Department of Physics & Astronomy "Colloquia and Seminars" Series

Virtual or R-150, Hilbun Hall, Mississippi State University

Fridays @ 3:00 PM

Nov. 14^th, 2025 Dr. Benne Holwerda, Physics & Astronomy Department, University of Louisville

  What can the Occult Do for You? using overlapping galaxies to probe dust properties in galaxies

  Host: Dr. Angelle Tanner

  Instruction: Virtual in ZOOM ONLY

  Abstract:

       Interstellar dust is still a dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy. Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses Hubble to map the distribution of dust in foreground galaxies in fine ( 100 pc) detail. Integral Field Unit (IFU) observations map the effective extinction curve, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy. The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: geometry, a probability function of dimming as a function of galaxy mass and radius, and its dependence on wavelength. I will present our results on VV191, a nearby pair observed with Hubble, JWST, and IFU to link attenuation curves and Balmer Decrements.

Nov. 21^st, 2025 Robert Swanson, Physics & Astronomy Department, Mississippi State University

   The Optics of It All

  Host: Dr. Jeff Winger

  Instruction: In-person in Hilbun R-150

  Abstract:

      This case study uses a viewer-submitted photograph of a suspected funnel cloud to examine how atmospheric optics, meteorology, and cognitive bias influence interpretation of visual evidence. This guided discussion (and live performance of some “Power Pop-tics” music) will allow participants to analyze reflections, shadowing, and cloud illumination to evaluate whether the image shows a weather feature or a dashboard reflection. Social media reactions and a broadcast meteorologist’s public explanation are then discussed to highlight confirmation bias, appeals to authority, and logical fallacies. The case ultimately emphasizes the need for humility, collaboration, and careful communication when conveying scientific interpretations to the public.

Past Colloquia/Seminars

Nov. 7^th, 2025 Dr. Ben Crider, Physics & Astronomy Department, Mississippi State University

  Extremes and Connections: Exploring the Boundaries of Nuclear Matter and Human Potential

  Host: Dr. Jeff Winger

  Instruction: In-person in Hilbun R-150

  Abstract:   Physics, at its best, explores both the fundamental and the human through asking what binds the smallest parts of matter and what connects us as a community. In this talk, I will discuss how our research group at Mississippi State University probes the very limits of nuclear existence while also extending the reach of physics education to students in our own backyard. At one extreme, we explore the boundaries of nuclear stability, where the balance between protons and neutrons determines whether a nucleus can exist at all. These limits, known as the proton and neutron “drip lines,” define where nuclei literally fall apart, marking the edges of the nuclear landscape. Experiments at the Facility for Rare Isotope Beams (FRIB) provide rare opportunities to study these short-lived nuclei and reveal how nuclear shells evolve under extreme neutron-to-proton ratios. I will highlight recent measurements of beta decay half-lives for 31F and 37Na using the FRIB Decay Station Initiator (FDSi), as well as new results on an isomeric state in the very neutron-rich isotope 73Co, which together help test and refine modern nuclear theory in exotic nuclear systems at or near the neutron dripline. At another extreme, which is much closer to home, our group has launched the MSU Physics Summer Camp for Students with ASD, an initiative designed to open doors for young learners with autism through hands-on discovery and mentorship. This effort reflects the same spirit of exploration that drives our nuclear research: curiosity about how complex systems, whether nuclei or people, come together and what we can learn from them to help pave the path forward. By reaching both the neutron drip line and our local community, we strive to expand not only the boundaries of nuclear matter but also the potential of human connection through physics.~

Oct. 31^st, 2025 Dr. Sarah Nagel, Physics & Astronomy Department, Mississippi State University

   Title: Connections: community outreach, recruiting, retention, and teaching in the Department of Physics and Astronomy at Mississippi State University

  Host: Dr. Jeff Winger

  Instruction: In-person in Hilbun R-150

  Abstract:

       This colloquium presents recent developments in our department’s efforts to strengthen engagement and student success across four strategic areas: community outreach, student recruitment, retention, and teaching. Outreach initiatives have focused on building meaningful connections with local schools and organizations to promote physics literacy and inspire future scientists. Recruitment strategies now emphasize inclusive messaging and targeted engagement with underrepresented groups, contributing to a more diverse applicant pool. Retention efforts include early intervention programs, endorsed grad student tutors, and curricular adjustments designed to support students through critical transitions. In the classroom, we continue to refine our teaching practices through active learning, research-based pedagogy, and integration of computational tools. These updates reflect a department-wide commitment to fostering a vibrant, inclusive, and academically rigorous environment for all physics students.

