The mass of this particle could break known physical rules

SCIENCE – This could very well be a great physical discovery, changing all laws known to date. Physicists have discovered that one of the 17 elementary particles known to physics, the W boson, is 0.1% heavier than expected. Reported in the magazine Sciences On April 7, this new measurement comes from the particle accelerator of the Fermilab laboratory in the United States (or CDF), specialized in the physics of particles high energies.

If this difference in mass may seem small, however, it could herald a revolution in fundamental physics. “It would be a complete change in the way we see the world”, even potentially rivaling the discovery of the Higgs’ Boson in 2012 in terms of importance, declares for quantum magazine, Sven Heinemeyer, physicist at the Institute of Theoretical Physics of Madrid. In fact, it would be the first major rewrite of the laws of quantum physics in half a century.

change model

Specifically, if the mass of this particle is actually greater than previously estimated, this changes all physical laws. Imagine a game of Tetris. Each particle constitutes a piece, forming a perfect whole. Only if one of the parts grows, then everything stops working. Therefore, it is necessary to rearrange the whole, modifying the shape of the parts, or even adding new ones to find the exact balance.

In this way, if the W boson has a slightly heavier mass, it means that the current physical laws no longer apply, and that a new model must be found to explain the functioning of the universe, from stars to everyday objects.

In fact, everything around us is made up of subatomic particles of matter. They are divided into two families: quarks (like neutrons and protons, elements that make up the nucleus of atoms) and leptons (like electrons). In total, today 12 elementary particles are listed, which form the category of fermions.

These particles of matter interact with each other. For this, another type of PARTICLE intervenes: the interaction particles. Called bosons, there are four of them, not counting the exception of the Higgs boson (or god particle). It is the interacting particles that are at play in three of the fundamental forces.

In total, there are four forces and they define the standard model of fundamental physics: the strong force, the weak force, the electromagnetic force, and the gravitational force. If the first three interact with each other, gravity is (for now) a special case.

Although it is the force with which we are most familiar, physicists have struggled to find a place for it in the Standard Model, despite the fact that the particle that carries gravity (in theory, the “graviton”) has yet to be observed. This is the reason why it is not present in the following table:

The particle physicists are interested in here is called the W boson, one of the sources of the weak force. To calculate its mass, the physicists relied on an analysis of around 4 million W bosons produced at the Tevatron (named after the CDF particle accelerator) between 2002 and 2011.

East discovery it comes at a time when the physics community is hungry for flaws in the standard model of particle physics. In fact, the standard model is known to be incomplete, leaving several big mysteries unsolved, such as the nature of dark matter.

“It’s a monumental piece of work,” said Frank Wilczek, a Nobel Prize-winning physicist at the Massachusetts Institute of Technology. “Overall, I feel like we’re getting close to the point where something is going to break,” El-Khadra said. “We are getting closer to the time when we can really see beyond the standard model.”

Caution Advised

However, no one is opening the champagne yet. While the new W mass measurement, taken in isolation, deviates sharply from the Standard Model prediction, other experiments weighing the W boson have yielded less spectacular results.

In 2017, for example, the ATLAS experiment at the Large Hadron Collider in Europe (a particle accelerator 27 km in circumference, the largest and most powerful in the world) measured the mass of the W particle and found that it was only a little. heavier than the standard model says.

It is important to understand the measurement difference between the two laboratories. In fact, as stated by Guillaume Unal, a physicist at CERN (the laboratory that houses the Large Hadron Collider), “the W boson must be the same on both sides of the Atlantic”.

See also in The HuffPost: This ‘Fire Cannon’ Appeared on the Sun Is 5 Times the Size of Earth

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