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Thursday, Sept. 19
- Breakfast: Canadian bacon, egg and cheese Texas toast
- Breakfast: corned-beef hash and eggs
- Carolina pulled-pork sandwich
- Mediterranean-style ziti with asparagus
- Honey baked ham
- Buffalo chicken tender wrap
- Grilled- or crispy-chicken Caesar salad
- Chef's choice soup
- White-chicken chili
Wilson Hall Cafe menu |
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Friday, Sept. 20
Dinner
Closed
Saturday, Sept. 21
- Vol-au-vents with mushroom duxelle
- Brandy-braised pork tenderloin
- Cauliflower gratin
- Green bean amandine
- Apple walnut cake with spiced cream
Wednesday, Sept. 25
Lunch
- Parmesan broiled tilapia
- Kale, quinoa and avocado with lemon dijon vinaigrette
- Strawberry lemon tart
Chez Leon menu
Call x3524 to make your reservation.
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New Intensity Frontier seminar series begins Sept. 26
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A new seminar series on Fermilab's Intensity Frontier program begins next week. |
Fermilab's Intensity Frontier Department will launch a regular seminar series starting Sept. 26. The new series kicks off with a talk from Fermilab scientist Tingjun Yang titled "Liquid-Argon Time Projection Chambers." The seminars will be held on select Thursdays from 11 a.m. to noon in the Hornet's Nest, Wilson Hall, 8th floor.
The Intensity Frontier experiment talks will cover a broad array of topics, including neutrinos, lepton flavor conservation, electric dipole moments and others. The aim of these talks is to facilitate communication between the scientists, staff and users working on Fermilab's more than 15 different Intensity Frontier experiments and projects. The talks also provide an opportunity for experts in other fields to both learn from and provide input into the exciting work happening at the Intensity Frontier.
Seven resident and guest speakers are scheduled through the end of 2013. (The Intensity Frontier talks will take place during the off weeks of the Allure of Ultrasensitive Experiments series.) The speakers include world leaders in neutrino, proton decay and lepton conversion measurements and two of the recent Intensity Frontier Fellowship Award winners.
Details are available the Intensity Frontier Seminar Series Web page. Please fell free to contact the organizers with any requests or comments.
We hope you can find time in your busy schedule to join us.
—Minerba Betancourt and Mathew Muether, seminar series organizers
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Leaves of lotus
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| American lotus plants cover the pond in the Main Ring across from the D4 service building. Photo: Pat Sheahan, AD |
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Fermilab Arts and Lecture Series: The Second City comes to Fermilab Saturday
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On Sept. 21, renowned Second City brings its improv to Fermilab's Ramsey Auditorium. |
Never the same, always hilarious, The Second City is the nation's leading brand in improv-based sketch comedy.
Now "Second City: Happily Ever Laughter" comes to Fermilab on Saturday, Sept. 21, at 8 p.m. in Ramsey Auditorium.
The Second City has been called "a comedy empire" by The New York Times, and it's no wonder. The Second City boasts theaters in Chicago and Toronto, training centers in those cites as well as in Hollywood, 11 full-time touring ensembles, thriving corporate communications and theatricals, and television and film operations.
Second City first opened its doors on a snowy night in 1959. Today, Second City continues to produce the premier comic talent in the industry: Steve Carell, Stephen Colbert, Tina Fey, Mike Myers and Amy Poehler are all Second City alumni.
Come see comedy improv at its best on Saturday. Tickets are $25, $13 for those ages 18 and under. You can purchase them online or by calling 630-840-2787. Chez Leon will also be open that evening at 6 p.m. To make dinner reservations, call 630-840-3524.
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Just how weak is the weak force?
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Using a unique technique, the Q-weak collaboration has found the value of the weak force to be in agreement with theory — so far. Photo: Q-weak collaboration |
In an early analysis of its data, the Q-weak collaboration, based at Jefferson Lab in Virginia, has determined that the value of the weak charge matches what's predicted by theory.
