Fermilab Today

This conference room in the IARC Office, Technical and Education Building needs a name, so the Fermilab directorate is hosting a contest to gather the best suggestions. Photo: Cindy Arnold

One of the fun things about working at Fermilab is discovering the name of some meeting room you never knew existed, and there are plenty to discover: the ConFESSional, Outfield, Quarium, Wormhole.

Now the folks at IARC are giving all Fermilab badge holders a chance to let loose their whimsical sides by holding a meeting room naming contest. The charge: Propose a name for the IARC third-floor southeast conference room, which seats 15 and has an uncharacteristic narrow, pointed shape; see above picture.

IARC's mission is to advance accelerator technology, so the name should be related to accelerators, innovation, inventions, patents or new ideas.

As mentioned, the contest is open to Fermilab badge holders. The deadline for submissions is Friday, Aug. 28. The winning entry will be announced on Sept. 1, and the winner, chosen by committee, will receive a $100 gift certificate to Two Brothers Roundhouse in Aurora.

This is the first of five naming contests for the IARC meeting rooms. The subject of the next contest, scheduled for October, will be the room directly below the one pictured, on IARC's second floor. It is nearly identical to its third-floor counterpart, so you can already start thinking of possibile new names.

Submit your submissions by email to Dawn Staszak, and enter "IARC conference room naming contest" in the subject line.

From symmetry

Testing the nature of neutrinos

The Majorana Demonstrator experiment is looking for a sign that neutrinos are their own antiparticles. Photo: Matt Kapust, Sanford Lab

A mile below the Earth's surface, a large copper cylinder sits behind a thick shield of lead bricks stacked into what could be confused for a wood-burning pizza oven. Inside, 29 hockey pucks of germanium sit in strings and send information out through a gleaming copper arm.

This is the Majorana Demonstrator, an experiment housed in a former gold mine at Sanford Lab in Lead, South Dakota. It's searching for a rare process that would help scientists explain why matter exists in our universe instead of nothing at all.

"To me, it's our version of going to the moon right now," says Julieta Gruszko, a PhD student from the University of Washington working on the experiment. "We're not going to the moon. Instead we're doing these experiments that tell us why the universe is the way it is. It really is the way in which we do discovery these days."

—Lauren Biron

Photos of the Day

Storm's coming

Enormous clouds, captured on camera near Kirk Road, tell of an approaching thunderstorm. See more photos of gorgeous Fermilab skies at Fermilab at Work. Photo: Jamieson Olsen, AD

This photo of an impending storm was taken on Tuesday. See more photos of gorgeous Fermilab skies at Fermilab at Work. Photo: Benjamin Galan, TD

Frontier Science Result: DZero

Polarization of top quarks

"Lefty-tighty" (left) and "righty-tighty" (right).

Disponible en español

Subatomic particles are like nuts and bolts. The old rule "righty-tighty" reminds us that a rotation like this (see above figure) causes a threaded object to move in that (tightening) direction.

Unless the threads are left-handed. There are a few places where left-handed threads are needed. For example, bicycle pedals will fall off without left-handed threads. In that case a rotation in the other direction will cause the threaded object to move in that same tightening direction.

Quarks, and indeed most subatomic particles, have a certain built-in intrinsic spin to them, just as they have a certain mass or electric charge. That spin can be either right- or left-handed. The difference is that rather than asking in which direction the screw will move when it is turned, we ask in which direction the quark moves relative to how it is turning. So, in the figure, if the quark moves to the right, the "righty-tighty" picture corresponds what we call a right-handed polarization. The "lefty-tighty" picture corresponds to what we call a left-handed polarization.

When top quarks were produced in the Tevatron, they should have had, according to the Standard Model, a small average polarization. On average, the polarization should be -0.19 percent, (0.19 percent to the left) with a margin of error of 0.05 percent; lefties and righties should be made in about equal quantities.

Here is why that matters: When a top quark and a top antiquark are produced by colliding a proton and antiproton, the direction of the top quark tends to be along the direction of the proton (see the July 3, 2014, issue of Fermilab Today). This "forward-backward asymmetry" has been a cause of excitement because early measurements were higher than expected. It turns out that the asymmetry has a strong dependence on the polarization. If either, or both, the asymmetry or the polarization is different from the expectation, that is a major discovery of new physics.

DZero has recently measured simultaneously the average polarization and the forward-backward asymmetry of top quarks created by the Tevatron. We find that the average polarization is righty, at +7.5 percent. But the margin of error in the measurement is 11.3 percent; the measurement is consistent with expectations. The asymmetry is 15.0 percent, with an 8.1 percent margin of error; that too is consistent with expectations.

Alas, no unexpected result that could lead to a major discovery is in evidence!

—Leo Bellantoni

Alexandre Faure, Slava Shary and Boris Tuchming (all of CEA, Irfu, SPP, Saclay, France) and Andreas Jung (Fermilab) are the primary analysts for this measurement.

The DZero collaboration relies upon many of its collaborators to carefully review analyses for scientific quality before they are released. This analysis was guided by Editorial Board Chair Ken Bloom of the University of Nebraska, Lincoln.

In the News

Fastest ever neutrino among slew of fresh findings

From BBC News, Aug. 9, 2015

Physicists have unveiled a raft of new findings about neutrinos bombarding the Earth from above, below — and within.

An experiment built in a vast slab of Antarctic ice has doubled its count of "cosmic neutrinos" from outer space, by searching for arrivals passing through the planet from the north.

The same team this week announced the highest-energy neutrino ever detected.

Meanwhile, a detector in Italy reported the first firm evidence for neutrinos produced beneath the Earth's crust.

These "geo-neutrinos" carry much less energy but can inform scientists about the radioactive processes generating heat inside our planet.