Friday, Sept. 14, 2012

Have a safe day!

Friday, Sept. 14

3:30 p.m.

4 p.m.
Joint Experimental-Theoretical Physics Seminar - One West
Speaker: Peter Onyisi, University of Texas at Austin
Title: Recent W and Z Production and Decay Results from ATLAS

Monday, Sept. 17

2:30 p.m.
Particle Astrophysics Seminar - One West
Speaker: Alex Geringer-Sameth, Brown University
Title: Results of Dark Matter Searches in Dwarf Galaxies with Fermi



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Wilson Hall Cafe

Friday, Sept. 14

- Breakfast: French bistro breakfast
- New England clam chowder
- Becks-battered fish sandwich
- Tortellini alfredo
- Smart cuisine: herb and lemon fish
- Cuban panini
- Garden vegetable pizza by the slice
- Chili cheese nacho platter

Wilson Hall Cafe Menu
Chez Leon

Friday, Sept. 14
- Potato, bacon and cheese soufflé
- Lobster tail with champagne butter sauce
- Spaghetti squash
- Snowpeas
- Strawberry crepes

Wednesday, Sept. 19
- Chicken and artichoke calzone
- Salad
- Chocolate fondue

Chez Leon Menu
Call x3524 to make your reservation.


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Special Director's Corner

Involuntary separation

Fermilab Director
Pier Oddone

Today, the final phase of the workforce reduction announced in May is taking place. This involuntary phase affects 22 employees across the lab. It follows the voluntary separation that occurred in June, when Fermilab management was able to accept 27 individuals who applied for the program.

When I originally announced that a workforce reduction would be necessary due to reduced federal funding, we anticipated that approximately 80 employees would be affected. Because of attrition over the past few months, we were able to significantly reduce the number of involuntarily separated employees.

Staff reductions are always a last resort, and they are not taken lightly here at the lab. Spending was reduced in many other areas, but, unfortunately, a reduction in force was necessary to bring the staffing level in line with anticipated budgets.

As always, I will keep you apprised regarding the lab's budget and funding, particularly as we approach the start of a new fiscal year. In the meantime, if you have any questions, please contact laboratory management.

From symmetry

Scientists already planning for LHC long shutdown

Next year, scientific collaborations will take full advantage of the Large Hadron Collider's time without beam.

The Large Hadron Collider will go into a long shutdown early next year to allow scientists and technicians to prepare it for higher collision energy in 2015.

It has been running at 7 TeV; scientists plan for it to reemerge at upward of 13 TeV. Beginning in February of 2013, highly coordinated teams will spend 20 months preparing its equipment for the change.

Higher luminosity means more particle collisions, and the experiments will need more advanced equipment to keep up. With the detectors the most accessible they have been since their original construction, the four big LHC experiments will take the opportunity to perform upgrades and routine repairs. The collaborations already have plans for the new year.

Read more

Signe Brewster

Construction Update

Atrium west stair construction nearly complete, east stair construction begins next week

The Wilson Hall atrium west stairway construction is nearly complete.

Installation of the railings and safety barriers for the west stairway is nearly complete. It will be open next week.

Beginning next week, the east stairs will be closed off from usage, and the plywood construction barricades that were on the west side of the atrium will be moved to the east side. Work on the east stair is scheduled to be completed by the end of December. As on the west side, access will be restored from the top down as floors are completed.

In the News

Dark-matter hope fades in microwave haze

From Physics World, Sept. 10, 2012

The latest results from the Planck space telescope have confirmed the presence of a microwave haze at the centre of the Milky Way. However, the haze appears to be more elongated than originally thought, which casts doubt over previous claims that annihilating dark matter is the cause of the emissions.

A roughly spherical haze of radiation at the heart of our galaxy was identified as far back as 2004 by the Wilkinson Microwave Anisotropy Probe (WMAP). Since then, some astrophysicists have suggested that this haze is produced by annihilating dark-matter particles.

Read more

CMS Result

Precision smashing

Analyzing jets from a particle collision is something like analyzing the aftermath of the collision of two pocket-watches. CMS scientists recently analyzed collisions in which hundreds of particles seemed to be channeled into six streams.

It is sometimes said that if particle physicists wanted to figure out how an expensive Swiss watch works, they would smash it and deduce its structure from the cogs, springs and glass that fly apart. To understand the inner life of protons, this is exactly what they do—smash two of them together and analyze the aftermath. It is not as ridiculous as it sounds. The basic laws of energy and momentum conservation make a precision science of this violent practice.

Energy and momentum are both quantities that describe the inertia of an object or a system of particles. Energy is the sum of motion in all directions, while momentum is the net motion, depending on direction. These quantities are useful because they are constants—even the messiest explosion maintains a constant momentum because leftward-going particles exactly balance rightward-going particles. The energy of an explosion is also conserved, as long as the potential energy that caused the explosion is counted. Among subatomic decays, this initial energy is the mass of the decaying particle, according to E = mc2 (energy equals mass times a large constant).

To analyze a collision, physicists add up the observed energy and momentum and solve both equations to deduce the masses of the particles that decayed before they could be observed directly. In a recent paper, CMS scientists applied an extreme version of this technique. They looked at events in which hundreds of visible particles seemed to be channeled in six streams, known as jets. Assuming that each jet was caused by a cascade of decays, starting from a single quark, they applied energy and momentum conservation to find out if triplets of quarks descended from an as-yet unknown particle.

Although the search turned up negative (no new particles yet), the experimenters' ability to deal with so many jets is impressive. There are 10 different ways to identify two triplets among six quarks. If all combinations are considered, the nine wrong ones would drown out the right one, weakening the sensitivity of the analysis. These scientists noticed that wrong combinations usually produce more energetic quarks than right ones, and used this correlation to sharpen the precision of their search. Not bad for smashing watches.

—Jim Pivarski

The Rutgers physicists pictured above were all major contributors to this analysis.
The Fermilab physicists above provided invaluable help with Monte Carlo generators, which are computer simulations of theoretical expectations.

Weekly Qigong, balance and lower-body strength class - begins Sept. 17

Fermilab Arts & Lecture Series: Broadway's Next H!T Musical - Sept. 22

NALWO and Playgroup SciTech Museum visit - Oct. 6

Fermilab Friends for Science Education and grants from Chase Community Giving

Change in Users' Office hours

International Folk Dancing returns to Kuhn Village Barn

Scottish country dancing returns to Kuhn Village Barn

Martial Arts classes

Outdoor soccer - Tuesdays and Thursdays at 6 p.m.

Professional development courses

Atrium work updates

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