What children like in elementary principals

Thesis (Ed.M.)--Boston Universit

NNLO QCD predictions for W+c-jet production at the LHC

Abstract: We study the production of a W boson in association with a c-jet at the LHC. We calculate, for the first time, the complete set of NNLO QCD corrections to the dominant CKM-diagonal contribution to this process. Both signatures, pp → μ+νμjc and pp →μ−ν¯μjc are considered. We present predictions for fiducial cross sections and differential distributions for each one of the two signatures as well as for their ratio. The theoretical predictions are compared with ATLAS measurements at 7 TeV. The results of this work are essential for the precision description of associated heavy flavor production at hadron colliders and for the determination of the strange-quark content of the proton from LHC data in NNLO QCD

NNLO QCD predictions for W+c-jet production at the LHC

Abstract: We study the production of a W boson in association with a c-jet at the LHC. We calculate, for the first time, the complete set of NNLO QCD corrections to the dominant CKM-diagonal contribution to this process. Both signatures, pp → μ+νμjc and pp →μ−ν¯μjc are considered. We present predictions for fiducial cross sections and differential distributions for each one of the two signatures as well as for their ratio. The theoretical predictions are compared with ATLAS measurements at 7 TeV. The results of this work are essential for the precision description of associated heavy flavor production at hadron colliders and for the determination of the strange-quark content of the proton from LHC data in NNLO QCD

Three-dimensional force measurements in optical tweezers formed with high-NA micromirrors

The three-dimensional trap stiffness of optical tweezers formed with high-NA micromirrors is investigated by back-focal-plane interferometry and power spectrum analysis. Normalized stiffness values of kappa(xy)/P-trap =1.2(mu N/m)/mW and kappa(z)/P-trap = 0.52(mu N/m)/mW in the transverse and axial directions, respectively, have been measured for polystyrene spheres with a radius of 1.03 mu m. Compared with high-NA microscope objectives, micromirrors achieve much better trapping performances, particularly in the axial direction. (C) 2009 Optical Society of Americ