The Higgs boson is the elementary particle linked with the Higgs field. It is a field that imparts mass to other subatomic particles, such as quarks and electrons. In other words, it is the boson or carrier particle of the Higgs field which fills the space and equips all the elementary particles with mass through its interplay with them. The Higgs particle is a scalar boson with positive parity, no electric charge
, no colour charge and zero spins. It is very unstable, and perhaps it decays into other elementary particles instantly.
The Higgs boson and Higgs field are named after the theoretical physicist Peter Higgs. He is one of the physicists who introduced the basic concept of the Higgs field. Interestingly, science enthusiasts call it the God particle.
The Higgs field is an energy field that is believed to be present in every area of the known universe. The field co-occurs with an elementary particle called the Higgs boson. The field constantly interacts with other fundamental particles like electrons, quarks, etc. In simple words, when indivisible particles interact with this field, they gain mass.
The Higgs field does not create mass. If that is the case, it would violate the laws of conservation (matter or energy cannot be created or destroyed). In reality, mass is gained by the particles through the interaction of the Higgs field with the Higgs boson. The Higgs boson has a relative mass in the form of energy. When a massless particle interacts with the field, the particle will slow down as the particle’s mass increases exponentially. If there is no Higgs field, particles will not have any mass and will float effortlessly at light speed.
The Higgs field is a scalar quantity, with two electrically charged and two neutral components that make a sophisticated doublet of weak isospin symmetry. Its potential has nonzero reading everywhere, which shatters the weak isospin symmetry of the electro-weak interaction, and through the Higgs field, some particles gain mass. In technical terms, the Higgs mechanism uses bosons to acquire rest mass without directly disrupting gauge invariance.
Higgs field was zero immediately after the big bang. As the universe’s temperature
dropped below a threshold value, the Higgs field grew instantaneously. Elementary particles started to gain mass by interacting with this field. The more a fundamental particle reacts with the field, the heavier it will become.
Physicists have searched for the elusive ‘god particle’ since the 1960's. The Higgs boson is extremely unstable and decays instantaneously. Therefore, it wasn’t easy to detect or observe it. Particle accelerators in CERN have been conducting continuous experiments to find the particle. After 40 years of search, on 4 July 2012, an elementary particle with the exact characteristics (Higgs boson) was discovered by CMS and ATLAS experiments at the LHC (Large Hadron Collider)*.
Scientists have observed the new particle in the region in the vicinity of 125 GeV.
The detected particle was consistent with the properties of the theoretical Higgs boson. However, further extensive studies have to be done to determine whether the particle is exactly the Higgs particle forecasted by the Standard Model.
* Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator
. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex
. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.
Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum
. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets
. The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy. This requires chilling the magnets to ‑271.3°C – a temperature colder than outer space
. For this reason, much of the accelerator is connected to a vast distribution system of liquid helium, which cools the magnets, as well as other supply services.
The inability to predict the mass of the Higgs Boson is one of many reasons most theoretical physicists believe that the Standard Model is not complete and may never be able to describe the whole particle story. Theoretical physicists are searching for extensions to the Standard Model that make it more coherent, more predictive, and more complete. Some possible theoretical extensions are Supersymmetry and the various String Theories.