79,593 research outputs found

    Pomeron pole plus grey disk model: real parts, inelastic cross sections and LHC data

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    I propose a two component analytic formula F(s,t)=F(1)(s,t)+F(2)(s,t)F(s,t)=F^{(1)}(s,t)+F^{(2)}(s,t) for (abab)+(abˉabˉ)(ab\rightarrow ab) +(a\bar{b}\rightarrow a\bar{b}) scattering at energies 100GeV\ge 100 GeV ,where s,ts,t denote squares of c.m. energy and momentum transfer.It saturates the Froissart-Martin bound and obeys Auberson-Kinoshita-Martin (AKM) \cite{AKM1971} scaling. I choose ImF(1)(s,0)+ImF(2)(s,0)Im F^{(1)}(s,0)+Im F^{(2)}(s,0) as given by Particle Data Group (PDG) fits to total cross sections. The PDG formula is extended to non-zero momentum transfers using partial waves of ImF(1)Im F^{(1)} and ImF(2)Im F^{(2)} motivated by Pomeron pole and 'grey disk' amplitudes . ReF(s,t)Re F(s,t) is deduced from real analyticity: I prove that ReF(s,t)/ImF(s,0)(π/lns)d/dτ(τImF(s,t)/ImF(s,0))Re F(s,t)/ImF(s,0) \rightarrow (\pi/\ln{s}) d/d\tau (\tau Im F(s,t)/ImF(s,0) ) for ss\rightarrow \infty with τ=t(lns)2\tau=t (ln s)^2 fixed, and apply it to F(2)F^{(2)}.Using also the forward slope fit by Schegelsky-Ryskin , the model gives real parts,differential cross sections for (t)<.3GeV2(-t)<.3 GeV^2, and inelastic cross sections in good agreement with data at 546GeV,1.8TeV,7TeV546 GeV, 1.8 TeV,7 TeV and 8TeV 8 TeV . It predicts for inelastic cross sections for pppp or pˉp\bar{p} p, σinel=72.7±1.0mb\sigma_{inel}=72.7\pm 1.0 mb at 7TeV7TeV and 74.2±1.0mb74.2 \pm 1.0mb at 8TeV8 TeV in agreement with pppp Totem experimental values 73.1±1.3mb73.1\pm 1.3 mb and 74.7±1.7mb74.7\pm 1.7 mb respectively, and with Atlas values 71.3±0.9mb71.3\pm 0.9 mb and 71.7±0.7mb71.7\pm 0.7mb respectively. The predictions at 546GeV546 GeV and 1800GeV1800 GeV also agree with pˉp\bar{p} p experimental results of Abe et al \cite{Abe} at 546GeV546 GeV and 1800GeV1800 GeV. The model yields for s>0.5TeV\sqrt{s}> 0.5 TeV, with PDG2013 total cross sections , and Schegelsky-Ryskin slopes as input, σinel(s)=22.6+.034lns+.158(lns)2mb,andσinel/σtot0.56,s,\sigma_{inel} (s) =22.6 + .034 ln s + .158 (ln s)^2 mb , and \sigma_{inel} / \sigma_{tot} \rightarrow 0.56, s\rightarrow \infty , where ss is in GeV2GeV^2Comment: 6 pages, 5 figures, 2 table

    Of Rocks and Revolutions

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    This post is part of a series featuring behind-the-scenes dispatches from our Pohanka Interns on the front lines of history this summer as interpreters, archivists, and preservationists. See here for the introduction to the series. It is difficult to explain how the most advanced military technology of the 18th century relies upon a rock to function. Examined with modern eyes, the flintlock musket is as absurd as the macaroni fashion of the era. A petite vise grips a hunk of flint, which when thrown upon a steel battery, showers sparks on a criminally unmeasured amount of black powder. This produces a blinding flash, ushering a jet of flame through an eighth inch wide hole in the barrel. The powder condensed behind the ounce ball of lead is transformed from inert sulfur, charcoal and potassium nitrate into instant leviathan strength. The bullet careens down the barrel until its ejection from the twelve gauge bore, destined for whatever organic matter may halt the progress of this thoroughly unnatural reaction. [excerpt

    Contextual Deterministic Quantum Mechanics

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    We present a simple proof of quantum contextuality for a spinless particle with a one dimensional configuration space. We then discuss how the maximally realistic deterministic quantum mechanics recently constructed by this author and V. Singh can be applied to different contexts.Comment: 7 pages,latex,no fig

    Application of Mechanical and Electronic Devices to Legal Literature

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    published or submitted for publicatio

    They Were Only Playin\u27 Leapfrog! : The Infantryman and the Staff Officer in the British Army in the Great War

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    The British Infantryman of the First World War hated Staff Officers more than any other supporting or service branch in the BEF. This essay explores this attitude, its motivations, and the ways complaining helped British Infantrymen endure the Great War. It argues that the British Infantryman felt separate from the Staff Officers because of his intimate understanding of combat and killing and manifested his frustration with the helpless circumstances of war by hating Staff Officers, but ultimately understood the Staff Officer\u27s role and the necessity of their service. By reconsidering the hackneyed views of the \u27Poor Bloody Infantry\u27 a new source of endurance is identified

    Astroenzymology – the environmental limits of enzyme activity

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    Using organisms from extreme terrestrial environments as models for extraterrestrial life may lead us to underestimate the range of environments that life may inhabit. An alternative approach is to inspect the range of conditions over which crucial biomolecules might function. Recent investigations of enzyme activity suggest that they have the potential to function over a wider range of environmental conditions than expected. Although the upper temperature limit for enzyme stability is unclear, some enzymes are active up to 130°C. The evidence is that the instability of enzymes is a functional requirement, rather then because of any restraint on achieving higher stability. There is no evidence that enzyme activity ceases at low temperatures; it declines in a predictable manner to the lowest temperature at which it has been possible to make measurements, -100°C. It has been generally accepted that dehydration stops enzyme activity but this acceptance may have arisen partly from the technical difficulty of assessing enzyme activity without a fluid medium for diffusion. Experiments using anhydrous organic solvents or gas phase substrates suggest activity occurs in enzymes at very low hydration

    Equatorial ionospheric currents derived from MAGSAT data

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    The MAGSAT data on the three component's of the geomagnetic field are subjected to ring current correction and crustal anomaly elimination near the dip equator. The evidence of a strong west east electrojet current below the satellite height (approximately 350 km) is confirmed. Strong evidence of east-west component of the field suggests the existence of a vertical current originating at the jet level and extending upwards. A model calculation shows that such a current system can explain the satellite data as well as the ground data
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