3,958 research outputs found
Top Quark Pairs at High Invariant Mass - A Model-Independent Discriminator of New Physics at the LHC
We study top quark pair production to probe new physics at the LHC. We
propose reconstruction methods for semileptonic events and use them
to reconstruct the invariant mass. The angular distribution of top
quarks in their c.m. frame can determine the spin and production subprocess for
each new physics resonance. Forward-backward asymmetry and CP-odd variables can
be constructed to further delineate the nature of new physics. We parametrize
the new resonances with a few generic parameters and show high invariant mass
top pair production may provide an early indicator for new physics beyond the
Standard Model.Comment: 5 pages, 4 figures; version to appear in PR
Proceedings of the 1974 Lyndon B. Johnson Space Center Wheat-Yield Conference
The proceedings of the 1974 Lyndon B. Johnson Space Center Wheat-Yield Conference are presented. The state of art of wheat-yield forecasting and the feasibility of incorporating remote sensing into this forecasting were discussed with emphasis on formulating common approach to wheat-yield forecasting, primarily using conventional meteorological measurements, which can later include the various applications of remote sensing. Papers are presented which deal with developments in the field of crop modelling
Inclusive and exclusive diffractive production of dilepton pairs in proton-proton collisions at high energies
We calculate for the first time cross sections for single and central
diffractive as well as exclusive diffractive production of dilepton pairs in
proton-proton collisions. Several differential distributions are shown. The
inclusive diffractive processes are calculated using diffractive parton
distributions extracted from the analysis of diffractive structure function and
dijet production at HERA. We find that the inclusive single-diffractive
Drell-Yan process is by about 2 orders of magnitude smaller than ordinary
Drell-Yan process. The central-diffractive processes are smaller by one order
of magnitude compared to single-diffractive ones. We consider also exclusive
production of dilepton pairs. The exclusive photon-pomeron (pomeron-photon)
process constitutes a background to the QED photon-photon process proposed to
be used for controlling luminosity at LHC. Both processes are compared then in
several differential distributions. We find a region of the phase space where
the photon-pomeron or pomeron-photon contributions can be larger than the
photon-photon one.Comment: 20 page, 19 figure
A Separate Higgs?
We investigate the possibility of a multi-Higgs doublet model where the
lightest neutral Higgs boson () decouples from the fermion sector. We are
partially motivated by the four events with
\,GeV recently observed by the L3 collaboration,
which could be a signal for .
Collider signatures for the additional physical Higgs bosons present in such
models are discussed.Comment: 8 pages (plus 2 figures, available by request), latex,
ANL-HEP-PR-92-10
How Much Rain Makes Corn?
Records show that an average of about 1 inch of rainfall a week during the growing season will insure an average crop of corn. But of course that doesn\u27t tell the whole story
Searching for a heavy Higgs boson via the H --> l nu jj decay mode at the CERN LHC
The discovery of a heavy Higgs boson with mass up to m_H = 1 TeV at the CERN
LHC is possible in the H--> W^+W^- --> l nu jj decay mode. The weak boson
scattering signal and backgrounds from t\bar tjj and from W+jets production are
analyzed with parton level Monte Carlo programs which are built on full tree
level amplitudes for all subprocesses. The use of double jet tagging and the
reconstruction of the W invariant mass reduce the combined backgrounds to the
same level as the Higgs signal. A central mini-jet veto, which distinguishes
the different gluon radiation patterns of the hard processes, further improves
the signal to background ratio to about 2.5:1, with a signal cross section of 1
fb. The jet energy asymmetry of the W --> jj decay will give a clear signature
of the longitudinal polarization of the W's in the final event sample.Comment: 23 pages (with 7 embedded figures), Revtex, uses epsf.sty.
Z-compressed postscript version also available at
http://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-1017.ps.Z or at
ftp://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-1017.ps.
Medium effects for terrestrial and atmospheric neutrino oscillations
Matter effects in neutrino propagation translate into effective parameters
for the oscillation and fake CP- and CPT-odd quantities, even in a scenario,
such as , where no genuine CP violation is present. This fact
seems to impose severe restrictions on the determination of intrinsic
parameters of the system from long-baseline experiments. We show, however, that
the resonance in the effective mixing can be observed for
a certain range of baselines. This provides a way to measure the vacuum mixing
angle and the sign of from atmospheric
neutrinos, using a detector with energy resolution and charge discrimination.Comment: 13 pages with 5 figure
Robust, automated sleep scoring by a compact neural network with distributional shift correction.
Studying the biology of sleep requires the accurate assessment of the state of experimental subjects, and manual analysis of relevant data is a major bottleneck. Recently, deep learning applied to electroencephalogram and electromyogram data has shown great promise as a sleep scoring method, approaching the limits of inter-rater reliability. As with any machine learning algorithm, the inputs to a sleep scoring classifier are typically standardized in order to remove distributional shift caused by variability in the signal collection process. However, in scientific data, experimental manipulations introduce variability that should not be removed. For example, in sleep scoring, the fraction of time spent in each arousal state can vary between control and experimental subjects. We introduce a standardization method, mixture z-scoring, that preserves this crucial form of distributional shift. Using both a simulated experiment and mouse in vivo data, we demonstrate that a common standardization method used by state-of-the-art sleep scoring algorithms introduces systematic bias, but that mixture z-scoring does not. We present a free, open-source user interface that uses a compact neural network and mixture z-scoring to allow for rapid sleep scoring with accuracy that compares well to contemporary methods. This work provides a set of computational tools for the robust automation of sleep scoring
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