4,276 research outputs found
Soft-gluon resummation for Higgs differential distributions at the large hadron collider
No full textWe study the transverse-momentum and rapidity distributions of the Standard Model Higgs boson in perturbative QCD, including die most advanced theoretical information presently available: fixed-order perturbation theory at Next-to-Leading Order (NLO) and soft-gluon resummation at the Next-to-Next-to-Leading Logarithmic accuracy (NNLL). Numerical results show sizeable contributions from resummation and an overall improvement of the stability with respect to scale variation and to the inclusion of higher perturbative orders
Selected items in jet algorithms
No full textI provide a very brief overview of recent developments in jet algorithms, mostly focusing on the issue of infrared-safety
Higgs boson production at the LHC: Transverse-momentum resummation and rapidity dependence
No full textWe consider Higgs boson production by gluon fusion in hadron collisions. We study the doubly-differential transverse-momentum (qT) and rapidity (y) distribution of the Higgs boson in perturbative QCD. In the region of small qT (qT ≪ MH, MH being the mass of the Higgs boson), we include the effect of logarithmically-enhanced contributions due to multiparton radiation to all perturbative orders. We use the impact parameter and double Mellin moments to implement and factorize the multiparton kinematics constraint of transverse- and longitudinal-momentum conservation. The logarithmic terms are then systematically resummed in exponential form. At small qT, we perform the all-order resummation of large logarithms up to next-to-next-to-leading logarithmic accuracy, while at large qT (qT ∼ MH), we apply a matching procedure that recovers the fixed-order perturbation theory up to next-to-leading order. We present quantitative results for the differential cross section in qT and y at the LHC, and we comment on the comparison with the qT cross section integrated over y. © 2007 Elsevier B.V. All rights reserved.Fil: Bozzi, Giuseppe. Universität Karlsruhe; AlemaniaFil: Catani, Stefano. Università di Firenze; ItaliaFil: de Florian, Daniel Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Grazzini, Massimiliano. Università di Firenze; Itali
Threshold effects in slepton pair production at the LHC
No full textWe present a study of threshold resummation effects for slepton pair production at the Large Hadron Collider (LHC). After confirming the known NLO QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the Mellin N-space resummation formalism to compute logarithmically enhanced soft-gluon terms to all perturbative orders
W mass: a theory overview
No full textThe measurement of the W boson mass represents a very important test for the internal consistency of the standard model of particle physics, and could also possibly highlight signals of New Physics. We provide a concise theory overview on the topic, presenting the typical measuring strategies, the known perturbative and non-perturbative theoretical ingredients used to predict the relevant observables, the treatment of theoretical systematics in recent experimental measurements and some future prospects to reduce modelling uncertainties
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