Testing Naturalness

Abstract

Solutions to the electroweak hierarchy problem typically introduce a new symmetry to stabilize the quadratic ultraviolet sensitivity in the self-energy of the Higgs boson. The new symmetry is either broken softly or collectively, as for example in supersymmetric and little Higgs theories. At low energies such theories contain naturalness partners of the Standard Model fields which are responsible for canceling the quadratic divergence in the squared Higgs mass. Post the discovery of any partner-like particles, we propose to test the aforementioned cancellation by measuring relevant Higgs couplings. Using the fermionic top partners in little Higgs theories as an illustration, we construct a simplified model for naturalness and initiate a study on testing naturalness. After electroweak symmetry breaking, naturalness in the top sector requires $a_T=-{\lambda }_t^2$ at leading order, where ${\lambda }_t$ and $a_T$ are the Higgs couplings to a pair of top quarks and top partners, respectively. Using a multivariate method of Boosted Decision Tree to tag boosted particles in the Standard Model, we show that, with a luminosity of 30 $a{b}^{-1}$ at a 100 TeV $pp$-collider, naturalness could be tested with a precision of 10 % for a top partner mass up to 2.5 TeV.

20 pages, 7 figures, 2 tables

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Cited by in corpus (5)

• Strong first order electroweak phase transition in 2HDM confronting future Z & Higgs factories
• Universal Imprints of a Pseudo-Nambu-Goldstone Higgs Boson
• Six Top Messages of New Physics at the LHC
• Portal Effective Theories: A framework for the model independent description of light hidden sector interactions
• Naturalness Sum Rules and Their Collider Tests