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M. Voutilainen

Publications and source records attributed to M. Voutilainen.

4 recordsLinked to original sources

Top mass shift resulting from the recalibration of flavor-dependent jet energy corrections in the DØ lepton+jets top mass measurement

We review the possible effects of the miscalibration of the flavor-dependent Jet Energy Corrections ($F_{\mathrm{Corr}}$) on the DØ lepton+jets top mass measurement. The work is based on a previous study, where the DØ $F_{\mathrm{Corr}}$ calibration procedure was repeated based on the release of the internal DØ notes after a 5-year moratorium. The cited study was motivated by the extraordinary precision claimed by DØ in their top mass measurement. Using a Pythia6-based $F_{\mathrm{Corr}}$ recalibration, the $m_t$ result was shifted from 174.95 to 173.16 GeV. Moreover, utilizing a Herwig7-based $F_{\mathrm{Corr}}$ calibration (not accounted for in DØ studies), a shift down to 171.84 GeV was observed. We find this both convincing and specific evidence for re-reviewing a part of the $F_{\mathrm{Corr}}$ calibration process. However, DØ has been unwilling to open such studies or to provide other convincing counter-evidence.

hep-ex

D0 QCD studies

A number of recent measurements from D0 that can be used to constrain parton distributions and tune QCD Monte Carlo models are presented. The selection includes W charge asymmetry, Z+jet event properties, dijet azimuthal decorrelations and the inclusive jet cross section.

hep-ex

Inclusive jet cross section measurement at D0

We present a new preliminary measurement of the inclusive jet cross section in pp-bar collisions based on a integrated luminosity of about 0.8 fb-1. The data were acquired using the D0 detector between 2002 and 2005. Jets are reconstructed using an iterative cone algorithm with radius R_cone = 0.7. The inclusive jet cross section is presented as a function of transverse jet momentum and rapidity. Predictions from perturbative QCD in next-to-leading order, plus threshold corrections in 2-loop accuracy describe the shape in the transverse jet momentum.

hep-ex

Novel Data Acquisition System for Silicon Tracking Detectors

We have developed a novel data acquisition system for measuring tracking parameters of a silicon detector in a particle beam. The system is based on a commercial Analog-to-Digital VME module and a PC Linux based Data Acquisition System. This DAQ is realized with C++ code using object-oriented techniques. Track parameters for the beam particles were reconstructed using off-line analysis code and automatic detector position alignment algorithm. The new DAQ was used to test novel Czochralski type silicon detectors. The important silicon detector parameters, including signal size distributions and signal to noise distributions, were successfully extracted from the detector under study. The efficiency of the detector was measured to be 95 %, the resolution about 10 micrometers, and the signal to noise ratio about 10.

physics.ins-det