KU Physics & Astronomy LOcally Organized Assembly (PALOOZA) meeting 2020-2021

Feb 23, 2021, 5:00 PM → Feb 26, 2021, 7:00 PM America/Chicago

Zoom Link: https://kansas.zoom.us/j/92389769214 (Zoom Passcode: 990417)

NOTICE: PALOOZA will now start on Tuesday February 23rd at 5 pm due to the severe winter weather situation.

This first Physics & Astronomy LOcally Organized Assembly (PALOOZA) meeting has been organized by students with the intention of bringing the KU Physics & Astronomy undergraduate and graduate student community together. While students are developing interesting research results day-by-day, we presently do not count with a common space where we can learn and share what every student is working on. This event has the intention of providing a venue that would help fill those gaps, and hopefully bring us closer together as a student community, as well.

The event takes place virtually over Zoom this year. Each session will be about 1-2 hours in the evening with a plenary talk at the beginning of each session (20 minutes) followed by shorter talks (10 minutes). Plenary talks will be chosen at random. Each talk should be for the wide audience of the Department of Physics & Astronomy (Not too technical).

This event is supported by the University of Kansas Department of Physics & Astronomy. 

Tuesday, February 23

5:00 PM → 7:00 PM First Day

First Day of Talks

Convener: Alex Polanski (University of Kansas)

5:00 PM Introduction

Speaker: Alex Polanski (University of Kansas)

5:05 PM A search for circumbinary substellar objects orbiting three post-common envelope binaries

In recent discovery, detailed modeling of eclipse timing variations (ETVs) of the Post-common-envelope binary has resulted in the claimed detection of multiple circumbinary companions. We combine recent primary eclipse timing observations with previously published values to solve for possible substellar companions that can account for the observed timing variations for three sub-dwarf short-period stellar binary systems. We also analyze the orbital stability of the proposed systems using numerical simulation of orbital dynamics and testing for chaotic behavior over long timescales. For HS2231+2441, we find that the timing data is consistent with a constant period and that there is no evidence to suggest orbiting planets. For HS0705+6700, we present a 3-planets solution with long-term stability. For HW Vir, our data show that period variations cannot be modelled simply by circumbinary companions. This implies more complex processes other than the influence of planetary companions might be the cause of the observed eclipse timing variations.

Speaker: Ms Xinyu Mai (University of Kansas)

PALOOZA _Talk.pdf

5:25 PM The Satellite Population Around Luminous Red Galaxies in the Legacy Surveys

Luminous Red Galaxies, or LRGs, were originally selected in the Sloan Digital Sky Survey as good tracers of large scale structure. Subsequent investigations showed them to be among the most massive galaxies in the Universe and dominated by uniformly old stellar populations. Despite being dominated by old stars, however, they have grown in stellar mass since z=1, implying that they grow predominantly via accretion of mostly passive satellites. This picture has not yet been tested because of the lack of deep imaging data sets that both covers a large enough area of the sky to contain substantial numbers of LRGs and also is deep enough to detect faint satellites. I will present our initial characterization the satellite galaxy population of LRGs out to z=0.65. To accomplish I use the Legacy Surveys, which are comprised of grz imaging to 2-2.5 mag deeper than SDSS, over a larger footprint, and with better image quality. Specifically, I will present our first measurement of the percentage of LRGs that have significant satellite populations.

Speaker: Mindy Townsend (University of Kansas)

townsend_palooza_s21.pdf

5:35 PM Quiz Time

5:45 PM Coffee Break

5:55 PM Search for new physics via the photo-production of tau leptons

There is a two sigma discrepancy between the standard model predictions and the experimental values of the anomalous magnetic moment of the muon ($a_{\mu}$). This difference suggests the possibility of beyond the standard model physics. The tau lepton, $\tau$, is 16 times more massive than the muon, $\mu$.
Measuring $a_{\tau}$ would be an even better test of the standard model, since sensitivity to new physics is expected to be proportional of the lepton's mass squared. Such a measurement is complicated by the short $\tau$ lifetime. A theoretical analysis done by Beresford and Liu \cite{Beresford:2019gww} using Monte Carlo data shows that measurement of the $a_{\tau}$ is possible in ultra peripheral collisions. We propose measuring $a_{\tau}$ using existing Pb-Pb data at $\sqrt{s_{NN}} = 5.02 $ TeV from the CMS detector. With this data we hope to reduce uncertainty by a factor of 3 over existing measurements of $a_{\tau}$.

