2023 Departmental Poster Competition

The nanorods of ZnO have gained much importance regarding their potential applications in electronic and optoelectronic devices. Particularly, thin films and bulk ZnO depict prominent absorption of light, especially in ultra violet range. For the devices, working in visible and IR range, for instance photovoltaic cells and optoelectronic sensors, there is always a need for improving the absorption profile from UV to higher wavelength region. The process of chemical bath deposition has been used for the synthesis of undoped and Fe doped ZnO nanorods. Thin films were produced by doping iron in ZnO in range of 0, 3, 6, 9 and 12%. Pre-cleaned glass substrates (1× 0.5 inch) were used for the deposition of the nanorods. Precursors used in this study were zinc nitrate hexahydrate, hexamethyl tetra amine (HMTA) and iron nitrate nonahydrate. X-ray diffraction technique was used for measuring the structural parameters of the nanorods. XRD confirmed the incorporation of iron ions in place of zinc ions in the hexagonal wurtzite lattice of ZnO. SEM was used for studying the microstructure and morphology of the nanorods. SEM analysis revealed uniformly distributed hexagonal nanorods. The diameter of nanorods increased gradually by enhancing the doping concentration of Fe.  Ultraviolet visible spectroscopy was used for studying the optical properties of the sample. Absorption spectra pointed out a gradual decrease in the bandgap of the sample by incorporation of iron in ZnO. Photoluminescence spectra pointed out that highest emission peaks were observed for high doping of Fe in the ZnO nanorods. Such material with better optical characteristics would be fruitful for application in optoelectronic devices like bio sensors, piezoelectric generators etc.

We present the application of deep-learning-based computer vision techniques for quality control (QC) of silicon-based particle detectors construction, focusing on wire bonds and sensor surfaces, characterizing the features into classes such as 'no wires,' 'glue,' 'broken wires,' and more. Manual QC of printed circuit boards, electronics components, and silicon sensor surfaces are generally costly, labor-intensive, and error-prone. The use of You Only See Once (YOLOV5) object detection for QC purposes is not only an effective tool for the current Compact Muon Solenoid Endcap Calorimeter Upgrade project at the Advanced Particle Detector Laboratory, but also for the future applications to other detector construction projects, promising increased efficiency and precision.

We introduce our recent development in nuclear-powered rocket technology, specifically employing fission fragments as the fuel source. The pursuit of alternative propulsion technologies beyond traditional chemical fuels has spurred numerous breakthroughs in the field of space exploration, including electric, solar, and nuclear propulsion systems, each with its distinct advantages and drawbacks. Among these, nuclear rocket propulsion stands out for its potential to offer superior thrust and efficiency when compared to conventional chemical rockets. Our primary focus revolves around enhancing proposed nuclear rocket designs and empirically assessing their operational efficiency through both experimentation and simulations.
In our research, we employ Th-232 as the source of alpha particles, serving as a surrogate for fission fragments. This source is situated within a cylindrical vacuum chamber, maintained within a robust magnetic field of 3 Tesla, effectively constraining the flight paths of emitted alpha particles. We present the outcomes of our experiments and simulations, affirming the successful magnetic confinement of alpha particle trajectories within ultra-high magnetic fields. Additionally, we introduce our innovative system and design, specially to detect alpha particles under these extreme magnetic conditions.

Magnetars are highly magnetized neutron stars with a variety of electromagnetic emission, including x-ray flares and fast radio bursts (FRBs). Searches for gravitational waves coincident with magnetar x-ray bursts and FRBs during the third observing run of Advanced LIGO and Virgo (O3) found no evidence of gravitational waves, but did place upper limits on gravitational-wave energy emission. Here we present modifications to an existing LIGO pipeline to allow for a 'stacked' search over multiple electromagnetic burst events. We present the methods of stacking, as well as approximate the improvement in sensitivity for different numbers of bursts in the stack. We discuss the limitations of stacking, as well as parameters of the analysis that are available for adjustment. Potential uses of this stacking pipeline include the x-ray bursts from SGR 1935+2154 during O3, the repeated FRBs from the same source in 2020, and any repeated magnetar bursts and FRBs that happen in O4.

