PIPages
Labs

Jonathan Engel

University of North Carolina at Chapel Hill, NC·Physics

Why does the universe contain so little antimatter? Part of the answer may lie with neutrinos, the lightest known particles, whose masses and basic nature are still unknown.

Fields

Physics

Topics

neutrinoless double-beta decay

neutrinos

Majorana neutrino

Grants
1 known grant, through Jul 2029

What they work on

  1. Compute nuclear matrix elements for neutrinoless double-beta decay in experimentally used isotopes, using three ab initio nuclear-structure methods that build nuclei from their protons and neutrons.
  2. Determine the decay operator from particle physics and quark-gluon behavior using lattice quantum chromodynamics, linking energy scales with chiral effective field theory.
  3. Combine uncertainties across scales and methods with Bayesian model mixing, a statistical technique, to produce the first reliable error estimate on double-beta decay matrix elements.

More about the research

A key test is a rare process called neutrinoless double-beta decay. In this process, two neutrons in an atomic nucleus turn into protons without releasing the usual two neutrinos. It can happen only if neutrinos are their own antiparticles. Its rate depends both on the neutrinos and on any undiscovered particles they interact with. Experiments searching for this decay can only be interpreted if physicists know how the host nucleus affects it, and they need to know this precisely and with an honest error estimate.

Why it matters

Large experiments are searching for neutrinoless double-beta decay. Their results can only be turned into statements about neutrino mass and new particles if the nuclear matrix elements are known. Precise matrix elements with reliable uncertainties would let physicists read these experiments correctly. That could clarify whether neutrinos are their own antiparticles and why matter outnumbers antimatter.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

FRHTP: Advancing Theory for Nuclear Double-Beta Decay (@NDBD)

NSF · Aug 2024 – Jul 2029

Closest labs

Andrea Shindler

University of California-Berkeley, CA·Physics

Calculate the electric dipole moments of protons and neutrons induced by theories beyond the Standard Model, to probe the source of the universe's matter-antimatter asymmetry.

Walter Pettus

Indiana University, IN·Physics

Scale Cyclotron Radiation Emission Spectroscopy (CRES), which measures electron energy from emitted radio waves, toward a multi-cubic-meter tritium experiment by leading control systems for Project 8 demonstrator apparatuses.

Steven Stroberg

University of Notre Dame, IN·Physics·Early-career

Develop a computationally tractable way to include three-particle interactions in the in-medium similarity renormalization group (IMSRG), a method for solving the quantum many-body problem of atomic nuclei.

The school

University of North Carolina at Chapel Hill: 72 labs on PI Pages, $1.6B a year on research, 523 research doctorates a year.

More about University of North Carolina at Chapel Hill

Reach out

A start for your email. Fill in the brackets.