A search for direct pair production of scalar partners of the top quark (top squarks or scalar third-generation up-type leptoquarks) in the all-hadronic tt¯ plus missing transverse momentum final state is presented. The analysis of 139 fb - 1 of s=13 TeV proton–proton collision data collected using the ATLAS detector at the LHC yields no significant excess over the Standard Model background expectation. To interpret the results, a supersymmetric model is used where the top squark decays via t~→t(∗)χ~10, with t(∗) denoting an on-shell (off-shell) top quark and χ~10 the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where mt~>mt+mχ~10, top squark masses are excluded in the range 400–1250 GeV for χ~10 masses below 200 GeV at 95% confidence level. In the situation where mt~∼mt+mχ~10, top squark masses in the range 300–630 GeV are excluded, while in the case where mt~
Search for a scalar partner of the top quark in the all-hadronic tt¯ plus missing transverse momentum final state at √s=13 TeV with the ATLAS detector / Aloisio, A., Alviggi, M., Canale, V., Della Pietra, M., Merola, L., Conventi, F., Rossi, E., Massarotti, P., De Asmundis, R., Cirotto, F., Lavorgna, M., Giannini, A., Di Donato, C., Iengo, P., Sekhniaidze, G., Izzo, V., Carlino, G., Doria, A., Loffredo, S.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 80:8(2020). [10.1140/epjc/s10052-020-8102-8]
Search for a scalar partner of the top quark in the all-hadronic tt¯ plus missing transverse momentum final state at √s=13 TeV with the ATLAS detector
ALOISIO ALBERTO;ALVIGGI MARIAGRAZIA;CANALE VINCENZO;DELLA PIETRA MASSIMO;MEROLA LEONARDO;ROSSI ELVIRA;MASSAROTTI PAOLO;DE ASMUNDIS Riccardo;CIROTTO FRANCESCO;LAVORGNA MARCO;GIANNINI ANTONIO;LOFFREDO, Salvatore
2020
Abstract
A search for direct pair production of scalar partners of the top quark (top squarks or scalar third-generation up-type leptoquarks) in the all-hadronic tt¯ plus missing transverse momentum final state is presented. The analysis of 139 fb - 1 of s=13 TeV proton–proton collision data collected using the ATLAS detector at the LHC yields no significant excess over the Standard Model background expectation. To interpret the results, a supersymmetric model is used where the top squark decays via t~→t(∗)χ~10, with t(∗) denoting an on-shell (off-shell) top quark and χ~10 the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where mt~>mt+mχ~10, top squark masses are excluded in the range 400–1250 GeV for χ~10 masses below 200 GeV at 95% confidence level. In the situation where mt~∼mt+mχ~10, top squark masses in the range 300–630 GeV are excluded, while in the case where mt~I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
