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Posts Tagged ‘Snowmass’

Unanswered questions

Tuesday, October 22nd, 2013

This article appeared in symmetry on Oct. 22, 2013.

Do you think scientists have the answers to all the questions? As these researchers admit, there’s still so much to discover. Particle physics is brimming with mysteries and unknowns. Photo: Sandbox Studio, Chicago

Do you think scientists have the answers to all the questions? As these researchers admit, there’s still so much to discover. Particle physics is brimming with mysteries and unknowns. Photo: Sandbox Studio, Chicago

Bring hundreds of smart physicists together and what do you get? Lots of questions!

This summer, more than 700 particle physicists from nearly 100 universities and laboratories across the United States came together on the University of Minnesota’s Twin Cities campus for the Snowmass Community Summer Study meeting. There, they discussed the decades ahead in US particle physics, carefully considering the next steps in their studies of energy, matter, space and time.

During coffee breaks, symmetry asked attendees to share open questions in particle physics. Here’s a sample of what particle physicists think about and what they hope to discover in the coming decades.

View an image gallery of particle physicists asking their most pressing questions.


Snowmass Came and Passed. What have we learned from it?


Skyline of Minneapolis, home of the University of Minnesota and host city of the Community Summer Study 2013: Snowmass on the Mississippi.

Hi All,

Science is big. It is the systematic study of nature, so it has to be big. In another way, science is about asking questions, questions that expands our knowledge of nature just a bit more. Innocuous questions like, “Why do apples fall to the ground?”, “How do magnets work?”, or “How does an electron get its mass?” have lead to understanding much more about the universe than expected. Our jobs as scientists come down to three duties: inventing questions, proposing answers (called hypotheses), and testing these proposals.

As particle physicists, we ask “What is the universe made of?” and “What holds the universe together?”  Finding out that planets and stars only make up 5% of the universe really makes one pause and wonder, well, what about everything else?

From neutrino masses, to the Higgs boson, to the cosmic microwave background, we have learned  much about the origin of mass in the Universe as well as the origin of the Universe itself in the past 10 years. Building on recent discoveries, particle physicists from around the world have been working together for over a year to push our questions further. Progress in science is incremental, and after 10 days at the Community Summer Study 2013: Snowmass on the Mississippi Conference, hosted by the University of Minnesota, we have a collection of questions that will drive and define particle physic for the next 20 years. Each question is an incremental step, but each answer will allow us to expand our knowledge of nature.

I had a chance to speak with SLAC‘s Michael Peskin, a convener for the Snowmass Energy Frontier study group and author of the definitive textbook on Quantum Field Theory, on how he sees the high energy physics community proceeding after Snowmass. “The community did a lot of listening at Snowmass. High energy physics is pursuing a very broad array of questions.  I think that we now appreciate better how important all of these questions are, and that there are real strategies for answering them.”  An important theme of Snowmass, Peskin said, was “the need for long-term, global planning”.  He pointed to the continuing success of the Large Hadron Collider, which is the result of the efforts of thousands of scientists around the world.  This success would not have happened without such a large-scale, global  effort.  ”This is how high energy physics will have to be, in all of its subfields, to answer our big questions.”

Summary presentations of all the work done for Snowmass are linked below in pdf form and are divided into two categories: how to approach questions (Frontiers) and what will enable us to answer these questions. These two categories represent the mission of the US Department of Energy’s Office of Science. A summary of the summaries is at the bottom.

What is the absolute neutrino mass scale? What is the neutrino mass ordering? Is CP violated in the neutrino sector? What new knowledge will neutrinos from astrophysical sources bring?

What is dark matter? What is dark energy? Why more matter than anti-matter? What is the physics of the Universe at the highest energies?

Where are the new particles that modify the Higgs, t, W couplings? What particles comprise the dark matter? Why is the Higgs boson so light?

