Abstract

The top quark was discovered at the Tevatron in 1995. Measuring its intrinsic properties can provide good tests of the Standard Model. These quantities are also sensitive to models beyond the Standard Model. This document reviews the measurements, performed by the ATLAS Collaboration, of three properties of the top quark: mass, charge and polarisation. They are based on data collected with the ATLAS detector at the LHC during the year 2011 at a proton-proton centre-of-mass energy of p s = 7 TeV. The top quark is the heaviest known elementary parti- cle. This particle plays a particular role in Particle Physics, especially in the electroweak symmetry breaking mecha- nism. Its properties are also very sensitive to Physics be- yond the Standard Model (BSM), as numerous hypothe- sised particles would couple to the top quark. The mea- surement of the intrinsic top quark properties is therefore a powerful probe for new Physics, and the detailed studies of these parameters can possibly lead to new discoveries. In this paper, the measurement of three properties

Highlights

  • The top quark is the heaviest known elementary particle

  • Qso f tμ is the charge of the soft muon

  • The unbinned likelihood fit leads to the following measured values for mtop, JSF and bJSF: mtop = 172.31±0.75±1.35 GeV, JSF = 1.014 ± 0.003 ± 0.021, bJSF = 1.006 ± 0.008 ± 0.020

Read more

Summary

Introduction

The top quark mass (mtop) is a fundamental parameter of SM and BSM physics. It is important to measure it with the highest posssible accuracy. The current precision does not allow to know whether the vacuum is in a stable or metastable state [15]. The use of this parameter in electroweak fits to test SM and BSM predictions is another example of the motivation for measuring the top quark mass precisely. The ATLAS measurements are performed in all ttdecay modes, the most precise measurement being performed in the +jets channel with 4.7 fb−1 of data. This measurement is emphasized here, and more details about it are provided in Ref. For the measurements in the dilepton and all hadronic channels, one can refer to [17] and [18], respectively

Event selection and reconstruction
Description of the method
Systematic uncertainties
Track charge weighting method
The 3d-analysis
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.