New physics: latest results from Cern further boost tantalising evidence - The Conversation UK

Famously, it describes only three of the four fundamental forces – the electromagnetic force and strong and weak forces, leaving out gravity.

Most physicists are therefore confident that there must be more cosmic ingredients yet to be discovered, and studying a variety of fundamental particles known as beauty quarks is a particularly promising way to get hints of what else might be out there.

Beauty quarks, sometimes called bottom quarks, are fundamental particles, which in turn make up bigger particles.

Up and down quarks, for example, make up the protons and neutrons in the atomic nucleus.

Beauty quarks are unstable, living on average just for about 1.5 trillionths of a second before decaying into other particles.

The way beauty quarks decay can be strongly influenced by the existence of other fundamental particles or forces.

When a beauty quark decays, it transforms into a set of lighter particles, such as electrons, through the influence of the weak force.

One of the ways a new force of nature might make itself known to us is by subtly changing how often beauty quarks decay into different types of particles.

(The “b” in LHCb stands for “beauty”.) It found that beauty quarks were decaying into electrons and their heavier cousins called muons at different rates.

This means that all the forces should pull on electrons and muons with equal strength – when a beauty quark decays into electrons or muons via the weak force, it ought to do so equally often.

Assuming the result is correct, the only way to explain such an effect would be if some new force of nature that pulls on electrons and muons differently is interfering with how beauty quarks decay.

Strictly speaking, we never actually study beauty quark decays directly, since all quarks are always bound together with other quarks to make larger particles.

The March study looked at beauty quarks that were paired up with “up” quarks.

Our result studied two decays: one where the beauty quarks that were paired with “down” quarks and another where they were also paired with up quarks.