LITTLE BANG — Particles spray from the collision between deuterons and gold ions in this image from the STAR detector at Brookhaven. Collisions like this one hint at a form of matter called the quark-gluon plasma, thought to exist in the first microseconds after the Big Bang. Image courtesy Brookhaven National Laboratory/RHIC-STAR.

Research hints at extreme form of matter

By Dave Jacqué

Researchers have come a step closer to creating the most extreme form of matter known to physics. Supported by a small team from Argonne, researchers at Brookhaven National Laboratory found tantalizing clues that suggest a “quark-gluon plasma” was created by the Relativistic Heavy Ion Collider (RHIC).

A quark-gluon plasma is an unimaginably hot, dense stew of elementary particles thought to exist only for a few microseconds after the Big Bang and possibly in the centers of neutron stars. At ultra-high densities and temperatures more than 300 million times the surface temperature of the sun, individual protons and neutrons -- the particles that make up atomic nuclei -- dissolve into a soup of quarks and the force-carrying particles that once held them together, whimsically called gluons (see sidebar story, page 2).

“This is the only state of matter in which quarks are liberated from the inside of protons and neutrons, and can roam free inside a larger volume,” said Argonne physicist Birger Back (PHY), who leads the laboratory’s research with the Phobos detector at RHIC. Back works in close collaboration with former Argonne researchers Russell Betts and David Hofman, now with the University of Illinois at Chicago (UIC).

One of four particle detectors at RHIC, Phobos was built by a collaboration that included Argonne, the Massachusetts Institute of Technology, Brookhaven, UIC, the Universities of Maryland, Rochester, and Krakow, Poland, and the National Central University in Taiwan.

Although relatively small in comparison to its 1,200-ton brethren at the accelerator facility, Phobos provided valuable data in the quark-gluon plasma experiments.

“Phobos has a unique ability to measure all charged particles from a collision,” Back said. “It’s almost custom-made for this experiment.” Back and his colleagues from UIC were responsible for building and testing the “multiplicity” section of the detector. Technicians at Fermilab performed the intricate task of bonding micro-wires to thousands of silicon plates, similar in function to CCD camera chips, that measure the energies and direction of nearly all charged particles emitted from a particle collision. A second part of the detector analyzes how particles are deflected by a magnetic field.

Such complex detectors are needed in the search for the quark-gluon plasma. The signal is extremely subtle and difficult to single out from the avalanche of particles emitted during the experiments.

When nuclei collide at high energies, a pair of quarks can be knocked loose from inside a proton or neutron. Quarks normally can’t exist outside a proton or neutron. They disintegrate into “jets,” back-to-back fountains of other particles.

In experiments conducted during 2002, RHIC collided gold nuclei at nearly the speed of light. One of the jets went missing.

“The prevailing explanation is that the high-energy particles get slowed down or stopped by the medium you’re producing,” Back said. “The leading particles from the jets get suppressed. That’s generally taken as the signal of a quark-gluon plasma -- it’s predicted to have a high stopping power.”

The Phobos detector provided a check on these findings. In experiments conducted from January to March, Phobos analyzed the effects of colliding deuterons (elementary nuclei comprising a proton and neutron) with gold nuclei. Deuterons are much lighter than gold nuclei; the relatively low-energy collisions produced jets, as predicted by theory. Whatever was “quenching” the jets in the gold-gold collisions only occurred at energies consistent with a quark-gluon plasma.

Although the findings fit predictions, “scientists are very cautious about claiming that it’s a direct smoking gun,” Back said. Jet suppression could be caused by other effects, such as “gluon saturation,” although it’s “a stretch of the model,” Back said.

If further research proves the existence of a quark-gluon plasma in RHIC collisions, physicists will analyze the behavior of free quarks and gluons to learn more about the strong nuclear force, which holds quarks together in protons and neutrons.

“These experiments are an important step,” he said. “Everyone agrees more experiments and different signals are needed before we can claim victory.”

This research was funded primarily by the U.S. Department of Energy, Office of Science, Nuclear Physics Division, with additional funding from the National Science Foundation and a large number of international agencies.

The inner life of a nucleon

Protons and neutrons consist of three quarks: two “up” quarks and a “down” quark make a proton (top image), and two downs and an up comprise a neutron. They’re held together by the constant exchange of particles called gluons. In a quark-gluon plasma (below), this structure breaks down and quarks and gluons are freed from their confines. The “c” and “c-bar” particles created by the energy of the collision can escape as “jets” at lower energies but are trapped by the dense plasma. A quark-gluon plasma created at the Relativistic Heavy Ion Collider would last for just 0.00000000000000000000001 seconds and may reach temperatures of more than a trillion degrees.

