Электронный каталог

Статья

Aad, G.
Search for Flavor-Changing Neutral-Current Couplings Between the Top Quark and the Z Boson with Proton-Proton Collisions at *%s=13 TeV with the ATLAS Detector / G.Aad, F.Ahmadov, I.N.Aleksandrov, V.A.Bednyakov, I.R.Boyko, I.A.Budagov, G.A.Chelkov, A.Cheplakov, E.Cherepanova, M.V.Chizhov, D.V.Dedovich, M.Demichev, A.Gongadze, M.I.Gostkin, S.N.Karpov, Z.M.Karpova, U.Kruchonak, V.Kukhtin, E.Ladygin, V.Lyubushkin, T.Lyubushkina, S.Malyukov, M.Mineev, E.Plotnikova, I.N.Potrap, N.A.Rusakovich, M.Shiyakova, A.Soloshenko, S.Turchikhin, I.Yeletskikh, A.Zhemchugov, N.I.Zimine, N.Huseynov, Y.Kulchitsky, [ATLAS Collab.] // Physical Review D [Electronic resource]. – 2023. – Vol.108, No.3. – P.032019. – URL: https://doi.org/10.1103/PhysRevD.108.032019. – Bibliogr.:116.

A search for flavor-changing neutral-current couplings between a top quark, an up or charm quark, and a Z boson is presented, using proton–proton collision data at √s=13  TeV collected by the ATLAS detector at the Large Hadron Collider. The analyzed data set corresponds to an integrated luminosity of 139  fb−1. The search targets both single-top-quark events produced as gq→tZ (with q=u, c) and top-quark-pair events, with one top quark decaying through the t→Zq channel. The analysis considers events with three leptons (electrons or muons), a b-tagged jet, possible additional jets, and missing transverse momentum. The data are found to be consistent with the background-only hypothesis and 95% confidence-level limits on the t→Zq branching ratios, assuming only tensor operators of the Standard Model effective field theory framework contribute to the tZq vertices. These are 6.2×10−5 (13×10−5) for t→Zu (t→Zc) for a left-handed tZq coupling, and 6.6×10−5 (12×10−5) in the case of a right-handed coupling. These results are interpreted as 95% CL upper limits on the strength of the corresponding couplings, yielding limits for |C(13)*uW| and |C(13)*uB| (|C(31)uW| and |C(31)uB|) of 0.15 (0.16), and limits for |C(23)*uW| and |C(23)*uB| (|C(32)uW| and |C(32)uB|) of 0.22 (0.21), assuming a new-physics energy scale ΛNP of 1 TeV.



ОИЯИ = ОИЯИ (JINR)2023
Спец.(статьи,препринты) = С 346.2в - Взаимодействие протонов с протонами
Спец.(статьи,препринты) = С 346.6д1 - Чармоний, боттомоний, топ-кварк. Очарованные частицы и др. резонансы из тяжелых кварков