Speaker: Mr Matthew Matthew T Nickel (University of Kansas)

Search for new physics-short.pdf

6:05 PM Performance of CMS Endcap Precision Timing Sensors

The Large Hadron Collider, a particle accelerator in Geneva, Switzerland, will enter its High Luminosity (HL) phase, whose upgrade has already started. This phase will include an increase in particle collisions, achieving instantaneous luminosities of 5 to 7 times the nominal luminosity, $1 \times 10^{34}$ cm$^{-2}$ s$^{-1}$. This increase gives more opportunities for rare processes to come to light, however it also means that there is more overlapping particle interactions, called pileup, in the detectors. To address this added pileup, the Compact Muon Solenoid (CMS) detector at the LHC will install a new precision timing detector, the MIP Timing Detector (MTD), as part of the upgrades for the HL-LHC. The sensors comprising the endcap section of the MTD are silicon low gain avalanche detectors (LGADs). From extensive tests at the Fermilab test beam facility, it has been shown that prototypes of these sensors perform in accordance to our expectations and requirements for the MTD. Specifically, these sensors have demonstrated a timing resolution within 30-40 picoseconds.

Speaker: Margaret Lazarovits

PALOOZA_2.23.21.pdf

6:15 PM KAST Red Spectroscopy of Very Low Mass Stars

Very Low Mass (VLM) stars and Brown Dwarfs (BDs) are the most numerous objects in the universe. Yet, due to their extreme redness and dimness, the population of VLM stars and BDs even in the immediate vicinity of the Sun remains incomplete. The Gaia proper motion survey, the Motion-Verified Red Stars catalog (MoVeRS), and the Late-Type Extension to MoVeRS (LaTE-MoVeRS) are recent surveys that have identified numerous VLM star and BD candidates through their red colors and high angular motions on the sky. However, the majority of these candidates have no spectroscopic data to confirm or characterize them. During my time with Dr. Burgasser’s Cool Star Lab at the University of California, San Diego, I was a part of a leading effort to observe and classify these nearby star candidates. At the time, infrared spectroscopy of some candidates had been achieved, but no optical observations had been made. I present my work developing the tools necessary to reduce and analyze our optical spectra and some preliminary results from this ongoing population study.

Speaker: Ryan Low

PPresentation.pdf

Wednesday, February 24

5:00 PM → 7:00 PM Second Day

Second Day of Talks

Convener: Zach Flowers

5:00 PM Introduction

Speaker: Zach Flowers

5:05 PM Anomaly detection with machine learning in LHC Olympics 2020

The search for physics beyond standard model in LHC experiments has been strong interest. However, we have yet been able to discover new physics through model dependent search. Recent developments in machine learning offers great potential in the direction of model independent search. The LHC Olympics 2020 is a challenge for researchers to determine whether there are BSM events in black box data consists mostly of generic QCD events. I will explain my attempts to the challenege, as well as some of the more successful attempts done by other participants.