Oct. 24^th, 2025 Mr. Daniel Araya$*$ and Mr. Sapan Luitel$**$ , Department of Physics & Astronomy, Mississippi State University

   Title: $*$ Probing Atomic Nuclei with Neutrons: Measuring Neutron Scattering Cross Sections at the University of Kentucky Accelerator Laboratory

   $**$ Study of N=20 island of inversion using beta decay at NSCL

  Host: Dr. Jeff Winger

  Instruction: In-person in Hilbun R-150

  Abstract: $*$ Many neutron scattering measurements have been performed at the University of Kentucky Accelerator Laboratory (UKAL), providing valuable data on nuclear interactions. In this presentation, I will discuss the experimental procedures used to measure differential neutron scattering cross sections, using the 51V(n,n′) reaction as an illustrative example. Incident neutrons with energies of 3, 3.5 and 4 MeV were scattered off vanadium targets, and scattered neutrons were detected at multiple angles using a time-of-flight setup with scintillation detectors. These measurements allow extraction of angular distributions for both elastic and inelastic scattering, offering insights into nuclear structure and reaction mechanisms. The methods and results serve as a reference for neutron scattering studies and contribute to the refinement of nuclear data evaluations.

$**$Studies of the strong nuclear force far from stability give insight on how shell structure evolves across the nuclear landscape, where the traditional shell closures observed near the valley of beta stability are challenged. The N=20 Island of Inversion (IoI) remains a critical testbed for shell structure in exotic nuclei where the simple filling of nuclear orbitals is insufficient to describe the features of ground state. The “inversion” refers to the energy ordering where intruder or cross-shell excited states drop below the normal configuration that would be expected if the shell gaps remain robust. This structural evolution is governed by the competition between the normal, spherical shell-model configurations and low-lying, multi-particle, multi-hole intruder configurations, and can point to a phenomenon known as shape coexistence. Precise experimental observables are required to distinguish between competing theoretical predictions for the nature and extent of this shape mixing. I will discuss results from a National Superconducting Cyclotron Laboratory (NSCL) experiment using beta decay to populate and study nuclei in the neutron-rich region near N=20. One result obtained from this dataset involves the spectroscopic study of a μs-beam isomer in the odd-odd nucleus 32Na, which sits in N=20 IoI. The observation and characterization of this isomer provide a sensitive measure of the underlying degrees of freedom in the key neighbor, 32Mg. An update on details of the experiment isomers finding and status on current effort to build new beta decay level schemes will be presented.

$$

Oct. 17^th, 2025 Dr. Donna M. Pierce, Physics & Astronomy Department, Mississippi State University

   Chemical and Physical Properties of Comets: Observations and Challenges

  Host: Dr. Angelle Tanner

  Instruction: In-person in Hilbun R-150

  Abstract:

       The current motivations of cometary science are to understand both the chemical and physical construction of these bodies, and in turn, place them into the context of solar system formation and evolution. Thanks to technological advances in both ground-based observing and robotic spacecraft design, we have now been able to see multiple comets in situ, compare flyby data with remote ground-based observations, and observe changes in nucleus surface morphology over time. In the wake of these advances, key questions about comets remain unanswered, and additional questions have now been posed. For instance, what are the carbon-chain molecule depletions seen in some comets actually telling us about their formation and evolutionary circumstances? Why are the lines of distinction starting to blur between comets and asteroids? What drives some comets to undergo outbursts while others don’t display such behavior? In this presentation, I will provide an overview of what is known about the physical and chemical properties of comets, what is being done to answer these questions, and what my research group here at MSU is doing to advance research in these and related areas.

Oct. 10^th, 2025 Fall Break: No Colloquium; Enjoy :) and be Safe!

Oct. 3^rd, 2025 Michael McDonald, Kinectrics

  Overview of the Canadian Nuclear Power Industry

  Host: Dr. Ben Crider

  Instruction: Virtual in ZOOM ONLY

  Abstract:

      This presentation offers a perspective on working in the nuclear power industry, with a focus on the unique features of the Canada Deuterium Uranium (CANDU) reactor system. The talk will briefly introduce the CANDU reactor’s design and physics, then delve into real-world applications, challenges, and the evolving landscape of nuclear power industry. The presentation aims to highlight a few of the diverse roles available to physicists and scientists in the nuclear sector, and illustrate how foundational physics knowledge can be applied in potentially unexpected and impactful ways.

