Guang Yang working on big ideas

Guang Yang

Stony Brook University postdoc Guang Yang has contributed to two big ideas coming out of the Near Detector Concept Study.  A DUNE collaborator for a year and a half — while also working on T2K  for almost two years — and previously collaborating on Double Chooz and JUNO, he is happy to be part of a group that “is playing a leading role in the DUNE near detector design.”

One of the big ideas from the Concept Study is a fine-grained, three-dimensional scintillating plastic detector, called the 3DST.  This detector consists of a large number of 1x1x1 cmcubes read out along three separate directions for true 3D spatial information.  The recommendations from the study place the 3DST inside a high-pressure gas TPC that would sit behind the liquid argon TPC in the near detector complex.

According to Yang, the 3DST has great potential in the areas of charge separation, neutron tagging with time-of-flight, and flux measurement with neutrino-electron elastic scattering techniques and the so-called low-nu method (a method that effectively yields the shape of the neutrino flux as a function of energy).  Yang has participated in detailed simulations on 3DST that reveal expected performance in such areas as direction and momentum resolution. The ability to compare measurements in the 3DST to previous results on plastic scintillator taken with MINERvA and T2K increases the value of these measurements and could help tune the simulations.  This work will be incorporated into the T2K upgrade super-FGD work, as well as into the DUNE near detector, he said.

Yang is also involved in DUNE-prism, a proposed “big idea” to move the near detector off-axis at different positions to allow disentangling of the flux-plus-cross section degeneracy. The DUNE-prism concept yields changes in the energy spectrum of the neutrino flux versus position, thus making it possible to untangle different effects that can contribute to the signal.

“DUNE-prism would provide us an excellent opportunity to do the ‘calibration’,” said Yang, referring to a calibration-like technique in which they build the oscillated spectrum from a linear combination of un-oscillated off-axis measurements and use the measured spectra across a wide energy range. “We have demonstrated that having only on-axis measurements leads to potential mixing of the degeneracies of flux, cross-section and oscillation parameters, which in turn can lead to a significant bias in our result.”  The Stony Brook team thinks that DUNE-prism can potentially solve this problem.

Yang is not one to pass up opportunities. With fellow Stony Brook postdoc Jose Palomino he developed a general geometry generation tool called DUNENDGGD that is widely used in the DUNE ND community. In T2K, Yang participates in the Super-Kamiokande experiment, and is working to include a new channel, CC1pi+ with pion above Cherenkov threshold, in the oscillation analysis.

“I’ve also gotten involved in other activities, such as the ProtoDUNE cold electronics test and the THEIA experiment NC background reduction,” he said.

Does he sleep?