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The Top Quark Mass at the LHC
I briefly discuss some theoretical aspects of top mass measurements at the LHC. In particular, I illustrate a recent theoretical study performed using next-to-leading order (NLO) calculations interfaced to shower generators (NLO+PS) of increasing accuracy, interfaced to both Pythia8 and Herwig7 Mont...
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| Lenguaje: | eng |
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2017
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| Acceso en línea: | http://cds.cern.ch/record/2300287 |
| _version_ | 1780957087093751808 |
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| author | Nason, Paolo |
| author_facet | Nason, Paolo |
| author_sort | Nason, Paolo |
| collection | CERN |
| description | I briefly discuss some theoretical aspects of top mass measurements at the LHC. In particular, I illustrate a recent theoretical study performed using next-to-leading order (NLO) calculations interfaced to shower generators (NLO+PS) of increasing accuracy, interfaced to both Pythia8 and Herwig7 Monte Carlo generators. |
| id | cern-2300287 |
| institution | Organización Europea para la Investigación Nuclear |
| language | eng |
| publishDate | 2017 |
| record_format | invenio |
| spelling | cern-23002872020-12-14T13:46:17Zhttp://cds.cern.ch/record/2300287engNason, PaoloThe Top Quark Mass at the LHChep-exParticle Physics - Experimenthep-phParticle Physics - PhenomenologyI briefly discuss some theoretical aspects of top mass measurements at the LHC. In particular, I illustrate a recent theoretical study performed using next-to-leading order (NLO) calculations interfaced to shower generators (NLO+PS) of increasing accuracy, interfaced to both Pythia8 and Herwig7 Monte Carlo generators.I briefly discuss some theoretical aspects of top mass measurements at the LHC.In particular, I illustrate recent theoretical studies performed using next-to-leading order (NLO) calculations interfaced to shower generators (NLO+PS) ofincreasing accuracy. I consider three generators: one that has NLO accuracy onlyat the production stage, and implements spin correlations in an approximate way;one that implements NLO corrections also in decay, and includes exact spincorrelations in the narrow-width limit; and one that includes NLO corrections inproduction and decays, also taking care of finite width, non-resonantcontributions and interference of radiation in production and decay. Animportant goal of the LHC top-physics program is the measurement of its mass.Since the Higgs mass is known with high precision, improvements of both the Wand top mass measurements may lead to a refinement of the Electro-Weak precisiontests 1, 2). The current precision of the W mass measurement, of about 15 MeV,would match a precision on the top mass of about 2.4 GeV. There is some tensionat present between the value of the top mass obtained indirectly throughelectro-weak fits 1) , 176.7 ± 2.1 GeV, and the direct determinations, with thevalue of 173.34 ± 0.76 GeV from the latest combination 3) , and with latermeasurements yielding values smaller by about 1 GeV 4, 5, 6, 7). 1 The value ofthe top mass is also relevant for the issue of vacuum stability in the StandardModel 10, 11, 12). Direct measurements are now well below the instabilityregion, while the central value extracted from electro-weak fits is near itsedge. The only conclusion that one can draw from these results is that noindication of new physics scales below the Plank scale arises from the vacuum 1For recent reviews of top-mass measurements by the ATLAS and CMS collaborationssee Refs. 8) and 9) from these proceedings.CERN-TH-2018-008arXiv:1801.04826oai:cds.cern.ch:23002872017 |
| spellingShingle | hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology Nason, Paolo The Top Quark Mass at the LHC |
| title | The Top Quark Mass at the LHC |
| title_full | The Top Quark Mass at the LHC |
| title_fullStr | The Top Quark Mass at the LHC |
| title_full_unstemmed | The Top Quark Mass at the LHC |
| title_short | The Top Quark Mass at the LHC |
| title_sort | top quark mass at the lhc |
| topic | hep-ex Particle Physics - Experiment hep-ph Particle Physics - Phenomenology |
| url | http://cds.cern.ch/record/2300287 |
| work_keys_str_mv | AT nasonpaolo thetopquarkmassatthelhc AT nasonpaolo topquarkmassatthelhc |