ACA raffle raises record-breaking $4,287.50

Thomas Wiencek (ET) won the grand prize of two United Airlines round-trip tickets in this year’s Argonne Combined Appeal (ACA) raffle drawing, held at the Argonne-East picnic July 12.

“My wife and I will be using the tickets to visit the west coast for our 15th wedding anniversary,” said Wiencek.

The ACA raffle and hat sales raised a record-breaking $4,287.50, up from last year’s total of $3,843. The money raised from the raffle will pay for ACA campaign expenses and will be donated to charities not in the ACA program. Suggestions on worthy charities are welcome, and should be directed to Bryan Schmidt (IPD) at ext. 2-4122 or bschmidt@anl.gov.

Other winners of major prizes ($30 or more) were:

Cheryl Drugan (IPD-MED) and Lisa Reyes (CMT-ESH), Baymont Inn one-night stays

Joe Gagliano (ASD), DJM Travel and Cruise gift basket, $200 value

Al Barcikowski (NE-EO), Omega Restaurant, dinner for two

Rich Benn (BIO), Tassos Porterhouse, $50 gift certificate

Mary Hodshire (PFS-FEC), Tallgrass Restaurant, $50 gift certificate

Francis Strehl (HR-MD), Traverso’s dinner for two ($60 value)

Lucy Sanchez (AIP), Just Ducky $100 gift basket

Albert T. Keane (CMT-ESH) and Gian Trento (ASD), Gleneagles Country Club, round of golf for two with cart

Mary Jo Koldenhoven (OTT), Noreen Czyz (APS-PA) and Stephen Denny (OCF-PRO), Caring Hands Massage Therapy, $60 gift certificates

Deon Ettinger (DEP), Suburbanite Bowl, Family Fun Pack, $40 value

Norm Rendon (OCF-ACT), Kerry Piper, $50 gift certificate

Lisa Reed (DEP), Holiday Inn one-night stay

George Joch (IPD-MED), Pappadeaux Seafood Kitchen, $50 gift certificate

Mike Fagan, Weber One-Touch Gold Charcoal grill, $150 value

A complete list of winners and prizes is available on the ACA Web site on the raffle page.

Discoverer of fullerenes to speak

Nobel Prize winner Richard Smalley, whose research in chemical physics led to the discovery of a third elemental form of carbon called “fullerenes,” will speak on “Our Energy Challenge” at a Director’s Special Colloquium Tuesday, Aug. 5.

Smalley’s talk will begin at 3 p.m. in Argonne-East’s Advanced Photon Source Conference Center, Building 402. All employees whose schedules permit are invited to attend the talk.

Smalley has pioneered new experimental techniques, including supersonic beam laser spectroscopy, and applied them to a broad range of scientific questions. He shared the 1996 Nobel Prize in chemistry for the discovery and characterization of Buckminsterfullerene, a soccer-ball- shaped carbon molecule. His current research focuses on the production of continuous carbon fibers that are essentially giant single-fullerene molecules. These fibers are expected to be the strongest ever made, 100 times stronger than steel.

He was appointed a professor at Rice University, Houston, Texas, in 2002, and holds the Gene and Norman Hackerman Chair in Chemistry. Smalley is a member of the National Academy of Sciences and the American Academy of Arts and Sciences.

Interns to discuss experiences, future plans

A group of summer interns will relate their experiences, their work and their plans for the future at the First Friday Forum meeting Thursday, July 31, at 12:15 p.m. in Argonne-East’s Building 203, Room R150.

Micah Baquera (ET), Zoe Paukstys (MSD), Arthur Reynolds (PHY) and Monica Villar (CHM) will present a summary of their internships.

The First Friday Forum is an informal gathering of Argonne women usually held on the first Friday of the month. The group explores career and gender issues related to women. Meetings are open to all Argonne and U.S. Department of Energy employees.

Child center plans picnic, science fair

The Argonne Child Development Center will get excited about Science Tuesday, July 29, with a special science show and mini-golf from 4-6 p.m.

The center’s children will be introduced to simple science ideas as they prepare for a Science Fair in the late fall. Employees are invited to join the activities and learn more about the center. Light refreshments will be served.

Picnic

The center’s annual picnic will be held Saturday, Aug. 2, from 10 a.m. to 2 p.m. at the Argonne Park pavilion.

The picnic will feature a hayride, ponies, a moon jump, food and other activities. All center families and center alumni are invited to attend. An information booth and tours will be available for families interested in placing a child with the center.

To RSVP for the picnic, call ext. 2-9601 by Tuesday, July 29. The cost will be $3 per adult and $2 per child.

Wednesday shrimp boils planned

Argonne’s Guest House will hold a lunchtime shrimp boil every Thursday during August from 11:30 a.m. to 1:30 p.m.

