Friday, Sept. 20, 2013

Have a safe day!

Friday, Sept. 20

1 p.m.
LHC Physics Center Topic of the Week Seminar - WH11NE
Speaker: Paolo Giacomelli, INFN, Bologna
Title: Future Physics Prospects at LHC and HL-LHC

3:30 p.m.

4 p.m.
Joint Experimental-Theoretical Physics Seminar - One West
Speaker: Manuel Kambeitz, Karlsruhe Institute of Technology
Title: Study of Orbitally Excited B Mesons at CDF and Evidence for a New Bπ Resonance

Saturday, Sept. 21

8 p.m.
Fermilab Arts Series - Auditorium
Second City: Happily Ever After
Tickets: $25/$13

Monday, Sept. 23

2 p.m.
LHC Physics Center Topic of the Week Seminar - WH11NE
Speaker: Deepak Kar, University of Glasgow
Title: Improving Monte Carla Generators for ATLAS Run 2

2:30 p.m.
Particle Astrophysics Seminar - WH6W
Speaker: Keith Bechtol, University of Chicago
Title: Searching for Satellite Galaxies of the Milky Way in the Dark Energy Survey

3:30 p.m.

4 p.m.
All Experimenters' Meeting - Curia II
Special Topics: Mu2e solenoids; 3-D ASIC Progress

Click here for NALCAL,
a weekly calendar with links to additional information.

Ongoing and upcoming conferences at Fermilab


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Wilson Hall Cafe

Friday, Sept. 20

- Breakfast: chorizo and egg burrito
- Breakfast: French bistro breakfast
- Beer-battered fish sandwich
- Smart cuisine: Teriyaki pork stir-fry
- Vegetarian eggplant lasagna
- Cuban panino
- Breakfast-for-lunch omelet bar
- Tomato basil bisque
- Texas-style chili

Wilson Hall Cafe menu
Chez Leon

Friday, Sept. 20

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
- 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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Frontier Science Result

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Steve Nahn takes over US CMS detector upgrade project

Steve Nahn

This fall, Steve Nahn begins work as project manager of the US CMS phase I detector upgrade project. Nahn comes to Fermilab as a guest scientist and will be in charge of upgrading equipment that is vital to the CMS experiment at CERN.

CMS is designed to study the products of collisions from two counter-circulating proton beams, and in the next few years the rate of these collisions is expected to increase. The experiment's detector will need to be upgraded in order to handle the additional particles that will be produced.

In fact, the project will replace all or part of three different systems: the forward pixel detector, which tracks charged particles very close to the beam; the electronics of the hadron calorimeter, which measures the energy of particles after they go through the tracking system; and the trigger, which selects the most interesting particle interactions to record for further study.

Nahn's responsibility with US CMS at Fermilab will be the overall oversight of the project's construction to ensure that the upgraded components are available for installation in two LHC shutdown periods, one in early 2017 and one in 2018. Until each upgrade is installed, CMS will continue to operate according to schedule using its current detectors and trigger system.

"Steve understands CMS and US CMS, and he's very good technically, so he's going to do a great job on managing this project," said Joel Butler, head of the US CMS Operations Program. Butler was running the project on an interim basis up until Nahn was hired in August, during which time the project passed two DOE reviews.

Nahn is no stranger to Fermilab, since, as an associate research scientist with Yale, he worked on CDF for eight years. More recently, Nahn worked on the CMS silicon strip tracker while continuing to work as an associate professor at MIT.

Butler calls Nahn one of the "real heroes" of preparing the silicon strip tracker for CMS. This involved commissioning the detector and fine-tuning it before the experiment began — an important task since, once underground, it would be much more difficult to solve problems.

Nahn looks forward to the additional responsibilities that come with his new position, which will entail communicating with 32 different institutions involved in the upgrade. After all is said and done, though, Nahn is a scientist at heart and cannot wait until the detector starts to come together, years down the road.

"The fun stuff is building it, making it work, installing it and seeing it produce physics," Nahn said. "I'm a bit removed from that now, but I think I will get involved to some extent if I can."

Sarah Witman

Photo of the Day

Morning breaks over "Broken Symmetry"

The Sun rises over Fermilab's west entrance. Photo: Jim Freeman, PPD
In Brief

FSPA now accepting nominations for officers

If you are a graduate student or postdoc at Fermilab, here's an opportunity to boost your leadership skills and to add a meaningful line to your CV.

The Fermilab Student and Postdoc Association is currently accepting nominations for officers for the 2013-14 term. Nominations will be accepted through Monday, Sept. 30.

FSPA officers organize social events, communicate with students and postdocs at other laboratories, participate in monthly Users Executive Committee meetings as well as the annual users trip to Washington, D.C., and organize the annual New Perspectives conference and poster session.

