1,721,042 research outputs found
Two-loop master integrals for the planar QCD massive corrections to di-photon and di-jet hadro-production
Full text linkAbstract We present the analytic calculation of the Master Integrals necessary to compute the planar massive QCD corrections to Di-photon (and Di-jet) production at hadron colliders. The master integrals are evaluated by means of the differential equations method and expressed in terms of multiple polylogarithms and one- or two-fold integrals of polylogarithms and irrational functions, up to transcendentality four
Two-Loop Corrections to Top-Antitop Production at Hadron Colliders
Full text linkBonciani R, Ferroglia A, Gehrmann T, von Manteuffel A, Studerus C. Two-Loop Corrections to Top-Antitop Production at Hadron Colliders. In: PoS. Vol ICHEP2010. 2010: 098
Two-loop form factors for diphoton production in quark annihilation channel with heavy quark mass dependence
Full text linkWe present the computation of the two-loop form factors for diphoton production in the quark annihilation channel. These quantities are relevant for the NNLO QCD corrections to diphoton production at LHC recently presented in [1]. The computation is performed retaining full dependence on the mass of the heavy quark in the loops. The master integrals are evaluated by means of differential equations which are solved exploiting the generalised power series technique
On-shell Z boson production at hadron colliders through O(ααs)
Full text linkThe analytical expressions of the mixed QCD-EW corrections to on-shell Z boson inclusive production cross section at hadron colliders are presented, together with computational details. The results are given in terms of polylogarithmic functions and elliptic integrals. The impact on the prediction of the Z boson production total cross section is discussed, comparing different proton parton density sets
A rigorous simulation model of geothermal power plants for emission control
Full text linkGeothermal power plant (GTPP) operating conditions and associated emissions mainly depend on the endogenic fluid used to generate power, and the case of GTPPs located in Tuscany (Italy) is considered in this study. Since measuring on-line the quantity of emitted pollutants is a difficult task, a process simulation model featuring all unit operations of the GTTP is developed using UniSim Design® to forecast and control pollutant emissions. An accurate identification of the thermodynamic correlation parameters for the solubility of the considered pollutants (mercury and hydrogen sulfide) in water has been performed to match literature values. A data reconciliation procedure is used to match the simulation model outcome with real measurements of two (20 MWe and 40 MWe) GTTPs. Results are fully satisfactory as the mercury emission forecasted is always slightly above the measured data, evidencing the model is conservative, and hence reliable in ensuring satisfaction of emission limits established by law. For the 20 MWe plant, the simulated total mercury emissions are 3.31 g/h exceeding the measured ones by 27%, while for the 40 MWe plant, they are 1.38 g/h above the measured ones by 4%. In addition, for the 20MWe plant, pollutants emission and net power production are both considered in a performance analysis. The worst case scenario for power generation (18.7 MW) is in summer conditions, while for pollutant emission is in winter conditions with 5.22 g/h of total mercury and 20.46 kg/h of hydrogen sulfide. Finally, energetic performances result to be independent from the environmental measures adopted
Full top-quark mass dependence in diphoton production at NNLO in QCD
Full text linkIn this paper we consider the diphoton production in hadronic collisions at the next-to-next-to-leading order (NNLO) in perturbative QCD, taking into account for the first time the full top quark mass dependence up to two loops (full NNLO). We show selected numerical distributions, highlighting the kinematic regions where the massive corrections are more significant. We make use of the recently computed two-loop massive amplitudes for diphoton production in the quark annihilation channel. The remaining massive contributions at NNLO are also considered, and we comment on the weight of the different types of contributions to the full and complete result
Analytic results for virtual QCD corrections to Higgs production and decay
No full textWe consider the production of a Higgs boson via gluon-fusion and its decay into two photons. We compute the NLO virtual QCD corrections to these processes in a general framework in which the coupling of the Higgs boson to the external particles is mediated by a colored fermion and a colored scalar. We present compact analytic results for these two-loop corrections that are expressed in terms of Harmonic Polylogarithms. The expansion of these corrections in the low and high Higgs mass regimes, as well as the expression of the new Master Integrals which appear in the reduction of the two-loop amplitudes, are also provided. For the fermionic contribution, we provide an independent check of the results already present in the literature concerning the Higgs boson and the production and decay of a pseudoscalar particle
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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