Where is higgs boson

At the subatomic scale, the universe is a complex choreography of elementary particles interacting with one another through fundamental forces, which can be explained using a term that physicists of all persuasions turn to: elegance.

In quantum field theory, both matter particles fermions such as electrons, or the quarks inside protons and the force carriers bosons such as the photon, or the gluons that bind quarks are manifestations of underlying, fundamental quantum fields. Today we call this elegant description the Standard Model of particle physics.

The Standard Model is based on the notion of symmetries in nature, that the physical properties they describe remain unchanged under some transformation, such as a rotation in space. Using this notion, physicists can provide a unified set of equations for both electromagnetism electricity, magnetism, light and the weak nuclear force radioactivity. The force which is thus unified is dubbed the electroweak force. The Brout-Englert-Higgs mechanism introduced a new quantum field that today we call the Higgs field, whose quantum manifestation is the Higgs boson.

Only particles that interact with the Higgs field acquire mass. Originally conceived to explain the masses of the W and Z bosons only, scientists soon found they could extend the Brout-Englert-Higgs mechanism to account for the mass of all massive elementary particles. The mathematical puzzle had been solved decades ago but whether the maths described physical reality remained to be tested. Imagine an empty region of space, a perfect vacuum, without any matter present in it.

Quantum field theory tells us that this hypothetical region is not really empty: particle—antiparticle pairs associated with different quantum fields pop into existence briefly before annihilating, transforming into energy. The Higgs field on the other hand has a really high vacuum expectation value. When the universe had just come into being and was extremely hot, its energy density was higher than the energy associated with the vacuum expectation value of the Higgs field.

As a result, the symmetries of the Standard Model could hold, allowing particles such as the W and Z to be massless. As the universe started to cool down, the energy density dropped, until — fractions of a second after the Big Bang — it fell below that of the Higgs field.

This resulted in the symmetries being broken and certain particles gained mass. A clear pattern is also evident in the case of a compass: Move it and the needle points north again. I can imagine a young Einstein thinking there must be a general law stipulating that suspended metallic needles are pushed north.

But no such law exists. The example is simple but the lesson profound. In the case of a compass, disentangling the two is not difficult. But there can be other situations where environmental influences are so pervasive, and so beyond our ability to manipulate, it would be far more challenging to recognize their influence.

Physicists tell a parable about fish investigating the laws of physics but so habituated to their watery world they fail to consider its influence. The fish struggle mightily to explain the gentle swaying of plants as well as their own locomotion. The laws they ultimately find are complex and unwieldy.

Then, one brilliant fish has a breakthrough. At first, the insightful fish is ignored, even ridiculed. But slowly, the others, too, realize that their environment, its familiarity notwithstanding, has a significant impact on everything they observe.

Does the parable cut closer to home than we might have thought? The discovery of the Higgs particle by the Large Hadron Collider in Geneva has convinced physicists that the answer is a resounding yes. Nearly a half-century ago, Peter Higgs and a handful of other physicists were trying to understand the origin of a basic physical feature: mass.

Push on a freight train or a feather to increase its speed, and the resistance you feel reflects its mass. But where do the masses of these and other fundamental particles come from? When physicists in the s modeled the behavior of these particles using equations rooted in quantum physics, they encountered a puzzle.

If they imagined that the particles were all massless, then each term in the equations clicked into a perfectly symmetric pattern, like the tips of a perfect snowflake. And this symmetry was not just mathematically elegant. It explained patterns evident in the experimental data. The equations became complex and unwieldy and, worse still, inconsistent. What to do? Instead, keep the equations pristine and symmetric, but consider them operating within a peculiar environment.

Imagine that all of space is uniformly filled with an invisible substance—now called the Higgs field—that exerts a drag force on particles when they accelerate through it. Push on a fundamental particle in an effort to increase its speed and, according to Higgs, you would feel this drag force as a resistance. For a mental toehold, think of a ping-pong ball submerged in water. When you push on the ping-pong ball, it will feel much more massive than it does outside of water.

Its interaction with the watery environment has the effect of endowing it with mass. So with particles submerged in the Higgs field. In , Higgs submitted a paper to a prominent physics journal in which he formulated this idea mathematically. While this is true for the photon, we know that the W and Z have mass, nearly times that of a proton.

Just after the big bang , the Higgs field was zero, but as the universe cooled and the temperature fell below a critical value, the field grew spontaneously so that any particle interacting with it acquired a mass.

The more a particle interacts with this field, the heavier it is. Particles like the photon that do not interact with it are left with no mass at all. Like all fundamental fields, the Higgs field has an associated particle — the Higgs boson. The Higgs boson is the visible manifestation of the Higgs field, rather like a wave at the surface of the sea.

A problem for many years has been that no experiment has observed the Higgs boson to confirm the theory. This particle is consistent with the Higgs boson but it will take further work to determine whether or not it is the Higgs boson predicted by the Standard Model.

The Higgs boson, as proposed within the Standard Model, is the simplest manifestation of the Brout-Englert-Higgs mechanism. Other types of Higgs bosons are predicted by other theories that go beyond the Standard Model. How do the elementary particles get their mass?