TY - JOUR
T1 - Search for flavour-changing neutral-current couplings between the top quark and the Higgs boson in multi-lepton final states in 13 TeV pp collisions with the ATLAS detector
AU - ATLAS Collaboration
AU - Allport, Phil
AU - Auriol, Adrien
AU - Bellos, Panagiotis
AU - Bracinik, Juraj
AU - Charlton, David
AU - Chisholm, Andrew
AU - Cooke, Harry
AU - Dimitrievska, Aleksandra
AU - George, Will
AU - Gonella, Laura
AU - Gonnella, Francesco
AU - Hawkes, Chris
AU - Hillier, Stephen
AU - Krizka, Karol
AU - Liu, Eric
AU - Lomas, Josh
AU - Marinescu, Mihaela
AU - Neep, Thomas
AU - Newman, Paul
AU - Nikolopoulos, Konstantinos
AU - Skorda, Eleni
AU - Stampekis, Alexis
AU - Thomas, Jurgen
AU - Thompson, Paul
AU - Virdee, Gov
AU - Ward, Robert
AU - Watson, Alan
AU - Watson, Miriam
AU - Wu, C.
PY - 2024/7/2
Y1 - 2024/7/2
N2 - A search is presented for flavour-changing neutral-current interactions involving the top quark, the Higgs boson and an up-type quark (q=u,c) with the ATLAS detector at the Large Hadron Collider. The analysis considers leptonic decays of the top quark along with Higgs boson decays into two W bosons, two Z bosons or a τ+τ− pair. It focuses on final states containing either two leptons (electrons or muons) of the same charge or three leptons. The considered processes are tt¯ and Ht production. For the tt¯ production, one top quark decays via t→Hq. The proton-proton collision data set analysed amounts to 140 fb−1 at √s = 13 TeV. No significant excess beyond Standard Model expectations is observed and upper limits are set on the t→Hq branching ratios at 95\% confidence level, amounting to observed (expected) limits of B(t→Hu) < 2.8(3.0) × 10−4 and B(t→Hc) <3.3(3.8) × 10−4. Combining this search with other searches for tHq flavour-changing neutral-current interactions previously conducted by ATLAS, considering H→bb¯ and H→γγ decays, as well as H→τ+τ− decays with one or two hadronically decaying τ-leptons, yields observed (expected) upper limits on the branching ratios of B(t→Hu) < 2.6(1.8) × 10−4 and B(t→Hc) < 3.4(2.3) × 10−4.
AB - A search is presented for flavour-changing neutral-current interactions involving the top quark, the Higgs boson and an up-type quark (q=u,c) with the ATLAS detector at the Large Hadron Collider. The analysis considers leptonic decays of the top quark along with Higgs boson decays into two W bosons, two Z bosons or a τ+τ− pair. It focuses on final states containing either two leptons (electrons or muons) of the same charge or three leptons. The considered processes are tt¯ and Ht production. For the tt¯ production, one top quark decays via t→Hq. The proton-proton collision data set analysed amounts to 140 fb−1 at √s = 13 TeV. No significant excess beyond Standard Model expectations is observed and upper limits are set on the t→Hq branching ratios at 95\% confidence level, amounting to observed (expected) limits of B(t→Hu) < 2.8(3.0) × 10−4 and B(t→Hc) <3.3(3.8) × 10−4. Combining this search with other searches for tHq flavour-changing neutral-current interactions previously conducted by ATLAS, considering H→bb¯ and H→γγ decays, as well as H→τ+τ− decays with one or two hadronically decaying τ-leptons, yields observed (expected) upper limits on the branching ratios of B(t→Hu) < 2.6(1.8) × 10−4 and B(t→Hc) < 3.4(2.3) × 10−4.
UR - https://link.springer.com/journal/10052
U2 - 10.1140/epjc/s10052-024-12994-1
DO - 10.1140/epjc/s10052-024-12994-1
M3 - Article
SN - 1434-6044
VL - 84
JO - European Physical Journal C
JF - European Physical Journal C
M1 - 757
ER -