Sept. 26^th, 2025 Dr. Dipangkar Dutta, Physics & Astronomy Department, Mississippi State University

   Let there be dark: the search for "dark light" with electron scattering

  Host: Dr. Ben Crider

  Instruction: In-person in Hilbun R-150

  Abstract:

       The quest to understand the nature of invisible (dark) matter and discover its non-gravitational interactions with ordinary matter is over half a century old. As experiments searching for direct interaction with invisible matter have come up empty-handed, a new model for dark matter has recently been introduced, where a "heavy, dark" photon couples to ordinary matter by inducing a "milli-charge". These models have been motivated by several recent anomalous observations and measurements. One such measurement is the observation of a 17 MeV particle in some nuclear decays, dubbed the X(17) anomaly. A new electron scattering experiment to search for this particle is about to begin at Jefferson Lab. I will discuss the measured X(17) anomaly, the new experiment, and other future prospects.

Sept. 19^th, 2025 Dr. Yukai Ai, Physics & Astronomy Department, Mississippi State University

   Characterization of single aerosol particles using optical trapping and Raman spectroscopy

  Host: Dr. Chuji Wang

  Instruction: In-person in Hilbun R-150

  Abstract:

       Optical trapping (OT) and manipulation of single nano- and micron-sized particles has become a powerful tool used in diverse research fields, such as physics, chemistry, biology, materials, atmospheric sciences, etc. From the early optical tweezers approach, which uses a single tightly focused laser beam to levitate micron-sized particles in liquid media, to the recently developed universal optical trap, which can trap particles of arbitrary chemical and physical properties in air, optical trapping has evolved significantly over the last decades.
      I will show the combined technique of optical trapping and Raman spectroscopy (OT-RS) to study the physical and chemical properties, as well as the dynamic surface changes, of single aerosol particles in air. This work will cover a wide range types of airborne aerosols, including bioaerosols (such as pollen, bacteria, and fungi), dust particles (such as black carbon, terrestrial, and extraterrestrial materials), and liquid droplets (such as sea-spray aerosols).

Sept. 12^th, 2025 Dr. Mahesh K. Gangishetty, Physics & Astronomy Department, Mississippi State University

   Organic-Inorganic Hybrid Metal Halides for Light-Emitting Application​s

  Host: Dr. Chuji Wang

  Instruction: In-person in Hilbun R-150

  Abstract:

       Organic-inorganic hybrid metal halides, such as lead halide perovskites and their cousins, are emerging materials for light-emitting applications. Although they have been known since the 1970s, they were not used in light-emitting devices (LEDs) until recent years. Due to their flexible lattice structure, their composition and electronic dimensionality are easily tunable. Consequently, desirable emission colors with narrow to broadband emission can be achieved, showing great promise for display and lighting applications. Our group is working on developing efficient LEDs through the fundamental understanding of structure-property relations in hybrid metal halides. We use several spectroscopic techniques to study optical properties and engineer various devices to investigate their electronic properties. In this talk, I will discuss two active research areas of my group: 1) developing efficient blue perovskite LEDs through the understanding of interfacial interactions, charge leakage dynamics, and metal ion doping, and 2) understanding the origin of broadband emission in low-dimensional metal halides and empowering organic A-site ions to improve their electronic conductivity.

Sept. 5^th, 2025 Dr. Jaspreet Randhawa and Mr. Maruf Abubakar, Department of Physics & Astronomy, Mississippi State University

   Unveiling the production of radionuclides in Core-Collapse Supernovae

  Host: Dr. Ben Crider

  Instruction: In-person in Hilbun R-150

  Abstract:

       Massive stars conclude their lives through violent explosions known as Core Collapse Supernovae (CCSNe). CCSNe play an important role in galactic chemical evolution as they can contribute to a broad range of elements (e.g., through the weak r-process). Yields of r-process elements in CCSNe depend on details of the explosion, which are not completely understood. The neutrino-driven convection models for the explosion mechanism, which is one of the most favored CCSNe models, have many uncertainties in the explosion parameters, e.g., the explosion energies and the remnant masses. The observations of gamma-rays from radionuclides produced in explosive nucleosynthesis could shed light on some of these questions. On the other hand, understanding the production of radionuclides in the CCSNe is important to decipher the birth environment of our own Solar System, as its formation might have been triggered by a nearby supernova explosion. We will trace the synthesis/origin of two radionuclides: 43K and 10Be in CCSNe. Production and destruction of these isotopes depend on the interplay between various nuclear reactions. Some of the most important nuclear reactions to understand the yield of these radionuclides will be discussed, and results from recent measurements, being led by Mississippi State University, will be presented.

