Friday, June 26, 2015
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Abri Credit Union celebrates the next generation - today

NALWO potluck picnic in Kuhn Barn - July 1

art/LArSoft course at Fermilab, free registration - Aug. 3-7

Wilson Hall annual abandoned bike removal

WalkingWorks week six winners

Wednesday Walkers

Preschool and youth swim lessons session 2

Outdoor soccer

Fermilab Board Game Guild

Scottish country dancing moves to auditorium, meets Tuesday evenings through summer

International folk dancing moves to auditorium, meets Thursday evenings through summer

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In Brief

DASTOW takes place today

Fermilab's Daughters and Sons to Work (DASTOW) day takes place during the first half of today.

Families can enjoy a Fermilab Fire Department demonstration and a Mr. Freeze demonstration outside of Wilson Hall during lunch. Those registered can also see physics demonstrations on the 15th floor of Wilson Hall and science presentations in One West. Lunch will be offered in the Wilson Hall atrium.

For a full schedule of events, visit the DASTOW Web page.

Video of the Day

Gravitational lensing

Einstein's theory of general relativity tells us that what we experience as gravity can be most accurately described as the bending of space itself. Gravitational lensing is caused by light traveling in curved space. U.S. CMS Education and Outreach Coordinator Don Lincoln explains a little general relativity, a little gravitational lensing and tells us how this phenomenon allows us to map out the matter of the entire universe View the video. Video: Fermilab
Wellness Feature of the Month

July wellness programs and fitness classes

Complimentary Wellness

Lunch and Learn About Colon Cancer
Tuesday, July 7, noon-1 p.m.
Curia II
Presented by Presence Health.

Wednesday Walkers
Wednesdays. Depart from Wilson Hall east side at noon. Time, distance and speed are up to you.

Preschool and Youth Swim Lessons
Register online at Jeff Ellis Management.
Session II, July 6–16, Monday-Thursday. Register by June 29.
Session III, July 20-30, Monday-Thursday. Register by July 13.
Session IV, Aug. 3-13, Monday-Thursday. Register by July 27.

Fitness Class
Mondays, July 20-Aug. 31, noon-12:45 p.m.
Fitness Center Exercise Room
$87. Register by July 13.

Employee Club
Go Club
Wednesdays, 7-10:15 p.m.
Users Center
Interested in go, baduk or weiqi? New, beginner, and experienced players are welcome, Player strength ranges from beginner to 1 kyu. Bring a board if you have one.

Athletic League
Outdoor Soccer
Tuesdays and Thursdays, 6 p.m.
Fermilab Village soccer field
Contact O'Sheg Oshinowo for more information.

Employee Discounts
Raging Waves Waterpark
Bristol Renaissance Faire
Visit the employee discount Web page.

Photos of the Day

Grass and gravel

A painted turtle takes a walk near Wilson Hall. Photo: Gregory Cisko, CCD
It makes its way to the Wilson Hall parking lot. Photo: Gregory Cisko, CCD
In the News

The fuzzball fix for a black hole paradox

From Quanta Magazine, June 23, 2015

In the late 18th century, the scientist John Michell pondered what would happen if a star were so massive, and its gravity so strong, that its escape velocity would be equivalent to the speed of light. He concluded that any emitted light would be redirected inward, rendering the star invisible. He called these hypothetical objects dark stars.

Michell's 1784 treatise languished in quiet obscurity until it resurfaced in the 1970s. By then, theoretical physicists were well acquainted with black holes — the dark star idea translated into Albert Einstein's theory of gravity. Black holes have a boundary called an event horizon that represents the point of no return, as well as a singularity, a point of infinite density within.

Read more

Frontier Science Result: MINERvA

Seeing two sides of the same coin

This plot and the one below show the differential cross sections (or likelihood per proton or neutron) for a neutrino to make one or more pions and a muon with respect to the muon momentum, with a few different models used by neutrino oscillation experiments. This plot is for events in which charged pions are made by neutrinos. The plot below is for events in which neutral pions are made by antineutrinos. The two different models represent turning on and off the effects of the nucleus where the neutrino interacted. The data clearly represent the effects of the nucleus being "turned on," and the two different predictions have the same shape. The inner error bars are statistical and the outer error bars are the total uncertainties.

Para una versión en español, haga clic aquí. Para a versão em português, clique aqui. Pour une version en français, cliquez ici.

It can be hard to detect the ghostly neutrino, which rarely interacts with matter. To overcome this, neutrino experiments use detectors made of neutrons and protons bound up in heavy nuclei. The way these nuclei affect the particles made by neutrino interactions is not well understood, so MINERvA is working to measure this in as many ways as possible.

Sometimes a neutrino creates a quark-antiquark pair called a pion, and the neutrino itself can change into a charged particle called a muon (an antineutrino can create an antimuon). The pions often interact with the nucleus where they were made, changing their charge or even stopping before they can leave. On the other hand, the muons or antimuons are not affected by the nucleus at all, according to predictions. So one way to measure the effects of the nucleus is to take the same interaction and look at it from both sides: from the pion side and from the muon side.

MINERvA presented results about the pion side neutrino measurements and the antineutrino measurements. At today's Joint Experimental-Theoretical Physics Seminar, the MINERvA collaboration will show new information about the muons that are made along with the pions in these interactions and provide a more complete picture of the interaction.

There are models that try to describe this process. Neutrino experiments, especially those that try to measure how neutrinos change over time, need those models to get both the muon side and the pion side right: It's not enough to describe only one kind of particle. Creating these models has been a challenge due to the complicated nature of the nucleus. In addition, there are disagreements between these models and the experimental data taken by many neutrino experiments. To make matters even more confusing, sometimes different measurements of this process at different energies (or on different nuclei) don't all agree with the same model.

By studying the muons as well as the energies of the pions, we can compare between the different models of the nucleus and their effects on the interaction. Eventually there will be at least one model that can describe all the data. This will give us a better picture of the nucleus, which ultimately improves our ability to measure the neutrino.

Aaron Bercellie, University of Rochester

This plot shows the cross sections described in the top figure caption with several models. The cross sections here are shown for antineutrinos and neutral pions (instead of for neutrinos and charged pions as in the top figure).
Carrie McGivern of the University of Pittsburgh worked on this analysis and will present the results and more at the Joint Experimental-Theoretical Seminar today.
In the News

Neutrinos' shape-shifting abilities confirmed

From Discover, June 24, 2015

Neutrinos are often called "ghost particles," and for good reason. Neutral in charge and tiny in mass, neutrinos are incredibly elusive and mostly pass unnoticed through ordinary matter, including you and me.

In fact, neutrinos, one of physics' fundamental particles, were once thought to be completely massless. A recent observation from researchers in Italy, however, adds to mounting evidence however that neutrinos do have some — very tiny — mass.

Specifically, it was found that neutrinos, which come in three varieties or "flavors," can spontaneously change their flavor in a process known as oscillation. And because of the nature of quantum mechanics, oscillation only occurs if the flavors have unique masses.

Read more