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

# 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 (August 17th 2017)

### Estimation of M1 scissors mode strength for deformed nuclei in the medium to heavy mass region by statistical Hauser-Feshbach model calculations

Radiative neutron capture is an important nuclear reaction whose accurate description is needed for many applications ranging from nuclear technology to nuclear astrophysics. The description of such a process relies on the Hauser-Feshbach theory which requires the nuclear optical potential, level density and $\gamma$-strength function as model inputs. It has recently been suggested that the M1 scissors mode...

# Select Papers

#### The link between rare earth peak formation and the astrophysical site of the $r$ process

M. Mumpower, G. C. McLaughlin, R. Surman, A. W. Steiner
ApJ 833, 282 - Published December 21st 2016
The primary astrophysical source of the rare earth elements is the rapid neutron capture process ($r$ process). The rare earth peak that is seen in the solar $r$-process residuals has been proposed to originate as a pile-up of nuclei during the end of the $r$ process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare earth region, that includes self-consistently adjusting $\beta$-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare earth peak. We demonstrate our method with two types of astrophysical scenarios, one corresponding conditions typical of core-collapse supernova winds and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical conditions, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the $r$ process...

#### The impact of uncertain nuclear masses near closed shells on the $r$-process abundance pattern

M. Mumpower, R. Surman, D.-L. Fang, M. Beard, A. Aprahamian
J. Phys. G 42 034027 - Published February 5th 2015
Calculations of rapid neutron capture nucleosynthesis involve thousands of pieces of nuclear data for which no experimental information is available. Of the nuclear data sets needed for $r$-process simulations---masses, $\beta$-decay rates, $\beta$-delayed neutron emission probabilities, neutron capture rates, fission probabilities and daughter product distributions, neutrino interaction rates---masses are arguably the most important, since they are a key ingredient in the calculations of all of the other theoretical quantities. Here we investigate how uncertainties in nuclear masses translate into uncertainties in the final abundance pattern produced in $r$-process simulations. We examine the influence of individual mass variations on three types of $r$-process simulations---a hot wind, cold wind, and neutron star merger $r$ process---with markedly different $r$-process paths and resulting final abundance patterns. We find the uncertainties in the abundance patterns due to the mass variations exceed the differences due to the astrophysics. This situation can be improved, however, by even modest reductions in mass...

## 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.