Conveners
Tests of Symmetries and the Electroweak Interaction: Parallel 2 — Nucleon and Nuclear Electric Dipole Moments
- Vincenzo Cirigliano (Los Alamos National Laboratory)
Tests of Symmetries and the Electroweak Interaction: Parallel 4 — Beta Decays
- Robert Redwine (Massachusetts Institute of Technology)
Tests of Symmetries and the Electroweak Interaction: Parallel 9 — Hadronic Parity Violation | Symmetries in Atoms
- Brad Filippone (caltech)
Emanuele Mereghetti
(LANL)
29/05/2018, 16:10
TSEI
Parallel
Electric dipole moments (EDMs) are extremely sensitive probes of physics beyond the Standard Model (SM). A vibrant experimental program is in place, with the goal of improving existing bounds on the electron and neutron EDMs by one/two orders of magnitude, while testing new ideas for the measurement of EDMs of light ions, such as the proton and the deuteron, at a comparable level. The success...
brad filippone
(caltech)
29/05/2018, 16:30
TSEI
Parallel
Existing limits on the electric dipole moment (EDM) of the free neutron have provided critical constraints on new sources of CP violation for more than 60 years. A new round of searches are actively underway with the goal of improving the sensitivity to CP violation by up to two orders of magnitude. The status of these new searches will be discussed, including recent progress on the nEDM...
Dr
Wolfgang Schreyer
(TRIUMF)
29/05/2018, 16:50
TSEI
Parallel
TUCAN (TRIUMF ultracold advanced neutron source) is a transpacific collaboration with the objective to measure the neutron electric dipole moment (nEDM) with unprecedented precision. We aim at a precision of $10^{-27}$ e.cm, an improvement by a factor of 30 over the current upper limit for this elusive quantity. A non-zero nEDM violates parity and time-reversal symmetry, and is thus...
Selcuk Haciomeroglu
(Institute for Basic Science, Korea)
29/05/2018, 17:10
TSEI
Parallel
Charged particle EDM experiments can be done with high sensitivity using storage rings. Radial electric fields bend a longitudinally polarized beam for storage while at the same time couple with the particle EDM. Having the so-called magic momentum, the spin precession in the horizontal plane can be frozen. Still, the spin can make a precession in the vertical plane with a rate proportional to...
Dr
Matthew Dietrich
(Argonne National Laboratory)
29/05/2018, 17:30
TSEI
Parallel
Due to its large nuclear octupole deformation and high atomic mass, the radioactive isotope $^{225}$Ra is a favorable case to search for an electric dipole moment (EDM); it is particularly sensitive to CP-violating interactions in the nucleus. However, its scarcity and low vapor pressure present significant challenges. To measure this rare isotope, we have developed an approach to measuring...
Prof.
Sergey Syritsyn
(Stony Brook University)
29/05/2018, 17:50
TSEI
Parallel
EDM of the nucleon, whether observed or further constrained, can be traced back to various CP-violating quark and gluon effective interactions. In order to constrain these effective interactions and, subsequently, the extensions of the Standard Model, nonperturbative calculations of nucleon structure are necessary. Low-energy theories and nucleon models provide ballpark estimates for the nEDM...
Dr
Libertad Barrón-Palos
(Universidad Nacional Autónoma de México)
29/05/2018, 18:10
TSEI
Parallel
One of the main puzzles in contemporary physics is the asymmetry between matter and antimatter observed in the Universe. In our current understanding, one of the necessary ingredients to explain such asymmetry is the violation of CP (or equivalently the TRIV), however it has only been observed in the weak interaction and with a very small amplitude. Searches of new mechanisms of CP violation...
Mr
Nathan Callahan
(Indiana Univeristy)
30/05/2018, 16:10
TSEI
Parallel
Precision measurements of the free neutron lifetime $\tau_n$, when combined with measurements of the axial vector coupling, can be used to test unitarity of the CKM matrix. Nonunitarity is a signal for physics Beyond the Standard Model (BSM). Sensitivity to BSM physics requires measurements of $\tau_n$ to a precision of 0.1 s. However, the two dominant techniques to measure $\tau_n$...
Prof.
Fred Wietfeldt
(Tulane University)
30/05/2018, 16:30
TSEI
Parallel
The aCORN experiment uses a novel “wishbone asymmetry” method to measure the electron-antineutrino correlation ($a$-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line in 2013–2014 obtained the result $a =0.1090 \pm 0.0030 \mathrm{(stat)} \pm 0.0028...
