Friday, Sept. 5, 2014

Have a safe day!

Friday, Sept. 5

3:30 p.m.


Monday, Sept. 8

2 p.m.
Particle Astrophysics Seminar - Curia II
Speaker: Eric Linder, University of California, Berkeley and Lawrence Berkeley National Laboratory
Title: Time Delay Cosmology

3:30 p.m.

4 p.m.
All Experimenters' Meeting - Curia II

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Wilson Hall Cafe

Friday, Sept. 5

- Breakfast: chilaquiles
- Breakfast: chorizo and egg burrito
- Beer-battered fish sandwich
- Smart cuisine: chana masala
- Traditional turkey dinner
- Vegetarian eggplant parmesan panino
- Chicken fajitas plate
- Texas-style chili
- Tomato basil bisque
- Assorted pizza by the slice

Wilson Hall Cafe menu

Chez Leon

Friday, Sept. 5

Wednesday, Sept. 10
- Chicken piccata with capers
- Angel hair pasta
- Wilted spinach
- Blueberry cobbler

Chez Leon menu
Call x3524 to make your reservation.


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Neutrinos permeate Fermilab's past, present and future

This aerial view shows the Neutrino Area under construction in May 1971. The 15-foot bubble chamber, pictured on the left, would later be moved to the present-day location of Lab B. Photo: Fermilab

It was called Target Station C. One of three stations north of Wilson Hall at the end of beamlines extending from the Main Ring (later replaced by the Tevatron), Target Station C was assigned to experiments that would require high beam intensities for investigating neutrino interactions, according to a 1968 design report.

Within a few years, Target Station C was officially renamed the Neutrino Area. It was the first named fixed-target area and the first to be fully operational. Neutrinos and the Intensity Frontier had an early relationship with Fermilab. But why is it resurfacing now?

"The experimental program is driven by the current state of knowledge, and that's always changing," said Jeffrey Appel, a retired Fermilab physicist and assistant laboratory director who started research at the lab in 1972.

When Appel first arrived, there was intense interest in neutrinos because the weak force was poorly understood, and neutral currents were still a controversial idea. Fermilab joined forces with many institutions both in and outside the United States, and throughout the 1970s and early 1980s, neutrinos generated from protons in the Main Ring crashed through a 15-foot bubble chamber filled with super-heated liquid hydrogen. Other experiments running in parallel recorded neutrino interactions in iron and scintillator.

"The goal was to look for the W and Z produced in neutrino interactions," said Appel. "So the priority for getting the beam up first and the priority for getting the detectors built and installed was on that program in those days."

It turns out that the W and Z bosons are too massive to have been produced this way and had to wait to be discovered at colliding-beam experiments. As soon as the Tevatron was ready for colliding beams in 1985, the transition began at Fermilab from fixed-target areas to high-energy particle colliding.

More recent revelations have shown that neutrinos have mass. These findings have raised new questions that need answers. In 1988, plans were laid to add the Main Injector to the Fermilab campus, partly to boost the capabilities of the Tevatron, but also, according to one report, because "intense beams of neutral kaons and neutrinos would provide a unique facility for CP violation and neutrino oscillation experiments."

Although neutrino research was a smaller fraction of the lab's program during Tevatron operations, it was far from dormant. Two great accomplishments in neutrino research occurred in this time period: One was the most precise neutrino measurement of the strength of the weak interaction by the NuTeV experiment. The other was when the DONUT experiment achieved its goal of making the first direct observation of the tau neutrino in 2000.

Read more

Troy Rummler

Video of the Day


The Dark Energy Survey recently began its second season. From the images of the sky, scientists distill vast catalogs of celestial bodies, an accounting of what the universe has so far created. This catalog can be further distilled when studied as a whole. The final concentrate is a small set of numbers that summarizes the fate of our universe: a measurement of the strength of dark energy. View the 15-second video and read more at Dark Energy Detectives. Video: Dark Energy Survey
Photo of the Day

Surfing waves of green

A green heron surfs on a lotus leaf. Image: James Clemons Jr., AD
In the News

Strange neutrinos from the sun detected for the first time

From Scientific American, Aug. 27, 2014

Deep inside the sun pairs of protons fuse to form heavier atoms, releasing mysterious particles called neutrinos in the process. These reactions are thought to be the first step in the chain responsible for 99 percent of the energy the sun radiates, but scientists have never found proof until now. For the first time, physicists have captured the elusive neutrinos produced by the sun's basic proton fusion reactions.

Read more

Frontier Science Result: CMS

Subatomic chimeras

In biology, a chimera is a creature whose cells contain the DNA, combined in utero, of two distinct individuals. In today's column, we describe leptoquarks, a hypothetical new particle that combines the properties of both quarks and leptons.

In mythology, the chimera is a beast that is part lion, part snake and part goat. However, in modern times, the term has come to mean any organism that consists of cells from two distinct organisms. Inside the womb, two organisms merge when they consist of just a few cells. The result is kind of the opposite of identical twins. Rather than having two creatures with identical genetics, two creatures with distinct genetics merge to become a single organism.

There is a theoretical particle that could be said to be a chimera. In the Standard Model, there are two distinct classes of particles of matter. These are the quarks, which are typically found inside protons and neutrons, and leptons, of which the electron is the most familiar example. Quarks feel the electromagnetic and the strong and weak nuclear forces, while charged leptons feel the electromagnetic and weak forces. (The neutral leptons feel only the weak force.)

While it might not seem all that surprising that there are two classes of subatomic matter particles, this observation dampens the dreams of physicists who hope to be able to unify all phenomena and show that, ultimately, there is a single fundamental particle from which all other things derive. There is ample historical evidence that this unification is possible, for example the demonstration that the complicated world of chemistry stems from just a few particle species (protons, neutrons and electrons). Another simpler example is the very ordinary observation that water, ice and steam — all materials with very different properties — are really the same thing.

Perhaps there exists a particle called a leptoquark, which contains all of the properties of a quark and a lepton. In a sense, a leptoquark is a subatomic chimera. Note that the leptoquark is not generally accepted in particle physics, but neither has it been disproven.

In the Standard Model, we observe three "generations," with up and down quarks, electrons and electron neutrinos being generation number 1. Generation number 2 consists of charm and strange quarks and muons and muon neutrinos. Generation number 3 consists of top and bottom quarks and tau leptons and tau neutrinos. If leptoquarks exist, perhaps they respect the observed generations.

Accordingly, CMS physicists looked for third-generation leptoquarks. In the model that was tested, scientists searched for a hypothetical leptoquark that decayed into a bottom quark and tau lepton. The measurement was consistent with predictions of the Standard Model, which allowed researchers to set a stronger limit on this theoretical idea than had been available previously.

Don Lincoln

These U.S. scientists contributed to this analysis.
These Fermilab visiting engineers have made very significant contributions to CMS computing operations. Their home institutions are the Universidad San Francisco de Quito, Ecuador (John Artieda) and Universidad de los Andes, Bogota, Colombia (Luis Contreras, Jorge Diaz and Juan Mosquera).

Today's New Announcements

Needed: BeV Accelerators: Studies on Experimental Use, vols. 1 and 2

English country dancing Sunday afternoon at Kuhn Barn - Sept. 7

Users Executive Committee election voting deadline Sept. 8

Weight management class - register by Sept. 11

NBI 2014 Workshop - Sept. 23-26

Scottish country dancing Tuesday evenings at Kuhn Barn

International folk dancing Thursday evenings in Kuhn Barn

TeX Users Group journal

Outdoor soccer

Batavia Smashburger employee discount

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