We investigate trilepton final states to probe top anomalous couplings at the Large Hadron Collider. We focus on events originating from the associated production of a single top quark with a ...Z-boson, a channel sensitive to several flavor-changing neutral interactions of top and up/charm quarks. In particular, we explore a way to access simultaneously their anomalous couplings to Z-bosons and gluons and derive the discovery potential of trilepton final states to such interactions with 20 fb−1 of 8 TeV collisions. We show that effective coupling strengths of O(0.1–1) TeV−1 can be reached. Equivalently, branching fractions of top quarks into lighter quarks and gluons or Z-bosons can be constrained to be below O(0.1–1)%.
Monotop phenomenology at the Large Hadron Collider Agram, Jean-Laurent; Andrea, Jeremy; Buttignol, Michael ...
Physical review. D, Particles, fields, gravitation, and cosmology,
01/2014, Letnik:
89, Številka:
1
Journal Article
Odprti dostop
We investigate new physics scenarios where systems comprised of a single top quark accompanied by missing transverse energy, dubbed monotops, can be produced at the LHC. Following a simplified model ...approach, we describe all possible monotop production modes via an effective theory and estimate the sensitivity of the LHC, assuming 20 fb super(-1) of collisions at a center-of-mass energy of 8 TeV, to the observation of a monotop state. Considering both leptonic and hadronic top quark decays, we show that large fractions of the parameter space are reachable and that new physics particles with masses ranging up to 1.5 TeV can leave hints within the 2012 LHC data set, assuming moderate new physics coupling strengths.
The CMS Silicon Strip Tracker (SST), consisting of 9.6 million readout channels from 15,148 modules and covering an area of 198 square meters, needs to be precisely calibrated in order to correctly ...reconstruct the events recorded. Calibration constants are derived from different workflows, from promptly reconstructed events with particles as well as from commissioning events gathered just before the acquisition of physics runs. The performance of the SST has been carefully studied since the beginning of data taking: the noise of the detector, data integrity, signal-over-noise ratio, hit reconstruction effciency and resolution have all been investigated. In this paper we describe the reconstruction strategies, the calibration procedures and the detector performance results from the 2010 CMS operation.
We investigate new physics scenarios where systems comprised of a single top quark accompanied by missing transverse energy, dubbed monotops, can be produced at the LHC. Following a simplified model ...approach, we describe all possible monotop production modes via an effective theory and estimate the sensitivity of the LHC, assuming 20 fb\(^{-1}\) of collisions at a center-of-mass energy of 8 TeV, to the observation of a monotop state. Considering both leptonic and hadronic top quark decays, we show that large fractions of the parameter space are reachable and that new physics particles with masses ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming moderate new physics coupling strengths.
We investigate trilepton final states to probe top anomalous couplings at the Large Hadron Collider. We focus on events originating from the associated production of a single top quark with a ...Z-boson, a channel sensitive to several flavor-changing neutral interactions of top and up/charm quarks. In particular, we explore a way to access simultaneously their anomalous couplings to Z-bosons and gluons and derive the discovery potential of trilepton final states to such interactions with 20 fb-1 of 8 TeV collisions. We show that effective coupling strengths of O(0.1-1) TeV-1 can be reached. Equivalently, branching fractions of top quarks into lighter quarks and gluons or Z-bosons can be constrained to be below O(0.1-1)%.
Ce travail présente une mesure de la section efficace inclusive de production des jets dans l'expérience DØ. Cette section efficace est déterminée en fonction de l'impulsion transverse des jets et ...dans plusieurs domaines en rapidité. Elle est sensible à la structure du proton et joue ainsi un rôle important dans la détermination des fonctions de distribution des partons (PDF), notamment celle du gluon pour des grandes fractions d'impulsion du proton. La mesure, qui est présentée en détail, donne les premières valeurs pour le Run II de la section efficace et ses incertitudes dans plusieurs domaines en rapidité, pour une luminosité intégrée de 143 pb-1. Les résultats obtenus sont, au vu de leur incertitude, en bon accord avec les prédictions théoriques ne laissant pas présager de phénomènes nouveaux. Ce travail met en évidence les points de compréhension du détecteur à améliorer pour atteindre le degré de précision du Run I et apporter des contraintes pour la détermination des PDF.
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