1,307 research outputs found

    What do experimental data "say" about growth of hadronic total cross-section?

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    We reanalyse pˉp\bar p p and pppp high energy data of the elastic scattering above s=5\sqrt{s}=5 GeV on the total cross-section σtot\sigma_{tot} and on the forward ρ\rho-ratio for various models of Pomeron, utilizing two methods. The first one is based on analytic amplitudes, the other one relies on assumptions for σtot\sigma_{tot} and on dispersion relation for ρ\rho. We argue that it is not possible, from fitting only existing data for forward scattering, to select a definite asymptotic growth with the energy of σtot\sigma_{tot}. We find equivalent fits to the data together with a logarithmic Pomeron giving a behavior σtotlnγs\sigma_{tot} \propto \ln ^\gamma s, γ[0.5,2.20]\gamma\in [0.5,2.20] and with a supercritical Pomeron giving a behavior σtotsϵ\sigma_{tot} \propto s^\epsilon , ϵ[0.01,0.10]\epsilon\in [0.01,0.10].Comment: LaTeX, 18 pages, 5 eps figures included, to be published in Il Nuovo Ciment

    Onsager-Machlup theory and work fluctuation theorem for a harmonically driven Brownian particle

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    We extend Tooru-Cohen analysis for nonequilirium steady state(NSS) of a Brownian particle to nonequilibrium oscillatory state (NOS) of Brownian particle by considering time dependent external drive protocol. We consider an unbounded charged Brownian particle in the presence of an oscillating electric field and prove work fluctuation theorem, which is valid for any initial distribution and at all times. For harmonically bounded and constantly dragged Brownian particle considered by Tooru and Cohen, work fluctuation theorem is valid for any initial condition(also NSS), but only in large time limit. We use Onsager-Machlup Lagrangian with a constraint to obtain frequency dependent work distribution function, and describe entropy production rate and properties of dissipation functions for the present system using Onsager-Machlup functional.Comment: 6 pages, 1 figur

    Macroscopic fluctuation theory

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    Stationary non-equilibrium states describe steady flows through macroscopic systems. Although they represent the simplest generalization of equilibrium states, they exhibit a variety of new phenomena. Within a statistical mechanics approach, these states have been the subject of several theoretical investigations, both analytic and numerical. The macroscopic fluctuation theory, based on a formula for the probability of joint space-time fluctuations of thermodynamic variables and currents, provides a unified macroscopic treatment of such states for driven diffusive systems. We give a detailed review of this theory including its main predictions and most relevant applications.Comment: Review article. Revised extended versio

    Theoretical Uncertainties in Electroweak Boson Production Cross Sections at 7, 10, and 14 TeV at the LHC

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    We present an updated study of the systematic errors in the measurements of the electroweak boson cross-sections at the LHC for various experimental cuts for a center of mass energy of 7, 10 and 14 TeV. The size of both electroweak and NNLO QCD contributions are estimated, together with the systematic error from the parton distributions. The effects of new versions of the MSTW, CTEQ, and NNPDF PDFs are considered.Comment: PDFLatex with JHEP3.cls. 22 pages, 43 figures. Version 2 adds the CT10W PDF set to analysis and updates the final systematic error table and conclusions, plus several citations and minor wording changes. Version 3 adds some references on electroweak and mixed QED/QCD corrections. Version 4 adds more references and acknowledgement

    End-Stage Renal Disease After Renal Surgery in Patients with Normal Preoperative Kidney Function: Balancing Surgical Strategy and Individual Disorders at Baseline

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    Although nephron-sparing surgery (NSS) has demonstrated benefit in terms of renal function preservation, it is unclear whether NSS might also decrease the risk of end-stage renal disease (ESRD) relative to radical nephrectomy (RN). In the current paper, we aimed to report the rate and the predictors of ESRD after surgery, accounting for detailed individual baseline characteristics and comorbidities. A multi-institutional collaboration among five European tertiary care centers allowed study of 2027 patients with normal preoperative renal function and a clinically localized T1abN0M0 renal mass. Cox regression analyses were used to predict the risk of ESRD (defined as the onset of a postoperative estimated glomerular filtration rate <15 ml/min per 1.73 m2) after adjusting for the individual baseline risk of developing chronic kidney disease. Univariable ESRD rates at 5 and 10 yr of follow-up were virtually equivalent for patients who underwent NSS (1.5% and 2.5%, respectively) versus RN (1.9% and 2.7%, respectively; hazard ratio [HR]: 0.8; 95% confidence interval [CI], 0.4\ue2\u80\u931.6). However, diabetes, smoking, uncontrolled hypertension, and other comorbidities were consistently more frequent in the NSS group relative to their RN counterparts. After adjusting for detailed baseline individual characteristics, NSS was shown to have an independent protective effect relative to RN (HR: 0.4; 95% CI, 0.2\ue2\u80\u930.8; p = 0.02) at multivariable analyses. Patient summary After accounting for individual baseline characteristics, such as age, diabetes, uncontrolled hypertension, or other comorbidities, partial nephrectomy independently protects against end-stage renal disease and the consequent need for dialysis relative to radical nephrectomy
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