Universidad Iberoamericana Ciudad de México

About: Universidad Iberoamericana Ciudad de México is a education organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Large Hadron Collider & Standard Model. The organization has 2259 authors who have published 3981 publications receiving 109298 citations.

Alignment of the CMS tracker with LHC and cosmic ray data

Abstract: © CERN 2014 for the benefit of the CMS collaboration, published under the terms of the Creative Commons Attribution 3.0 License by IOP Publishing Ltd and Sissa Medialab srl. Any further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation and DOI.

Measurement of t t ¯ production with additional jet activity, including b quark jets, in the dilepton decay channel using pp collisions at √s = 8 TeV

Abstract: Jet multiplicity distributions in top quark pair (tt) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7fb^(-1). The measurement is performed in the dilepton decay channels (e^+e^−, μ^+μ^−, and e^±μ^∓). The absolute and normalized differential cross sections for tt production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential ttb and ttbb cross sections are presented for the first time as a function of the kinematic properties of the leading additional b jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation.

Measurement of the cross section for electroweak production of a Z boson, a photon and two jets in proton-proton collisions at √s = 13 TeV and constraints on anomalous quartic couplings

Abstract: A measurement is presented of the cross section for electroweak production of a Z boson and a photon in association with two jets (Zγjj) in proton-proton collisions. The Z boson candidates are selected through their decay into a pair of electrons or muons. The process of interest, electroweak Zγjj production, is isolated by selecting events with a large dijet mass and a large pseudorapidity gap between the two jets. The measurement is based on data collected at the CMS experiment at $ \sqrt{s} $ = 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. The observed significance of the signal is 3.9 standard deviations, where a significance of 5.2 standard deviations is expected in the standard model. These results are combined with published results by CMS at $ \sqrt{s} $ = 8 TeV, which leads to observed and expected respective significances of 4.7 and 5.5 standard deviations. From the 13 TeV data, a value is obtained for the signal strength of electroweak Zγjj production and bounds are given on quartic vector boson interactions in the framework of dimension-eight effective field theory operators.[graphic not available: see fulltext]

Measurement of the inclusive jet cross section in pp collisions at √s = 2.76 TeV

Abstract: The double-differential inclusive jet cross section is measured as a function of jet transverse momentum $$p_{\mathrm {T}}$$ and absolute rapidity $$|y |$$ , using proton-proton collision data collected with the CMS experiment at the LHC, at a center-of-mass energy of $$\sqrt{s} = 2.76\,{\mathrm{TeV}}$$ and corresponding to an integrated luminosity of 5.43 $$\,\text {pb}^{-1}$$ . Jets are reconstructed within the $$p_{\mathrm {T}}$$ range of 74 to 592 $$\,\text {GeV}$$ and the rapidity range $$|y |<3.0$$ . The reconstructed jet spectrum is corrected for detector resolution. The measurements are compared to the theoretical prediction at next-to-leading-order QCD using different sets of parton distribution functions. This inclusive cross section measurement explores a new kinematic region and is consistent with QCD predictions.