In a famous suspicion experiment, Erwin Schrödinger due putting a cat in a box with a quantum automatic device that competence or competence not kill a cat. Until a box is opened, a cat is both alive and dead.
There are many reasons since this can’t be finished in practice, one of that is that we can’t make a walls of a box ambiguous adequate to truly censor all information. However, molecule physicists frequently understanding with an analogue of a cat-in-a-box: middle particles that are too ephemeral to be observed. These particles disappear before they can correlate even once with their environment, so they are totally hidden.
Take, for example, a theme of a recent investigate by CMS scientists, B0 → K∗0μ+μ−. The B0 meson (which is a b quark firm to a lightweight quark) decays into 3 particles: K∗0 (which is an s quark firm to a lightweight quark), μ+ and μ−. For this spoil to be possible, inlet contingency find a approach to bond a one-particle initial state to a three-particle final state regulating elemental interactions. In a Standard Model, negatively charged bquarks can't renovate directly into negatively charged s quarks, so we competence consider that this spoil can never occur.
Two probable solutions are shown above, and both engage a span of transformations: b quark to t quark and tquark to s quark. Either way, ephemeral particles are indispensable to overpass a gap. Much like Schrödinger’s hapless cat, a dual middle processes are both function during a same time: a t-W-Zloop lives and dies in a same place during a same time as a t-W-ν-W loop. All of a final particles can be entirely reconstructed as tracks, so physicists can see justification of a dual realities blending in their bony distributions.
Exciting as it sounds, that partial is aged news. This research was achieved since a dual overlapping Standard Model solutions competence not be a usually ones. If as-yet undiscovered particles correlate with any of a above, there competence be a third approach to get from from a B0 meson to K∗0µ+µ−, serve distorting a bony distributions.
This could even occur if a new molecule is too complicated to emanate directly. Short-lived intermediaries can exist with opposite masses than their genuine counterparts, so they can be celebrated this approach even if they are over a strech of a LHC. Nothing surprising was seen this time, serve tightening constraints on new physics.
Source: FNAL, created by Jim Pivarski