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 $t\bar{t}$ semileptonic events and use them to reconstruct the $t\bar{t}$ 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 ($h^0$) decouples from the fermion sector. We are partially motivated by the four $\ell^+\ell^-\gamma\gamma$ events with $M_{\gamma\gamma}\simeq60$\,GeV recently observed by the L3 collaboration, which could be a signal for $Z\to (Z^*\to \ell^+\ell^-)+(h^0\to \gamma\gamma)$. 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 $\Delta_{12}=0$, 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 $\tilde{\theta}_{13}$ can be observed for a certain range of baselines. This provides a way to measure the vacuum mixing angle $\theta_{13}$ and the sign of $\Delta m_{23}^2$ 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