A search for resonances decaying into a Higgs boson and a new particle X in the XH -> qqbb final state with the ATLAS detector

2018 The Author(s) A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb1 of protonproton collision data at s=13TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state XHqqbb is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the XHqqbb resonance.

Aaboud, M., Aad, G., Abbott, B., Abdinov, O., Abeloos, B., Abidi, S. H., ... Zwalinski, L.

Aaboud, M||Aad, G||Abbott, B||Abdinov, O||Abeloos, B||Abidi, SH||AbouZeid, OS||Abraham, NL||Abramowicz, H||Abreu, H||Abreu, R||Abulaiti, Y||Acharya, BS||Adachi, S||Adamczyk, L||Adelman, J||Adersberger, M||Adye, T||Affolder, AA||Afik, Y||Agheorghiesei, C||Aguilar-Saavedra, JA||Ahlen, SP||Ahmadov, F||Aielli, G||Akatsuka, S||Akerstedt, H||Åkesson, TPA||Akilli, E||Akimov, AV||Alberghi, GL||Albert, J||Albicocco, P||Alconada Verzini, MJ||Alderweireldt, SC||Aleksa, M||Aleksandrov, IN||Alexa, C||Alexander, G||Alexopoulos, T||Alhroob, M||Ali, B||Aliev, M||Alimonti, G||Alison, J||Alkire, SP||Allbrooke, BMM||Allen, BW||Allport, PP||Aloisio, A||Alonso, A||Alonso, F||Alpigiani, C||Alshehri, AA||Alstaty, MI||Alvarez Gonzalez, B||Álvarez Piqueras, D||Alviggi, MG||Amadio, BT||Amaral Coutinho, Y||Amelung, C||Amidei, D||Amor Dos Santos, SP||Amoroso, S||Anastopoulos, C||Ancu, LS||Andari, N||Andeen, T||Anders, CF||Anders, JK||Anderson, KJ||Andreazza, A||Andrei, V||Angelidakis, S||Angelozzi, I||Angerami, A||Anisenkov, AV||Anjos

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