Journal Article

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at√s̅=8TeV with the ATLAS detector

Lucotte, A., Trocmé, B., Wu, M., Gris, Ph, Jézéquel, S., Koletsou, I., Diglio, Sara, Donini, J., Fayard, L., Przysiezniak, H., Schaffer, A.C., Schwoerer, M., Hrivnac, J., Lombardo, V.P., Gilles, G., Doan, T.K.O., Binet, S., Santoni, C., Gabaldon, C., Ledroit-Guillon, F., Pallin, D., Bourdarios, C., Makovec, N., Theveneaux-Pelzer, Timothée, Rybkin, G., Rahal, G., Zhang, Zhiqing, Valery, Loïc, Brown, J., Lafaye, R., Fournier, D., Serin, L., Ghodbane, N., Bertella, C., Lleres, A., Podlyski, F., Calvet, S., Simard, O., Le, B.T., Elles, S., Crépé-Renaudin, S., Guicheney, C., Keoshkerian, H., Calvet, D., Grivaz, J.-F., de Vivie de Regie, J.B., Abdel Khalek, S., Tran, H.L., Massol, N., Scifo, E., Berger, N., Renaud, A., Sauvan, E., Boumediene, D., Puzo, P., Liao, H., Wingerter-Seez, I., Simion, S., Dubreuil, E., Escalier, M., Malek, F., Poggioli, L., Stark, J., Henrot-Versillé, S., Guillemin, T., Coadou, Y., Barnovska, Z., Alio, L., Barbero, M., Duflot, L., Goy, C., Monini, C., Matricon, P., Bassalat, A., Lounis, A., Di Ciaccio, L., Todorov, T., Albrand, S., Iconomidou-Fayard, L., Hryn'Ova, T., Aad, G., Clémens, J.C., Delmastro, M., Tanaka, R., Becot, C., Par

2014

Overview

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of20.1 \\rm{fb}{⁻¹}{}of proton-proton collision data at√s̅=8TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay viat̃ → t χ̃₁⁰ort̃→ bχ̃₁^(±) → b W^(\\left{(}{∗}{\\right)}) χ̃₁⁰ , whereχ̃₁⁰( χ̃₁^(±) ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction oft̃ → t χ̃₁⁰ . For a branching fraction of 100%, top squark masses in the range 270-645 GeV are excluded forχ̃₁⁰masses below 30 GeV. For a branching fraction of 50% to eithert̃ → t χ̃₁⁰ort̃→ bχ̃₁^(±) , and assuming theχ̃₁^(±)mass to be twice theχ̃₁⁰mass, top squark masses in the range 250-550 GeV are excluded forχ̃₁⁰masses below 60 GeV.

• Publisher: Springer
• Subject: High Energy Physics - Experiment / Physics