Quantum Diaries

As a postdoc, Giovanni Tassielli has the whole particle physics landscape to survey for the most stimulating future job prospects.

The researcher from INFN in Italy feels a pull toward the most challenging experiments at the Intensity Frontier: those that seek out the rarest of all particle interactions, the smallest of effects and provide a glimpse of physics beyond what experiments at particle colliders can reach.

Intensity Frontier experiments such as Mu2e look for occurances that are not only difficult to detect, like pulling a needle out of a haystack, but occur very rarely. It is as if the needle only existed in one out of hundreds of haystacks.

“I love the precision,” said Tassielli while attending a Department of Energy-organized workshop in Washington, D.C., last week to explore scientific opportunities at the Intensity Frontier. This research area uses densely packed particle beams and complex detectors to allow physicists to see particle interactions occurring as rarely as once in a million million times.

Tassielli says it’s a research area that the world should invest in exploring to expand our understanding of nature, just as other scientists explore the depths of the ocean or craters of the moon.

The Fundamental Physics at the Intensity Frontier Workshop was set up to survey existing research and future scientific possibilities in this area, and to gauge the level of interest from the physics community. Organizers had to start turning people away after the 515 participant cap was reached more than a week before the workshop. Participant enthusiasm and energy exceeded expectations, said Glen Crawford, head of the research and technology division of DOE’s Office of High Energy Physics.

“There were a lot of lively discussions,” he said. “There were lots of young people asking good questions, people saying, ‘I learned something,’ people stopping you in the hall and saying, ‘This is great. I’m exploring opportunities for what I want to do next.’”

Yuhsain Tsi, a theory postdoc from Cornell University, said he’s interested in neutrino physics because Intensity Frontier science has as much discovery opportunity as other areas of particle physics.

Registration for the Intensity Frontier Workshop was cut off at 515 people because of space contstraints.

Physicists spent three days in six working groups listening to more than 100 presentations identifying promising research areas that use neutrinos, nucleons, nuclei, heavy quarks, charged leptons and exotic particles such as axions. The consensus was that a host of experiments have the potential to answer the biggest questions: How did the universe begin? What is it made of? How does it work? How did we come to exist? Answers from this research could aid studies in cosmology, nuclear physics and other areas of particle physics.

“What came out was that there is a broad program that has interconnections inside the Intensity Frontier and outside the Intensity Frontier that addresses fundamental symmetries of physics,” said workshop co-convenor Harry Weerts from Argonne National Laboratory.

Experiments probing the Intensity Frontier are currently running in Europe, Asia and the United States, with more proposed for the future. Flip Tanedo, a theory postdoc from Cornell University, said the ability to work face-to-face with experimental colleagues on an experiment in the United States is a key draw of the Intensity Frontier and opens the door to more productive research.

The results of the workshop will be summarized in a report that will be presented to the DOE and the High Energy Physics Advisory Panel before its March meeting. This report will provide a survey of the physics community’s thoughts about the Intensity Frontier and its scientific potential.

“The Intensity Frontier is rich. That is what we have discovered during the last three days,” said JoAnne Hewett, co-convener and SLAC physicist, said in a closing speech at the workshop. “And I think we have demonstrated a strong desire to do this physics.”

—Tona Kunz

Editor’s note: Follow the hashtag #intensityfrontier for information from the workshop.

At the Intensity Frontier, scientists use high energy beams and sensitive particle detectors to explore rare subatomic processes in search of answers to profound questions. More than 500 scientists are gathering this week to discuss the future role of the U.S. in these experiments. They will discuss the most exciting opportunities, the potential for new discoveries and the equipment and technology required for these new experiments.

The workshop, named “Fundamental Physics at the Intensity Frontier” and held from Nov. 30 to Dec. 2 near Washington, D.C., is split into six working groups. Speakers from each group will provide an overview of their study area and its future goals to an audience spanning the breadth of the physics community. Then medium-sized groups will break away for debates and discussions designed to stimulate open conversations.

“This will be a good opportunity for people in more specialized areas to interact and learn from each other and hopefully reinforce each other’s case for this physics,” said Jack Ritchie, a co-convener for the Heavy Quarks group and professor in the physics department at the University of Texas, Austin.

In recent years, the Intensity Frontier has become a top priority for fields like nuclear physics, according to Michael Ramsey-Musolf, a physics professor at the University of Wisconsin at Madison and a co-convener for the Nucleons, Nuclei and Atoms group.

“There’s a lot of synergy between high-energy physics, nuclear physics and cosmology and they all meet at the Intensity Frontier field,” he said.

The workshop also brings together scientists from similar research areas, such as muon physicists from experiments like Muon g-2, Mu2e and the proposed Long-Baseline Neutrino Experiment, according to David Hertzog, a University of Washington physics professor and member of the Charged Leptons group.

“This community is scattered all over the planet,” he said. “In any one snapshot you don’t have everybody in the same room like this.”

While the DOE’s Office of Science will use the event to evaluate the science opportunities for the U.S. particle physics community in this field, the workshop will also be a learning experience for those new to the Intensity Frontier.

“It will be very good for me to learn more about what the physics goals are,” said Gerben Stavenga, a postdoctoral fellow researching theoretical physics and a speaker for the Proton Decay group. “We’re looking forward to what the Intensity Frontier will bring us.”

From graduate students to Fermilab physicists and DOE staff, the community in attendance will comprise a large spectrum of physics professionals. The working groups have spent months preparing for the workshop.

“It’s going to be a big crowd of people and a wide range of physics to cover,” said Rouven Essig, an assistant professor from Stony Brook University and co-convener for the Hidden Sector Photons, Axions, and WISPs group. “Many eyes are on the workshop and it will have an important impact on the future direction of this field.”

—Brad Hooker

Intensity Frontier workshop

This article first appeared in Fermilab Today, Nov. 2.

Last month we celebrated the final chapter in Tevatron operations. Already, as I go through the CDF and DZero buildings I see major changes. Partical Physics Division technical teams are securing the detectors and preparing the buildings for their next use. At CDF the work inside the building is going at a furious pace to match the construction schedule of the Illinois Accelerator Research Center building, and at DZero we are clearing out two decades of equipment from the high bay to prepare for construction of the MicroBooNE experiment, starting right after Christmas. This work helps us to close a historic chapter for the lab and helps usprepare for the next one.

The director and DOE have articulated a clear focus for particle physics in the three experimental frontiers: Energy, Intensity and Cosmic. With the close of the Tevatron, PPD’s focus on the Intensity Frontier has gotten even stronger, mirroring the direction of the future program in the U.S. At the end of November, many PPD scientists will travel to Rockville, MD to participate in a DOE Office of Science Intensity Frontier workshop that will help define our future work.

There are exciting opportunities at the Intensity Frontier to build and operate experiments that use rare processes to search for new physics. For some, their study requires intense beams and large detectors. In others, highly precise detectors capable of distinguishing between rare processes and mundane backgrounds are needed.

At the workshop, we will work to identify these opportunities, determine what can be learned, assess what can be done with current facilities and technology, and explore what new facilities or new technology are needed to reach this frontier’s full physics potential. Many of PPD’s most talented people, both experienced and early in their careers, have been preparing materials and case studies for some time. They are still recruiting help for the final push that is needed during the next few weeks. The results that come out of the workshop will help DOE provide direction for the field, and for the work that PPD scientists, engineers, technicians and staff will focus on for the next decade.

–Mike Lindgren, head of the Fermilab’s Particle Physics Division, wrote this column.