2021 TUNL REU Projects

Nuclear Physics Projects

1. Data Evaluation Activities at TUNL

Advisor: John Kelley

Student: Reed Spitzer

The nuclear data group at TUNL compiles, evaluates and disseminates nuclear structure data relevant to A=2-20 nuclides. Our activities primarily involve surveying literature articles and producing recommended values for inclusion into various US Nuclear Data Program databases. We have projects related to compiling structure data from recently published articles, and producing full nuclear structure data evaluations of nuclides based on all existing literature. An involved student could select activities based on their interests.

2. Characterization of Broad Energy Germanium (BEGe) Detectors in the Low-Energy Regime (5-50 keV)

Advisor: Krishichayan

Student: Ben Cochran

To obtain high-quality gamma spectrometry results, it is necessary to select the best HPGe detector for particular measurements and calibrate the gamma detector's energy and efficiency response as accurately as possible. The recently acquired BEGe detector covers the wide energy range (3 keV – 3 MeV) by combining the spectral advantages of Low Energy (LEPS) and Coaxial HPGe detectors. However, a detailed characterization of these detectors at energy lower than 50 keV is not available, though crucial for cases where nuclei of interest decay via low-energy gamma transitions. Such detailed characterization requires dedicated and reliable energy and efficiency response function measurements of BEGe detectors using several calibration sources covering the energy range of interest (3 – 50 keV).

3. Geant4 Simulation of the Shielded Neutron Source Area

Advisor: Sean Finch

Student: Molly DeLuca

The shielded source area is one of four target rooms at the TUNL tandem accelerator laboratory. The shielded source area is unique in that it produces quasi-monoenergetic neutrons from 4-15 MeV, which are finely collimated by a large shielding wall. The shielding wall was rebuilt in 2014 in order to reduce the off-axis neutron flux. The student will develop a Geant4 simulation of the shielding wall and target room by implementing the room's complete geometry, taken from a CAD model, into a Geant4 model. This simulation will be able to predict the neutron flux at different locations inside the target room, and is necessary to understand the backgrounds present for proposed future experiments. Beam time at the tandem accelerator will be used to acquire experimental data necessary to benchmark the simulations.

4. Electron Accelerator Development for Beta-Decay Studies

Advisor: Albert Young

Student: John Rabaey

The Young research group at TUNL is heavily involved in measurements of the properties of neutrons, especially those that pertain to a fundamental understanding of the weak interactions between nucleons. To facilitate the calibration and testing of equipment used in these searches, a small electron accelerator is being constructed at TUNL. The REU student on this project will be heavily involved in assembling, testing, and upgrading the pulsed linear electron accelerator from 100 keV to (after upgrade) 1 MeV. The project will combine hands-on activities in assembling and operating the accelerator for tests and
modeling of electron trajectories in the system.


5. Physics studies for a large liquid argon detector

Advisor: Kate Scholberg

Student: Amelia Genus

A 40-kton underground liquid argon detector is being designed for DUNE, the Deep Underground Neutrino Experiment. Physics capabilities include neutrino oscillations with a long-baseline beam, solar and atmospheric neutrinos, and supernova neutrinos. This project will involve participation in simulation and physics sensitivity studies for this detector. The student will gain experience with a variety of simulation and data analysis software tools. Programming experience will be useful but is not required.


6. Implementation of EIC Detector Proposal in Fast Simulation Package

Advisor: Anselm Vossen

Student: Joseph Grassi

The nuclear physics community decided to build a new Electron Ion Collider (EIC) at Brookhaven National Laboratory. At this stage, different detector concepts have to be evaluated. One such concept is the COmpact detectoR for the EIC, (CORE). In this project, the student will implement parts of CORE in a fast simulation package (Delphes). This will enable the evaluation of the performance of the detector in measuring different physics signals at a later stage. The physics studies can also be started as part of the summer project, time permitting. Basic programming experience required.


7. Optimization of Selection Criteria for Rare B-meson Decay at Belle

Advisor: Anselm Vossen

Student: Anna Costelle

The student will work on the optimization of the selection criteria of the semi-leptonic decay of using simulated data of the Belle data. At Belle mesons are created in annihilation at or near the resonance. The semi-leptonic decay has not been observed in data yet but preliminary studies on Monte-Carlo data indicate that this might be possible using the statistics of the Belle data sample. A measurement of this decay is important in our quantitative understanding of semi-leptonic decays that are sensitive to CKM matrix elements and possibly to contributions of physics beyond the standard model. Currently it is foreseen to use boosted decision trees (BDTs) for the selection of the decay products. The student would explore the usefulness of different input variables and optimize the BDT. Some programming experience is required, ideally in python and C++.


