64 research outputs found

    Beam polarization at LHC and SSC. Expected asymmetries in the Bess model and comparison with other models

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    In view of recent and foreseen technical advances in beam polarization in future proton colliders we discuss possible tests of non-standard physics at LHC and SSC assuming initial proton polarization, specifically to test for a strong electroweak sector and compairing with different extended gauge models. We examine lepton pair production, studying left-right and forward-backward asymmtries, assuming quark-antiquark and WW fusion production mechanisms. We discuss the uncertainties related to polarized proton structure functions

    Does firm environmental performance mitigate the market reaction to COVID-19 uncertainty?

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    This paper investigates how firms’ environmental performance affected the market reaction caused by the uncertainty of the COVID-19 pandemic. Our analysis focuses on a sample of 3854 non-financial listed companies from 21 advanced economies. We find that high environmentally sustainable practices (ESP) are associated with lower returns during the COVID-19 crisis, especially when the pandemic began to spread globally. Also, our results show that ESP is not significantly related to volatility in the whole COVID-19 period. We find a positive relationship between ESP and volatility only in the early phases of the pandemic. The stronger contraction in earnings and cash flow forecasts for high ESP firms explains the negative effect of ESP on market returns. The cost structure of high ESP firms makes them more exposed to the unexpected global demand shock. Our findings suggest that firm environmental performance did not immunise against market turmoil

    Top Quark Production in Extended Bess Model

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    We study top production at Tevatron collider in the extended BESS model, which is an effective lagrangian parametrization of a dynamical symmetry breaking of the electroweak symmetry. The existence of a colored octet of gauge vector bosons can increase top production at a rate still consistent with recent experimental data and lead to distorsions in the transverse momentum spectrum of the top.Comment: 13 pages, LaTeX, 4 figure

    Z' Physics

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    The limits on extra neutral gauge bosons, which could be reached at LEP2, are reviewed. Exclusion and discovery limits are discussed for f\bar f and WW production.Comment: 20 pages Latex, 7 figures included by epsfig, Contribution to the Proceedings the workshop "Physics at LEP2", Geneva, 199

    The Impact of SARS-COVID-19 Outbreak on European Cities Urban Mobility

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    The global outbreak of the SARS-COVID-19 pandemic has changed our lives, driving an unprecedented transformation of our habits. In response, the authorities have enforced several measures, including social distancing and travel restrictions that lead to the temporary closure of activities centered around schools, companies, local businesses to those pertaining to the recreation category. As such, with a mobility reduction, the life of our cities during the outbreak changed significantly. In this paper, we aim at drawing attention to this problem and perform an analysis for multiple cities through crowdsensed information available from datasets such as Apple Maps, to shed light on the changes undergone during both the outbreak and the recovery. Specifically, we exploit data characterizing many mobility modes like driving, walking, and transit. With the use of Gaussian Processes and clustering techniques, we uncover patterns of similarity between the major European cities. Further, we perform a prediction analysis that permits forecasting the trend of the recovery process and exposes the deviation of each city from the trend of the cluster. Our results unveil that clusters are not typically formed by cities with geographical ties, but rather on the spread of the infection, lockdown measures, and citizens’ reactions

    The CORONA business in modern cities

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    As a response to the global outbreak of the SARS-COVID-19 pandemic, authorities have enforced a number of measures including social distancing, travel restrictions that lead to the "temporary" closure of activities stemming from public services, schools, industry to local businesses. In this poster we draw the attention to the impact of such measures on urban environments and activities. For this, we use crowdsensed information available from datasets like Google Popular Times and Apple Maps to shed light on the changes undergone during the outbreak and the recovery

    Drell-Yan forward-backward and spin asymmetries for arbitrary vector boson production at next-to-leading order

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    Longitudinally polarized, unpolarized and forward-backward mass differential cross sections for Drell-Yan lepton-pair production by arbitrary vector bosons are calculated in next-to-leading order (NLO) QCD. Analytical results are presented in a form valid for all consistent nn-dimensional regularization schemes, with the mass factorization scheme kept general. NLO predictions for all Drell-Yan type processes (W±W^\pm, ZZ and γ\gamma^*) at BNL's relativistic heavy ion collider (RHIC) are made using polarized parton distributions which fit the recent deep-inelastic scattering data. These are examined as tools in the determination of the polarized parton distributions and the unpolarized uˉ/dˉ\bar{u}/\bar{d} ratio. NLO predictions for the forward-backward lepton asymmetry at Fermilab are made and the precision determination of sin2θW\sin^2 \theta_W from future runs is studied. In all the above, the QCD corrections are found to be significant. An introductory discussion is given of various theoretical issues, such as allowable factorization and regularization schemes, and scale dependences.Comment: 34 pages, figures included, revtex. Some discussions and references added/modified. In more compact form. To appear in Phys. Rev.
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