TY - JOUR

T1 - Search for flavour-changing neutral tqH interactions with H → γγ in pp collisions at s = 13 TeV using the ATLAS detector

AU - ATLAS Collaboration

AU - Barton, A.E.

AU - Bertram, I.A.

AU - Borissov, G.

AU - Bouhova-Thacker, E.V.

AU - Ferguson, R.A.M.

AU - Fox, H.

AU - Hagan, Alina

AU - Henderson, R.C.W.

AU - Jones, R.W.L.

AU - Kartvelishvili, V.

AU - Love, P.A.

AU - Marshall, E.J.

AU - Meng, L.

AU - Muenstermann, D.

AU - Ribaric, N.

AU - Rybacki, K.

AU - Smizanska, M.

AU - Spinali, S.

AU - Wharton, A.M.

PY - 2023/12/28

Y1 - 2023/12/28

N2 - A search for flavour-changing neutral interactions involving the top quark, the Higgs boson and an up-type quark q (q = c, u) is presented. The proton-proton collision data set used, with an integrated luminosity of 139 fb−1, was collected at s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. Both the decay process t → qH in tt¯ production and the production process pp → tH, with the Higgs boson decaying into two photons, are investigated. No significant excess is observed and upper limits are set on the t → cH and the t → uH branching ratios of 4.3 × 10−4 and 3.8 × 10−4, respectively, at the 95% confidence level, while the expected limits in the absence of signal are 4.7 × 10−4 and 3.9 × 10−4. Combining this search with ATLAS searches in the H → τ+τ− and H → bb¯ final states yields observed (expected) upper limits on the t → cH branching ratio of 5.8 × 10−4 (3.0 × 10−4) at the 95% confidence level. The corresponding observed (expected) upper limit on the t → uH branching ratio is 4.0 × 10−4 (2.4 × 10−4).

AB - A search for flavour-changing neutral interactions involving the top quark, the Higgs boson and an up-type quark q (q = c, u) is presented. The proton-proton collision data set used, with an integrated luminosity of 139 fb−1, was collected at s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. Both the decay process t → qH in tt¯ production and the production process pp → tH, with the Higgs boson decaying into two photons, are investigated. No significant excess is observed and upper limits are set on the t → cH and the t → uH branching ratios of 4.3 × 10−4 and 3.8 × 10−4, respectively, at the 95% confidence level, while the expected limits in the absence of signal are 4.7 × 10−4 and 3.9 × 10−4. Combining this search with ATLAS searches in the H → τ+τ− and H → bb¯ final states yields observed (expected) upper limits on the t → cH branching ratio of 5.8 × 10−4 (3.0 × 10−4) at the 95% confidence level. The corresponding observed (expected) upper limit on the t → uH branching ratio is 4.0 × 10−4 (2.4 × 10−4).

KW - Top Physics

KW - Higgs Physics

KW - Flavour Changing Neutral Currents

KW - Hadron-Hadron Scattering

U2 - 10.1007/jhep12(2023)195

DO - 10.1007/jhep12(2023)195

M3 - Journal article

VL - 2023

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1029-8479

IS - 12

M1 - 195

ER -