A sub-component of dark matter with a short collision length compared to a planetary size leads to efficient accumulation of dark matter in astrophysical bodies. Such particles represent an interesting physics target since they can evade existing bounds from direct detection due to their rapid thermalization in high-density environments. In this talk, I will show that their annihilation to visible matter inside large-volume neutrino telescopes can provide a novel way to constrain or discover such particles. The signal is the most pronounced for relic masses in the GeV range, and can be efficiently constrained by existing Super-Kamiokande searches for dinucleon annihilation. I will also talk about possible neutrino signals from the annihilation of such dark matter particles, demonstrating that neutrino signals from the center of the Earth provide sensitivity to the unexplored parts of the parameter space.
For a discrete symmetry that is anomalous under QCD, the domain walls produced in the early universe from its spontaneous breaking can naturally annihilate due to QCD instanton effects. We point out that the QCD phase transition within some domains with an effective large QCD theta angle could be a first-order one. This class of domain-wall models predicts an interesting gravitational wave spectroscopy with frequencies spanning more than ten orders of magnitude, from nanohertz to 100 Hz.
Neutron beta decay provides a sensitive means to uncover the details of the weak interaction by evaluating the ratio of axial-vector to vector coupling constants in the standard model, λ = GA/GV , through multiple decay correlations. The Nab experiment at the SNS in ORNL will make precise measurements of the electron-neutrino correlation parameter a and the Fierz interference term b in unpolarized free neutron beta decay. These results aim to deliver an independent determination of λ that will sensitively test CKM unitarity, as well as probe exotic electroweak scalar and tensor currents. Nab utilizes the world’s largest cryogen-free superconducting magnet spectrometer to guide the decay products to two large-area silicon detectors in order to precisely determine the electron energy and proton momentum. The Nab apparatus is being commissioned with more data to be taken soon. We will present an overview and updates of the Nab experiment, including a discussion of some systematic studies and effects we are working on at EKU.
Nonrelativistic bound states lie at the core of quantum physics,
permeating the fabric of nature across diverse realms, spanning particle
to nuclear physics, and from condensed matter to astrophysics. These
systems are pivotal in addressing contemporary challenges at the forefront
of particle physics. Characterized by distinct energy scales, they serve
as unique probes of complex environments. Historically, their
incorporation into quantum field theory was fraught with difficulty until
the emergence of nonrelativistic effective field theories (NREFTs).
In this talk, we delve into the construction of a potential NREFT
(pNREFT), a framework that directly tackles bound state dynamics
reimagining quantum mechanics from field theory.
Focusing on heavy quarkonia, pNRQCD facilitates systematic definitions and
precise calculations for high-energy collider
observables. At the cutting edge, we investigate nonrelativistic bound
states in intricate environments, like the newly discovered exotics X, Y,
Z above the strong decay threshold and the behavior in out-of-equilibrium
scenarios, such as quarkonium suppression in a Quark Gluon Plasma or dark
matter interactions in the early universe.
Our ability to achieve precision calculations and control strongly
interacting systems is closely linked to bridging perturbative methods
with nonperturbative tools, notably numerical lattice gauge theories.
The ultracold neutron (UCN) source at the Paul Scherrer Institut (PSI) is
being successfully operated since 2011 and has provided UCN for example
to the nEDM experiment, which has placed the tightest constraints to
date on the neutron's electric dipole moment in 2020. Currently the
successor experiment n2EDM is being commissioned at the same position.
At the second beam port, the neutron lifetime experiment τSPECT,
developed at Johannes Gutenberg University Mainz, is currently being set up for data taking. τSPECT is the first neutron lifetime experiment using spin-flip loading and 3-dimensional magnetic storage of neutrons.
In this seminar, I will talk about electroweak symmetric balls, which are macroscopic objects that exhibit restored electroweak symmetry within. These objects can arise in models featuring a dark sector containing monopoles or non-topological solitons that interact with the Standard Model through a Higgs portal. In the early universe, they could have emerged via a phase transition or preheating mechanism, accounting for all dark matter. Because of their electroweak symmetric cores, these objects have a large geometric cross-section relative to a nucleus, which generates a multi-hit signature in large-volume detectors. Furthermore, they can capture a nucleus through radiative means, releasing up to a GeV of energy for each interaction. This makes them excellent targets for large-volume neutrino detectors. The IceCube detector, in particular, provides a promising avenue for exploring the properties of these fascinating objects, with the potential to probe dark matter balls weighing up to one gram.