182,009 research outputs found
Polynomials, Riemann surfaces, and reconstructing missing-energy events
We consider the problem of reconstructing energies, momenta, and masses in
collider events with missing energy, along with the complications introduced by
combinatorial ambiguities and measurement errors. Typically, one reconstructs
more than one value and we show how the wrong values may be correlated with the
right ones. The problem has a natural formulation in terms of the theory of
Riemann surfaces. We discuss examples including top quark decays in the
Standard Model (relevant for top quark mass measurements and tests of spin
correlation), cascade decays in models of new physics containing dark matter
candidates, decays of third-generation leptoquarks in composite models of
electroweak symmetry breaking, and Higgs boson decay into two tau leptons.Comment: 28 pages, 6 figures; version accepted for publication, with
discussion of Higgs to tau tau deca
Comparing the EPA Indoor Air Quality Personal Computer Model and Field Data
The authors recommend caution in using an EPA model for reconstructing past exposure events as well as for predicting future exposures
Reconstructing semi-invisible events in resonant tau pair production from Higgs
We study the possibility of utilising the constrained mass variable,
, in reconstructing the semi-invisible events originated from a
resonant production at the LHC. While this proposal is effective for any
similar antler type production mechanism, here we demonstrate with potentially
interesting scenario, when the Higgs boson decays into a pair of third
generation leptons. Buoyed with a relatively large Yukawa coupling, the
LHC has already started exploring this pair production to investigate the
properties of Higgs in the leptonic sector. Dominant signatures through
hadronic decay of tau, associated with invisible neutrinos compound the
difficulty in the reconstruction of such events. Exploiting the already
existing Higgs mass bound, this new method provides a unique event
reconstruction, together with a significant enhancement in terms of efficiency
over the existing methods.Comment: 14 pages, 3 figures; addition of text and footnote for further
clarification, Figure 3 modified to append the further improvement of
efficiency in selected events; version accepted for publication in Phys.
Lett.
The Physics of ALICE HLT Trigger Modes
We discuss different physics cases, mainly of the ALICE TPC, such as pile-up,
jets in pp and PbPb, Bottonium and Charmonium spectroscopy, and there
corresponding demands on the ALICE High Level Trigger (HLT) System. We show
that compression and filter strategies can reduce the data volume by factors of
5 to 10. By reconstructing (sub)events with the HLT, background events can be
rejected with a factor of up to 100 while keeping the signal (low cross-section
probes). Altogether the HLT improves the discussed physics capabilities of
ALICE by a factor of 5-100 in terms of statistics.Comment: 25 pages, 4 figure
ArgoNeuT and the Neutrino-Argon Charged Current Quasi-Elastic Cross Section
ArgoNeuT, a Liquid Argon Time Projection Chamber in the NuMI beamline at
Fermilab, has recently collected thousands of neutrino and anti-neutrino events
between 0.1 and 10 GeV. The experiment will, among other things, measure the
cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic
interaction and analyze the vertex activity associated with such events. These
topics are discussed along with ArgoNeuT's automated reconstruction software,
currently capable of fully reconstructing the muon and finding the event vertex
in neutrino interactions.Comment: 6 pages, 4 figures, presented at the International Nuclear Physics
Conference, Vancouver, Canada, July 4-9, 2010, to be published in Journal of
Physics: Conference Series (JPCS
- …