The growth in data drives need for continued R&D investment in data management, data access methods, networking. Challenging resource needs require efficient and flexible use of all resources HEP needs both Distributed High-Throughput computing (experiment program) and High-Performance computing (mostly theory/simulation/modeling)

Encourage and enable physicists to be involved in and support local, national and world-wide efforts that offer long–term professional development and training opportunities for educators (including pre-service educators), using best practice and approaches supported by physics education research. and Create learning opportunities for students of all ages, including classroom, out-of-school and online activities that allow students to explore particle physics

Our vision is for the US to have an instrumentation program for particle physics that enables the US to maintain a scientific leadership position in a broad, global, experimental program; and develops new detection capabilities that provides for cutting edge contributions to a world program

Is dark energy a cosmological constant? Is it a vacuum energy? From where do ultra high energy cosmic rays originate? From where do ultra high energy neutrinos originate?

How would one build a 100 TeV scale hadron collider? How would one build a lepton collider at >1 TeV? Can multi-MW targets survive? If so, for how long?

To provide a conduit for untenured (young) particle physicists to participate in the Community Summer Study. To facilitate and encourage young people to get involved.
Become a long term asset to the field and a place where young peoples voices can be heard

Several great posts from QD (Family, Young, Frontierland), Symmetry Magazine (Push, Q&A, IceSlam, Decade), and even real-time updates from QD’s Ken Bloom (@kenbloomunl) and myself (@bravelittlemuon) via #Snowmass are available. All presentations can be found at the Snowmass Indico page.

Until next time, happy colliding.

- Richard (@bravelittlemuon)

Community Summer Study: Snowmass 2013 Poster

Community Summer Study: Snowmass 2013 Poster


The Snowmass at Minnesota Community Summer Study Meeting is one month away, and the Young Physicists Group is planning for a strong participation. Students, postdocs and other untenured scientists are all encouraged to attend.

In addition to a wealth of physics results, many contributed by some of our brightest young people, the program includes:

  • a plenary talk (7/29, 1:30 p.m.) presenting results of the Career and Science Prospects Survey, which has gathered 1000+ responses so far and remains open until 7/15
  • a parallel session (date and time TBD) to discuss and edit the paper summarizing our views

The information and registration page is: http://www.hep.umn.edu/css2013/

The accommodations page lists hotels with rooms available at a reduced rate for participants.

Those traveling to or from Fermilab might be interested in this carpooling option.

Important deadlines are 7/7 for hotel reservations and 7/15 for registration to the meeting and inputs to the survey.

If you have not yet completed our brief survey, please do so. If you have done it already — many thanks! — please encourage others to do the same. The link to the survey is: http://tinyurl.com/snowmassyoung

See you in Minnesota!

Snowmass Young Conveners


The US high-energy physics community is planning the next two or three decades of its future. The process, called Snowmass, is a big deal for everyone interested in astro/particle physics, cosmology and related areas. That is especially important in these times of shrinking budgets and dire job prospects, which affect academic career paths of researchers worldwide — the folks at PhD Comics have a great take on this topic. Brilliant.

At Snowmass, the contribution of all segments of the community is necessary to ensure that its outcome truly reflects our views. The Snowmass Young Physicists group was formed to facilitate the participation of young people in this process. I am one of the organizers of this group and we are pursuing a Career and Science Aspirations Survey as an opportunity for everyone in our field to have their voices heard and help paint the big picture.

We are reaching out to people in all demographics: current, past and prospective students at the undergraduate and graduate levels; postdocs or former postdocs now working in other areas; and you, Quantum Diaries reader.

If you are part of our community, please take 10 minutes to respond the online survey. If you think this doesn’t apply to you, then please help us spread the news! The link is: http://tinyurl.com/snowmassyoung

The survey was launched in April and will be open until mid-July. Results will be published by the Snowmass Young team later this summer.

Marcelle Soares-Santos


“Snowmass” (Not Snowmass)

Saturday, October 13th, 2012

Every so often, perhaps once or twice a decade, particle physics in the United States comes to some kind of a crossroads that requires us to think about the long-term direction of the field. Perhaps there is new experimental data that is pointing in new directions, or technology developments that make some new facility possible, or we’re seeing the end of the previous long-term plan and it’s time to develop the next one. And when this happens, the cry goes up in the community — “We need a Snowmass!”

