Friday, April 24, 2015
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Weather at Fermilab


Bardeen Engineering Leadership Program lecture - today

Linux User Group meets April 29

For the Life of the World video series starts May 5

National Day of Prayer Observance - May 7

Interpersonal Communication Skills on May 20

MS Excel 2013: Introduction offered two half days - April 28 and 30

2014 FSA deadline is April 30

Managing Conflict (a.m. only) on June 10

Interaction Management course (three days) scheduled for June 28, July 9, July 28

Performance review training for managers and supervisors - Aug. 4, 5, 6

Mac OS X security patches enabled

Zumba Toning and Zumba Fitness registration due soon

Yoga registration due soon

Players needed for 2015 Fermilab co-ed softball league

Indoor soccer

Scottish country dancing Tuesday evenings at Kuhn Village Barn

International folk dancing Thursday evenings at Kuhn Barn

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Wellness Feature of the Month

May wellness, special events and fitness classes

Complimentary Wellness

Lunch and Learn About Allergies
Tuesday, May 5, noon-1 p.m.
Curia II
Presented by Virginia Madla, Presence Health

Wednesday Walkers
Wednesdays beginning May 6.
Departs from the east side of Wilson Hall at noon.
Time, distance and speed are up to you.

Tai Chi for Health, BuZheng Qigong and Silk Reeling Practices
Mondays and Fridays, May 11-Aug. 28, noon-1 p.m.
Ramsey Auditorium

Wednesdays, May 13-Aug. 26, 7-8 a.m.
Ramsey Auditorium

Special Event
Employee Health and Fitness Day and Kick-off to WalkingWorks®
Tuesday, May 12, 11:30 a.m.-1:30 p.m.
Walk, run, bike or inline skate with your co-workers. T-shirts, water bottles, pedometers, earbuds and sunglasses go to the first 300 participants.

Fitness Classes

Zumba® Toning
Tuesdays, May 5-June 9, noon-12:45 p.m.
Fitness Center Exercise Room
$40. Register by April 28.

Zumba® Fitness
Thursdays, May 7-June 4, noon-12:45 p.m.
Fitness Center Exercise Room
$35. Register by April 30.

Athletic Leagues

Open Broomball
FBBL broomball is a year-round sport — think field hockey with homemade "brooms" (we have extras) and a large tennis ball. Games are on a pick-up basis, either in the Fitness Center Gym (membership required) or outdoors at lunchtime or 5 p.m. Contact Chris Greer at x4847.

Softball League
The Fermilab co-ed recreational 12-inch-softball league has openings for male and female players. Games are once a week in the Village on Wednesdays or Thursdays from May 6-Sept. 10, including playoffs. No experience is necessary. Contact Chris Greer at x4847.

Employee Discounts
Visit the employee discount Web page.

In Brief

Spring wildflower hike through Big Woods

Fermilab staff go for a hike in Big Woods to learn to identify wildflowers on site. Photo: Leticia Shaddix, PPD

Earth Week kicked off on Monday with a wildflower hike in Big Woods, near the Interpretive Trail. Ecologist Ryan Campbell (pictured above, left) led Fermilab staff on the tour, helping them learn how to identify spring wildflowers such as bloodroot, Jacob's ladder, trout lily and woodland phlox.

Photo of the Day

M is for muon

Spotted earlier this week: The booms of concrete pumping trucks used to pump the concrete for the future Mu2e building form the letter M. Photo: Ron Evans, FS
Frontier Science Result: CMS

Fractured protons

Photograph of out-of-focus Christmas tree lights (large circles) that instead focuses on dust on the lens of the camera (small dark spots with rings). The rings around the dust are caused by diffraction. Photo: Jon Rista

In a bright light, you can sometimes see specks in your field of vision that resemble the picture above. If you try to turn your eyes to look at them, they move because these objects are sitting on your eyeball — blinking jostles them. They may be dust grains, cells or bubbles, but they are small enough to diffract light, making concentric rings like the ones shown in the picture.

Diffraction is a general phenomenon in which waves curl around small objects, with more or less intensity at different angles, like light around a dust grain. Protons in the LHC also diffract because protons are quantum mechanical waves. Sometimes protons simply bounce off each other, making ring-like patterns exactly like light bouncing off dust, but more often one or both of the protons break apart.

Diffraction in which one or both protons dissociate (break apart) is important to measure at LHC energies because it is a basic property of proton collisions that can't be calculated from first principles. In a recent paper, CMS scientists measured the probability of two protons diffracting with single dissociation (one breaks apart) and double dissociation (both break apart).

This measurement is unlike most performed at the LHC. Most LHC measurements involve a search for exceedingly rare phenomena, events that occur in one out of 10 trillion collisions, but diffractive events occur in about one out of four collisions. Instead of describing how individual particles decay, this analysis studies collective effects in the combined two-proton system.

One challenge of dealing with the combined system is the problem of determining which particles came from which proton when both protons break apart. In practice, physicists distinguish the two clouds of debris by looking for cases with a large angular separation between them relative to the beamline, but the available angular range is limited by the size of the CMS detector. This analysis used an additional detector, CASTOR, which extends the combined coverage all the way from 90 degrees to a 10th of a degree from the beamline.

Though weird, this study has far-reaching implications. By improving the world's knowledge of collective proton collision effects, these effects can be better simulated in predictions of nearly every other measurable at the LHC.

Jim Pivarski

These U.S. physicists contributed to this analysis.
These U.S. CMS students and postdocs have made a big impact on the commissioning of the CMS cathode strip chamber muon detector. From left: Jesse Heilman (UC Riverside), David Morse (Northeastern), Devin Taylor (Wisconsin), Christine McLean (UC Davis), Elizabeth Kennedy (UC Riverside), Senka Duric (Wisconsin), Justin Pilot (UC Davis), Hualin Mei (Florida), Wells Wulsin (Ohio State). Inset, from left: Pieter Everaerts (UCLA), Frank Golf (UC Santa Barbara).
In the News

Galactic collisions rattle current theories of dark matter

From Christian Science Monitor, April 15, 2015

A quartet of colliding galaxies in a vast cluster 1.4 billion light-years away may prompt scientists to rethink their notions about the nature of dark matter — a hidden form of matter that makes up some 85 percent of all the matter in the universe.

Read more