Over the years many different modalities have been created and studied to improve the physics classroom at the K-12 and undergraduate level. However there has been very little to no published research on how graduate students learn with these different modalities that improve the physics classroom. We have created materials to teach graduate level methods to solve classical systems through lagrangian mechanics and analyze the symmetries of the system. To analyze these materials, we are developing a rubric for analyzing answers to lagrangian mechanics problems. We are using the rubric to analyze both an inquiry-based modality and a lecture based modality.  This poster will go over the development of the materials and the application of the rubric.

Various advances in materials science and computer engineering have rendered a fully comprehensive and intrinsic understanding of the behaviors of most common semiconductor heterojunctions, especially as it pertains to their respective electrodynamics on the quantum scale. Thus, the present study interpolates the material and operational understandings of semiconductor heterojunctions into low temperature settings via observations previously published in journals and subsequent physical analysis of these findings. Comprehensive thermodynamic understanding of heterojunction behavior in extreme conditions could lead to interesting developments in semiconductor physics, materials science and solid-state physics.

Our nearest star-forming galaxy, the Large Magellanic Cloud (LMC), has been largely neglected in X-ray binary (XRB) populations studies targeting quiescent luminosities. In Chandra Cycle 24, we were awarded a Very Large Program (1 Msec) to perform a comprehensive survey of sources brighter than 2×10^32 erg s^(−1) in 10 LMC fields dominated by young (10 – 100 Myr) stellar populations of different ages, matching those sampled in the similar survey of the Small Magellanic Cloud (SMC). This luminosity limit probes all active XRBs and reaches into the regime of quiescent binaries and X-ray emitting normal stars. This program will provide the deepest X-ray luminosity functions (XLFs) for XRBs ever recorded, and in combination with the SMC survey will allow us to directly measure their formation efficiency as a function of age and metallicity and address the XLF evolution in the 10 – 100 Myr range. Here we present the first promising results from the analysis of the first observations of the LMC fields.

The purpose of this study was to examine the relationships between epistemic cognition, metacognition, recognition, physics self-efficacy, interest and gender for high school students. Also, how epistemic cognition, metacognition, recognition, physics self-efficacy, interest and gender predicted physics identity was observed. The study involved a sample of 1197 high school students. Likert-type scales were used to gather the data. The Physics Personal Epistemology Questionnaire (PPEQ) was used to measure epistemic cognition. Also, to check students’ metacognition, the Metacognitive Awareness Inventory (MAI) was used. The physics identity scale measured interest, self-efficacy, recognition, and physics identity. The data was collected via convenience sampling. Descriptive statistics, correlation and multiple regression analyses were used to analyze the data. The study showed that there was a very high positive correlation between identity, recognition, self efficacy and interest constructs. Identity, recognition, self-efficacy and interest were moderately positively correlated with epistemic cognition and metacognition. Also, there was a high positive correlation between metacognition and epistemic cognition. Interest, recognition and self-efficacy positively predicted physics identity, while the strongest predictor was recognition. Metacognition and epistemic cognition did not predict physics identity. Regarding gender differences, males had higher levels of physics identity, recognition, interest and self-efficacy than females. On the other hand, there was no gender difference observed in metacognition and epistemic cognition.

We conducted a centrally-concentrated search of the Galactic Center for new pulsars at high radio frequencies with data collected from the 100-m Green Bank Telescope. This search accumulated a total of 11 hours of observation time at a central frequency of 9200 MHz. The purpose of using high radio frequencies was to minimize the propagation effects of the interstellar medium. We conducted fourteen pointings to search multiple positions in the Galactic Center, which should have a high density of pulsars, particularly those residing in exotic binary systems. This analysis was done by creating a range of dispersion measure values that would be sensitive to these sources, conducting periodicity searches and single-pulse searches at each specified dispersion measure, then creating diagnostic plots for the periodicity and single-pulse candidates. These diagnostic plots were then evaluated for characteristics resembling those of a pulsar to determine if the candidate could be classified as such. In this search, we also inspected dispersion measure ranges at sufficiently high values that would be sensitive to distant fast radio burst detections, and analyzed dynamic spectra from J1745-2900.

