Dortmund 2021 – scientific programme
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T: Fachverband Teilchenphysik
T 87: Extended Higgs Models III
T 87.5: Talk
Thursday, March 18, 2021, 17:00–17:15, Tl
A search for resonances decaying into a Higgs boson and a new particle X with the ATLAS detector — •Nicola de Biase1,2, Vincenzo Canale2, Francesco Conventi2, Francesco Cirotto2, Silvia Auricchio2, and Antonio Giannini2 — 1DESY Hamburg — 2Università Federico II e sezione INFN di Napoli
Several theories beyond the Standard Model (SM) are theoretically well motivated and predict the existence of high mass particles that are likely to produce a Higgs boson when decaying.
In this talk, a search for a new narrow resonance Y at the TeV scale, decaying into a Higgs boson and a new boson (X), with a completely hadronic XH→ qq′bb final state is presented. The search uses data from proton-proton collisions at a center of mass energy √s=13 TeV and corresponding to a 139 fb−1 integrated luminosity, collected by the ATLAS experiment at CERN.
The X boson decay can have two different signatures: for low momenta of the X, the quarks qq′ hadronize into a pair of well separated jets, while for high momenta they merge into a single large radius jet.
A new tagging algorithm, based on a feed forward Deep Neural Network, is used to identify the Higgs decay.
A set of signal hypotheses, characterized by two continuous parameters, the masses of the new particles, is investigated. A machine learning algorithm (parametrized Deep Neural Network) that takes into account this dependence is used to enhance the discovery sensitivity for new signals over SM background processes.