Thomas Speer | Searcharxiv

arXiv2011

Single Top production at CMS

A first measurement of the cross section of single top quark production in the t channel in pp collision at sqrt(s)=7 TeV is presented. The measurement is performed on a data sample corresponding to an integrated luminosity of 35.9 pb^-1 recorded at the LHC with the CMS detector. Leptonic decay channels with an electron or a muon in the final state are considered. After a selection optimized for the t-channel mode, two different and complementary analyses have been performed. Both analyses confirm the Tevatron's observation of single top, and their combination measures a cross section of sigma = 83.6 +/- 29.8(stat.+syst.) +/- 3.3 (lumi.) pb, which is consistent with the Standard Model prediction.

hep-ex↗

arXiv2005

Simulation of Heavily Irradiated Silicon Pixel Sensors and Comparison with Test Beam Measurements

Charge collection measurements performed on heavily irradiated p-spray DOFZ pixel sensors with a grazing angle hadron beam provide a sensitive determination of the electric field within the detectors. The data are compared with a complete charge transport simulation of the sensor which includes signal trapping and charge induction effects. A linearly varying electric field based upon the standard picture of a constant type-inverted effective doping density is inconsistent with the data. A two-trap double junction model implemented in the ISE TCAD software can be tuned to produce a doubly-peaked electric field which describes the data reasonably well. The modeled field differs somewhat from previous determinations based upon the transient current technique. The model can also account for the level of charge trapping observed in the data.

physics.ins-det↗