Conveners
Nuclear structure: Nuclear structure 1
- Alain Bellerive (Carleton University)
Nuclear structure: Nuclear Structure
- Noah Yazdandoost (TRIUMF)
Ultracold neutrons enable some of the most precise measurements of neutron properties. With energies in the nano-electronvolt range, these neutrons can be trapped in material or magnetic bottles and observed for extended periods. These long observation times allow for highly accurate determinations of fundamental quantities, including the electric dipole moment of the neutron, the neutron...
One of the most important nuclear reactions in astrophysics is the 15O(α,γ)19Ne(p,γ)20Na reaction, which provides a possible breakout pathway from the hot CNO cycle in stars. Studying this reaction directly in the laboratory is challenging, instead, an indirect study using β-decay proton and α decays of 20Mg was recently performed at TRIUMF. The experiment used the Gamma-Ray Infrastructure for...
A muon bound in the 1S state of a hydrogen-like ion can decay into an electron and a pair of neutrinos. For small nuclear charge Z, Überall (1960) predicted a suppression of the total rate relative to the free-muon width, 1−Γ/Γ0≃(αZ)^2/2, α≃1/137. The first all-orders numerical calculation in αZ (Watanabe et al., 1993) reported for oxygen (Z=8) Γ/Γ0=0.994, in tension with Überall’s analytic...
The neutron electric dipole moment (nEDM) is an important property that can reveal additional breaking of fundamental symmetries, such as charge-parity symmetry, which may help explain why the universe is dominated by matter. The TUCAN collaboration is commissioning a next-generation ultracold neutron (UCN) source to deliver higher UCN density to experiments, aiming to improve the statistical...
The unexpectedly large charge radius of the doubly magic nucleus ${}^{52}$Ca, with the new neutron magic number $N=32$, has puzzled theoretical studies, as this trend differs from a decrease in charge radius observed for closed-shell isotopes ${}^{40,48}$Ca. Only the Hartree-Fock-Bogolyubov calculation with the Fayans energy density function was able to reproduce this experimental result. On...
Exploring neutron-rich nuclei near the drip line with significant neutron/proton asymmetry exposes exotic phenomena like the existence of a neutron halo or skin and (dis)appearance of existing magic numbers. Nuclear halos result from the spatial distribution of outermost neutrons, causing a low-density extende. A systematic study of the point proton radii (root mean square radii of the density...
This presentation will show ongoing R&D of the new ultra cold neutron detectors. These detectors, filled with He3 at 15 mbar and CF4 to atmospheric pressure, detects neutrons via capture on He3. The resulting proton and triton deposit energy in the CF4, producing scintillation light. These detectors will be used to measure the neutron electric dipole moment (nEDM) by TRIUMF Ultracold Advanced...
Motivated by the need for a more comprehensive algebraic structure to calculate coincidence probabilities of a general decay scheme for gamma ray spectroscopy, we model the decay scheme, rather naturally, as a quiver through which we define a decay quiver. The path algebra of quivers is the underlying, more general, algebra for transition matrices that is typically used in modeling decay...
Cd isotopes, particularly $^{110,112}$Cd, have long been considered the best examples of nuclei with vibrational behaviour. However, recent studies challenge this interpretation, suggesting that Cd isotopes possess characteristics of multiple shape coexistence. To further investigate this issue, a series of $\beta$-decay experiments were conducted to improve the spectroscopic information on...
The intruder bands in the mid-shell Sn isotopes, built on the proton 2p-2h excitation across the $Z = 50$ shell gap, are well-known examples of shape coexistence, where more than one shapes appear within the same nucleus. Spectroscopic signatures for shape coexistence include enhanced $E0$ transitions between the $0^+$ band heads. However, until now, lifetime information for the $0^+$ states...