Speaker: Cosmos Dong

LHC olympic talk.pptx

5:25 PM Diffractive Dijet Photoproduction in Proton-lead Collisions

At particle colliders, there exists a subset of events where the distance between the interacting particles is actually greater than the sum of their radii, yet they are still able to interact electromagnetically. These are known as ultra-peripheral collisions, and such collisions between protons and lead nuclei offer a unique probe of the parton structure of the proton. By utilizing pseudorapidity gaps (angular regions void of particles) in the final state, it is possible to isolate interactions where there is the exchange of a photon off the nucleus and a two-gluon exchange off the proton (pomeron exchange). Such collisions can be utilized to directly probe the gluonic structure of the proton with an electromagnetic probe. Events such as these have been studied at HERA, but currently there exists a gap at the LHC where we can utilize the much larger energies to get a higher resolution than previously studied. The measurement I am working on with CMS makes a bridge between what we can do at the LHC and what will be done at a future Electron Ion Collider.

Speaker: Cole Lindsey (KU)

5:35 PM Quiz Time

5:45 PM Coffee Break

5:55 PM Fun With Atmospheric Spectroscopy

How do we know what planets are made of when we can't send rovers out to dig up dirt and sample the air? Transmission spectroscopy! When exoplanets transit their host stars, they transmit and absorb starlight differently depending on the types of gases present in their atmosphere. Knowing the types of gases and their concentrations is important to understanding how these planets formed and evolved. I provide a quick overview of the technique, show some data of various planets taken by the Hubble Space Telescope, and discuss their implications.

Speaker: Yoni Brande

Brande_PALOOZA.pdf

6:05 PM V2O5 for battery cathode application

Current lithium ion batteries are facing not only a sustainability issue but also an energy density mismatch issue between the cathode and anode. There is a sufficient need to look for alternate materials for this purpose, one such material being V2O5. On top of being able to host lithium it can also host more terrestrially abundant ions such as: Na, Mg, Zn, Ca, K and Al. V2O5 however can exist in a variety of structural phases subject to different conditions. Structural phase transitions can be detrimental to battery operation. We explore the structural and energetic properties of these various phases using simulations based on density function theory (DFT).

Speaker: Sakthi Kasthurirengan (University of Kansas)

6:15 PM Martian Crustal Field Modifications in the Dayside Ionosphere

Crustal magnetic fields were first discovered at Mars by the Mars Global Surveyor (MGS) mission (Acuña et al., 1998). Since then, there have been several crustal field models and maps produced, as well as many missions to Mars to better study the crustal fields. The crustal fields are thought to influence ion loss from the planet, so having a precise understanding of the structure of these fields is vital. The Mars Atmospheric and Volatile EvolutioN (MAVEN) explorer is yet another mission to the red planet, and its magnetometer (MAG) instrument has been returning interesting data on both induced and crustal fields. Induced magnetic fields are the result of the solar wind interaction with the Martian ionosphere, in areas where crustal fields are less strong. Sometimes, a current sheet is formed when these 2 types of fields are found in close proximity to one another. Cravens et al. (2020) and Harada et al. (2017) considered cases in which magnetic reconnection took place in these current sheets. But what was not explored in these papers is that the currents in the boundary will not just affect the external induced field regions, but will affect the crustal field regions as well. In this talk, we discuss this "extended" interaction and consider what can be learned from the perturbation of the crustal magnetic field in the dayside ionosphere.

Speaker: Antonio Renzaglia (University of Kansas - Dept of Physics and Astronomy)

PALOOZA 2021 talk - Martian Crustal Field Modifications in the Dayside Ionosphere.pdf

Thursday, February 25

5:00 PM → 7:00 PM Third Day

Third Day of Talks

Convener: Margaret Lazarovits

5:00 PM Introduction

Speaker: Margaret Lazarovits

5:05 PM The high energy limit of strong interactions

The physics program of the CERN LHC relies on our description of the interactions of quarks and gluons, the degrees of freedom of quantum chromodynamics (QCD), in high-energy hadronic collisions. When the interactions occur at very short distances, cross sections can be calculated in a power expansion of the strong coupling, $\alpha_s \ll 1$. However, there are regions of phase-space where perturbative QCD (pQCD) techniques break down, despite there being a hard energy scale to do pQCD calculations. One such kinematic region is the high-energy limit of QCD, where the center-of-mass energy is much larger than the momentum transfer in the collision. In this limit, logarithms of energy multiply some powers of $\alpha_s$ order-by-order, such that they compensate for the smallness of $\alpha_s$. An all-orders resummation of these terms is necessary to obtain finite cross sections. This regime of QCD is described by means of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution equations of pQCD.