Although the weak force, one of the four fundamental forces of nature, is stronger than gravity, it got its name because it's effective only at extremely short distances. If two particles are 0.000000000000001 millimeters apart, they feel the weak force. Much farther way than that, and the force's strength drops off sharply.
The weak force is the main driver behind radioactive decay and is the reason that stars shine. Inside stars like our sun, protons and neutrons fuse to form deuterium. The stars release excess energy from this reaction through the weak force in the form of heat.
This research offers the first measurement of the weak charge within the proton.
Previous experiments had studied the force in simpler particles including the electron. Unlike the point-like electron, protons are made of three smaller particles called quarks, complicating the experiment.
If the value of the weak charge differs — even by a very small bit — from what's expected, it could be evidence of as-yet-undiscovered particles influencing the results. Or perhaps it could point physicists toward a way to understand all of nature's fundamental forces as a single force in a "grand unified theory."
Read more
—Kelen Tuttle
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Improved measurement of the top quark width
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| The figure shows the limits on the top quark width at the 68 percent and 95 percent confidence levels and the result of a fit to the data. |
The top quark is the heaviest currently known elementary particle. The only way the top quark can decay is through the weak interaction, which is the only interaction that allows quarks to change flavor (t → W + b). Its large mass endows it with the largest so-called decay width, and hence, the shortest lifetime of any of the known fermions, which include both the quark and lepton classes of particles. The time it would take for the top quark to form hadrons — particles that contain either two or three quarks — is incredibly short (3.3 × 10-24 seconds), and scientists predict using the Standard Model that the top quark lifetime is even shorter (5.0 x 10-25 seconds). Thus physicists believe that, when they measure the properties of the top quark system, they are looking directly at the top quark itself.
Precise measurements of the top quark decay width allow us to measure its lifetime, exploiting a principle of quantum mechanics
called the Heisenberg uncertainty principle. This principle states that certain complementary variables, such as energy and time, are subject to a mathematical inequality that limits the precision with which they can be simultaneously measured. Here we measure the width of the top mass distribution, which is related to the particle's energy. By measuring the top's mass distribution, we can also determine its lifetime, since the lifetime is inversely proportional to the mass.
This is CDF's final measurement of the top quark decay width. Earlier results showed that the decay width is shorter than the time required to form hadrons. The experiment improves on an earlier measurement by using a larger sample, as well as through a better understanding of the systematic errors that go into the top mass distribution.
CDF scientists have measured the top quark width using the full Run II data set by comparing the shape of the reconstructed mass distribution of top quarks with samples whose top quark widths are already known. Scientists extract most-likely top quark widths for the data by deciding which known sample looks the most like the unknown data. Using the Heisenberg uncertainty principle, CDF determined the top quark lifetime at the 68 percent confidence level to be greater than 1.6 x 10-25 seconds and less than 6.0 x 10-25 seconds. This measurement supports the Standard Model lifetime of 5.0 x 10-25 and thus places limits on non-Standard Model decays.
Learn more
—edited by Andy Beretvas
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| These CDF physicists contributed to this data analysis.
From left: Hyun Su Lee, Ewha Womans University, Seoul, Korea; Jian Tang, University of Chicago; and Young-Kee Kim, University of Chicago. |
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Particle party - tonight at Adler Planetarium
Tonight Fermilab will be an event partner in Adler Planetarium's monthly Adler After Dark.
Discover otherwise invisible particles with a special cloud chamber, check out how particle accelerators work and enjoy all the museum has to offer at the best party in Chicago. Fermilab scientists will be on hand for a special panel discussion exploring the three frontiers of particle physics.
Doors open at 6 p.m. Admission is for those 21 and up only. Advance-purchase tickets are $15 general admission, $10 for Adler members. Tickets purchased at the door are $20 general admission, $15 for Adler members.
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A jewel at the heart of quantum physics
From Quanta Magazine, Sept. 17, 2013
Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality.
"This is completely new and very much simpler than anything that has been done before," said Andrew Hodges, a mathematical physicist at Oxford University who has been following the work.
Read more
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Thunderstorms likely
