Search for a Heavy Gauge Boson W' in the Final State with an Electron and Large Missing Transverse Energy in Pp Collisions at Sqrt(s)


Book Description

A search for a heavy gauge boson W has been conducted by the CMS experiment at the LHC in the decay channel with an electron and large transverse / energy imbalance, E T, using proton-proton collision data corresponding to an integrated luminosity of 36 pb[-]1 . No excess above standard model expectations / is seen in the transverse mass distribution of the electron-E T system. Assuming standard-model-like couplings and decay branching fractions, a W boson with a mass less than 1.32 TeV/c2 is excluded at the 95% confidence level.




Search for a Heavy Gauge Boson $W$ ' in the Final State with an Electron and Large Missing Transverse Energy in $pp$ Collisions at $\sqrt{s}


Book Description

A search for a heavy gauge boson W' has been conducted by the CMS experiment at the LHC in the decay channel with an electron and large transverse energy imbalance, using proton-proton collision data corresponding to an integrated luminosity of 36 inverse picobarns. No excess above standard model expectations is seen in the transverse mass distribution of the electron-(missing E_T) system. Assuming standard-model-like couplings and decay branching fractions, a W' boson with a mass less than 1.36 TeV/c2̂ is excluded at 95% confidence level.




Neutrinos in High Energy and Astroparticle Physics


Book Description

This self-contained modern textbook provides a modern description of the Standard Model and its main extensions from the perspective of neutrino physics. In particular it includes a thorough discussion of the varieties of seesaw mechanism, with or without supersymmetry. It also discusses schemes where neutrino mass arises from lighter messengers, which might lie within reach of the world's largest particle accelerator, the Large Hadron Collider. Throughout the text, the book stresses the role of neutrinos due to the fact that neutrino properties may serve as a guide to the correct model of unification, hence for a deeper understanding of high energy physics, and because neutrinos play an important role in astroparticle physics and cosmology. Each chapter includes summaries and set of problems, as well as further reading.




Search for Heavy Gauge W' Boson in Events with an Energetic Lepton and Large Missing Transverse Momentum at Sqrt(s)


Book Description

A search is presented for W' bosons in events with an electron or muon and large missing transverse momentum, using proton-proton collision data at sqrt(s) = 13 TeV collected with the CMS detector in 2015 and corresponding to an integrated luminosity of 2.3 inverse femtobarns. No evidence of an excess of events relative to the standard model expectations is observed. For a W' boson described by the sequential standard model, upper limits at 95% confidence level are set on the product of the production cross section and branching fraction and lower limits are established on the new boson mass. Masses below 4.1 TeV are excluded combining electron and muon decay channels, significantly improving upon the results obtained with the 8 TeV data. Exclusion limits at 95% confidence level on the product of the W' production cross section and branching fraction are also derived in combination with the 8 TeV data. Finally, exclusion limits are set for the production of generic W' bosons decaying into this final state using a model-independent approach.




Search for a W' Boson Decaying to a Muon and a Neutrino in Pp Collisions at Sqrt(s)


Book Description

A new heavy gauge boson, W', decaying to a muon and a neutrino, is searched for in pp collisions at a centre-of-mass of 7 TeV. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 36 inverse picobarns. No significant excess of events above the standard model expectation is found in the transverse mass distribution of the muon-neutrino system. Masses below 1.40 TeV are excluded at the 95% confidence level for a sequential standard-model-like W'. The W' mass lower limit increases to 1.58 TeV when the present analysis is combined with the CMS result for the electron channel.




The Physics Associated with Neutrino Masses


Book Description

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.







W Boson Production in /bar P/p Collisions At. Sqrt. S


Book Description

The cross section for the production and subsequent decay of the W Intermediate Vector boson to electron and neutrino has been measured in .sqrt.s = 1.8 TeV /bar p/p collisions using the CDF Collider Detector at Fermilab. For this measurement, W events were identified from the large missing transverse energy associated with the unseen neutrino and an electromagnetic cluster passing rather loose electron criteria. 22 events passing the selection missing transverse energy greater than 25 GeV and electron transverse energy greater than 15 GeV were observed in a sample of 25nb/sup /minus/1/ yielding a sigma /center dot/ B = 2.6 ± 0.6 ± 0.5nb. This report agrees well with a parallel analysis based primarily on the identification of isolated electron and is in excellent agreement with theoretical predictions. 12 refs., 7 figs.




A Measurement of W Boson Pair Production in Pp Collisions at Sqrt(s)


Book Description

Zusammenfassung: In this thesis, measurements of the W boson pair production cross section in proton-proton collisions at a centre-of-mass energy of 8 TeV are presented. A dataset corresponding to an integrated luminosity of 22.3 /fb recorded by the ATLAS experiment in the year 2012 is used. The W bosons are identified by their decay products of exactly two leptons with opposite electrical charge, electrons or muons, and missing transverse momentum induced by their corresponding neutrinos. First, a measurement restricted to final states without hadronic jets is presented and differential fiducial cross sections, total cross sections and limits on anomalous triple gauge boson couplings are obtained. A second measurement of the fiducial cross section in association with exactly one hadronic jet is presented. The ratio of fiducial cross sections for different jet multiplicities is reported and the combined fiducial cross section is extrapolated to the total phase space.




Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector


Book Description

The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W′,W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of ppcollisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb−1. No excess beyond standard model expectations is observed. A W′ with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.