Dyson-Schwinger Equations - aspects of the pion

The contemporary use of Dyson-Schwinger equations in hadronic physics is exemplified via applications to the calculation of pseudoscalar meson masses, and inclusive deep inelastic scattering with a determination of the pion's valence-quark distribution function.Comment: 4 pages. Contribution to the Proceedings of ``DPF 2000,'' the Meeting of the Division of Particles and Fields of the American Physical Society, August 9-12, 2000, Department of Physics, the Ohio State University, Columbus, Ohi

Cyclotomic integers, fusion categories, and subfactors

Dimensions of objects in fusion categories are cyclotomic integers, hence number theoretic results have implications in the study of fusion categories and finite depth subfactors. We give two such applications. The first application is determining a complete list of numbers in the interval (2, 76/33) which can occur as the Frobenius-Perron dimension of an object in a fusion category. The smallest number on this list is realized in a new fusion category which is constructed in the appendix written by V. Ostrik, while the others are all realized by known examples. The second application proves that in any family of graphs obtained by adding a 2-valent tree to a fixed graph, either only finitely many graphs are principal graphs of subfactors or the family consists of the A_n or D_n Dynkin diagrams. This result is effective, and we apply it to several families arising in the classification of subfactors of index less then 5.Comment: 47 pages, with an appendix by Victor Ostri

Aerosol-assisted fabrication of tin-doped indium oxide ceramic thin films from nanoparticle suspensions

Sn-doped In2O3 (ITO) thin films were fabricated on float glass substrates from a nanoparticle suspension using a new and inexpensive aerosol-assisted chemical transport (AACT) process. The influence of the solvent type, loading level and film deposition time on the structural, electrical and optical properties of the deposited thin films was investigated. In addition, the effect of post-deposition heat-treatment of ITO films on the film resistivity and transparency was investigated using microwave radiation and compared with more conventional radiant heat-treated films. The SEM images of the films prepared using a 30 min deposition time with 0.20% (wt/vol%) methanolic ITO suspension provided better surface coverage compared to the other deposition times investigated. The optimised ITO films were heat-treated after deposition by either conventional radiant or microwave assisted heating methods in order to improve the inter-particle connections and film adherence. The films heat-treated after deposition by microwave annealing exhibited an average transmittance of >85% in the visible region with a resistivity of 12 Ω cm and a carrier concentration of -3.7 x 1016 cm 3 , which was superior to films that were heat-treated using more conventional thermal processing (despite the shorter processing time for the microwave process). The resistivity of ITO films was further decreased to 6.0 x 10-2 Ω cm with increased carrier concentration of -8.0 x 1018 cm 3 when ethyl cellulose was added to the ITO suspension prior to the AACT deposition. The enhanced conductivity of this film is due to the improved particle-particle and particle-substrate connections as observed by SEM imaging

Dispersion and microwave processing of nano-sized ITO powder for the fabrication of transparent conductive oxides

Aqueous dispersions of tin-doped indium oxide (ITO) nanopowder were prepared and the effect of the addition of PEG 400, Tween 80 and β-alanine as dispersants was investigated using zeta potential and particle size distribution measurements. Both PEG 400 and β-alanine were found to produce stable dispersions that were used to deposit ITO thin films on glass substrates by dip and spin coating methods. The ITO thin films were heat-treated using both conventional and microwave heat treatment in order to improve the inter-particle connections and hence the resistivity and transparency of the films. All the films exhibited an average transmittance of >80% over the visible spectrum after being subjected to the heat treatment process. ITO films prepared with no dispersant showed very high resistivity values for both heating methods, however addition of 2 wt% PEG 400 to the dispersion yielded a reduction in the resistivity values to 1.4×10−1 Ω cm and 3.8×10−2 Ω cm for conventionally and microwave treated films, respectively. The surface morphological studies confirmed that addition of dispersants improved the film uniformity and inter-particle connections of the ITO films considerably

