Particle physics laboratory

Cambridge University’s Cavendish lab finds more evidence that the Standard Model of physics needs to be revised


Further evidence that the current theory of fundamental physics needs to be revised was revealed yesterday (Tuesday), following measurements by scientists at the Cavendish Laboratory at Cambridge University.

The results of the LHCb experiment at CERN near Geneva cannot be explained by the Standard Model, they said.

The LHCb experiment at CERN. Photo: CERN (45646694)

The Standard Model describes all of the known particles that make up the universe and the forces by which they interact. He had passed all the experimental tests.

But in March, the experiment found evidence of particles breaking one of its fundamentals. Now other measures have found similar effects.

Physicists have long known that the Standard Model is not complete. It does not include the force of gravity, nor does it take into account how matter was produced during the Big Bang. It also doesn’t contain any particles that could explain dark matter – which astronomy has shown to be five times more abundant than all of the things that make up the visible world.

The search for new particles and forces has led physicists to study beauty quarks – exotic cousins ​​of the “up and down” quarks that make up the nucleus of every atom.

These beauty quarks survive on average only a trillionth of a second before transforming or decaying into other particles.

But billions of them are produced each year by CERN’s giant particle accelerator, the Large Hadron Collider, and are recorded by a specially designed detector called LHCb.

In March, physicists at LHCb published evidence that beauty quarks decay less often into particles called muons than their lighter cousins, electrons, which was impossible to explain in the Standard Model, which treats equally.

There was only a 1 in 1000 chance that it was a statistical fluke.

Cambridge physicists re-examining the decay of beauty quarks recorded similar results, although this time there was a little more than two chances that it was a statistical fluke.

“The fact that we saw the same effect as our colleagues in March certainly increases the chances that we are truly about to discover something new,” said Dr Harry Cliff of the Cavendish Lab.

“It’s great to shed some light on the puzzle a bit more. “

The most likely explanation for the measurements is believed to be that a new force that pulls electrons and muons with different forces is interfering with decay.

“Excitement at the Large Hadron Collider is growing as the improved LHCb detector is about to be turned on and other data collected that will provide the statistics needed to claim or disprove a major discovery,” added Professor Val. Gibson, also of the Cavendish Laboratory.

Read more

Cambridge scientists move closer to the holy grail of particle physics with discovery that challenges the laws of nature

Obituary: Professor Antony Hewish, Cambridge astrophysicist, Nobel laureate, dies at 97

New initiative puts University of Cambridge at the forefront of the search for extraterrestrial life

Sign up for our weekly newsletter and stay up to date with Cambridge science



Your email address will not be published.