Interpretation of Angular Distributions of ZZ-boson Production at Colliders

High precision data of dilepton angular distributions in $\gamma^*/Z$ production were reported recently by the CMS Collaboration covering a broad range of the dilepton transverse momentum, $q_T$, up to $\sim 300$ GeV. Pronounced $q_T$ dependencies of the $\lambda$ and $\nu$ parameters, characterizing the $\cos^2\theta$ and $\cos 2\phi$ angular distributions, were found. Violation of the Lam-Tung relation was also clearly observed. We show that the $q_T$ dependence of $\lambda$ allows a determination of the relative contributions of the $q \bar q$ annihilation versus the $qG$ Compton process. The violation of the Lam-Tung relation is attributed to the presence of a non-zero component of the $q - \bar q$ axis in the direction normal to the "hadron plane" formed by the colliding hadrons. The magnitude of the violation of the Lam-Tung relation is shown to reflect the amount of this `non-coplanarity". The observed $q_T$ dependencies of $\lambda$ and $\nu$ from the CMS and the earlier CDF data can be well described using this approach.Comment: 5 pages, 3 figure

Leading-Log Effects in the Resonance Electroweak Form Factors

We study log corrections to inelastic scattering at high Bjorken x for Q^2 from 1 to 21 GeV^2. At issue is the presence of log corrections, which can be absent if high x scattering has damped gluon radiation. We find logarithmic correction of the scaling curve extrapolated to low Q^2 improves the duality between it and the resonance plus background data in the Delta region, indicating log corrections exist in the data. However, at W > 2 GeV and high x, the data shows a (1-x)^3 form. Log corrections in one situation but not in another can be reconciled by a W- or Q^2- dependent higher twist correction.Comment: 13 pages, report nos. RPI-94-N90 and WM-94-106, revtex, two figures (available by fax or post

W-band waveguide-packaged InP HEMT reflection grid amplifier

This letter presents a 79-GHz broadband reflection-type grid amplifier using spatial power combining to combine the power of 64 unit cells. Each unit cell uses a two-stage cascade configuration with InP HEMTs arranged as a differential pair. A broadband orthogonal mode transducer (OMT) separates two orthogonally polarized input and output signals over a 75 to 85GHz range. In conjunction with the OMT, a mode converter with quadruple-ridged apertures was designed to enhance the field uniformity over the active grid. Measurements show 5-dB small signal gain at 79GHz and an 800-MHz 3-dB bandwidth. The amplifier generates an output power of 264mW with little evidence of saturation

W/Z properties and V+jets at the Tevatron

We present a summary of recent measurements of $W$ and $Z$ properties and $W/Z$ production in association with jets in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV with the CDF and D\O\ detectors. Latest measurements of $Z/\gamma^*$ transverse momentum and are presented along with new measurements of the angular distributions of final state electrons from Drell Yan events as a way to probe $Z$ boson production mechanisms. The mass dependence of the forward-backward asymmetry in $p\bar{p} \rightarrow Z/\gamma^{*} \rightarrow e^+e^-$ interactions is measured, the effective weak mixing angle extracted, and the most precise direct measurement of the vector and axial-vector couplings of $u$ and $d$ quarks to the $Z$ boson presented. New measurements of jets produced in association with $Z$ and $W$ bosons for inclusive, beauty and charm jets are also discussed.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 13 figure

Rotation-invariant relations in vector meson decays into fermion pairs

The rotational properties of angular momentum eigenstates imply the existence of a frame-independent relation among the parameters of the decay distribution of vector mesons into fermions. This relation is a generalization of the Lam-Tung identity, a result specific to Drell-Yan production in perturbative QCD, here shown to be equivalent to the dynamical condition that the dilepton always originates from a transversely polarized photon

Studies of Single Electroweak Bosons at the Tevatron

Tests of the Standard Model with Electroweak Physics have been performed over many decades. In these proceedings, we present several analyses from the Tevatron involving single $W$ or $Z$ bosons.Comment: XIX International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2011

Mechanical properties of tungsten alloys with Y2O3 and titanium additions

In this research the mechanical behaviour of pure tungsten (W) and its alloys (2 wt.% Ti–0.47 wt.% Y2O3 and 4 wt.% Ti–0.5 wt.% Y2O3) is compared. These tungsten alloys, have been obtained by powder metallurgy. The yield strength, fracture toughness and elastic modulus have been studied in the temperature interval of 25 °C to 1000 °C. The results have shown that the addition of Ti substantially improves the bending strength and toughness of W, but it also dramatically increases the DBTT. On the other hand, the addition of 0.5% Y2O3, is enough to improve noticeably the oxidation behaviour at the higher temperatures. The grain size, fractography and microstructure are studied in these materials. Titanium is a good grain growth inhibitor and effective precursor of liquid phase in HIP. The simultaneous presence of Y2O3 and Ti permits to obtain materials with low pores presenc

The Effect of Metallic Fluorides on Oleic Acid at Elevated Temperatures

The problem of finding the effect of metallic fluorine compounds on oleic acid at elevated temperatures was presented in connection with the thesis of J.J. Wocasek of Marquette University. Doctor Wocasek had used fluorine compounds as catalysts in a.n attempt to find a sub­stitute for tung oil. He used the fluorides as catalysts in the esterification of glycerol with unsaturated acids

Go west for fame and fortune? The role of internationalization in the growth of Chinese telecom firms

This paper focuses on the role played by internationalization in the growth of Chinese telecom firms by comparing the three cases from China’s telecom sector – Huawei Technologies (Huawei), Zhongxing Telecom Equipment Corporation (ZTE), Datang Telecom Technology (Datang). Faced with a global market that was strongly oligopolistic and dominated by Western firms, we show that internationalization strategies triggered by resource seeking played different roles in the growth strategies of these three firms. The contrasting fortunes of these firms also underscores the fact that the success of internationalization strategies of firms from emerging markets cannot be understood without reference to the global competitive environment faced by firms