W&M faculty organize workshop on neutrino 'factories'| July 24, 2012
By the time you’re reading this, neutrino physicists from around the world will have descended upon Williamsburg. NuFact 2012, a unique workshop on all things accelerator-based neutrino physics and related topics, is being jointly hosted by the College of William and Mary and Jefferson Lab. It is the first time since 2002 that an high-energy physics (HEP) event with an experimental focus has been hosted by William and Mary, and the first with a focus on neutrino physics. The workshop is unique in that it brings theorists, experimentalists and accelerator physicists together with a focus on future experiments, particularly the development of an accelerator called a neutrino factory from which the workshop derives its name.
A neutrino factory would be a completely new type of accelerator capable of producing huge quantities of neutrinos through muon decay that would pave the way for high-precision studies of the particle. Neutrinos are notoriously difficult to detect as they only weakly interact with other particles, to the point where existing neutrino detectors are typically built underground to be shielded from any sort of background noise that might be picked up on. Existing experiments create neutrino beams by colliding protons into a fixed target. This results in a spray of subatomic particles which are then focused into a large vessel, where some of these resulting particles, dominantly charged pions, decay into neutrinos. The main issue with this is that only the parent particles can be controlled, not the neutrinos. One of the goals of a neutrino factory would be separating neutrino production from that target process, which would result in fewer unwanted particles, thus a beam with less contamination or better understood neutrino flux. To do this, neutrino factories would produce neutrinos via muon decay.
NuFact provides an excellent environment to work towards this goal as the workshop brings together people with expertise in designing experiments, building experiments, and building the neutrino beams. This in turn enables a discussion of what direction should be taken in to optimize future experiments. The focus is on discussing better ways of doing neutrino research itself, although new experimental results are announced as well. Engineering studies or tests of technology are given a much stronger forum than at most conferences, as they are what will pave the way to the next development in research. Due to this, about half the results announced at NuFact will be technological advancements towards making better neutrino beams, along with much of the content being about building detectors and technological progress. This forward-thinking mentality produces a positive feeling for the workshop, as, in Jeffery Nelson’s words, it’s a “bunch of people looking forward to things they might get to do” while working to better the future of physics research.
The particularly interesting thing about NuFact 2012 is that a very important observation was made that will color the direction neutrino physics takes. The observation and verification of the neutrino oscillation value known as θ13 (read theta 1-3) marks a shift in what is being looked for by neutrino factories. Previously it was thought that the neutrino factory might be used to determine the θ13 value itself, but now that this value has been observed a neutrino factory must instead focus on other questions armed with this knowledge, such as the mass ordering or neutrino states or if neutrinos are the same as their antimatter counterparts.
To better address the broad topic that is neutrino physics the workshop features four working groups that meet in parallel, with each working group focusing on a different aspect. Two of the working groups, the Neutrino Oscillations and Neutrino Scattering Groups, have William and Mary professors Patricia Vahle and Michael Kordosky respectively as their North American convener. This means that they are responsible for coordinating talks and discussions on that group’s focus along with the conveners from Europe and Asia, as well as giving a summary of the working group’s progress since last year and over the workshop itself. They are also part of the local organizing committee along with Robert McKeon and co-chair Jeffery Nelson.
As conveners, Kordosky and Vahle had to pay even closer attention to the work being done in their fields than they typically would have, ever on the alert for a potential talk for the workshop. The ideal is a balance of talks between experimentalists and theorists to get an idea of what the latest results are as well as what might be done in the future. Experimentalists can talk with theorists to determine what they might need tested, while accelerator physicists can confer with experimentalists on what limits exist on their experiments. As Kordosky explains, “It’s more of a way for people to come together to discuss better ways of doing their research.”
Apart from the first day, all sessions of the workshop will be held in the Sadler Center and are open to people stopping in for the talks (so long as they don’t invade the coffee breaks!). “Having been to a number of these in the past, it’s cool to bring people to campus,” Nelson explains. In particular, it is exciting to hold NuFact 2012 at William and Mary as it serves as a reminder to the scientific community that while William and Mary may use College in its name it is technically a university, producing strong research and equipped with a PhD program in Physics.
The schedule is available online from NuFact 2012’s website.