The Columbia University Nevis Labs program encompasses a broad spectrum of five fundamental experiments in particle physics: ATLAS; MiniBooNE/SciBooNE; D0; eBubble; and Double Chooz. Work on two other future projects is also proposed: the new MicroBooNE and NuSOnG experiments. Particle physics considers a vast range of questions, from subatomic to cosmic scales. It is expected that new physics beyond the Standard Model will hold the key to making progress in our understanding. Some of the most important questions are: How do we explain the large disparity between the weak scale, the grand-unification scale and the Planck scale? What is the dark matter and dark energy in the universe? What is responsible for the large matter-antimatter asymmetry in the universe; is it related to CP violation for the neutrinos? Why are the neutrino masses so small?
This award provides funds to support this group in the following research program: top quarks (D0, ATLAS), neutrinos (BooNE, Double Chooz), and sparticles (ATLAS). These last particles could yield candidates for dark matter. The neutrino sector has many unanswered questions: How many are there? Can we measure CP violation now that we know they have mass and oscillate? These are questions that are being answered by the MiniBooNE experiment and, in the future, by Double Chooz. In addition, precision neutrino experiments like NuSOnG will examine if the neutrinos have unexpected properties that give them a special place among the other particles.
The Columbia groups place a high priority on education and outreach and plan to build on their past very successful efforts by integrating a number of these activities into the ongoing research. The goal is to engage a full spectrum from high school students and teachers, undergraduates and the general public in understanding and doing high energy physics. A primary emphasis of the Columbia programs is to target underrepresented groups to participate in these activities. The activities range from individual faculty efforts to structured programs such as the Research Experience for Undergraduates, Quarknet, and Fermilab Public Affairs Internship Program.
The Columbia University Nevis Labs program encompasses a broad spectrum of particle physics in several of the forefront areas of the field. A main part of the program is associated with physics at the Large Hadron Collider (LHC) at the CERN laboratory in Geneva, Switzerland, where Columbia scientists work in the ATLAS collaboration. The LHC is the world’s highest energy particle accelerator, and scientists use the collisions of very high-energy protons produced there to search for answers to fundamental questions about the universe, including the origin of mass, the nature of the so-called Dark Matter that accounts for most of the mass in the universe, the reason for the matter-antimatter asymmetry in the universe, and the possible existence of new particles and forces. One of the main recent results was the discovery of the Higgs boson, which is one of the key building blocks of our understanding of how particles interact and the origin of mass. This discovery resulted in the awarding of the 2013 Physics Nobel Prize. Going beyond the discovery of the Higgs boson, the Columbia group is deeply involved with searches for new particles and phenomena. Our current understanding of particle physics is believed to be only an approximate theory, and these new physics signatures will hold the key to making progress in understanding the ultimate, underlying theory. As of yet, collider physicists including the Columbia group have only been able to rule out possible new signatures but the LHC opens a wide region with great discovery potential for these searches, especially as the LHC upgrades to higher energy and higher intensities. Part of the Columbia program has been the development of upgrades for the ATLAS detector electronics for the higher intensities. In addition, the Columbia group has been active in the commissioning of the new innermost layer of the detector, closest to the proton-proton collisions, to be used for the first time in the upcoming high-energy run. The LHC has been an unquestioned success and resource for making progress in understanding the universe and clearly will continue to be one of the most important scientific endeavors for the next several decades. Another key part of the Columbia program is neutrino physics and neutrino oscillations. Neutrinos are one of the most elusive particles since they interact very weakly being the only matter particle that has no strong or electric charge. There are three types of neutrinos associated with the three types of leptons including the well known electron. In the standard theory, neutrinos are massless but, as of 20 years ago, we know that they do have very small masses, which cause the neutrinos to change their type as they move, a phenomena called neutrino oscillations. By studying the patterns of these neutrino oscillations, we are trying to answer several of the key questions in particle physics: Why is the neutrino mass so small? Are there new types of "sterile" neutrinos that are only produced by new interactions? Are neutrinos the reason for the matter to antimatter asymmetry in the universe due to oscillation differences of neutrinos and their antimatter partners? The Columbia group has a major role in exploring all of these questions. Specifically, the Columbia neutrino group participated in the Double Chooz reactor antineutrino experiment and, with significant Columbia leadership, published several oscillation measurements including the first measurement showing that the oscillation strength was large. The large value opens the way for future oscillation experiments to study neutrino to antineutrino and other neutrino mass asymmetries. The group is also actively involved in the MicroBooNE and MiniBooNE experiments that are investigating the indications that there might be a fourth type of sterile neutrino. These sterile neutrinos would have no standard interactions and be produced through neutrino oscillations. Establishing the existence of sterile neutrinos would be a major result for particle physics and is now a priority for the neutrino community. The Columbia group has been leaders in the MiniBooNE analysis that showed significant anomalies that could be interpreted as sterile neutrino effects. More recently, the group has been working on the MicroBooNE experiment, developing the detector readout and the data analysis software. The Columbia group places a high priority on education and outreach and has integrated these activities into the ongoing research program. The activities have ranged from individual faculty outreach efforts (lectures, tours, etc) to structured programs like the Research Experience for Undergraduates (REU). A primary emphasis of the Columbia programs is to target underrepresented groups to participate in these activities. For example, over the past 14 years over half of the group’s REU participants were women and almost a third were minorities. On the technological side, the neutrino group is working with industry to develop new types of cyclotrons that could be used for enhanced medical isotope production or possibly for accelerator driven reactor systems.
