What is the Standard Model of Particle Physics?
Read moreRecently, researchers announced that they had made a precise measurement of the mass of the so-called W boson.
What did the researchers find? Why is it important?
Scientists stated that the W boson is slightly heavier than that predicted by the so-called Standard Model of particle physics. This result is highly significant because this hints at the incompleteness of the standard model description.
The new measurements challenge the Standard Model and show that there is physics beyond this. Do we need to rewrite particle physics?
What is the Standard Model of Particle Physics?
The Standard Model of Particle Physics is scientists’ current best theory to describe the most basic building blocks of the universe. It explains how particles called quarks (which make up protons and neutrons) and leptons (which include electrons) make up all known matter.
The Model describes three of the four fundamental forces that govern the universe: electromagnetism, the strong force, and the weak force.
It is believed to be incomplete because it totally omits gravity, the fourth fundamental force. Also, the Model does not include a description of dark matter particles and dark energy, which constitutes 95% of the universe. Currently, these have been detected only through their gravitational pull on surrounding matter. So, in the grand scheme of unifying all forces so that a single equation could describe all matter interactions, the standard Model was discovered to be deficient.
What is W Boson?
The W Boson was discovered in 1983 at CERN, located on the Franco-Swiss border.
The W boson is a fundamental particle. Together with the Z boson, it is responsible for the weak force. It converts protons into neutrons and vice versa. The weak force is responsible for the nuclear fusion reactions that power the sun and produce the energy required for life on Earth. In contrast to the photon (that makes up one of the fundamental forces that govern the universe: electromagnetism), which is massless, the W bosons are quite massive.
Higgs Boson ( God particle ) – CERN (European Organisation for Nuclear Research) is the world’s largest nuclear and particle physics laboratory and operates the Large Hadron Collider, which found the elusive Higgs boson in 2012.
Theorists Robert Brout, Francois Englert, and Peter Higgs proposed the Brout-EnglertHiggs mechanism that gives a mass to the W and Z Boson when they interact with an invisible field, now called the “Higgs field,” which spreads throughout the universe.
The Higgs field was zero just after the Big Bang, but as the universe cooled, the field grew automatically, and any particle that interacted with it acquired mass. The greater a particle’s interaction with this field, the heavier it becomes. Particles, like the photon that do not interact with it, are left with negligible mass. Like all fundamental fields, the Higgs field is described in the form of a particle called the Higgs boson and is often called the “God particle.”
Source: TH