$U(r)=-\frac{W_0r_0}{r}\exp\left(-\frac{r}{r_0}\right)$
$\frac{E_{bind}}{c^2}=a_1A-a_2A^{2/3}-a_3\frac{Z(Z-1)}{A^{1/3}}-a_4\frac{(N-Z)^2}{A}+\epsilon a_5A^{-3/4}$
$R=R_0\left[1+\sum_{lm}a_{lm}Y_l^m(\theta,\varphi)\right]$

# Matthew Mumpower

Staff Scientist @ Los Alamos National Lab

I'm a theoretical physicist working at Los Alamos National Lab. I received my PhD at North Carolina State University under the direction of Gail McLaughlin. At the University of Notre Dame I worked under the direction of Ani Aprahamian and Rebecca Surman. My research interests are in nuclear structure and reaction mechanisms. The study of these models has a wide range of applicability from nuclear medicine, to stockpile stewardship and even the cosmos.

At Los Alamos we seek to solve national security challenges through scientific excellence. This means we not only apply our models to the task at hand, but we seek to push them to the limits by probing the edges of our knowledge with basic science research. One way I contribute to basic science research at the lab is to study the applicability of LANL nuclear models to nucleosynthesis. Nucleosynthesis is the study of the processes by which chemical elements are synthesized in cosmic environments. In other words, this part of my research focuses on how the elements on the periodic table were created. This field is extremely challenging and also very rewarding with many real world applications. Check out the research section of this website for more information.

I firmly believe that practicing in scientific inquiry is both empowering and a necessary requirement for success in today's world. You can learn more about my teaching efforts in the teach section of this website.

Outside of Physics I enjoy keeping up with latest technology trends and coming up with unique solutions to challenging problems. For more about my entrepreneurial endeavours check out Solace Development Group. In my free time I try to stay in shape by playing racquetball. If you are interested in a game, shoot me an e-mail.

## Latest Paper (September 3rd 2018)

### FRIB and the GW170817 kilonova

In July 2018 an FRIB Theory Alliance program was held on the implications of GW170817 and its associated kilonova for r-process nucleosynthesis. Topics of discussion included the astrophysical and nuclear physics uncertainties in the interpretation of the GW170817 kilonova, what we can learn about the astrophysical site or sites of the r process from this event, and the advances...

# Select Papers

#### Strong neutron-$\gamma$ competition above the neutron threshold in the decay of $^{70}$Co

A. Spyrou, et al.
PRL 117, 142701 - Published September 29th 2016
The $\beta$-decay intensity of $^{70}$Co was measured for the first time using the technique of total absorption spectroscopy. The large $\beta$-decay Q value [12.3(3) MeV] offers a rare opportunity to study $\beta$-decay properties in a broad energy range. Two surprising features were observed in the experimental results, namely, the large fragmentation of the $\beta$ intensity at high energies, as well as the strong competition between $\gamma$-rays and neutrons, up to more than 2 MeV above the neutron-separation energy. The data are compared to two theoretical calculations: the shell model and the quasiparticle random phase approximation (QRPA). Both models seem to be missing a significant strength at high excitation energies. Possible interpretations of this discrepancy are discussed. The shell model is used for a detailed nuclear structure interpretation and helps to explain the observed neutron-$\gamma$ competition. The comparison to the QRPA calculations is done as a means to test a model that provides global $\beta$-decay properties for astrophysical calculations. Our work demonstrates the importance of performing detailed comparisons to experimental results, beyond the simple half-life comparisons. A realistic and robust description of the $\beta$-decay intensity is crucial for our...

#### Sensitivity studies for a main $r$ process: nuclear masses

A. Aprahamian, I. Bentley, M. Mumpower, R. Surman
AIP Advances 4, 041101 - Published February 16th 2014
The site of the rapid neutron capture process ($r$ process) is one of the open challenges in all of physics today. The $r$ process is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both the uncertainties associated with astrophysical conditions that are needed to allow an $r$ process to occur and a vast lack of knowledge about the properties of nuclei far from stability. One way is to disentangle the nuclear and astrophysical components of the question. On the nuclear physics side, there is great global competition to access and measure the most exotic nuclei that existing facilities can reach, while simultaneously building new, more powerful accelerators to make even more exotic nuclei. On the astrophysics side, various astrophysical scenarios for the production of the heaviest elements have been proposed but open questions remain. This paper reports on a sensitivity study of the $r$ process to determine the most crucial nuclear masses to measure using an $r$-process simulation code, several mass models (FRDM, Duflo-Zuker, and HFB-21), and three potential astrophysical...

## Racquetball

In my free time I play competitive racquetball. I was one of the top ranked players of the North Carolina State University Racquetball Club from 2008 to 2012. I designed their website which you can find an image of right here.