UNIGE document Scientific Article
previous document  unige:55780  next document
add to browser collection
Title

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at √s = 8 TeV with the ATLAS detector
CollaborationWith : Alexandre, Gauthier / Ancu, Lucian Stefan / Barone, Gaetano / Bell, Paul / Bell, William / Benhar Noccioli, Eleonora / Bilbao De Mendizabal, Javier / Bucci, Francesca / Camacho Toro, Reina / Clark, Allan Geoffrey / Delitzsch, Chris Malena / Della Volpe, Domenico / Doglioni, Caterina / Ferrere, Didier / Gadomski, Szymon / Gonzalez Sevilla, Sergio / Goulette, Marc / Gramling, Johanna Léna / Guescini, Francesco / Iacobucci, Giuseppe / Katre, Akshay / La Rosa, Alessandro / Mermod, Philippe / Miucci, Antonio / Muenstermann, Daniel / Nektarijevic, Snezana / Nikolics, Katalin / Picazio, Attilio / Pohl, Martin / Rosbach, Kilian / Tykhonov, Andrii / Vallecorsa, Sofia / Wu, Xin
Published in Journal of High Energy Physics. 2014, vol. 1409, p. 015-66
Collection Open Access - SCOAP3
Abstract The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1 fb −1 of proton-proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t ¯ → t χ ¯ 1 0 $$ \overline{t}\ \to t{\overline{\chi}}_1^0 $$ or t ¯ → b χ ¯ 1 ± → b W * χ ¯ 1 0 $$ \overline{t}\ \to b{\overline{\chi}}_1^{\pm }\ \to b{W}^{\left(*\right)}{\overline{\chi}}_1^0 $$ , where χ ¯ 1 0 χ ¯ 1 ± $$ {\overline{\chi}}_1^0\ \left({\overline{\chi}}_1^{\pm}\right) $$ 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 of t ¯ → t χ ¯ 1 0 $$ \overline{t}\ \to t{\overline{\chi}}_1^0 $$ . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ ¯ 1 0 $$ {\overline{\chi}}_1^0 $$ masses below 30 GeV. For a branching fraction of 50% to either t ¯ → t χ ¯ 1 0 $$ \overline{t}\ \to t{\overline{\chi}}_1^0 $$ or t ¯ → b χ ¯ 1 ± $$ \overline{t}\ \to b{\overline{\chi}}_1^{\pm } $$ , and assuming the χ ¯ 1 ± $$ {\overline{\chi}}_1^{\pm } $$ mass to be twice the χ ¯ 1 0 $$ {\overline{\chi}}_1^0 $$ mass, top squark masses in the range 250–550 GeV are excluded for χ ¯ 1 0 $$ {\overline{\chi}}_1^0 $$ masses below 60 GeV.
Keywords Hadron-Hadron Scattering — Supersymmetry — Top squark — Proton-proton scattering
Identifiers
arXiv: 1406.1122
Full text
Article (Published version) - public document Free access
Structures
Faculté des sciences / Section de physique / Département de physique nucléaire et corpusculaire
Citation
(ISO format) 		ATLAS COLLABORATION. Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at √s = 8 TeV with the ATLAS detector. In: Journal of High Energy Physics, 2014, vol. 1409, p. 015-66. https://archive-ouverte.unige.ch/unige:55780

182 hits

16 downloads

Contact an author

Update request

Update

Deposited on : 2015-04-27

Export document
Format :
Citation style :