After the Higgs boson discovery: a turning point in particle physics

Abstract

The discovery of the Higgs particle has completed the Standard Model of elementary interactions which is stunningly successful in describing most of the elementary processes observed so far in the laboratories. Nevertheless, it is not the Theory of Everything. Its structure faces some theoretical puzzles and, even more importantly, it leaves unexplained neutrino masses and several fundamental astrophysical observations. Thus, the quest for a deeper theory is at present the main experimental and theoretical challenge in particle physics. However, contrary to the past research characterized by certain continuity and clear goals, we are now in a turning point surfing into totally unknown territory beyond the Standard Model physics. Precision measurements of the Higgs particle properties is one of the promising directions in the search for extensions to the existing theory. This article is part of the theme issue ‘The particle-gravity frontier’.

The cosmological constant and scale hierarchies with emergent gauge symmetries

“…The mass scale of possible new dark matter particles is so far not known from experiments with ideas including new particles with masses ranging from 10 −22 eV up to 10 15 GeV-a range of 10 46 [102]. If the Standard Model does describe particle physics interactions at D = 4 up to the highest scales, then we do not expect lightest mass supersymmetry particles or extra inert Higgs doublet states as sources of dark matter.…”

“…Today a vigorous programme of experiments and theory is probing the high energy and precision frontiers together with cosmology looking for cracks in our description of Nature provided by the Standard Model and General Relativity. Ideas for new physics are discussed in the parallel theoretical contributions to this volume [15][16][17] with experiments discussed in [9,[18][19][20][21][22].…”

The particle-gravity frontier

“…Pokorski discusses the status of beyond the Standard Model theory after discovery of the Higgs boson and taking into account present constraints from collider and precision experiments [ 15 ]. Ideas for new particles include possible heavy supersymmetry particles and light mass axions.…”