The transport of photogenerated electrons in copper under the influence of an external electric field is analyzed through Monte Carlo simulations. The electron distribution at the surface, accounting for the scattering mechanisms during transport, is investigated. Internal potential profiles are determined using a density functional approach, and the one-dimensional Schrödinger wave equation is numerically solved with the Numerov technique to obtain appropriate wave functions at the emitting surface. Current density is then calculated utilizing the transmission coefficient and electronic distribution. To boost current output, an array of emitters is utilized, and consideration is given to the use of high aspect ratio materials like carbon nanotubes (CNTs) for enhanced electric field effects at emitter tips. Charge screening effects, and field distortion due to proximity effects associated with neighboring emitters are comprehensively taken into account. This leads to electric field reductions at the emitter tips due to the presence of other emitters. Theoretical framework is grounded in the Fowler-Nordheim equation for electron field emission. Various applications would benefit from this research, including flat panel displays, X-ray tube sources, cathode ray lamps, electron sources for microwave generation, and nanolithography, among others.

When it launches, LISA (Laser Interferometer Space Antenna) will probe a lower frequency portion of the gravitational wave spectrum. White dwarf binaries will be the most numerous sources in its catalog, with around 30,000 directly resolvable binaries which will reveal information about the structure and history of the Milky Way. To investigate this, we used COSMIC (Compact Object Synthesis and Monte Carlo Investigation Code) to generate Milky-Way-like populations of double white dwarfs with user-specified galactic assumptions. COSMIC is a quick population synthesis code and functions by creating a small fixed population and then drawing from that population until it reaches a specified mass. By varying the galactic assumptions put into COSMIC, specifically the metallicity for this work, we investigated how the metallicity will impact the galactic double white dwarf population and the sources eventually observed by LISA. We used four metallicities: 0.011, 0.014, 0.017, and 0.02. These were the metallicities given to both the thin disks and bulges, while the thick disk metallicities were 15% of these values. Since the galaxies drawn from the fixed populations are random, we made 500 galaxies per metallicity and compared their medians to minimize random effects. For each catalog, we created histograms of the binaries’ orbital periods, chirp masses, and individual masses to compare between metallicities. These histograms showed points in the parameter space where the distribution of histograms completely separates meaning that the metallicity of the galaxy has a potentially observable effect on the distribution of resolvable LISA double white dwarf binaries in the Milky Way. Future improvements on this project include examining the catalogs with Bayesian analysis and expanding the grid to include more galactic parameters such as the scale height, total galactic mass, and star formation history.

Particle detectors in large-scale high-energy physics experiments, such as those at the Large Hadron Collider at CERN, have become increasingly complex.  We studied the use of robotics in
the construction of these types of detectors and the integration of machine learning techniques 
to support future construction demands. We developed custom electronics and algorithms to control a high-precision robotic gantry often used in the construction of these detectors. We also implemented a machine learning algorithm to automate the quality control of detector construction process on the same gantry. This poster presents the R&D details of this project.

Abstract
The review of the Digital Holographic Microscopy DHM approach, a type of quantitative phase imaging (QPI), for the 3D shape reconstruction of red blood cells (RBCs) and the computation of their dry mass and refractive index is the main objective of this study. This study, which focuses on novel developments in the field of medical diagnostics with a major interest in illness diagnosis and monitoring, aims to offer insightful information on RBC properties. The DHM approach for RBC analysis is being improved upon in this work. We rigorously adjust DHM setups, accounting for light sources, numerical aperture, and acquisition parameters, to obtain improved accuracy and resolution in recreating RBC forms. Through the incorporation of phase information and relevant biophysical parameters, we established a robust relationship that allows for the accurate enough determination of RBC dry mass, offering crucial insights into cellular health and potential disease conditions. The study also delves into the measurement of the refractive index of RBCs using DHM. A method for precisely determining the refractive index is tested by taking advantage of the natural phase shifts that cellular components introduce. This knowledge is crucial for comprehending changes in cellular structure and hydration in various pathological states. We show how DHM can efficiently distinguish RBC abnormalities in patients with hematological disorders based on volumetric parameters, demonstrating the clinical usefulness of our method. Our method enables accurate disease monitoring and early disease detection through a thorough analysis of RBC morphology and biophysical properties. As a result, the study offers a fresh and distinctive method for using DHM for RBC analysis in the context of medical diagnosis. We contribute to the understanding of RBC characteristics by refining and advancing existing QPI methodologies, which may offer benefits in disease diagnosis and patient care. Our unique contributions are expected to drive further advancements in medical imaging and diagnostic applications as the field of QPI evolves.

