Note on Triangle Anomalies and Assignment of Singlet in 331-like Model

It is pointed out that in the $331-$like model which uses both fundamental and complex conjugate representations for an assignment of the representations to the left-handed quarks and the scalar representation to their corresponding right-handed counterparts, the nature of the scalar should be taken into account in order to make the fermion triangle anomalies in the theory anomaly-free, i.e. renormalizable in a sense with no anomalies, even after the spontaneous symmetry breaking.Comment: 8 page no figures, acknowledgments adde

Methanolysis (solvolysis) And Synthesis Of 4′'-substituted 4-benzyloxybenzyl Chlorides And Some Related Compounds: Comparisons With The Corresponding Benzoyl Compounds

The kinetics of methanolysis (solvolysis) in 97.4% MeOH-dioxan of a series of 4′-substituted 4-benzyloxybenzyl chlorides, and of 4-anisyl, 4-phenoxybenzyl, and benzyl chlorides have been studied and discussed, including comparisons with the data for the corresponding series of benzoyl chlorides, previously reported by us. The 4′-substituted precursor alcohols, chlorides, and product methyl ethers are all new compounds. 4-Anisyl chloride and the series of benzyloxybenzyl chlorides react by the SN1 mechanism, whereas benzyl chloride reacts by the SN2 mechanism. 4-Phenoxybenzyl chloride shows intermediate behaviour. A similar pattern was observed with the corresponding benzoyl compounds. In both series the reactivity order is CH3O > 4′-CH3C6H 4CH2O (-0.76) >C5H5CH 2O (-0.74) > 4′-ClC6H4CH2O (-0.69) > 4′-NO2C6H4CH2O (-0.60) > C6H5O > H (values in parentheses are new σ+ values). At 25° the overall range of rates is 4 290 in the benzyl series, compared with only 2.42 in the benzyl series. The Arrhenius parameters in the two series demonstrate, however, an underlying similarity with obvious differences superimposed. In both series, the introduction of 4-OR groups leads to a ΔS‡ increase of ca. 40 J mol-1 K -1. In the benzyl series this is accompanied by ΔE‡ decreases of ca. 6-10 kJ mol-1, whereas in the benzoyl series ΔE‡ values increase by ca. 10-15 kJ mol-1. The equation log k = log k0 + n[MeOH] in mixtures with increasing content of dioxan, was used to study the rate dependence on MeOH concentration. Values of n are ca. 5 between 97.4 and 8.3.% MeOH, and ca. 3 between 83.3 and 50.0% MeOH.110010

Photodetachment study of He^- quartet resonances below the He(n=3) thresholds

The photodetachment cross section of He^- has been measured in the photon energy range 2.9 eV to 3.3 eV in order to investigate doubly excited states. Measurements were made channel specific by selectively detecting the residual He atoms left in a particular excited state following detachment. Three Feshbach resonances were found in the He(1s2p ^3P)+e^-(epsilon p) partial cross section: a ^4S resonance below the He(1s3s ^3S) threshold and two ^4P resonances below the He(1s3p ^3P) threshold. The measured energies of these doubly excited states are 2.959260(6) eV, 3.072(7) eV and 3.26487(4) eV. The corresponding widths are found to be 0.20(2) meV, 50(5) meV and 0.61(5) meV. The measured energies agree well with recent theoretical predictions for the 1s3s4s ^4S, 1s3p^2 ^4P and 1s3p4p ^4P states, respectively, but the widths deviate noticeably from calculations for 1s3p^2 ^4P and 1s3p4p ^4P states.Comment: 10 pages, 3 figures, LaTeX2e scrartcl, amsmath. Accepted by Journal of Physics B; minor changes after referee repor

Stream Members Only: Data-Driven Characterization of Stellar Streams with Mixture Density Networks

Stellar streams are sensitive probes of the Milky Way's gravitational potential. The mean track of a stream constrains global properties of the potential, while its fine-grained surface density constrains galactic substructure. A precise characterization of streams from potentially noisy data marks a crucial step in inferring galactic structure, including the dark matter, across orders of magnitude in mass scales. Here we present a new method for constructing a smooth probability density model of stellar streams using all of the available astrometric and photometric data. To characterize a stream's morphology and kinematics, we utilize mixture density networks to represent its on-sky track, width, stellar number density, and kinematic distribution. We model the photometry for each stream as a single-stellar population, with a distance track that is simultaneously estimated from the stream's inferred distance modulus (using photometry) and parallax distribution (using astrometry). We use normalizing flows to characterize the distribution of background stars. We apply the method to the stream GD-1, and the tidal tails of Palomar 5. For both streams we obtain a catalog of stellar membership probabilities that are made publicly available. Importantly, our model is capable of handling data with incomplete phase-space observations, making our method applicable to the growing census of Milky Way stellar streams. When applied to a population of streams, the resulting membership probabilities from our model form the required input to infer the Milky Way's dark matter distribution from the scale of the stellar halo down to subhalos.Comment: 35 pages, 13 figures, 4 tables, fully open-source and reproducible using ShowYourWor