Mr
Eric Dees
(NCSU)
30/05/2018, 16:50
TSEI
Parallel
The primary goal of the UCNA experiment is to provide, using polarized ultracold neutrons (or UCN), a high precision measurement of the axial coupling constant in neutron decay, $g_A$. High precision predictions for neutron decay in the Standard Model can be achieved with just two measurements: one to fix the absolute vector coupling strength, and one to determine $g_A$. These parameters play...
Prof.
Dan Melconian
(Texas A&M University)
30/05/2018, 17:10
TSEI
Parallel
Nuclear $\beta$ decay's long history of shaping and testing the Standard Model of particle physics continues to this day with elegant, ultra-precise low-energy nuclear measurements. Experiments observing the angular correlations between the electron, neutrino and recoil momenta following beta decay can be used to search for exotic currents contributing to the dominant (V-A) structure of the...
Prof.
John C. Hardy
(Texas A&M University)
30/05/2018, 17:30
TSEI
Parallel
Results from superallowed $\beta$ decays between $0^+$, $T=1$ analog states yield the best value for $V_{ud}$, with a precision of $\pm$0.02%. World data now comprise 14 separate superallowed transitions having $\mathcal{F}t$ values known to 0.1% precision or better. These results, which cover a wide range of parent nuclei from $^{10}$C to $^{74}$Rb, constitute a very robust data set. Each...
Prof.
Kyle Leach
(Colorado School of Mines)
30/05/2018, 17:50
TSEI
Parallel
Tests of the Standard Model through precision measurements of nuclear decay properties have proven to be a valuable tool in experimental subatomic physics. Of these investigations, $0^+ \to 0^+$ $\beta$-decay decay data are among the most important, as they currently provide the most precise determinations of both the vector coupling strength in the weak interaction, $G_V$, and the up-down...
Dr
Mikhail Gorshteyn
(Mainz University)
30/05/2018, 18:10
TSEI
Parallel
Current most precise knowledge of the value of $V_{ud}$ is obtained from the analysis of a number of superallowed nuclear $\beta$-decays. At present, the main limitation in precision of this determination is due to radiative corrections, more specifically the "inner" $\gamma W$-box correction that is independent of the electron spectrum but depends on hadronic structure. A novel dispersion...
Prof.
Matthias Schindler
(University of South Carolina)
02/06/2018, 16:10
TSEI
Parallel
Parity-violating quark-quark interactions are well understood within the Standard Model, but their manifestation at the hadronic level is complicated by nonperturbative QCD effects. While different parameterizations of parity-violating nucleon-nucleon interactions exist, very little is known about the corresponding couplings. The application of the large-$N_c$ expansion to parity-violating...
Prof.
Michael Gericke
(University of Manitoba)
02/06/2018, 16:40
TSEI
Parallel
Parity violation (PV), first observed in semileptonic decays, has been determined precisely for quarks and leptons as part of the Standard Model. At the hadronic level, it offers a unique probe of nucleon structure and the underlying low-energy behavior of non-perturbative QCD. The hadronic weak interaction is characterized in terms of five spin and isospin dependent S-P transition...
Prof.
Wick Haxton
(UC Berkeley)
02/06/2018, 17:10
TSEI
Parallel
It has long been appreciated that low-energy weak parity non-conserving interactions between nucleons are governed by five S-P amplitudes, as originally described by Danilov. The formalism can also be recast in pionless effective field theory, where the low-energy constants (LECs) are the coefficients of the Danilov amplitudes. Lacking five high-quality independent constraints on these LECs,...
Andre Walker-Loud
02/06/2018, 17:30
TSEI
Parallel
The parity violating neutral current is the least well understood of all currents in the Standard Model. At low energies, these weak interactions manifest as short distance, 4-fermion operators. Unlike their flavor-changing charged counterparts, which are easy to detect experimentally, the neutral current interactions exist in the background of the strong interactions with a typical strength...
Dr
Sidney Cahn
(Yale University)
02/06/2018, 17:50
TSEI
Parallel
Purely hadronic weak interactions inside a nucleus produce a toroidal current distribution around the axis of nuclear spin. This distribution, known as the nuclear anapole moment, produces a local magnetic field that couples to the spin of a penetrating electron. This in turn gives rise to a nuclear spin-dependent parity-violating (NSD-PV) electron-nucleus interaction. We study NSD-PV effects...
Nick Hutzler
(Caltech)
02/06/2018, 18:10
TSEI
Parallel
The fact that the universe is made entirely out of matter, and
contains no free anti-matter, has no physical explanation. While we
cannot currently say what process created the matter in the universe,
we know that it must violate a number of fundamental symmetries,
including those that forbid the existence of certain electromagnetic
moments of fundamental particles. We can search for...