To get a taste of what FSPA is about, students and postdocs are welcome to attend the first Fermilab Duathlon on Saturday, Sept. 28, beginning at 8:30 a.m. in the AZero parking lot. The duathlon is composed of four bicycle laps and one run around the Main Ring. The top two participants in each category will receive prizes. Registration is free and open to individuals and teams of two people.

FSPA officer nominations should be emailed to Self-nominations should include a photo and some information about why you'd like to join the FSPA leadership. If nominating someone other than yourself, be sure to include the individual's contact information.

In the News

Astrophile: Cosmic poltergeist messed up Milky Way

From New Scientist, Sept. 16, 2013

Objects: strange stellar layers
Likely culprit: a dead dwarf galaxy

The dwarf galaxy was doomed, but it wasn't going down without a fight. Even as it was being ripped apart by the Milky Way it struck back with enough force to set our galaxy's bones rattling. Its ghost may still haunt us, as the vibrations from its death throes subtly move things around in the Milky Way.

That's one possible explanation for the cosmic poltergeist that has rearranged stars in the Milky Way, making odd stellar layers within the galaxy's spiral disc. The dwarf galaxy is a key suspect because its remains lie eerily close to the most disturbed zones.

Read more

Frontier Science Result: CMS

Branching fractions off the menu

The Higgs boson may decay into a Z boson and a photon through an intermediate pair of charged particles.

A particle's branching fractions — that is, the probability that it will decay into one set of particles rather than another — are a good way to see if physicists really understand what's happening at microscopic scales. Many things can affect a particle's decision to decay into, say, electrons rather than photons. If the physicists' predictions match the observed probability of decay, then the underlying mechanisms may be well understood, especially if it is a tight balance between opposing forces. If not, then there might be a new intermediate particle involved or some other new phenomena to be discovered.

Some branching fractions are determined by extremely complicated processes while others are relatively simple. The Z boson, for instance, decays into electron-positron, muon-antimuon and tau-antitau pairs with equal probability. It is as though the Z has a menu of everything less massive than it and blindly chooses from the menu.

The Higgs boson's decays are also pretty simple: It can only decay directly into particle-antiparticle pairs, but with a probability that depends on the mass of the decay products. To fulfill its role as origin of mass, the Higgs must couple to matter particles in proportion to their masses and force particles by the squares of their masses, and hence it decays mostly into heavy particles. It is as though the Higgs' menu is biased toward heavy final states.

However, the Higgs sometimes decides to decay in ways that aren't even on this menu. It was discovered, in part, by its decay into two photons. Photons are massless — their coupling to the Higgs (and hence branching fraction from the Higgs) ought to be zero. Physicists believe that this decay is possible because the Higgs first decays to a pair of heavy charged particles that then re-collide to produce two photons. (Charged particles couple to photons.) It's somewhat more complicated, but not unprecedented.

With this interpretation, other final states, such as a Z and a photon, are also possible. (Charged particles also couple to Z bosons.) This Z-photon pair isn't even a particle-antiparticle pair, but it should be allowed in the same way that photon pairs are. A group of CMS physicists are exploring that possibility now, searching for Z-photon pairs with the mass of a Higgs. If the theory is well-understood, they should have enough data to see this "off-the-menu" decay mode in the near future.

Jim Pivarski

The U.S. physicists pictured above made major contributions to the search for Higgs decaying into a Z boson and a photon.
These U.S. collaborators are upgrading the core and detector software for the CMS detector in preparation for the return of operations in 2015. Because of the long lead time these upgrades require, the work began over a year ago and will continue through the data taking period.
In the News

Experiment probes strength of the weak interaction

From Physics World, Sept. 16, 2013

An international collaboration has made the first determination of the proton's "weak charge" — a quantity that is related to the strength of the weak interaction. The Q-weak experimental collaboration, working at Jefferson Lab in Newport News, Virginia, says that the small number of data analysed so far agree with predictions of the Standard Model of particle physics but that it believes a full analysis could still reveal the existence of "new physics".

Read more


Today's New Announcements

NALWO "English Conversation" mornings

SharePoint designer training - today

SharePoint end-user training - today

Artist Reception for VIEWS exhibit - today

Second City: Happily Ever Laughter at Fermilab Arts Series - Sept. 21

Nominate a colleague for the Director's Award by Sept. 25

Power Writing Workshop offered Oct. 24

Access 2010 classes scheduled

MS Excel and Word classes offered this fall

Interpersonal Communication Skills class scheduled for Dec. 4

Writing for Results: Email and More class offered Dec. 11

Accelerate to a Healthy Lifestyle

Abri Credit Union special offers

International folk dancing meets Thursday evenings in Auditorium

Outdoor soccer at the Village

Chicago Blackhawks preseason discounts

Find new classified ads on Fermilab Today.