But the results lacked the necessary statistical certainty to claim discovery. The collaborations had performed better than expected to discover the Higgs boson with just two years of data from the LHC.
Gonzalez Suarez celebrated with mixed emotions. The road from data to discovery was challenging. But what have we learnt about the Higgs boson since then? Find out more in part two of the Higgs saga coming soon. The Higgs boson: What makes it special? Image: CERN. As a layman I would now say… I think we have it. Elegance and symmetries 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.
The Standard Model of particle physics represented in a single equation Image: CERN 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. Something in nothing The Higgs field is peculiar in two particular ways.
Bump-hunting at the Large Hadron Collider Particle collisions at sufficiently high energies are necessary to produce a Higgs boson, but for a long time physicists were hunting in the dark: they did not know what this energy range was. The Higgs boson explained How do the elementary particles get their mass?
The Higgs boson: What makes it special? Feature article. The Higgs discovery explained. YouTube video series. Latest Related News. CERN experiments announce first indications o Exploring new ways to see the Higgs boson. Over the years, scientists had searched for it across a wide range of possible masses. By , there was only a tiny region left to search; everything else had been excluded by previous generations of experimentation.
If the predicted Higgs boson were anywhere, it had to be there, right where the LHC scientists were looking. But Incandela says he was skeptical about these preliminary results. He knew that the Higgs could manifest itself in many different forms, and this particular channel was extremely delicate. A common mantra in science is that extraordinary claims require extraordinary evidence.
If the analysis is bulletproof, the next question is whether the evidence is substantial enough to claim a discovery. And if a discovery can be claimed, the final question is what, exactly, has been discovered?
Scientists can have complete confidence in their results but remain uncertain about how to interpret them. With all of that in mind, Incandela and his team made a decision: From that point on, everyone would refine their scientific analyses using special data samples and a patch of fake data generated by computer simulations covering the interesting areas of their analyses.
Then, when they were sure about their methodology and had enough data to make a significant observation, they would remove the patch and use their algorithms on all the real data in a process called unblinding.
A few weeks before July 4, all the different analysis groups met with Incandela to present a first look at their unblinded results. This time the bump was very significant and showing up at the same mass in two independent channels. Faster particles like photons which is a boson hardly interact with a Higgs field.
This extra mass can be accounted for by the fact that, when quarks or the fermions which make up the proton are confined in a tiny region, they contain much more energy.
This energy is expressed as the extra mass. This is because, when the quarks are confined in a small region, the uncertainty in their position is less, consequently increasing the uncertainty in momentum. The Higgs boson is expected to be quite heavy, and its presence might be inferred if an elementary particle is found in numbers greater than expected when two particles collide at high velocities.
This would indicate that the massive i. However, it cannot be conclusively assumed that such an excess of fundamental particles can occur only due to a Higgs boson decay[5]. Another interesting fact regarding the Higgs is that it can decay into quark-antiquark pairs. The antiquark is the antipartner of the quark, which means that it has the same properties of quark, but with an opposite charge.
The Higgs-boson can decay to any quark along with its antiquark, except the top quark, since the top quark is heavier than the Higgs-boson. How strongly Higgs-bosons couple with a quark depends on the mass of the quark; the heavier the quark, the more the connection with Higgs. Of all the quarks other than the top quark, the bottom quark is the heaviest.
Thus, the Higgs-boson couples to it most strongly, and decays to bottom-antibottom pairs more than any other quark-antiquark pair. The next heaviest quark is the charm quark, and Higgs decaying to charm-anticharm pairs have also been observed; the ratio between these two decays go exactly as expected from their masses. The other quarks are much lighter, so it is much more difficult to see Higgs-bosons decaying into them.
Huge machines called particle accelerators are employed to detect elementary particles like the Higgs boson. The cyclotron is the basic particle accelerator. In the cyclotron[6], a positively-charged particle is placed between two semicircular D-shaped plates, and there exists a transverse magnetic field.
The plates are charged, and it is periodically reversed. On reaching high velocities, it can be thrown at a target to disintegrate it for further investigations on its inner structure. Figure 1: Cyclotron. Particles are made to move in a spiral path, in the presence of electromagnets, thus accelerating the motion of the particle. The LHC accelerates two particles to near-light velocities and collides them.
The particles ejected due to the collision are then studied.
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