Isolated Photons in Deep Inelastic Scattering

Photon radiation at large transverse momenta at colliders is a detailed probe of hard interaction dynamics. The isolated photon production cross section in deep inelastic scattering was measured recently by the ZEUS experiment, and found to be considerably larger than theoretical predictions obtained with widely used event generators. To investigate this discrepancy, we perform a dedicated parton-level calculation of this observable, including contributions from fragmentation and large-angle radiation. Our results are in good agreement with all aspects of the experimental measurement.Comment: 4 pages, 3 figure

Therapist effects and IAPT Psychological Wellbeing Practitioners (PWPs): A multilevel modelling and mixed methods analysis

The aim of this research was (a) to determine the extent of therapist effects in Psychological Wellbeing Practitioners (PWPs) delivering guided self-help in IAPT services and (b) to identify factors that defined effective PWP clinical practice. Using patient (N = 1122) anxiety and depression outcomes (PHQ-9 and GAD-7), the effectiveness of N = 21 PWPs across 6 service sites was examined using multi-level modelling. PWPs and their clinical supervisors were also interviewed and completed measures of ego strength, intuition and resilience. Therapist effects accounted for around 9 per cent of the variance in patient outcomes. One PWP had significantly better than average outcomes on both PHQ-9 and GAD-7 while 3 PWPs were significantly below average on the PHQ-9 and 2 were below average on the GAD-7. Computed PWP ranks identified quartile clusters of the most (N = 5) and least (N = 5) effective PWPs. More effective PWPs generated higher rates of reliable and clinically significant change and displayed greater resilience, organisational abilities, knowledge and confidence. Study weaknesses are identified and methodological considerations for future studies examining therapist effects in low intensity cognitive behaviour therapy are provided

Rydberg Wave Packets are Squeezed States

We point out that Rydberg wave packets (and similar ``coherent" molecular packets) are, in general, squeezed states, rather than the more elementary coherent states. This observation allows a more intuitive understanding of their properties; e.g., their revivals.Comment: 7 pages of text plus one figure available in the literature, LA-UR 93-2804, to be published in Quantum Optics, LaTe

Acid-Labile Traceless Click Linker for Protein Transduction

Intracellular delivery of active proteins presents an interesting approach in research and therapy. We created a protein transduction shuttle based on a new traceless click linker that combines the advantages of click reactions with implementation of reversible pH-sensitive bonds. The azidomethyl-methylmaleic anhydride (AzMMMan) linker was found compatible with different click chemistries, demonstrated in bioreversible protein modification with dyes, polyethylene glycol, or a transduction carrier. Linkages were stable at physiological pH but reversible at the mild acidic pH of endosomes or lysosomes. We show that pH-reversible attachment of a defined endosome-destabilizing three-arm oligo(ethane amino)amide carrier generates an effective shuttle for protein delivery. The cargo protein nlsEGFP, when coupled via the traceless AzMMMan linker, experiences efficient cellular uptake and endosomal escape into the cytosol, followed by import into the nucleus. In contrast, irreversible linkage to the same shuttle hampers nuclear delivery of nlsEGFP which after uptake remains trapped in the cytosol. Successful intracellular delivery of bioactive ß-galactosidase as a model enzyme was also demonstrated using the pH-controlled shuttle system

The Stark effect in linear potentials

We examine the Stark effect (the second-order shift in the energy spectrum due to an external constant force) for two 1-dimensional model quantum mechanical systems described by linear potentials, the so-called quantum bouncer (defined by V(z) = Fz for z>0 and V(z) infinite for z<0) and the symmetric linear potential (given by V(z) = F|z|). We show how straightforward use of the most obvious properties of the Airy function solutions and simple Taylor expansions give closed form results for the Stark shifts in both systems. These exact results are then compared to other approximation techniques, such as perturbation theory and WKB methods. These expressions add to the small number of closed-form descriptions available for the Stark effect in model quantum mechanical systems.Comment: 15 pages. To appear in Eur. J. Phys. Needs Institute of Physics (iopart) style file

Production, Decay, and Polarization of Excited Heavy Hadrons

We discuss the production via fragmentation of excited heavy mesons and baryons, and their subsequent decay. In particular, we consider the question of whether a net polarization of the initial heavy quark may be detected, either in a polarization of the final ground state or in anisotropies in the decay products of the excited hadron. The result hinges in part on a nonperturbative parameter which measures the net transverse alignment of the light degrees of freedom in the fragmentation process. We use existing data on charmed mesons to extract this quantity for certain excited mesons. Using this result, we estimate the polarization retention of charm and bottom baryons.Comment: 37 pages, 3 figures available upon request, uses phyzzx forma

Revision of the African cichlid fish genus Ctenochromis (Teleostei, Cichliformes), including a description of the new genus Shuja from Lake Tanganyika and the new species Ctenochromis scatebra from northern Tanzania

Molecular phylogenetic evidence clearly resolves the African cichlid fish genus Ctenochromis, as defined by Greenwood (1979), as paraphyletic. Here, we redefine the genus Ctenochromis and assign Ctenochromis horei, a member of the Tropheini from Lake Tanganyika, to a new genus Shuja gen. nov. We restrict Ctenochromis to Ctenochromis pectoralis and Ctenochromis scatebra sp. nov., both of which are endemic to the Pangani River catchment in northern Tanzania, and are resolved as sister taxa in a phylogenetic analysis using genome-wide data. Ctenochromis pectoralis is the type species of the genus and described from specimens collected near Korogwe, Tanzania. The species was declared extinct in a 2016 IUCN Red List Assessment. We confirm the continued presence of a population of C. pectoralis within the Ruvu tributary linking Lake Jipe to Nyumba ya Mungu Reservoir. The new taxon Ctenochromis scatebra sp. nov. is described from Chemka Springs, and recognised on the basis of differences from C. pectoralis in tooth and jaw morphology

Strange Decays of Nonstrange Baryons

The strong decays of excited nonstrange baryons into the final states Lambda K, Sigma K, and for the first time into Lambda(1405) K, Lambda(1520) K, Sigma(1385) K, Lambda K*, and Sigma K*, are examined in a relativized quark pair creation model. The wave functions and parameters of the model are fixed by previous calculations of N pi and N pi pi, etc., decays. Our results show that it should be possible to discover several new negative parity excited baryons and confirm the discovery of several others by analyzing these final states in kaon production experiments. We also establish clear predictions for the relative strengths of certain states to decay to Lambda(1405) K and Lambda(1520) K, which can be tested to determine if a three-quark model of the Lambda(1405) K is valid. Our results compare favorably with the results of partial wave analyses of the limited existing data for the Lambda K and Sigma K channels. We do not find large Sigma K decay amplitudes for a substantial group of predicted and weakly established negative-parity states, in contrast to the only previous work to consider decays of these states into the strange final states Lambda K and Sigma K.Comment: 25 pages, 8 figures, RevTe

Analytic results for Gaussian wave packets in four model systems: I. Visualization of the kinetic energy

Using Gaussian wave packet solutions, we examine how the kinetic energy is distributed in time-dependent solutions of the Schrodinger equation corresponding to the cases of a free particle, a particle undergoing uniform acceleration, a particle in a harmonic oscillator potential, and a system corresponding to an unstable equilibrium. We find, for specific choices of initial parameters, that as much as 90% of the kinetic energy can be localized (at least conceptually) in the `front half' of such Gaussian wave packets, and we visualize these effects.Comment: 22 pages, RevTeX, four .eps figures, to appear in Found. Phys. Lett. Vol. 17, Dec. 200