The famous Higgs boson, co-responsible for the existence of masses in elementary particles, may also interact with a new and unknown physics about which some hypotheses have been raised and for which evidence of its existence has been sought for decades.
If so, the Higgs boson should decay in a characteristic way, involving exotic particles. Marcin Kucharczyk and Mateusz Goncerz, both from the Henryk Niewodniczanski Institute for Nuclear Physics under the Polish Academy of Sciences, have shown that if such decays actually occur, they will be observable in successors to the LHC (the world’s largest and most powerful particle accelerator). ) that are currently being designed.
The quaint term “hidden valley”, which would not be out of place in the title of a horror or sword and sorcery novel, nevertheless has a scientific meaning. In high energy physics, it is the name given to certain models that extend the set of currently known elementary particles. In these so-called Hidden Valley models, the particles of our world described by the Standard Model of physics belong to the low-energy group, while the exotic particles lurk in the high-energy region.
There are theoretical ideas about the exotic decay of the Higgs boson, but the truth is that this decay has never been captured at the LHC despite many years of searching. However, Kucharczyk and Goncerz argue that Higgs boson decays into exotic particles should already be perfectly observable in the successor accelerators to the LHC, if any of the Hidden Valley models turn out to be consistent with reality.
Possible search path to capture exotic decays of the Higgs boson in future particle accelerators using leptons. 1: an electron and a positron of opposite beams collide. 2: The collision produces a high-energy Higgs boson. 3: the boson disintegrates generating two exotic particles that move away from the axis of the beams. 4: exotic particles disintegrate generating quark-antiquark pairs, recognizable by detectors. (Image: IFJ PAN. CC BY SA)
“In the Hidden Valley models we have two groups of particles separated by an energy barrier. The theory is that there could be exotic massive particles capable of crossing this barrier under specific circumstances. Particles like the Higgs boson or the hypothetical Z boson’ (Z-prime boson) would act as communicators between the particles of one world and those of the other. The Higgs boson, one of the most massive particles in the Standard Model, is a very good candidate to be such a communicator,” he explains. Kucharczyk.
The communicator, after passing into the low energy region, would decay into two fairly massive exotic particles. In a matter of picoseconds (billionths of a second), each of these particles would disintegrate into two other particles of even smaller mass, which would fit into the Standard Model and would be detectable. The details of its appearance and behavior would be peculiar enough to, along with other clues, betray its ultimate origin in particles of other physics.
The study is titled “Search for exotic decays of the Higgs boson into long-lived particles with jet pairs in the final state at CLIC”. And it has been published in the Journal of High Energy Physics. (Fountain: NCYT by Amazings)