128,341 research outputs found
A model comparison of resonance lifetime modifications, a soft equation of state and non-Gaussian effects on correlations at FAIR/AGS energies
HBT correlations of pairs at FAIR/AGS energies are investigated
by using the UrQMD transport model and the CRAB analyzing program. Three
different possible sources (treatment of resonance lifetimes, a soft equation
of state and non-Gaussian effects) to understand the HBT puzzle are
investigated. Firstly, we find that different treatments of the resonance decay
time can not resolve the HBT time-related puzzle, however it can modify the HBT
radii at low transverse momenta to some extent to explain the data slightly.
Secondly, with a soft equation of state with momentum dependence, the measured
transverse momentum dependent HBT radii and ratio can be described
fairly well. Thirdly, non-Gaussian effects are visible in the calculated
correlation function. Using the Edgeworth expansion, one finds that the
non-Gaussian effect is strongest in the longitudinal direction and weakest in
the sideward direction.Comment: 18 pages, 6 figures. To be published in J.Phys.
Exporting, FDI, and Labour Demand Adjustment: Evidence from the UK Manufacturing
This paper documents evidence of differential speed of labour demand adjustment among exporters, foreign multinationals (henceforth MNEs) and domestic non-exporting firms from the UK manufacturing industry. Our findings show that MNEs exhibit the fastest speed of employment adjustment to its optimal level, followed by exporters and then domestic non-exporters. Interestingly, the long-run adjustment of labour demand with respect to factor price and demand shocks is less pronounced amongst MNEs and exporters, consistent with the view that firms engaged in international commerce activities generate more skilled jobs that are more costly to dispose of. Moreover, exporting intensity also seems to matter; MNEs with limited export-market commitment are found to have more rigid labour adjustment in response to output and wages shocks in the long run. These findings may allay fears on the footloose nature of MNEs in the sense that jobs in MNEs (followed by exporters) are expected to be more secure on average in response to any shocks affecting long-run labour demand.foreign direct investment (FDI); exports; employment adjustment
The Behaviour of Finely Ground Bottom Ash in Portland Cement
The aim of this project was to assess the effects of finely ground MSWI bottom ash in Portland cement. Mortar mixes were prepared with 10% and 40% replacement of cement by ground IBA and then tested with regards to their material composition and engineering behaviour. IBA was found not to be inert, but showed some degree of reactivity. Replacement of cement with IBA was found to have no detrimental effects at low concentrations. This was not the case for 40% replacement, where cement replacement greatly affected strength, creep and drying shrinkage
Exact Solutions to Sourceless Charged Massive Scalar Field Equation on Kerr-Newman Background
The separated radial part of a sourceless massive complex scalar field
equation on the Kerr-Newman black hole background is shown to be a generalized
spin-weighted spheroidal wave equation of imaginary number order. While the
separated angular part is an ordinary spheroidal wave equation. General exact
solutions in integral forms and in power series expansion as well as several
special solutions with physical interest are given for the radial equation in
the non-extreme case. In the extreme case, power series solution to the radial
equation is briefly studied. Recurrence relations between coefficients in power
series expansion of general solutions and connection between the radial
equation are discussed in both cases.Comment: 22 Pages, in LaTex, no figure, to appear in J. Math. Phy
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