Comparison Of Methanolysis Of A Series Of P-benzyloxybenzoyl Chlorides With That Of Benzoyl, P-phenoxybenzoyl, And P-methoxybenzoyl Chlorides

The kinetics of the methanolysis (solvolysis) of a series of p-benzyloxybenzoyl chlorides have been compared with values for benzoyl, p-methoxybenzoyl. and p-phenoxybenzoyl chloride. Small rate differences between benzoyl chloride and the other compounds stem from counterbalancing large changes in enthalpies and entropies of activation, ascribed to different degrees of SN1 character in the reactions. Differences within the benzyloxy-series are ascribed to effects of substituents on the inductive effect of the benzene ring of the benzyloxy-group. Data have been analysed in terms of the Hammett equation. Values of σ for the p-benzyloxy-group were obtained from both kinetic and acidity measurements : both are considerably less than the literature value, which we regard as suspect. A coefficient of transmission of electronic effects across a p-benzyloxy-group was determined as 0.17.141648165

Stat1 nuclear translocation by nucleolin upon monocyte differentiation

BACKGROUND: Members of the signal transducer and activator of transcription (Stat) family of transcription factors traverse the nuclear membrane through a specialized structure, called the nuclear pore complex (NPC), which represents a selective filter for the import of proteins. Karyophilic molecules can bind directly to a subset of proteins of the NPC, collectively called nucleoporins. Alternatively, the transport is mediated via a carrier molecule belonging to the importin/karyopherin superfamily, which transmits the import into the nucleus through the NPC. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we provide evidence for an alternative Stat1 nuclear import mechanism, which is mediated by the shuttle protein nucleolin. We observed Stat1-nucleolin association, nuclear translocation and specific binding to the regulatory DNA element GAS. Using expression of nucleolin transgenes, we found that the nuclear localization signal (NLS) of nucleolin is responsible for Stat1 nuclear translocation. We show that this mechanism is utilized upon differentiation of myeloid cells and is specific for the differentiation step from monocytes to macrophages. CONCLUSIONS/SIGNIFICANCE: Our data add the nucleolin-Stat1 complex as a novel functional partner for the cell differentiation program, which is uniquely poised to regulate the transcription machinery via Stat1 and nuclear metabolism via nucleolin

Photodetachment study of the 1s3s4s ^4S resonance in He^-

A Feshbach resonance associated with the 1s3s4s ^{4}S state of He^{-} has been observed in the He(1s2s ^{3}S) + e^- (\epsilon s) partial photodetachment cross section. The residual He(1s2s ^{3}S) atoms were resonantly ionized and the resulting He^+ ions were detected in the presence of a small background. A collinear laser-ion beam apparatus was used to attain both high resolution and sensitivity. We measured a resonance energy E_r = 2.959 255(7) eV and a width \Gamma = 0.19(3) meV, in agreement with a recent calculation.Comment: LaTeX article, 4 pages, 3 figures, 21 reference

Monochromatization of femtosecond XUV light pulses with the use of reflection zone plates

We report on a newly built laser based tabletop setup which enables generation of femtosecond light pulses in the XUV range via employing the process of high order harmonic generation HHG in a gas medium. The spatial, spectral, and temporal characteristics of the XUV beam are presented. Monochromatization of XUV light with minimum temporal pulse distortion is the central issue of this work. Off center reflection zone plates are shown to be superior to gratings when selection of a desired harmonic is carried out with the use of a single optical element. A cross correlation technique was applied to characterize the performance of zone plates in the time domain. By using laser pulses of 25 fs length to pump the HHG process, a pulse duration of 45 fs for monochromatized harmonics was achieved in the present setu

Electron affinity of Li: A state-selective measurement

We have investigated the threshold of photodetachment of Li^- leading to the formation of the residual Li atom in the $2p ^2P$ state. The excited residual atom was selectively photoionized via an intermediate Rydberg state and the resulting Li^+ ion was detected. A collinear laser-ion beam geometry enabled both high resolution and sensitivity to be attained. We have demonstrated the potential of this state selective photodetachment spectroscopic method by improving the accuracy of Li electron affinity measurements an order of magnitude. From a fit to the Wigner law in the threshold region, we obtained a Li electron affinity of 0.618 049(20) eV.Comment: 5 pages,6 figures,22 reference