The amplitude of the signal collected from the PbWO4 crystals of the CMS electromagnetic calorimeter is reconstructed by a digital filtering technique. The amplitude reconstruction has been studied ...with test beam data recorded from a fully equipped barrel supermodule. Issues specific to data taken in the test beam are investigated, and the implementation of the method for CMS data taking is discussed.
The energy resolution of the barrel part of the CMS Electromagnetic Calorimeter has been studied using electrons of 20 to 250 GeV in a test beam. The incident electron's energy was reconstructed by ...summing the energy measured in arrays of 3x3 or 5x5 channels. There was no significant amount of correlated noise observed within these arrays. For electrons incident at the centre of the studied 3x3 arrays of crystals, the mean stochastic term was measured to be 2.8% and the mean constant term to be 0.3%. The amount of the incident electron's energy which is contained within the array depends on its position of incidence. The variation of the containment with position is corrected for using the distribution of the measured energy within the array. For uniform illumination of a crystal with 120 GeV electrons a resolution of 0.5% was achieved. The energy resolution meets the design goal for the detector.
The top quark and its properties within and beyond the Standard Model will be
extensively studied at the incoming Large Hadron Collider. Nonetheless the top
quark will play the role of the main ...background for most of the Higgs and new
physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs
discovery channel will be studied. The current status of the Monte Carlo tools
for t-tbar and single top simulation will be presented. Finally the problem on
how to evaluate the top background from the data will be addressed and the
related systematics will be discussed.
The top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main ...background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current status of the Monte Carlo tools for t-tbar and single top simulation will be presented. Finally the problem on how to evaluate the top background from the data will be addressed and the related systematics will be discussed.
This Report summarises the activities of the "SM and Higgs" working group for
the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005.
On the one hand, we performed a variety of ...experimental and theoretical studies
on standard candles (such as W, Z, and ttbar production), treating them either
as proper signals of known physics, or as backgrounds to unknown physics; we
also addressed issues relevant to those non-perturbative or semi-perturbative
ingredients, such as Parton Density Functions and Underlying Events, whose
understanding will be crucial for a proper simulation of the actual events
taking place in the detectors. On the other hand, several channels for the
production of the Higgs, or involving the Higgs, have been considered in some
detail. The report is structured into four main parts. The first one deals with
Standard Model physics, except the Higgs. A variety of arguments are treated
here, from full simulation of processes constituting a background to Higgs
production, to studies of uncertainties due to PDFs and to extrapolations of
models for underlying events, from small-$x$ issues to electroweak corrections
which may play a role in vector boson physics. The second part of the report
treats Higgs physics from the point of view of the signal. In the third part,
reviews are presented on the current status of multi-leg, next-to-leading order
and of next-to-next-to-leading order QCD computations. Finally, the fourth part
deals with the use of Monte Carlos for simulation of LHC physics.
This Report summarises the activities of the "SM and Higgs" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. On the one hand, we performed a variety of ...experimental and theoretical studies on standard candles (such as W, Z, and ttbar production), treating them either as proper signals of known physics, or as backgrounds to unknown physics; we also addressed issues relevant to those non-perturbative or semi-perturbative ingredients, such as Parton Density Functions and Underlying Events, whose understanding will be crucial for a proper simulation of the actual events taking place in the detectors. On the other hand, several channels for the production of the Higgs, or involving the Higgs, have been considered in some detail. The report is structured into four main parts. The first one deals with Standard Model physics, except the Higgs. A variety of arguments are treated here, from full simulation of processes constituting a background to Higgs production, to studies of uncertainties due to PDFs and to extrapolations of models for underlying events, from small-\(x\) issues to electroweak corrections which may play a role in vector boson physics. The second part of the report treats Higgs physics from the point of view of the signal. In the third part, reviews are presented on the current status of multi-leg, next-to-leading order and of next-to-next-to-leading order QCD computations. Finally, the fourth part deals with the use of Monte Carlos for simulation of LHC physics.
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