A likely source of a gravitational-wave background (GWB) in the frequency band of the Advanced LIGO, Virgo and KAGRA detectors is the superposition of signals from the population of unresolvable stellar-mass binary-black-hole (BBH) mergers throughout the Universe. Since the duration of a BBH merger in band (∼1 s) is much shorter than the expected separation between neighboring mergers (∼10^3 s), the observed signal will be “popcorn-like” or intermittent with duty cycles of order 10^{−3}. This background is best described by a Gaussian mixture-model, which includes a duty cycle parameter that quantifies the degree of intermittence. We propose a stochastic-signal-based search for the GWB from subthreshold BBH mergers. While the development of this search is ongoing, results thus far are very promising that our search will perform much better than the standard search used in stochastic gravitational-wave data analysis.

Accreting black holes and neutron stars can launch relativistic jets, for which there are many open questions relating to how they are collimated and accelerated, as the environment surrounding these jets is extreme in temperature, gravity, velocities, and magnetic fields. Jets are also difficult to investigate as none can be fully imaged, thus timing studies are used instead. For this project I take archival radio data of accreting black holes and neutron stars and produce power spectral densities, quantifying the level of variability present in these systems. Variability is generally related to the culmination of many jet parameters such as speed and opening angle, thus comparing radio variability is a method to also compare how similar or different their jets are overall. So far we find that black hole and neutron star jet variability is remarkably similar across a range of frequencies, indicating that both classes of jet are very similar despite a large difference in radio luminosity.

Two-dimensional materials like the hexagonal Boron Nitride hBN and the transition metal dichalcogenides (TMDs) have attracted significant attention due to their unique properties that enable advanced optoelectronic device fabrication. They have also been studied as hosts of single photon emitters (quantum light emitters). To understand the electronic properties and lifetime of photoluminescence (PL) in hBN, which is part of the family of 2-dimensional materials, we used photoluminescence (PL) and time-resolved photoluminescence (TR-PL) spectroscopy. Our observations indicate that narrow-width PL emission in the spectral region between 693 and 698 nm occurs at room temperature from states in the bandgap of hBN. These states may originate from lattice-embedded carbon atoms, which can potentially act as quantum light emitters that can be used for quantum technology applications.

In the universe, celestial bodies tend to become gravitationally bound to one another. Examples of this are seen in subjects such as galaxies, planetary systems, and globular clusters. Globular clusters (GC) are dense, spherical accumulations of stellar populations. It has been observed that these systems occupy the halo of the Milky Way, which is the oldest section of our Galaxy. Because GC are comprised of old stars, they have a low abundance of heavy elements. Due to the stars within a GC forming within a similar point in time, these systems serve as cosmic clocks. The most massive star left on the Main Sequence provides the cluster's age through a process called isochrone fitting. The isochrone is a curve on the color-magnitude diagram (CMD), a scatter plot depicting the relationship between absolute magnitude, and collectively color and temperature, that represents a population of stars of the same age but with different masses. We have selected several GC to observe from Texas Tech’s Preston Gott Skyview Observatory, utilizing complementary metal oxide semiconductor (CMOS) detectors on 12-inch telescopes and 3 photometric broadband SLOAN/SDSS filters. Two of the CMOS cameras were purchased using funds from the 2021 Texas Tech Alumni Association Excellence Award. By directly comparing the CMDs of the different clusters and later each of them with CMDs found in the literature, we can (a) identify different CMD features based on the different stellar populations and their evolutionary stage each cluster hosts; (b) address the reliability of our Observatory equipment for research investigations. We conclude that the equipment is reliable for both undergraduate labs and research projects, thus offering for the first time the opportunity to undergraduate students to obtain, analyze, and publish their own data obtained from the TTU Skyview Observatory.

