From a distance, the Higgs Boson particle may seem completely irrelevant and disconnected from the real world, but it’s actually more integral to life and everything around you, than you may think.
Have you ever contemplated why you weigh what you do? I’m not alluding to the second doughnut you had this morning, or the ill advised chips on the way home, but rather the fundamental reason as to why the atoms that make up your body and everything else in the world, have a certain mass-If you haven’t you’re not alone-until recently, scientists haven’t thought about it much either.
Before the standard model of particle physics came along, the origin of mass was not even considered a problem; that an object had mass was simply assumed. But when scientists began probing objects at smaller and smaller scales, they discovered that it was not quite as simple as that: according to the standard model, fundamental particles should weigh nothing at all.
The standard model describes the behavior and interactions of all of the most fundamental particles we have seen – and one other particularly elusive one that, physicists hope, we will see in the near future. The model was developed throughout the 20th century and finalized when the existence of quarks, the particles that make up protons and neutrons, was confirmed in the 1970s. At the time many of the particles predicted by the standard model were yet to be seen. Over the years since then, physicists have ticked these particles off, one by one, like items on a shopping list. Now they are left with just one remaining unfound particle – the Higgs boson.
The Higgs requires a leap of faith, because so far it is entirely hypothetical. Some physicists are counting on it to help solve the most intractable riddles in their profession. It might, for instance, explain the preponderance of matter over antimatter in the cosmos. Or it might yield a formula that would unite gravity with the three other fundamental forces into a long-sought theory of everything. Above all, the Higgs could be the emissary of a ubiquitous force field that confers mass on matter. It could answer a huge question: Why does matter weigh something instead of nothing?
The Higgs was born of wishful thinking. British theoretical physicist Peter Higgs of the University of Edinburgh came up with the idea of the Higgs field and its associated particle – the Higgs boson – in 1964. The field he proposed extends throughout the universe, and interacts with matter particles in such a way as to give them mass. After an interaction the field leaves behind a telltale sign – the Higgs boson. Finding a Higgs boson would prove that the Higgs field exists.
The Higgs Field and the Large Electron Positron
Physicist Steven Weiberg of the University of Texas and Pakistani theorist Abdus Salam used the higgs concept to bring the theory in line with reality.
Weinberg (along with Ian Sample’s explanation of the Higgs Boson) describes the higgs field like a sea of molasses (or think of it as a massive plate completely filled with sugar grains) that fills all of space. It resists the movement of particles moving at light speed (and constantly crashing against each other), which in turn slows them down and creates a drag-the more a particle interacts with the field the heavier (and slower) it gets- which in turn causes the symmetry of the standard model to be restored because mass is no longer seen as an intrinsic property of matter,i.e all elementary particles weigh nothing until they interact with the higgs field.
The reason why the higgs field is such a solid theory is because the variations in the higgs field interactions are the only explanation physicist have for the fact that the heaviest known particle weighs 200,000 times as much as the lightest one, while protons weigh nothing at all.
Nobel laureate Leon Lederman wrote in his book (The God Particle, 1993) that “The Higgs field, the standard model and our picture of how God made the universe, all depends on finding the Higgs Boson”. His book paved the way for the Superconducting Supercollider, the $10 billion accelerator he designed to get the Higgs-due to it being thought of the most massive of all elementary particles the Higgs Boson would show up in only ultrahigh energy collisions-it was to be built, but after the book released the US congress pulled the plug on the project, of course this was the several heartbreaks for Higgs seekers. They came at the Large Electron Positron, or LEP, collider, a 17-mile-long particle smasher on the Franco-Swiss border at the European Center for Nuclear Research, called CERN for short. In August 2000, after a decade of collisions at gradually escalating energies, the collider team saw data that hinted at the presence of the Higgs. “We were sure we were going to find the Higgs particle,” says experimental physicist Christopher Tully of Princeton University, who heads the CERN search. “It was a very dramatic moment.”
Unfortunately, the LEP collider was shut down for good in November 2000 to make way for the $2.5 billion Large Hadron Collider.
The Large Hadron Collider and 4th of July 2012.
The LHC will be supported by 5,000 physicists and 500 research institutes around the world. It will hurl particles with seven times the energy of the Tevatron. “The LHC discovery of the Higgs is guaranteed-if it exists,” says experimental physicist Suyong Choi of Fermilab.
As a recap, we know that the origin of mass occurs at LHC energies. We know this because two fundamental forces, electromagnetism and the weak nuclear force, unify at these energies (see the second heading and the picture here). The reason these forces look different to us in everyday, low-energy, life is that the force-carrying-particles for the weak force (the W and Z) have mass.
In the Standard Model of particle physics, this mass can only happen if a certain kind of quantum field fills the universe, and sort of sticks to some particles to give them mass. Inventing a whole-universe-filling-field just to make your maths work is quite extreme. The only way of proving whether you’ve done the right thing or not, whether the field is real or not, is to make a wave in the field. This wave is, or would be, the Higgs boson. And it has to show up at the LHC or the field is either not there, or very different from what we expected. Nowhere to hide.
Anyway, as you heard in Fabiola’s talk today, ATLAS has found something. And as you and I heard today, CMS have found the same thing. Now, it looks like the Higgs boson. Or a Higgs boson. But it might not be. It has the right electric charge (i.e. none). It seems to appear about as often as it should in some decay modes. It is definitely a boson. But it is supposed to give mass to all fundamental particles, and we haven’t seen it do anything with fermions (quarks and leptons) yet, just bosons.
What does this all mean for ordinary people? And why should they care?
1) It is the most important scientific discovery of the 21st Century, and on par with Copernicus’s discovery that the sun is the center of our solar system.
2) It’s likely to have some practical uses that we can’t fathom right now, in much the same way as the discovery of the electron enabled every electronic device you use today.
3) We were right. Scientists theorized that a particle like the Higgs boson has to exist. They built a remarkable machine, the Large Hadron Collider (LHC) to find it. And they found it. Which not only allows us to feel good about ourselves as humans, it allows scientists to continue using a model of the universe that they’ve been working on for more almost 50 years. In short, scientists don’t have to start from scratch. And, this model and the LHC will allow us to explore even more nebulous ideas, such as dark matter.
Many people, including Peter Higgs himself, subscribe to the view that science for the sake of understanding the world around us is inherently valuable. If however, you need a more concrete reason to care about the Higgs, allow me to borrow some words from Carl Sagan: everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives on the pale blue dot we know as Earth – and none of it would have ever existed without the Higgs boson.