Session SH: Nuclear Structure: A > 100

Sub-Barrier Coulomb Excitation of $^{\mathrm{106}}$Cd with the JANUS setup at ReA3

Describing the evolution of B(E2) strengths with decreasing neutron number in the Sn isotopes from $^{\mathrm{130}}$Sn to $^{\mathrm{104}}$Sn is challenging for the shell model. This renders measures of collectivity near $^{\mathrm{100}}$Sn (N$=$Z$=$50) particularly interesting. We will explore the collectivity of Z$=$48, N$=$58 $^{\mathrm{106}}$Cd using Coulomb excitation. Previous measurements of $^{\mathrm{106}}$Cd are contradictory: a recent lifetime measurement disagrees with NNDC values, which originate from 40 year old CoulEx. The B(E2) values determined from the new lifetime disagree with recent large-scale shell model calculations, questioning the earlier good reproduction of collectivity in $^{\mathrm{106}}$Cd by the shell model. The results of an inverse-kinematics CoulEx measurement of $^{\mathrm{106}}$Cd using the JANUS setup at the NSCL ReA3 facility will be presented. The goal of the measurement is to clarify quadrupole transition strengths in this nucleus, extend the available data to states previously out of reach, and add understanding of quadrupole collectivity approaching N$=$Z$=$50 $^{\mathrm{100}}$Sn.   

Study of the deformed beta delayed neutron precursor $^{106}Nb$ with the new neutron tracking detector.

The neutron energy spectrum measurement of the deformed beta-delayed neutron precursor $^{106}Nb$ has been performed for the first time at Argonne National Laboratory using beams from the CARIBU facility. Neutron emission from the beta decay of implanted $^{106}Nb$ ions was measured with the recently developed neutron detector array called NEXT (Neutron Detector with Xn Tracking). The neutron tracking capability of NEXT provides a significant improvement in energy resolution in neutron time-of-flight measurements. The high intrinsic detection efficiency of NEXT is essential to study decays of neutron-rich nuclei, which are beta-delayed neutron precursors. The results of this measurement and future plans to measure nuclei in this region at CARIBU will be presented.   

Connecting Nuclear Structure to Stellar Astrophysics: Neutron Skin in Tin Isotopes

The first observation of a neutron star merger by the LIGO-Virgo collaboration in 2017 highlights the need to improve our fundamental understanding of the equation of state (EOS) of dense, neutron rich matter. The origin of heavy elements in the r-process and the structure of neutron stars are governed by the properties of neutron rich matter, for which experimental data is limited. Further analysis of this historic event and all future neutron star mergers relies on constraining the nuclear EOS with experimental observables. We propose a novel method for systematically studying the evolution of the neutron skin in stable tin isotopes, by measuring the low-energy nuclear dipole strength over the broadest possible range of neutron-to-proton ratios in a single element. Nuclear resonance fluorescence with 100% linearly polarized photons from the High Intensity $\gamma$-ray Source (HI$\gamma$S) facility was used to selectively measure the E1 photoabsorption strength of $^{112}$Sn and $^{124}$Sn at excitation energies from $\sim3$ MeV up to neutron separation, where the Pygmy Dipole Resonance dominates.   

Coexistence of transverse and longitudinal wobbling modes in $^{187}$Au

Nuclear wobbling motion has been investigated in the $^{187}$Au nucleus. The $^{174}$Yb($^{19}$F,6n)$^{187}$Au reaction was used to populate the levels of interest using the Gammasphere array. Detailed analysis has revealed two separate wobbling bands built on $(\pi h_{9/2})^{1}$ and $(\pi h_{11/2})^{-1}$ configurations. The wobbling nature of these bands has been verified by angular distribution measurements showing a $\Delta$I = 1, E2 nature of the $n_{\omega + 1}\to n_{\omega}$ transitions. Most interestingly, the two structures have been found to exhibit different types of wobbling: transverse and longitudinal. $^{187}$Au is the case of the first cleanly established longitudinal wobbler and of the coexistence of both forms of wobbling, a phenomenon never observed before. Particle Rotor Model calculations have been found to be in good agreement with the experiment.   

K-Isomers in the neutron-rich Hf region via fragmentation of $^{198}$Pt.

