Search For The Rare Decay of the W Boson İnto A Pion And A Photon İn Proton-Proton Collisions at ?s = 13 TeV

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Küçük Resim

Tarih

2021

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Yayıncı

Elsevier [Commercial Publisher]

Erişim Hakkı

Özet

A search is performed for the rare decay W-+/--> pi(+/-)gamma in proton-proton collisions at root s = 13 TeV. Data corresponding to an integrated luminosity of 137 fb(-1) were collected during 2016 to 2018 with the CMS detector. This analysis exploits a novel search strategy based on W boson production in top quark pair events. An inclusive search for the W-+/--> pi(+/-)gamma decay is not optimal at the LHC because of the high trigger thresholds. Instead, a trigger selection is exploited in which the W boson originating from one of the top quarks is used to tag the event in a leptonic decay. The W boson emerging from the other top quark is used to search for the W-+/--> pi(+/-)gamma signature. Such decays are characterized by an isolated track pointing to a large energy deposit, and by an isolated photon of large transverse momentum. The presence of b quark jets reduces the background from the hadronization of light-flavor quarks and gluons. The W-+/- -> pi(+/-)gamma decay is not observed. An upper exclusion limit is set to this branching fraction, corresponding to 1.50 x 10(-5) at 95% confidence level, whereas the expected upper exclusion limit is 0.85(-0.29)(+0.52) x 10(-5). (C) 2021 The Author(s). Published by Elsevier B.V.

Açıklama

Anahtar Kelimeler

CMS, Standard model, EWK

Kaynak

WoS Q Değeri

Q1

Scopus Q Değeri

N/A

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Sayı

Künye

Physics Letters B Volume 819 Article Number 136409, 2021