In this talk, a recent analysis done by the author within the CMS and TOTEM experiments that addresses this regime of QCD will be presented. In this investigation, the production of two jets separated by a large interval in pseudorapidity ($\eta = \log {\Large[} \tan{\large(} \theta/2 {\large)} {\Large]} $, where $\theta$ is the angle between the particle three-momentum and the beam axis) devoid of charged particle production (jet-gap-jet) is studied. This is expected from two-gluon $t$-channel exchange in pQCD, and is expected to be described well within the BFKL formalism.

Speaker: Cristian Baldenegro Barrera (The University of Kansas (US))

palooza_cbaldenegro.pdf

5:25 PM Black Hole Identification in James Webb Data with Ensemble Based Novelty Detection

The study of Active Galactic Nuclei (AGN) is important to further our understanding of galaxy evolution, and thus, reliable and accurate methods for the identification of AGN are crucial. With the unprecedented sensitivity of the James Webb Space Telescope (JWST), and in particular, the Mid-Infrared Instrument (MIRI), more reliable and sensitive classification techniques are needed. Traditional methods for AGN classification include color selection techniques and model fitting, but the former suffers from minimal use of available information (≤ 4 passbands), and the latter is dependent on the accuracy of existing models. We propose to improve existing color selection techniques with an ensemble-based novelty detection network, using existing catalogs of JWST MIRI galaxies for training and testing. This work will result in a publicly-available library of code that will allow for more accurate AGN identification in JWST MIRI galaxies.

Speaker: Mr Kurt Hamblin (University of Kansas)

Kurt_palooza_talk.pptx

5:35 PM Quiz Time

5:45 PM Coffee Break

5:55 PM AGILE: Development of a compact, low power, low cost and on-board detector for ion identification and energy measurement.

“AGILE (Advanced enerGetic Ion eLectron tEle- scope) instrument is being developed at KU and NASA Goddard Space Flight Center to be launched on board a CubeSat in 2022. AGILE instrument aims at identifying a large variety of ions (H-Fe) in a wide energy range (1-100 MeV/nucl) in real-time using fast silicon detectors and read-out electronics. This can be achieved by the first use of real-time pulse shape discrimination in space instrumentation. This method of discrimination relies on specific amplitude and time characteristics of the signals produced by ions that stop in the detector medium. AGILE will be able to observe, in-situ, the fluxes of a large variety of particles in a wide energy range to advance our knowledge of the fundamental processes in the Universe as well as getting a better understanding of space weather that affects human activities in space. I will present the current stage of development of the instrument, the discrimination method used, and the current design of the instrument to launch in June 2022.”

Speaker: Florian Gautier

6:05 PM Motivation and Methods for Studying Photocarrier Dynamics of MoO3

2D materials have come a long way since the discovery of graphene in 2004. They have become increasingly relevant for shrinking nanoelectronics, but development has recently become limited by a lack of 2D insulators. MoO3 is one possible candidate for a 2D insulator. By studying the photocarrier dynamics of monolayer, bilayer, and multi-layer MoO3, we may expand the number of available 2D dielectrics for use in nanoelectronics and van der Waals heterostructures, creating a cascading effect for future research opportunities.

Speaker: Mr Ryan Scott

6:15 PM Long-Lived Particles at the LHC

Long Lived Particles (LLPs) are an emerging hot topic in LHC physics due to the non-traditional event topology in the way new physics is produced. These are a feature in many extensions to the Standard Model with many different variations in the final state. The nature of these events make searches for LLPs difficult to conduct. This talk will cover an overview of both current searches during Run 2 of the LHC and prospects for the high luminosity run of the LHC (HL-LHC) with a focus on applications involving timing detectors.