Valence-quark distributions in the pion

We calculate the pion's valence-quark momentum-fraction probability distribution using a Dyson-Schwinger equation model. Valence-quarks with an active mass of 0.30 GeV carry 71% of the pion's momentum at a resolving scale q_0=0.54 GeV = 1/(0.37 fm). The shape of the calculated distribution is characteristic of a strongly bound system and, evolved from q_0 to q=2 GeV, it yields first, second and third moments in agreement with lattice and phenomenological estimates, and valence-quarks carrying 49% of the pion's momentum. However, pointwise there is a discrepancy between our calculated distribution and that hitherto inferred from parametrisations of extant pion-nucleon Drell-Yan data.Comment: 8 pages, 3 figures, REVTEX, aps.sty, epsfig.sty, minor corrections, version to appear in PR

Criterion A of the AMPD in HiTOP

The categorical model of personality disorder classification in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (5th ed. [DSM-5]; American Psychiatric Association, 2013) is highly and fundamentally problematic. Proposed for DSM-5 and provided within Section III (for Emerging Measures and Models) was the Alternative Model of Personality Disorder (AMPD) classification, consisting of Criterion A (self-interpersonal deficits) and Criterion B (maladaptive personality traits). A proposed alternative to the DSM-5 more generally is an empirically based dimensional organization of psychopathology identified as the Hierarchical Taxonomy of Psychopathology (HiTOP; Kotov etal., 2017). HiTOP currently includes, at the highest level, a general factor of psychopathology. Further down are the five domains of detachment, antagonistic externalizing, disinhibited externalizing, thought disorder, and internalizing (along with a provisional sixth somatoform dimension) that align with Criterion B. The purpose of this article is to discuss the potential inclusion and placement of the self-interpersonal deficits of the DSM-5 Section III Criterion A within HiTOP

Azimuthal asymmetries in lepton-pair production at a fixed-target experiment using the LHC beams (AFTER)

A multi-purpose fixed-target experiment using the proton and lead-ion beams of the LHC was recently proposed by Brodsky, Fleuret, Hadjidakis and Lansberg, and here we concentrate our study on some issues related to the spin physics part of this project (referred to as AFTER). We study the nucleon spin structure through $pp$ and $pd$ processes with a fixed-target experiment using the LHC proton beams, for the kinematical region with 7 TeV proton beams at the energy in center-of-mass frame of two nucleons $\sqrt{s}=115$ GeV. We calculate and estimate the $\cos2\phi$ azimuthal asymmetries of unpolarized $pp$ and $pd$ dilepton production processes in the Drell--Yan continuum region and at the $Z$-pole. We also calculate the $\sin(2\phi-\phi_S)$, $\sin(2\phi+\phi_S)$ and $\sin2\phi$ azimuthal asymmetries of $pp$ and $pd$ dilepton production processes with the target proton and deuteron longitudinally or transversally polarized in the Drell--Yan continuum region and around $Z$ resonances region. We conclude that it is feasible to measure these azimuthal asymmetries, consequently the three-dimensional or transverse momentum dependent parton distribution functions (3dPDFs or TMDs), at this new AFTER facility.Comment: 15 pages, 40 figures. Version accepted for publication in EPJ

Search for the standard model Higgs boson decaying to a bbˉb\bar{b} pair in events with no charged leptons and large missing transverse energy using the full CDF data set

We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at $\sqrt{s} = 1.96$ TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb$^{-1}$. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a $b$ quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and $150 \mathrm{GeV}/c^2$. For a Higgs boson mass of $125 \mathrm{GeV}/c^2$, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.Comment: Accepted by Phys. Rev. Let

Search for the standard model Higgs boson decaying to a bb pair in events with one charged lepton and large missing transverse energy using the full CDF data set

We present a search for the standard model Higgs boson produced in association with a W boson in sqrt(s) = 1.96 TeV p-pbar collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45 fb-1. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H->bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c2 we observe (expect) a limit of 4.9 (2.8) times the standard model value.Comment: Submitted to Phys. Rev. Lett (v2 contains clarifications suggested by PRL

Search for the standard model Higgs boson decaying to a bb pair in events with two oppositely-charged leptons using the full CDF data set

We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45/fb. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H -> bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^2 we observe (expect) a limit of 7.1 (3.9) times the standard model value.Comment: To be submitted to Phys. Rev. Let