presumably EtO(2)CC(NO(2))=C(OH)NHPh (9b), are also present. When Y = COEt, Y' = CO(2)Me or Y = COMe, Y' = CO(2)Et (10 and 11) enolization in solution and of 11 also in the solid state occurs at the carbonyl rather than at the ester site. With Y = Y' = CN a rapid exchange between the amide (NC)(2)CHCONHPh (12a) and a tautomer, presumably the enol, take place in several solvents on the NMR time scale. With YY' = barbituric acid moiety the species in DMSO-d(6) is an enol of an amide although which CONH group enolizes is unknown. B3LYP/6-31G calculations showed that the enol (NC)(2)C=C(OH)NH(2) (13b) is more stable by DeltaG of 0.4 kcal/mol than (NC)(2)CHCONH(2) (13a) due to a combination of stabilization of 13b and destabilization of 13a and both are much more stable than the hydroxyimine and ketene imine tautomers. The effect of Y,Y' and the solvent on the relative stabilization of enols of amides is discussed.     

Inverted neutrino mass hierarchy and new signals of a chromophobic charged Higgs at the Large Hadron Collider

We explore the signals of a charged Higgs arising in a two Higgs doublet model respecting SUL₍₂₎×U(1)×Z₂$\mathit{SU}{(2)}_L\times U(1)\times Z_2$ symmetry with three singlet right-handed neutrinos, NR$N_R$. The charged Higgs in this model has negligible coupling with quarks, and has unsuppressed coupling to leptons and neutrinos. This leads to novel signatures of the charged Higgs at the LHC, especially in the case of an inverted neutrino mass hierarchy, in the form of electrons and muons with missing energy.     

Polaronic effects in a Gaussian quantum dot

The problem of an electron interacting with longitudinal-optical (LO) phonons is investigated in an N$N$-dimensional quantum dot with symmetric Gaussian confinement in all directions using the Rayleigh–Schrödinger perturbation theory, a variant of the canonical transformation method of Lee–Low–Pines, and the sophisticated apparatus of the Feynman–Haken path-integral technique for the entire range of the coupling parameters and the results for N=2$N=2$ and N=3$N=3$ are obtained as special cases. It is shown that the polaronic effects are quite significant for small dots with deep confining potential well and the parabolic potential is only a poor approximation of the Gaussian confinement. The Feynman–Haken path-integral technique in general gives a good upper bound to the ground state energy for all values of the system parameters and therefore is used as a benchmark for comparison between different methods. It is shown that the perturbation theory yields for the ground state polaron self-energy a simple closed-form analytic expression containing only Gamma functions and in the weak-coupling regime it provides the lowest energy because of an efficient partitioning of the Gaussian potential and the subsequent use of a mean-field kind of treatment. The polarization potential, the polaron radius and the number of virtual phonons in the polaron cloud are obtained using the Lee–Low–Pines–Huybrechts method and their variations with respect to different parameters of the system are discussed.     

Visible‐Light‐Driven Water Oxidation with a Polyoxometalate‐Complexed Hematite Core of 275 Iron Atoms

Although metal oxide nanocrystals are often highly active, rapid aggregation (particularly in water) generally precludes detailed solution‐state investigations of their catalytic reactions. This is equally true for visible‐light‐driven water oxidation with hematite α‐Fe₂O₃ nanocrystals, which bridge a conceptual divide between molecular complexes of iron and solid‐state hematite photoanodes. We herein report that the aqueous solubility and remarkable stability of polyoxometalate (POM)‐complexed hematite cores with 275 iron atoms enable investigations of visible‐light‐driven water oxidation at this frontier using the versatile toolbox of solution‐state methods typically reserved for molecular catalysis. The use of these methods revealed a unique mechanism, understood as a general consequence of fundamental differences between reactions of solid‐state metal oxides and freely diffusing “fragments” of the same material.     

Identification of Non‐Carbonaceous Cathodes in Al Batteries: Potential Applicability of Black and Blue Phosphorene Monolayers

In the present era of growing energy demands, low‐dimensional materials are emerging as the suitable choices for energy storage due to their excellent ion transport properties, improved reversible capacity, fine rate performance and good cycling stability. In this context, we have investigated the applicability of black and blue phosphorene monolayers as potential cathodes for Al batteries. Both black and blue phosphorene monolayers show similar electrochemical behavior as that of experimentally reported graphite with a charge transfer from the surface in order to bind the tetrahedral geometry of AlCl₄ during the charging process. The adsorption of AlCl₄ drives semiconductor‐to‐metallic transformation of black/blue phosphorene, which ensures constant conductivity in Al batteries. Following the systematic adsorption of AlCl₄, the voltage for black and blue phosphorene is calculated to be ≈1.50 V and ≈1.80 V with storage capacities of 144 mAh g^?1 and 108 mAh g^?1, respectively. Besides, low diffusion barriers of 0.11 eV and 0.14 eV are predicted for AlCl₄ on the respective systems of black and blue phosphorene monolayers. Our work suggests that both black and blue phosphorene monolayers can be potential cathodes for Al batteries with delivery of high storage capacity and high voltage, respectively.     

Zur Theorie der Photospaltung des Deuterons bei mittleren Energien

The differential cross-section for the photo-disintegration of the deuteron has been calculated on the basis of a phenomenological theory for energies up to 80 MeV, assuming the validity of Siegert's theorem. We have used the Hulth'en wavefunction with a 4% D-state admixture for the ground state. The final state potential has been approximated by a square-well of a given radius, the depth of which has been calculated from the phase-shifts given by Marshak. For both the ground state and the final states a hard-core of radius 0,4 · 10^?13 cm is introduced. We have considered only the electric and magnetic dipole transitions. For the isotropic term we have obtained a fairly constant value which agrees, with the experimentally observed energy-dependence but is about 20% smaller than the experimental value. The coefficient of the sin² Θ-term agrees well with the experimental results.