8. Optimizing the Clover Array and Evaluating Data for the Nuclear Structure Program at HIγS

Advisors: Daniel Ayangeakaa and Robert Janssens

Student: Anne Williams

Nuclear structure research with photon beams requires measurements of gamma rays using sophisticated detection systems. At HIγS, the newly developed Clover Array, consists of an assembly of high-purity germanium (HPGe) and cerium bromide (CeBr3) detectors. Various other detectors such as sodium iodide and lanthanum bromide scintillators are also available for use in conjunction with the Clover Array. A campaign of measurements with the Clover Array is currently underway combining measurements proposed by TUNL scientists with other projects from outside users. The student will participate in every aspect of the program and will be involved in the conduct of experiments (data taking, calibration measurements etc.), changes in the experimental setups depending on the specific requirements of the experiment, and in data analysis. In addition, analysis of data accumulated in earlier experiments is already underway and will be part of the summer project when there is a natural overlap with the ongoing program.

9. Study and Characterization of a New Gamma-ray Imaging System

Advisors: Ying Wu and Jun Yan

Student: Lila Dabill

A high-quality gamma-ray imaging system (a gamma imager) is a critical instrument for scientific research using a gamma-ray beam. At the High Intensity Gamma-ray Source (HIGS) facility, we have developed three generations of gamma imagers. These imagers have been used for gamma-ray beam studies and tuning, nuclear target alignment and other research
applications. At present, the latest generation gamma imager is being developed. The student will be involved in the assembly and characterization of the system. In particular, the student will lead the effort to study and select a key component of the system---a crystal scintillator. The student will also explore the capabilities of this new gamma imager as a multi-functional instrument for gamma-ray diagnostics.


High-Energy Physics Research Projects

1. Jet Entropy Comparison

Advisor: Ayana Arce

Student: Peter Jacobson

Neill and Waalewijn (10.1103/PhysRevLett.123.142001) have suggested a jet entropy observable and predicted its scaling as the jet is ``resolved'' at finer distance scales. Entropy measurements in high-energy physics collisions have been interpreted as probes of entanglement between the observed particles and the unobserved radiation/scattering remnants (https://doi.org/10.1103/PhysRevD.95.114008). The scaling of jet entropy with resolution scale is of interest. A small group (1-2 students) would test this jet entropy observable in parton-level and particle level simulation to understand effects of hadronization and approximations in the calculation, and compare potential entropy observables for jets measured in ATLAS.

Skills: willingness to unpack theory papers, find connections to other ideas, and implement in code

You’ll learn: connections between quantum information and collider data, LHC standard model physics, ATLAS analysis software

2. Searching for Dark Matter at the LHC

Advisor: Ashutosh Kotwal

Student: Lincoln Draper

One of the greatest mysteries of the Universe is the nature of Dark Matter, which makes up 84% of all matter in the Universe. Other than its gravitational interaction, we know nothing about Dark Matter. Even more interesting is the fact that Dark Matter cannot be accommodated in the established theory of all fundamental particles and forces, called the Standard Model of Particle Physics. Therefore, new particles and interactions have been postulated that offer convincing explanations for Dark Matter. The Large Hadron Collider at CERN is the highest-energy particle collider, with a major instrumentation upgrade being planned. It provides a unique opportunity to produce and detect particles associated with Dark Matter. Prof. Kotwal has invented a novel electronics technique of detecting such particles, using algorithms that can be embedded directly into silicon integrated circuits. In this summer project, we will study this algorithm in detail and pursue its implementation in field-programmable gate arrays, a type of programmable integrated circuit.

3. Searching for Dark Matter and Dark QCD with Emerging Jets at the LHC: Trigger Study

Advisor: James Beacham

Student: Grace Minesinger

We know dark matter exists, but it has stubbornly resisted appearing in all our particle physics experiments so far. One way this is possible is if we are thinking about dark matter in the wrong way. If the hidden or dark sector has some complicated dynamics similar to QCD in the Standard Model, this would lead to detector signatures -- some of which are known as “emerging jets” -- that we may be missing with our triggering systems in ATLAS. This project will be to perform a study of the ability of the various exiting ATLAS triggers to catch some kinds of emerging jets we’re probably not currently catching, using simulated samples of signal process. Depending upon progress speed, there are many extensions to this project.

Skills: Some knowledge of / familiarity with coding in C++ will be useful, as well as persistence and physics reasoning.

You’ll learn: How dark QCD / emerging jets could be produced, missed, and then caught at the LHC; how working experimental particle physicists at the LHC search for new physics; how good our LHC detectors are and where their limitations arise

4. Searching for Higgs-like Particles with Photon-jets at the LHC: Trigger Study

Advisor: James Beacham

Student: Honor Hare

The Higgs boson is one of the most remarkable particles we’ve ever discovered, as it has zero spin and is evidence that at least one scalar field exists in nature. But is the Higgs boson alone? There could be cousins of the Higgs, Higgs-like particles, with masses higher than that of the SM Higgs and that could decay to collimated groups of photons at the LHC, called photon-jets. Some searches for such particles have been done but there are big gaps in our discovery potential. This project will be to perform a study of the ability of the various exiting ATLAS triggers to catch photon-jets, using simulated samples of signal process. Depending upon progress speed, there are many extensions to this project.

Skills: Some knowledge of / familiarity with coding in C++ will be useful, as well as persistence and physics reasoning.

You’ll learn: How cousins of the Higgs boson could be produced, missed, and then caught at the LHC; how working experimental particle physicists at the LHC search for new physics; how good our LHC detectors are and where their limitations arise