Snowmass refers to Snowmass Village in Colorado, just down the road from Aspen, the home of the Aspen Center for Physics, a noted haunt for theorists. During the winter, Snowmass a ski resort. During the summer, it’s a mostly empty ski resort, where it’s not all that expensive to rent some condos and meeting rooms for a few weeks. Over the past few decades there have been occasional “summer studies” held at Snowmass, typically organized by the Division of Particles and Fields of the American Physical Society (and sponsored by a host of organizations and agencies). It’s a time for the particle-physics community to come together for a few weeks and spend some quality time focusing on long-range planning.

The last big Snowmass workshop was in 2001. At the time, the Fermilab Tevatron was just getting started on a new data run after a five-year shutdown for upgrades, and the LHC was under construction. The top quark had been discovered, but was not yet well characterized. We were just beginning to understand neutrino masses and mixing. The modern era of observational cosmology was just beginning. A thousand physicists came to Snowmass over the course of three weeks to plot the future of the field. (And I was a lot younger.) Flash forward eleven years: the Tevatron has been shut down (leaving the US without a major high-energy particle collider), the LHC is running like gangbusters, we’re trying to figure out what dark energy is, and just in the past year two big shoes have dropped — we have measured the last neutrino mixing angle, and, quite famously, observed what could well be the Higgs boson. So indeed, it is time for another Snowmass workshop.

This week I came to Fermilab for a Community Planning Meeting for next year’s Snowmass workshop. Snowmass 2013 is going to be a bit different than previous workshops in that it will not actually be at Snowmass! Budgetary concerns and new federal government travel regulations have made the old style of workshop infeasible. Instead, there will be a shorter meeting this summer hosted by our colleagues at the University of Minnesota (hats off to thee for having us), so this time we won’t have as much time during the workshop to chew over the issues, and more work will have to be done ahead of time. (But I suspect that we’re still going to call this workshop “Snowmass”, just as the ICHEP conference was “the Rochester conference” for such a long time, even if it’s now the “Community Summer Study”.)

This Snowmass is being organized along the three “frontiers” that we’re using to classify the current research efforts in the field — energy, intensity and cosmic. As someone who works at the LHC, I’m most familiar with what’s going on at the energy frontier, and certainly there are important questions that have only come into focus this year. Did we observe the Higgs boson at the LHC? What more do we have to know about it to believe that it’s the Higgs? What are the implications of not having observed any other new particles yet for particle physics and for future experiments? The Snowmass study will help us understand how we answer these questions, and specifically what experiments and facilities are needed to do so. There are lots of interesting ideas that are out there right now. Can the LHC tell us what we need to know, possibly with an energy or luminosity upgrade? Is this the time to build a “Higgs factory” that would allow us to study measure Higgs properties precisely? If so, what’s the right machine for that? Or do we perhaps need an accelerator with even greater energy reach, something that will help us create new particles that would be out of reach of the LHC? What kind of instrumentation and computing technologies are needed to make sense of the particle interactions at these new facilities? The intensity and cosmic frontiers have equally big and interesting questions. I would posit that the scientific questions of particle physics have not been so compelling for a long time, and that it is a pivotal time to think about what new experiments are needed.

However, we also have the bracing reality that we are looking at these questions in a budget environment that is perhaps as constrained as it has ever been. Presentations from our champions and advocates at the Department of Energy and the National Science Foundation, the agencies that fund this research (and that sponsor the US LHC blog) were encouraging about the scientific opportunities but also noted the boundary conditions that arise from the federal budget as a whole, national research priorities, and our pre-existing facilities plan. It will continue to be a challenge to make the case for our work (compelling as it may be to us, and to someone who might be interested in looking at the Quantum Diaries site) and to envision a set of facilities that can be built and used given the funding available.

The first (non-native) settlers of Snowmass, Colorado, were miners, who were searching for buried treasure under adverse conditions. They were constrained by the technology of the time, and the facilities that were available for their work. I shouldn’t suggest that what we are doing is exactly like mining (it’s much safer, for one thing), but hopefully when we go to Snowmass (or really “Snowmass”) we will be figuring out how to develop the technology and facilities that are needed to extract an even greater treasure.