Heidelberg 2022 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 62: Higgs Boson: Extended Models 2

T 62.4: Talk

Wednesday, March 23, 2022, 17:00–17:15, T-H21

Search for A→ ZH→ ν ν bb at √s=13 TeV with the ATLAS detector — •Ilia Kalaitzidou, Tetiana Moskalets, and Spyridon Argyropoulos — University of Freiburg

The extension of the scalar SM Higgs sector, as described in the Two Higgs Doublet Models (2HDMs), could lead to a cosmological first order electroweak phase transition, which is necessary to explain the origin of the matter-antimatter asymmetry in the early Universe. The existence of a second Higgs doublet results in five physical scalar fields, two charged (H^±), a CP-odd (A) and two CP-even (h and H) neutral fields. A strong electroweak phase transition favours a heavy CP-odd scalar state A, together with a large mass splitting between the CP-odd A and CP-even H scalars. In this scenario, the A→ ZH decay becomes dominant. In the present work, the A→ ZH decay is investigated, with the H boson decaying to a pair of b-quarks and the Z boson decaying to neutrinos. The Z→ ν ν decay is examined, because of the expected increased sensitivity for large A masses. The optimisation studies for the A→ ZH→ ν ν bb analysis are presented, along with the expected exclusion in the m_H − m_A plane, covering a previously unexplored region.