Reconstructed Anti-neutrino Energy Spectrum and Ground State Branching Ratio of Laser Trapped $^{92}Rb\rightarrow $ $^{92}Sr$$\beta\bar{\nu}_e$

Reactor neutrino oscillation experiments observe two anomalies in anti-neutrino energy spectra: a total deficit of events, and an excess in the 5-7 MeV range compared to theory. A total deficit in anti-neutrino flux may support a non-SM sterile neutrino, but both discrepancies may result from inadequate understanding of the reactor fuel cycle. In the 5-7 MeV range first-forbidden $0^-\rightarrow0^+$ decays account for ~30\% of the total anti-neutrino flux, of which $^{92}Rb$ alone accounts for 10-15\%. Measuring the anti-neutrino ($\bar{\nu}_e$) energy spectra from $^{92}Rb$ decay, and the strong ground state branching ratio (GSBR) with 2\% accuracy and independent systematics to traditional total absorption spectrometers will aid in improving model predictions. Using the TRINAT neutral atom trap, and measured momenta of beta and recoiling daughter, kinematic reconstruction of $\bar{\nu}_e$ energy spectra is performed and GSBR extracted in low background beta, atomic shake-off electron (SOE), recoil coincidence channel. First data gives a preliminary beta-neutrino correlation coefficient $a_{\beta\nu}$ using the recoil-SOE coincidence channel below 280 eV in recoil energy of $0.32\pm0.04$, which can constrain the excited state branch.