Speaker: Zach Flowers

PALOOZA_LLP.pdf

Friday, February 26

5:00 PM → 7:00 PM Fourth Day

The fourth (and last) day of talks

Convener: Mindy Townsend (University of Kansas)

5:00 PM Introduction

Speaker: Mindy Townsend (University of Kansas)

5:05 PM THEORETICAL DETERMINATION OF THE TRIANGULAR NEUTRINO OSCILLATIONS PARAMETERS: A NEW APPROACH

In this paper we have discussed a theoretical approach to find out some of the parameters of neutrino oscillations. We have assumed that twice of the sum of the three neutrino mixing angles is ${180}^0$; in other words twice of the three mixing angles constitute a triangle. We have constructed one such triangle with proper scale factor such that among the three sides two are independent mass squared differences. This may solve the Octant problem of neutrino oscillations, suggest one more mass hierarchy pattern, and provide an alternative method to measure other neutrino oscillations parameters when the two mixing angles and one mass squared difference are known.

Speaker: Mohammad Ful Hossain Seikh (University of Kansas)

5:25 PM Precise Exoplanet Host Star Abundances for the JWST Era

Stars and their planets form from the same cloud of interstellar dust and gas implying a chemical link between the composition of exoplanets and the stars that host them. For the majority of exoplanet hosting stars, however, we only know the bulk metallicity rather than the abundances of particular elements such as magnesium, silicon, oxygen, and carbon. These elements, among others, are crucial for the building of planetary cores and can also offer clues to the location of the planet’s formation in the protoplanetary disk. Presented will be the plans to measure 18 stellar parameters, including 15 precise elemental abundances, for exoplanet host stars using a data-driven machine learning algorithm. With these measurements, we will identify correlations between stellar and exoplanetary compositions, help place our own Sun’s chemical abundance in context, test abundance-age relations for Sun-like stars, and help trace galactic chemical evolution.

Speaker: Alex Polanski (University of Kansas)

5:35 PM Quiz Time

5:45 PM Coffee Break

5:55 PM A First-Principles Investigation of Vanadium Pentoxide as a Sensor

Using density functional theory (DFT) as implemented in the Vienna Ab initio Simulation Package (VASP) and the Atomic Simulation Environment (ASE) Python module, we will investigate under what conditions Vanadium Pentoxide (V2O5) can be used as a material for chemical gas sensors by simulating adsorption processes for simple molecules such as NH3, CO, H2O, etc. Some experiments have revealed that it is possible to use V2O5 as a sensor with capabilities highly dependent on operating temperature and nanostructure. Thus our simulations focus on probing the physicochemical and electronic properties of V2O5 at an atomic level to better understand its practical limitations.

Speaker: Christopher Sherald (Department of Physics & Astronomy)

6:05 PM Merger Signatures in Cold Quasars

Cold Quasars ($ \rm L_x > 10^{44} $ erg/s, $\rm S_{250} > 30$ mJy) are a recently discovered, extremely rare galaxy. They are luminous in both the X-ray and infrared wavelengths and can have up to seven times as much star formation as normal quasars. They are predicted to be a step in the progression between the starburst galaxies that have undergone a recent galaxy merger and blue, unobscured quasars. However, they mainly look like blue point sources in Sloan Digital Sky Survey imaging. In order to test whether Cold Quasars are produced by mergers, we examine the deep images from the Hyper Suprime-Cam of the Subaru Telescope. We fit multiple models using GALFIT to look for double nuclei or asymmetrical residuals. We find that Cold Quasars are more asymmetrical than a control sample of unobscured, blue quasars, supporting a scenario in which the Cold Quasar phase occurs at the very end of a merger, directly preceding blow out and quenching.

Speaker: Casey Carlile (University of Kansas)

6:15 PM Closing Remarks

Speaker: Mindy Townsend (University of Kansas)