Observations and Measurement of W Boson Production and Triple Gauge Couplings at LEP II
Observations and Measurement of W Boson Production and Triple Gauge Couplings at LEP II

Author: Yoshi Uchida

Publisher:

Published: 2001

Total Pages: 104

ISBN-13:

DOWNLOAD EBOOK

W-Pair and Single-W production events are observed at LEP, the Large Electron Positron collider at CERN, using the L3 detector. All decay channels are considered, and data taken in the years 1998 and 1999, with electron-positron collision centre-of-mass energies from 189 GeV to 202 GeV are analysed. The integrated luminosity of the analysed data corresponds to approximately 400pb-1, and a total of approximately 5000 W-pair events and 100 single-W events are selected. The observed cross sections of these W production processes and the differential distributions of the event shapes are then used to measure the couplings of Wbosons with Z bosons and photons. Emphasis is placed on the unambiguous and efficient combination of the information from the different production and decay channels. For the couplings in the model in which gauge invariance is realised linearly, the following results are obtained ... where the errors shown are statistical, systematic and theoretical respectively. All results show consistency with expectations from the Standard Model.

Measurement of the $WZ\rightarrow \ell\nu\ell\ell$ Cross Section and Limits on Anomalous Triple Gauge Couplings in $p\bar{p}$ Collisions at $\sqrt{s}$
Measurement of the $WZ\rightarrow \ell\nu\ell\ell$ Cross Section and Limits on Anomalous Triple Gauge Couplings in $p\bar{p}$ Collisions at $\sqrt{s}$

Author:

Publisher:

Published: 2010

Total Pages: 8

ISBN-13:

DOWNLOAD EBOOK

The standard model (SM) of particle physics has been extensively tested in the past three decades and is found to be in excellent agreement with experimental observations. It is widely assumed, however, that the SM is only a low energy approximation of a more general theory. Therefore, any significant deviation from the SM predictions yields information on the nature of a more fundamental theory. Production of WZ pairs is the least studied diboson process within the SM, as it is a charged final state and can only be produced at hadron colliders. A detailed study of this process probes the electroweak sector of the SM. In addition, searches for new phenomena in the production of heavy gauge boson pairs are interesting, as many extensions of the SM predict 1-4 additional heavy gauge bosons that can decay into a WZ boson pairs.

Measurement of the Z? Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings
Measurement of the Z? Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings

Author:

Publisher:

Published: 2015

Total Pages: 40

ISBN-13:

DOWNLOAD EBOOK

The cross section for the production of Z? in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb-1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. Furthermore, the differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. These observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. As a result, limits on anomalous triple gauge couplings of ZZ? and Z?? are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.

Measurement of the Z[gamma] Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings
Measurement of the Z[gamma] Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings

Author:

Publisher:

Published: 2015

Total Pages: 39

ISBN-13:

DOWNLOAD EBOOK

The cross section for the production of Z[gamma] in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb-1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. Furthermore, the differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. These observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. As a result, limits on anomalous triple gauge couplings of ZZ[gamma] and Z[gamma][gamma] are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.