Department of Physics & Astronomy "Colloquia and Seminars" Series

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

Fridays @ 3:00 PM

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

Past Colloquia/Seminars

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.

Upcoming Colloquia/Seminars

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

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. Lamiaa El Fassi

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

   $*$ TBC

   $**$ TBC

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

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

   TBC

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

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

   TBC

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

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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 Dr. Robert Swanson, Physics & Astronomy Department, Mississippi State University

   Striking the Right Chord – Using Music for Science Outreach Efforts?

  Host: Dr. Lamiaa El Fassi

  Instruction: In-person in Hilbun R-150

  Abstract:

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2024-2025 Committee