University of Minnesota
School of Physics & Astronomy

Spotlight

The Intensity Frontier

Jianming Bian
Jianming Bian
Annie Bartels
                                                       

Jianming Bian is a research associate who works on both the BESIII and NOvA experiments. Both experiments operate at the so-called "Intensity Frontier" which means that they study fundamental particles and forces of nature using intense particle beams and highly sensitive detectors.

Bian does quark physics with the BESIII experiment and neutrino physics with NOvA. "At BESIII we use electron-positron collisions to search for new states composed of quarks and antiquarks that are outside the familiar pattern of mesons and baryons. We also measure decay rates and other properties to provide sensitive tests of theories of the strong interaction," Bian says. NOvA, uses one of the world’s most intense accelerator beams to investigate the mixing of different neutrino flavors. NOvA aims to resolve ambiguities in the understanding of neutrino masses and mixing and to shed light on the role of neutrinos in the evolution of the universe.

BESIII is a general-purpose magnetic spectrometer at the BEPCII collider in China. BESIII addresses many open questions in particle physics by collecting data samples that are not as large as some competing experiments, but are uniquely suited to precision physics. Research topics include light-hadron and charmonium spectroscopy, electroweak and strong physics at the charm scale and searches for rare processes. Bian’s recent work includes studying Zc, a particle observed by BESIII and other experiments that differs from the standard model of particle physics because it decays to charmonium and has an electric charge. He is also working on a measurement of “non-DD” decays of a state called ψ(3770). The quark model allows for decay primarily to pairs of D mesons, but two previous experiments presented conflicting evidence. One suggests a large component of decays to final states without D mesons and the other contradicts this. "Our BESIII analysis should resolve the controversy very soon," Bian says.

NOvA uses a NuMI muon-neutrino beam from Fermilab, aimed at northern Minnesota where the collaboration is assembling a 14,000-ton detector designed to detect electron-neutrinos generated by oscillations in the NuMI beam. Currently, Bian’s focus is identifying electron-neutrino interactions by distinguishing the energy deposited by an electron from the deposits left by other particles. Because the oscillated electron-neutrino signal is very small, the collaboration must work hard to maximize the efficiency and minimize backgrounds. "Many of our ideas for electron-identification in NOvA have been inspired by our experiences with particle identification in BESIII. The analysis tools I have developed are performing well and are widely used among members of the NOvA collaboration." In NOvA Bian is working on electron-neutrino appearance, the most eagerly anticipated measurement in the experiment’s scientific program. Neutrinos, among the most abundant particles in the universe, have no electric charge and come in three flavors - electron, muon and tau. The most interesting property of neutrinos is that they can transform from one flavor to another. The discovery of this neutrino oscillation was the first indication that there must be new particle physics beyond the highly successful Standard Model. Physicists believe neutrino oscillations may be the key to understanding the excess of matter over antimatter in the universe.

More information at http://www.physics.umn.edu/people/bianjm.html