All-you-can-eat, peel-and-eat shrimp is $8.95 per person. Other menu items will be available, including a barbeque entrée. A salad bar will be offered for an additional $1.95 with any entrée.

Safari in the park

Argonne and DOE employees and their families were kept entertained while attending this year’s Safari-themed picnic July 12.

“This year’s picnic was a big success,” said coordinator Steve Hanuska (ASD). “Employees and their families from almost every Argonne group attended the picnic this year. In the 10 or 11 years I have been involved with the Argonne Club, we have never had a better volunteer turnout.”

A wide selection of food was available to picnic-goers, including a complimentary box of animal crackers given out at the gate.

Children and adults alike enjoyed a variety of picnic attractions.

Guest House chef to host food classes

Guest House Executive Chef Chris Kaminski will host “Taste of America” cooking classes Monday, Aug. 4, and Thursday, Aug. 7, from 5:30-7:30 p.m.

Students will learn how to prepare several dishes, including grit soufflé with roasted garlic and cheddar cheese, cedar planked salmon, grilled chicken salad with spinach, avocado dressing and jicama slaw, shrimp with tequila and mango salsa and red, white and blue shortcake.

The two-hour classes cost $25. No experience is necessary.

Registration for the Aug. 4 class is due on Monday, July 28, and registration for the Aug. 7 class is due on Friday, Aug. 1. Pay by cash, check or credit card at the Argonne Guest House, Building 460. For more information, call Kathy at ext. 5-2006.

Fitness center boasts new equipment

An open house Thursday, July 31, will showcase new equipment recently added to the exercise facility on the Ground Level of Argonne-East’s Building 402.

The open house will be held from 11 a.m. to 1:30 p.m. Bob Perkins, a certified wellness trainer from the Total Body Fitness Center, will demonstrate the safe and proper use of all the fitness equipment. He will also answer questions about personal fitness programs.

No reservations are necessary to use the facility, which is available to all Argonne employees weekdays until 9 p.m. Advanced Photon Source employees can access the facility 24 hours.

RETIREES

Susan Ercoli (EQO) retired June 27 with 12 years of service.

Joseph E. Huceg (NE) retired June 27 with 29 years of service.

Larry McCure (OCF) retired June 30 with 25 years of service.

Richard J. Page (NE) retired June 30 with 23 years of service.

Robert Pfile (OCF) retired June 2 with 11 years of service.

Christopher Saricks (ES) retired June 30 with 22 years of service.

William B. Smith (PFS) retired June 16 with 27 years of service.

Joyce Taylor (OCF) retired June 16 with 26 years of service.

Ronald J. Thomas (FAC) retired June 30 with 29 years of service.

Leon C. Walters (ERA) retired June 30 with 37 years of service.

SERVICE AWARDS

Service Awards for June include:

40 Years

William P. McDowell (AOD).

35 Years

Dennis J. Kilsdonk (NE), Mike J. Monczynski (CIS), Richard W. Patete (PFS), Joyce A. Stephens (ET).

25 Years

Dorothy M. Cardia (CIS), Judith L. Carlson (ET), Raymond L. Carlson (CIS), Timothy M. Carothers (OSS), Lee F. Essenmacher (ET), Emil M. Franklin (FAC), Vivian Kay Johnson (PFS), V. Christos Stamoudis (CMT), Gary P. Zinkann (PHY).

20 Years

Eugene W. Brown (RPS), James P. Byrnes (CMT), George J. Joch (IPD), Edward R. Porlier (OCF), Elizabeth H. Rizzo (PHY).

15 Years

Kathleen A. Jarzynka (CMT), James J. Laidler (CMT), Marc A. Madore (DIS), Nicholas J. Malik (PFS), Robert D. Olson (MCS), Mohan Ramanathan (AOD).

10 Years

Kevin Byrne (CMT), Judy Frantini (PFS), Diane F. Hawk (BIO), Douglas R. Lucas (PFS), Gerald McMichael (IPNS), Scott W. Petersen (ASD), Jerry J. Rice (ASD), John Wammack (NE), Jerry Weverka (FAC).

5 Years

David A. Clinger (NPS), Richard B. Crowley (OCF), David D. Erickson (ENT), James R. Grogan (DIS), Sandra A. Guendling (NE), Keith B. Knight (ASD), Ali Mashayekhi (XFD), JoAnn Nelson (PFS), Thomas P. O’Connor (PHY), Robert T. Soliday (AOD), James D. Sommers (NT), Stephen K. Streiffer (MSD), Richard L. Swartz (PFS), Michelle A. Walden (HR), Yuejun Eugene Yan (ER).