Measurement of the beam-helicity asymmetry in photoproduction of π0η pairs on carbon, aluminum, and lead
| Parent link: | Physics Letters B Vol. 802.— 2020.— [135243, 8 p.] |
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| Corporate Author: | |
| Other Authors: | , , , , |
| Summary: | Title screen The first direct, model-independent measurement is presented of the modulus of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |η|Vtb, |η|Vtd, and |η|Vts, in final states enriched in single top quark t-channel events. The analysis uses proton-proton collision data from the LHC, collected during 2016 by the CMS experiment, at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. Processes directly sensitive to these matrix elements are considered at both the production and decay vertices of the top quark. In the standard model hypothesis of CKM unitarity, a lower limit of |η|Vtb>0.970 is measured at the 95% confidence level. Several theories beyond the standard model are considered, and by releasing all constraints among the involved parameters, the values |η|Vtb=0.988±0.024, and |η|Vtd2+|η|Vts2=0.06±0.06, where the uncertainties include both statistical and systematic components, are measured. |
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2020
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| Online Access: | https://doi.org/10.1016/j.physletb.2020.135243 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=664600 |