UCrea Repositorio abierto de la Universidad de Cantabria
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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Tue, 25 Feb 2020 22:31:09 GMT2020-02-25T22:31:09ZMeasurements of tt¯ differential cross sections in proton-proton collisions at √s=13 TeV using events containing two leptons
http://hdl.handle.net/10902/18277
Measurements of tt¯ differential cross sections in proton-proton collisions at √s=13 TeV using events containing two leptons
Sirunyan, A. M.; Cabrillo Bartolomé, José Iban; Calderón Tazón, Alicia; Chazín Quero, Bárbara; Duarte Campderros, Jorge; Fernández García, Marcos; Fernández Manteca, Pedro José; García Alonso, Andrea; García Ferrero, Juan; Gómez Gramuglio, Gervasio; López Virto, María Amparo; Marco de Lucas, Jesús; Martínez Rivero, Celso; Martínez Ruiz de Árbol, Pablo; Matorras Weinig, Francisco; Piedra Gómez, Jonatan; Prieels, Cedric Gerald; Rodrigo Anoro, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolo; Vila Álvarez, Ivan; Vilar Cortabitarte, Rocío
Measurements of differential top quark pair tt¯ cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb−1. The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the tt¯ system, and the total number of jets in the event. The differential cross sections are defined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract tt¯ and leptonic charge asymmetries.
Fri, 01 Feb 2019 00:00:00 GMThttp://hdl.handle.net/10902/182772019-02-01T00:00:00ZGoodness-of-fit tests for the functional linear model based on randomly projected empirical processes
http://hdl.handle.net/10902/18276
Goodness-of-fit tests for the functional linear model based on randomly projected empirical processes
Cuesta Albertos, Juan Antonio; García-Portugués, Eduardo; Febrero-Bande, Manuel; González-Manteiga, Wenceslao
We consider marked empirical processes indexed by a randomly projected functional covariate to construct goodness-of-fit tests for the functional linear model with scalar response. The test statistics are built from continuous functionals over the projected process, resulting in computationally efficient tests that exhibit root-n convergence rates and circumvent the curse of dimensionality. The weak convergence of the empirical process is obtained conditionally on a random direction, whilst the almost surely equivalence between the testing for significance expressed on the original and on the projected functional covariate is proved. The computation of the test in practice involves calibration by wild bootstrap resampling and the combination
of several p-values, arising from different projections, by means of the false discovery rate method. The finite sample properties of the tests are illustrated in a simulation study for a variety of linear models, underlying processes, and alternatives. The software provided implements the tests and allows the replication of simulations and data applications.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10902/182762019-01-01T00:00:00ZMeasurements of differential Z boson production cross sections in proton-proton collisions at √s = 13 TeV
http://hdl.handle.net/10902/18275
Measurements of differential Z boson production cross sections in proton-proton collisions at √s = 13 TeV
Sirunyan, A. M.; Cabrillo Bartolomé, José Iban; Calderón Tazón, Alicia; Chazín Quero, Bárbara; Duarte Campderros, Jorge; Fernández García, Marcos; Fernández Manteca, Pedro José; García Alonso, Andrea; Gómez Gramuglio, Gervasio; Martínez Rivero, Celso; Martínez Ruiz de Árbol, Pablo; Matorras Weinig, Francisco; Piedra Gómez, Jonatan; Prieels, Cedric Gerald; Rodrigo Anoro, Teresa; Ruiz Jimeno, Alberto; Russo, Lorenzo; Scodellaro, Luca; Vila Álvarez, Ivan; Vizán García, Jesús Manuel
Measurements are presented of the differential cross sections for Z bosons produced in proton-proton collisions at √s = 13 TeV and decaying to muons and electrons. The data analyzed were collected in 2016 with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb−1. The measured fiducial inclusive product of cross section and branching fraction agrees with next-to-next-to-leading order quantum chromodynamics calculations. Differential cross sections of the transverse momentum pT, the optimized angular variable ϕ∗ηϕη∗, and the rapidity of lepton pairs are measured. The data are corrected for detector effects and compared to theoretical predictions using fixed order, resummed, and parton shower calculations. The uncertainties of the measured normalized cross sections are smaller than 0.5% for ϕ∗ηϕη∗< 0.5 and for pZTpTZ< 50 GeV.
Sun, 01 Dec 2019 00:00:00 GMThttp://hdl.handle.net/10902/182752019-12-01T00:00:00ZMeasurement of exclusive Υ photoproduction from protons in pPb collisions at √sNN=5.02TeV
http://hdl.handle.net/10902/18274
Measurement of exclusive Υ photoproduction from protons in pPb collisions at √sNN=5.02TeV
Sirunyan, A. M.; Cabrillo Bartolomé, José Iban; Calderón Tazón, Alicia; Chazín Quero, Bárbara; Duarte Campderros, Jorge; Fernández García, Marcos; Fernández Manteca, Pedro José; García Alonso, Andrea; García Ferrero, Juan; Gómez Gramuglio, Gervasio; López Virto, María Amparo; Marco de Lucas, Jesús; Martínez Rivero, Celso; Martínez Ruiz de Árbol, Pablo; Matorras Weinig, Francisco; Piedra Gómez, Jonatan; Prieels, Cedric Gerald; Rodrigo Anoro, Teresa; Ruiz Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolo; Vila Álvarez, Ivan; Vilar Cortabitarte, Rocío
The exclusive photoproduction of Υ(nS) meson states from protons, γp→Υ(nS)p (with n=1,2,3), is studied in ultraperipheral pp Pb collisions at a centre-of-mass energy per nucleon pair of √sNN=5.02TeV . The measurement is performed using the Υ(nS)→μ+μ− decay mode, with data collected by the CMS experiment corresponding to an integrated luminosity of 32.6nb−1. Differential cross sections as functions of the Υ(nS) transverse momentum squared p2T, and rapidity y, are presented. The Υ(1S) photoproduction cross section is extracted in the rapidity range |y|<2.2, which corresponds to photon–proton centre-of-mass energies in the range 91<Wγp<826GeV. The data are compared to theoretical predictions based on perturbative quantum chromodynamics and to previous measurements.
Fri, 01 Mar 2019 00:00:00 GMThttp://hdl.handle.net/10902/182742019-03-01T00:00:00Z