Our work focuses on experimental neutrino physics. As members of the MINOS/MINOS+, NOA, SuperNEMO, DUNE, LEGEND, and MINER Collaborations, we study neutrino oscillations, neutrinoless double beta decay, and coherent neutrino scattering. Find out more about these topics and the research we conduct by clicking on the buttons below.
The Current Group.
Group Members
Karol Lang
Principal Investigator
Marek Proga
Research Scientist
John Cesar
Postdoctoral Researcher
Dalton G Myers
Graduate Student
Wonseok Bae
Graduate Student
Chinmay Murthy
Graduate Student
Yuan Wu
Graduate Student
Jingchun Liu
Undergraduate Student
Mohamad Zalikha
Undergraduate Student
Kale Chen
Undergraduate Student
Gabriel Greco
Undergraduate Student
William Earthman
Undergraduate Student
Eric Liang
Undergraduate Student
Kurt Cho
Undergraduate Student
Sydney Nguyen
Undergraduate Student
Chaewon Lee
Undergraduate Student
June Zey
Undergraduate Student
Saurav Bastola
Undergraduate Student
Christian Mathurin
Undergraduate Student
Alumni
Will Flanagan
John Ceasar
Brandon Soubasis
Abhishek Rajput
Son Cao
Kayla Leonard
Adam Rouhiainen
Federico Noca
Zach Liptak
Benton Pahlka
Adam Paul S.
Simon De Rijck
Shiv Yadavalli
Noah Vaughan
Reese S Lance
Aaron Bae
Jay Chen
Christopher Webster
Matthew Huynh
Junting Huang
Fernanda Psihas
Dennis Hong
Emily Tsai
Roney Andrade
Dung Phan
Ben Fox
Thomas Carroll
David Du
Ramon Salazar
Beatriz Tapia
Christopher Layden
Faith Reyes
Will Matawa
Kyle Klein
Micheal Gajda
Firas Abouzahr
Alex Kuo
Aryan Ojha
The Current Group.
Selected Work
Selected results from the UTKL Research Group.
First Results on the Search for Lepton Number Violating Neutrinoless Double Beta Decay with the LEGEND-200 Experiment
The LEGEND collaboration has performed the first search for neutrinoless double-beta (0νββ) decay with the LEGEND-200 experiment, operating enriched high-purity germanium detectors in a low-background liquid-argon environment. Using 61.0 kg·yr of exposure, and benefiting from advanced detector technology and active background rejection, the analysis achieves an estimated background level of 0.5+0.3-0.2 cts/(keV·ton·yr) in the 0νββ signal region. No evidence for 0νββ decay is observed. By combining LEGEND-200 with the final data sets from GERDA and the Majorana Demonstrator, we set a new observed lower limit of T1/20ν > 1.9 × 1026 yr (90% C.L.), corresponding to an upper bound on the effective Majorana mass of mββ < 75–200 meV, depending on the nuclear matrix element choice.
Joint neutrino oscillation analysis from the T2K and NOvA experiments
The landmark discovery that neutrinos have mass and can change type (or flavour) as they propagate—a process called neutrino oscillation—has opened up a rich array of theoretical and experimental questions being actively pursued today. Neutrino oscillation remains the most powerful experimental tool for addressing many of these questions, including whether neutrinos violate charge-parity (CP) symmetry, which has possible connections to the unexplained preponderance of matter over antimatter in the Universe Oscillation measurements also probe the mass-squared differences between the different neutrino mass states (Δm)2, whether there are two light states and a heavier one (normal ordering) or vice versa (inverted ordering), and the structure of neutrino mass and flavour mixing. Here we carry out the first joint analysis of datasets from NOvA and T2K, the two currently operating long-baseline neutrino oscillation experiments (hundreds of kilometres of neutrino travel distance), taking advantage of our complementary experimental designs and setting new constraints on several neutrino sector parameters. This analysis provides new precision on the Δm232 mass difference, finding -2.48+0.03-0.04 × 10-3 eV2 in the normal ordering and in the inverted ordering, as well as a 3σ interval on δCP of [−1.38π, 0.30π] in the normal ordering and [−0.92π, −0.04π] in the inverted ordering. The data show no strong preference for either mass ordering, but notably, if inverted ordering were assumed true within the three-flavour mixing model, then our results would provide evidence of CP symmetry violation in the lepton sector [Abstract taken from Nature 646, 818–824 (2025).] .
Design and modeling of a high resolution and high sensitivity PET brain scanner with double-ended readout
In the wake of recent advancements in scintillator, photodetector, and low-noise fast electronics technologies, as well as in fast reconstruction software, positron emission tomography (PET) scanners have seen considerable improvements in spatial resolution, time resolution, and absolute sensitivity. To continue this trend, we present a helmet type PET brain scanner design that combines high solid angle coverage and double-ended readout of 30 mm-thick scintillator crystals to achieve excellent absolute sensitivity, depth of interaction resolution, and time resolution. This scanner comprises 598 detector arrays, each with 8 × 8 Lu1.8Y0.2SiO5:Ce (LYSO:Ce) crystals with dimensions 3.005 × 3.005 × 30 mm3 one-to-one coupled on either end to silicon photomultipliers (SiPMs). Our Monte Carlo simulations based in the platform Geant4 predict that this scanner would attain an absolute sensitivity to a 35 cm line source placed at the center of the radial field of view of (17.1 ± 0.1)%, a depth of interaction resolution of (3.99 ± 0.05) mm, and a coincidence time resolution of (198 ± 5) ps. Our simulations also predict radial, tangential, and axial spatial resolutions at the center of the field of view of 3.3 mm, 3.1 mm, and 3.3 mm, respectively. As this set of simultaneous parameters compares favorably to today’s most advanced clinical PET scanners and other proposed designs, this scanner has a good chance of becoming a preferred tool for high quality brain imaging. [Abstract taken from Christopher Layden et al 2022 Biomed. Phys. Eng. Express 8 025011.] .
Large Extra Dimensions Search in MINOS
We report new
constraints on the size of large extra dimensions from data collected by
the MINOS experiment between 2005 and 2012. Our analysis employs a
model in which sterile neutrinos arise as Kaluza-Klein states in large
extra dimensions and thus modify the neutrino oscillation probabilities
due to mixing between active and sterile neutrino states. Using
Fermilab's NuMI beam exposure of
protons-on-target, we combine muon neutrino chargedx current and
neutral current data sets from the Near and Far Detectors and observe no
evidence for deviations from standard three-flavor neutrino
oscillations. The ratios of reconstructed energy spectra in the two
detectors constrain the size of large extra dimensions to be smaller
than at
in the limit of a vanishing lightest active neutrino mass. Stronger
limits are obtained for non-vanishing masses. [Abstract taken from Phys. Rev. D 94, 111101(R).]
MINOS+ Electron Neutrino Appearance Analysis
Neutrinos are
fascinating particles that undergo one of the most striking identity
crises in nature. While many of our UT researchers explore the neutrino
oscillation phenomenon through muon neutrino disappearance, we can also
look for the appearance of electron neutrinos in a muon neutrino beam.
Electron neutrino appearance helps us explore one of the fundamental
‘big whys’ of our universe: why is there more matter than antimatter?
This is done by probing a symmetry that is broken by the weak nuclear
force called CP-violation. We can also use electron neutrino appearance
to test exotic oscillation models that include non-standard
interactions, 3+1 sterile neutrino oscillations, and potential
decoherence effects.
