Top Quark Decays into Heavy Quark Mesons

For top quark decays into heavy quark mesons $\Upsilon$ and $\bar{B}_c^*$ , a complete calculation to the leading order both in QCD coupling constant $\alpha_s$ and in $v$, the typical velocity of the heavy quarks inside the mesons, is performed. Relatons between the top quark mass and the decay branching ratios are studied. Comparion with the results which are obtained by using the quark frangmentation functions is also discussed. The branching ratios are consistent (within a factor of $2\sim 3$) with that obtained using fragmentation functions at $m_t\sim 150$ GeV.Comment: 15 pages in LaTex form, 4 figures include

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Who Really Pays for Health Insurance? The Incidence of Employer-Provided Health Insurance with Sticky Nominal Wages

This paper addresses two seeming paradoxes in the realm of employer-provided health insurance: First, businesses consistently claim that they bear the burden of the insurance they provide for employees, despite theory and empirical evidence indicating that workers bear the full incidence. Second, benefit generosity and the percentage of premiums paid by employers have decreased in recent decades, despite the preferential tax treatment of employer-paid benefits relative to wages—trends unexplained by the standard incidence model. This paper offers a revised incidence model based on nominal wage rigidity, in an attempt to explain these paradoxes. The model predicts that when the nominal wage constraint binds, some of the burden of increasing insurance premiums will fall on firms, particularly small companies with low-wage employees. In response, firms will reduce employment, decrease benefit generosity, and require larger employee premium contributions. Using Current Population Survey data from 2000–2001, I find evidence for this kind of wage rigidity and its associated impact on the employment and premium contributions of low-wage insured workers during a period of rapid premium growth. Copyright Springer Science+Business Media, Inc. 2005employer-provided health insurance, wage stickiness, premium contributions,

Effect of the Addition of Potassium or Lithium on the Columbite Precursor Microstructure

Pechini method has been used to synthesize MN powders with stoichiometric control. By this method, K and Li-doped MN in the range from 0.1 to 5.0 mol% of dopants have been obtained at relatively lower temperatures than it is possible with the conventional mixture of oxides. The results from BET analysis indicated that the doped powders have lower surface area and the attrition milling promotes an increase in surface area values for all powders. Rietveld method was used to calculate the mean crystallite size and the microstrain in the crystal. With additions of up to 5.0 mol% of K or 2.0 mol% of Li, it is possible to obtain MN as a solid solution. Both dopants change the cell parameters of the columbite phase crystal, reduce the microstrain, and increase the main crystallite size. The analysis of results from SEM indicates that powders prepared with addition of dopants are more agglomerate than pure PMN powder