In a few facilities around the world, scientists are working on the answer to a question that almost seems foolish to ask: are we wrong about the very foundations of how we define our world?
The average person might think this seems like a good time to leave well enough alone. But a few physicists at Boston University and their colleagues disagree – and what’s more, they may be closer than ever to finding that the answer may be yes.
It’s a story with a lot of colorful characters, literally and figuratively. At its center is a what may be a new particle, one that could actually be nothing more than a fluke of the data. Proving its existence will require a delicate combination of luck and skill, but if it pans out, such a discovery will transform the standard model of particle physics and humanity’s most basic understanding of the universe.
LIFE IN TECHNICOLOR
In his fifth floor office in the BU Physics Research Building, Prof. Ken Lane is looking for a folder. It kind of seems like a needle in a haystack, but it’s no wonder – Lane is surrounded by the accumulated research of decades.
Lane, a theorist, along with his experimentalist colleagues at the Fermilab Tevatron Collider in Batavia, Ill. and the Large Hadron Collider at CERN in Geneva, Switzerland, may finally be nearing the solution to the problem that has long perplexed particle physicists.
Lane’s field is “electroweak symmetry breaking” – the physics of how the fundamental weak and electromagnetic forces got split apart in the early universe. Specifically, he is interested in a theory called “technicolor” that he has been developing since the 1970s.
Technicolor is what will make the new particle, if it exists, so important. It will signify that there is a new fifth force of nature.
“What we do in particle physics . . . the Holy Grail is to understand what are the fundamental most elementary particles and what are their interactions,” Lane said in an interview last Thursday. “We can write down on a small piece of paper a formula that contains everything, how they interact. And doing the calculations from that small formula is a big deal, but the formula sort of summarizes everything.”
But there are also certain problems with that Holy Grail theory, which Kevin Black, an assistant professor of physics at BU and a collaborating researcher, said the team hopes to fix.
“You collide two protons and you see what comes out, more or less,” he said in a telephone interview. “We’re trying to understand the structure of matter and what fundamental particles exist . . . and we’re exploring a few things at once. We’re testing our theories of elementary particles and looking for evidence of new particles.”
For the past several months, Black and other researchers working on different experiments at different labs have been carefully considering a blip in the data from their collisions. If they are independently able to isolate this blip from the background noise generated in the collisions, it would represent a new particle with technicolor properties – “new physics,” according to Lane, that in turn would explain fundamental interactions that have perplexed physicists for decades.
But it’s easier said than done. Standing at the chalkboard beside his desk, Lane likened the search for the particle in all that static to attempting to fine-tune an extremely finicky radio.
“Every once in a while one of these experiments sees something unexpected and new,” he said. “Many, many times it’s measurement error, because understanding how to calculate these backgrounds is very difficult.”
And the proverbial radio in this scenario is also vastly complex.
“These [detectors] are the most complicated things ever built by human beings,” he said. “The space program is building blocks – toy blocks – Legos compared to these detectors.”
One issue with the standard model of particle physics and the definitions of particle interactions, Lane explained, is called electroweak symmetry breaking. The electroweak interaction is between the electromagnetic and the weak force. The former involves photons; the latter involves particles known as W and Z bosons, which, unlike protons, have mass.
“There’s a symmetry that describes this interaction, and the symmetry says they all have the same mass, photon, W and the Z. But they don’t. One’s massless and the others are very heavy. So the question is, how did that happen?” Lane said. “Because if we understand how that happens, then first off, we can explain most of all the everyday phenomena around us. Weak interactions are responsible for keeping the sun lit.”
Not only do these interactions keep most everything in the universe running, but they also affect the way the universe is literally defined, mathematically and scientifically. One small change within that system could potentially upset a host of other long-held principles and could furthermore help answer other long-held questions.
“That would be big,” said collaborating researcher and BU assistant professor of physics Tulika Bose in a phone interview, referencing the validation of technicolor and techni-particles, as the potential new entities are known. “It would really shake our current understanding of the standard model.”
MATH IN REAL LIFE
But that average person who wanted to leave well enough alone is probably still wondering – what does this have to do with my life?
“We are trying to answer the fundamental questions of nature, and to me that’s as important as trying to understand, you know, how everything in everyday life works – how does your light bulb work and what’s the energy to run your car?” she said. “These are fundamental questions for our daily lives, but if you understand what’s going on in the universe, that helps you make progress in society.”
Black agreed that such discoveries as these have more relevance to human life than one might think.
“When people are doing cancer research or something, there’s a very obvious motivation that you can understand for something like that,” he said. “For fundamental science, you can’t point to something that directly, but . . . all the technology, all the computers, the phone relies on having understanding of how that all works.
“Even if you can’t see a direct connection of how this relates to your everyday life, in the long run understanding that fundamental science leads to all these applications,” he said.
THE ELEGANT UNIVERSE
On Cummington Street, hundreds of miles from the colliders that will make or break his theories, Professor Lane sits behind his desk, surrounded by 40 years’ of searching. He said there are many reasons for his self-described “obsession” with finding an answer to the questions he works on.
“Personality defects, or desire to be famous or deep curiosity about what causes these things,” he said. “Science is very, very beautiful, and physics is a very beautiful subject – the more you know about it, the more gorgeous it is, and mysterious and mind-bending.”
One experiment at Fermilab may have already observed the potential new particle that would so transform the standard model. Others at Fermilab and the LHC are still waiting to report.
“If these experimentalists, if they’re right, there’s probably a Nobel Prize in it for them, I hope,” Lane said. “It’s a very, very, very important discovery. And if they’re wrong, they’re wrong.”
But Lane said he sees some beauty in that black-and-white frame of possibility, too.
“That’s the wonderful thing about physics as opposed to many other things, there’s an absolute standard of right and wrong, and it’s either right or it’s wrong,” he said. “It’s an experimental science. All the theories are subject to experimental tests. If they aren’t subject to experimental tests, they aren’t really physics.”