Long-lived K-isomers in the neutron-rich Hf region have been predicted but not experimentally accessible to date. They are not only of interest from a nuclear structure perspective, but lie toward the r-process pathway and thus are relevant for heavy-element nucleosynthesis. An experiment was conducted at the NSCL to study neutron-rich nuclides in the Hf region, through the fragmentation of a newly-developed $^{198}$Pt primary beam on Be and Ni targets. Additional motivations for the experiment are to observe new isotopes, as well as quantify angular momentum generation in the fragments for various targets. The products were analyzed with the A1900+S800 beamlines and implanted into a stack of Si detectors, allowing for full event-by-event particle identification, surrounded by GRETINA to detect gamma ray cascades following isomer decays. The analysis techniques will be discussed using preliminary benchmark studies with known isomers in $^{190-193}$W.   

Superstring Theory {\&} The Structure of Electron, Proton and Neutron

In the case of~superstring theory,~consistency~requires~spacetime~to have at least 11 dimensions and everything in the Universe is made up of supersymmetric~strings. So the electron, proton and neutron must be made of them. In this paper we have proved that the photon could have the both. The generator of photon, electron, has rotational motions around itself and around the nuclei, so the photon also must have different external motions. The external motion of photon consists of a forward motion (3D) with a velocity equal to C and a rotational motion (2D) with various gyroradius which causes photon to be seen in various colors. The photon has internal motions too, which includes vibrational (3D), which leads photons to have small movements in the space and circular (3), which leads them to moves along an indirect, closed, and tiny path. So, if we look at the internal motion of the photon, we will find out the photon in its tiny motions, builds supersymmetric~strings. And all motions of photon could be defined in 11 dimensions. The electron is define as an array of photons that rotate on the surface of an imaginary sphere without any central nucleus and the proton as a dense compact globe filled up of photons with a radius three times smaller than that of an electron. Neutron is a sphere with the proton core, electron shell and an empty space. By this identification we could easily explain a lot of problems in physics like: \begin{figure}[htbp] \centerline{\includegraphics[width=0.11in,height=0.17in]{180620201.eps}} \label{fig1} \end{figure} decay, strong interaction, weak interaction, etc.   

In-beam and decay spectroscopy of $^{251}$Md

Spectroscopy of transfermium nuclei is an important frontier in nuclear science. Near $Z=100$ and $N=152$, production cross sections remain high enough that such studies are feasible and provide indirect insights into the structure of superheavy nuclei. Odd-mass nuclei present a particularly compelling opportunity, as the odd particle gives direct information regarding the orbitals near the Fermi surface. We have performed in-beam and decay spectroscopy of the odd-$Z$ nucleus $^{251}$Md using the Argonne Gas Filled Analyzer coupled with Digital Gammasphere, which allows us to identify rotational bands and search for excited states built on top of high-$K$ isomers. The results of the experiment will be presented and the nuclear structure implications will be discussed.   

Disrupting the 3-Quarks fermion/baryon neutron model, the neutron is a sub-hydrogen atom.

Plasma nuclear fusion has repeatedly failed for 50 years to produce any energy. It is thus urgent to reconsider the Standard Model of Elementary particles and the old Fermi elementary particle model for the neutron. Rutherford's assumption of the neutron as a proton with a closely bound electron, was thought dismissed by Chadwick's precise measure of the neutron mass which seemed too small, given estimates based on Heisenberg uncertainty, or too large as a simple proton electron addition. My new Post Quantum Physics, briefly presented at the recent April Washington Meeting of APS leads to a sub atomic model by rejecting three pillars of XXth Century Physics: 1) the theory of relativity, ( clearly violated in the moving clock experiments). 2) the Heisenberg uncertainty principle which can be reduced by the fine structure constant x 1836; and 3) the neutron as an 3 quarks elementary fermion. In my new theory the neutron is a sub hydrogen atom: a proton with an electron spinning at very high velocity, on a low unstable orbit, with a kinetic mass slightly larger than twice its rest mass and an unstable orbit about 137 times smaller than the Bohr radius. There are no quarks inside the neutron, just a proton and an electron. The potential impact is huge on new future approaches for fusion.