Fermilab Today

When physicists discovered the Higgs boson in 2012, they declared the Standard Model of particle physics complete; they had finally found the missing piece of the particle puzzle.

And yet, many questions remain about the basic components of the universe, including: Did we find the one and only type of Higgs boson? Or are there more?

A problem of mass
The Higgs mechanism gives mass to some fundamental particles, but not others. It interacts strongly with W and Z bosons, making them massive. But it does not interact with particles of light, leaving them massless.

These interactions don't just affect the mass of other particles, they also affect the mass of the Higgs. The Higgs can briefly fluctuate into virtual pairs of the particles with which it interacts.

Scientists calculate the mass of the Higgs by multiplying a huge number — related to the maximum energy for which the Standard Model applies — with a number related to those fluctuations. The second number is determined by starting with the effects of fluctuations to force-carrying particles like the W and Z bosons, and subtracting the effects of fluctuations to matter particles like quarks.

While the second number cannot be zero because the Higgs must have some mass, almost anything it adds up to, even at very small numbers, makes the mass of the Higgs gigantic.

But it isn't. It weighs about 125 billion electronvolts; it's not even the heaviest fundamental particle.

"Having the Higgs boson at 125 GeV is like putting an ice cube into a hot oven and it not melting," says Flip Tanedo, a theoretical physicist and postdoctoral researcher at the University of California, Irvine.

A lightweight Higgs, though it makes the Standard Model work, doesn't necessarily make sense for the big picture. If there are multiple Higgses — much heavier ones — the math determining their masses becomes more flexible.

"There's no reason to rule out multiple Higgs particles," says Tim Tait, a theoretical physicist and professor at UCI. "There's nothing in the theory that says there shouldn't be more than one."

The two primary theories that predict multiple Higgs particles are Supersymmetry and compositeness.

—Katie Elyce Jones

In Brief

Colloquium: 'DNDO Research Perspectives' - tomorrow at 4 p.m. in One West

Joel Rynes

Joel C. Rynes, assistant director of the Transformational and Applied Research Directorate, from the Domestic Nuclear Detection Office (DNDO) Department of Homeland Security, will describe the mission of DNDO and role that research plays in insuring national security.

The mission of the Transformational and Applied Research (TAR) Directorate in the DNDO is to develop breakthrough technologies that will have a dramatic impact on capabilities for detecting nuclear and radiological threats through an aggressive and expedited R&D program. This talk will discuss TAR's multiyear R&D approach to solve one of these challenges, the detection of nuclear threats even when heavily shielded. Special emphasis will be given on the role of traditional and nontraditional particle acceleration techniques to help solve this challenge.

Prior to his assignment as assistant director, Rynes served as program manager at DNDO, beginning in 2006. Before that, from 1999-2006, he was a program manager at General Dynamics and a staff scientist at both Ancore Corporation and Science Applications International Corporation. Rynes holds a Ph.D. in nuclear engineering from the University of California, Berkeley, and a B.S. in nuclear engineering from the University of Illinois at Urbana-Champaign.

In the News

Here's how monumental the LHC's mountain of data really is

From Popular Mechanics, Aug. 3, 2015

Twenty quadrillion bytes. Twenty million gigabytes. Twenty petabytes. That's how much data the Large Hadron Collider produces per year.

This Fermilab demonstration tries to contextualize just how much information that is. So it starts with a 2-by-2-foot tile on the surface of the Earth that represents a single bite. At that scale, a terabyte is the size of Thailand. To get one petabyte, you would need to coat the entire planet in these data tiles. You'd need 20 Earths to accommodate the LHC's yearly data haul, which would take up about a third of the volume of Neptune.

From the Deputy Director for LBNF

A fortnight at Fermilab

Chris Mossey

It's been a blur of long days and fast weeks since I joined the Fermilab team … and that was only two weeks ago! I greatly appreciate the warm welcome extended by everyone I've met and your patience with my (seemingly) endless questions, all of which have helped me get a much better appreciation of the experiments and initiatives under way at the lab. Having the opportunity to observe the LBNF/DUNE CD-1R review and meet so many members of the Fermilab and DOE international team was also invaluable.

I've been having a lot of fun explaining to my family what my new role at Fermilab will be. They quickly understand that I'll be involved in a large project, which I further explain will provide a platform for the next couple of decades for an international collaboration of scientists to extend our understanding of neutrinos. Their eyebrows generally go straight up at this point. Then I segue into my hopefully improving explanation of what neutrinos are: one of the most abundant and ubiquitous particles in the universe … billions passing through their body every second … poorly understood, etc. Their eyebrows get a bit furrowed at this point, until I assure them that my job will be to support the physicists that are doing the actual science. My role will be to work to establish and maintain connections between our international partners, coordinate and manage the construction project, and ensure that safety, quality, and budget objectives are met on schedule.

The next few months will be busy, obtaining final approval of the CD-1R review from DOE while simultaneously preparing for the CD-3A review and seeking the approval that will allow us to start construction for the conventional facilities of the LBNF far detector site at the Sanford Underground Research Facility in South Dakota. I feel extremely fortunate to have the opportunity to work with an extraordinary team assembled by Jim Strait and Elaine McCluskey and their international colleagues at CERN and around the world who, along with many others, have worked tirelessly to advance the overall project to this point.

Thanks to everyone, again, for making me feel so welcome. I'm excited about the work we have ahead and looking forward to many fast weeks!

Construction Update

A concrete foundation for Mu2e Building

Construction crews pour concrete for the future Mu2e Building. Photo: Marty Murphy, AD

Construction crews continue concrete work for the Mu2e Building. In the above picture, taken on July 28, three concrete pump trucks with extended booms pump approximately 800 cubic yards of concrete to complete the mat foundation.

—Thomas Hamernik

Photos of the Day

Summer pools

Last month's rains filled recesses in the ground all over the Fermilab site, making for beautiful scenes like this one of the willows along Batavia Road ... Photo: Marco Mambelli, SCD

... and this one of the bison pasture. Photo: Marco Mambelli, SCD

In the News

CK teens respond to our field trip to Fermilab

From Chicago Kaleidoscopes, July 30, 2015

We had great time on yesterday's field trip to Fermilab. Chicago Kaleidoscopes took a bus trip from Mozart Park to Fermilab in Batavia, and we were met by Fermilab staff in front of Wilson Hall. Docents gave us a tour — which included a focus on particle physics, how science has influenced the arts and vice versa (e.g. how James Joyce's neologism "quark" was chosen by a physicist to name a subatomic particle, how several of our CK sessions included preparations for our field trip (e.g. the "Poetry of Science" conversation with Neil DeGrasse Tyson and Richard Dawkins), and pop culture connections to what happens at Fermilab (e.g. The Big Bang Theory TV show). The view from the 15th floor of Wilson Hall is extraordinary, with a view of the Main Ring and the Tevatron accelerator, a vista of the surrounding prairie, and the Chicago skyline on the horizon.