Aug. 29^th, 2025 Mr. Matthew Maynes$*$ and Mr. Uditha Weerasinghe$**$, Department of Physics & Astronomy, Mississippi State University

   $*$ Chasing Color Transparency Effects via Vector Meson Electroproduction at Jefferson Lab

   $**$ Probing Hadronization Processes with Baryon Electroproduction at Jefferson Lab

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

      $*$ Understanding the confinement dynamics of quarks and gluons, the fundamental constituents of atomic nuclei, remains a critical challenge in hadronic physics. Quantum chromodynamics (QCD), the theory of strong interactions, predicts phenomena such as Color Transparency (CT), where small-size configurations traverse nuclei with reduced interactions. A new high-momentum transfer CT experiment collected data in fall 2023 with the CLAS12 detector, housed in Hall B at Jefferson Lab, using targets ranging from deuterium to tin. In this talk, I will briefly present my Ph.D. project and summarize ongoing efforts aimed at extracting preliminary CT results.​

      $**$ Collisions of high-energy particles with atomic nuclei produce cascades of new particles. A central question in hadronic physics is how these particles form and how the nuclear medium modifies the hadronization process. At Jefferson Lab, this is investigated by scattering energetic electron beams from targets ranging from deuterium to lead and detecting the products with the CLAS12 detector. These measurements constrain the space–time dynamics of hadron formation and provide new insights into the strong force that binds most of visible matter. In this talk, I will present progress on my Ph.D. research in hadronization studies and data reconstruction.

Aug. 28^th, 2025$☆$ Dr. Jinwu Ye, Great Bay University in Dongguan, Guangdong, China

   Relativity in statistical mechanics and black holes: its possible applications in the Quark Gluon Plasma phase

  Host: Dr. Jeff Winger

  Instruction: In-person in Hilbun R-150

  Abstract:

      The special theory of relativity dictates that relativistic quantum field theory at zero temperature and zero density must obey the Lorentz Invariance (LI). How to extend it to a quantum statistical mechanical system at a finite temperature and a finite volume remains an outstanding fundamental problem. Here we advocate that the LI is broken in any statistical mechanical system. A moving material or a moving observer displays different temperature effects. Correspondingly, a moving black hole or a moving distant observer shows different temperature effects. Renormalization group flow in the temperature of the statistical mechanical system is mapped to the gravitational effect on the temperature of the black hole through AdS/CFT correspondence. Some of the previous works along similar directions are reviewed and critically examined. The feasible experimental detections of these novel temperature effects in quantum materials, especially in the Quark Gluon Plasma phase in the particle physics are analyzed. This colloquium should be pedagogical and accessible to beginning graduate students.

$☆$ Please note the date and time of this special seminar/colloquium: Thursday, August 28^th @ 3:30 PM!

Aug. 22^nd, 2025 Dr. Robert Wagner, Physics & Astronomy Department, Mississippi State University

   What is a Measurement, Anyway?

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

      The measurement problem has been a central difficulty in the interpretation of quantum mechanics almost since the beginning of quantum theory. An important component of the measurement problem is the collapse of the wavefunction, which appears to follow an entirely different rule than the normal evolution under the Schrodinger equation. In this talk I will critically analyze the concept of wavefunction collapse and argue that it can, in fact, be understood using the Schrodinger time-evolution itself. This view of quantum interpretation has the significant advantage that all quantum phenomenon, incuding the measurement process, can be understood using a single physical principle. A comparison with alternative views, namely objective collapse theories, will also be undertaken.

2024-2025 Committee

Anatoli Afanasjev (325-2918, aa242-at-msstate.edu email)
Dipangkar Dutta (325-3105, d.dutta-at-msstate.edu email)
Lamiaa El Fassi (Chair) (325-0627, le334-at-msstate.edu email)
Seong-Gon Kim (325-8031, sk162-at-msstate.edu email)
Mark A. Novotny (325-7831, man40-at-msstate.edu email) )
Gautam Rupak (325-9451, gr145-at-msstate.edu email)
Chuji Wang (325-9455, cw175-at-msstate.edu email)
Secretary: Tracy Wilcox (325-2159, tld25-at-msstate.edu email)

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