In this study, the effects of anesthetic drug sevoflurane on membrane fluidity have been compared with isoflurane. To get complete picture, three representative membrane systems (pure DPPC, POPC/Chol and a 5-lipids mixture that mimics brain endothelial cell membrane) and red blood cells were chosen. Lipid membrane systems were labeled with dipyrene-PC fluorescent probe, whose excimer/monomer (E/M) fluorescence peak ratio showed an immediate increase after adding the drugs, indicating a sharp increase of membrane fluidity. We studied clinical concentrations of 0.5mM sevoflurane and 1mM isoflurane. The fluidity increase at these concentrations on DPPC lipid bilayer are comparable, and both drugs are quite effective to loosen up the highly ordered lipid domains of saturated lipids. The supra-clinical concentrations of these drugs, 2mM sevoflurane and 5mM isoflurane, have also been examined. The E/M ratio increases for POPC/Chol and 5-lipids mixture were similar, but the magnitude of increases were reduced to almost half of DPPC. Furthermore, washed human red blood cells were labeled with TMA-DPH fluorescent probe and fluorescence anisotropy measurements were carried out. At clinical concentrations, the decreases of anisotropy were comparable for these two drugs, and the effects are more than that of 174mM ethanol, which is ten times the legal alcohol limit level in human blood. All these findings depict that sevoflurane and isoflurane at clinical concentrations have similar effects on a wide range of membrane systems, and both significantly and rapidly increase membrane fluidity.

The Light Dark Matter eXperiment (LDMX) focuses on the detection of light dark matter particles in the sub-GeV mass range. It is based on generating dark matter particles by dark bremsstrahlung of electron beams scattered by a fixed tungsten target. Because dark matter does not participate in electromagnetic interactions, it passes undetected through the tracker and calorimeters. Thus, evidence of dark matter can be found by analysing missing energy (or momentum) distributions of the scattered electrons. The energy of these scattered electrons can be measured by the electromagnetic calorimeter (ECAL), and one can measure the incident energy by counting the number of electrons hitting the target. The LDMX Trigger Scintillator (TS) module is designed using Silicon PhotoMultipliers (SiPM) made of plastic or LYSO to rapidly count the number of electrons (minimum ionizing particles (MIPS)) in the incident beam pulses of fixed, known energy. It is important for the scintillators to accurately count these electrons for effective triggering of signal events and rejection of background events. In this project, we summarize the performance of a prototype TS module based on a three-week test beam experiment performed in April 2022 using different beam configurations. By carefully analysing the integrated output charge distributions, we measured different performance parameters like SiPM gains, pedestals and the system's response to MIPs. Over the period of the test beam experiment, we observed the module having a large response to MIPs and stability of the SiPM performance parameters.

The focus of our current analysis centers on constraining the mass of the excited bottom quark, denoted as b*. to achieve this, we initiate out investigation by dissecting a subset of high-mass dijet events, segregating them into control and signal regions. This segregation is accomplished by applying stringent selection criteria to fundamental jet properties such as reconstructed jet transverse momentum(pT), pseudorapidity (eta), azimuthal angle (phi), as well as variables like delta eta, delta phi, and dijet mass.
In our pursuit of precise analysis, understanding the background statistics with minimal uncertainty is paramount. To his end, we have diligently generated a dataset of 100 million dijet events using the positive weight hardest emission generator (POWHEG). This tool plays a pivotal role in augmenting our statistical precision.

Ammonia plays a vital role in the sustainability of human development as an artificial fertilizer and a future energy carrier. The current more efficient way to synthesize ammonia is CO2 emitting the Haber-Bosch (H-B) process, which is dependent upon the use of fossil fuels. Each year, around 150 million tons of NH3 is produced globally using the H−B process, which consumes 3−5% of the annual natural gas production worldwide, or approximately 1−2% of the global annual energy supply. Achieving a carbon-neutral sustainable process for ammonia production is necessary to reduce CO2, which results in global climate change. It is highly desirable to develop a scalable efficient process for NH3 synthesis that can use electricity from renewable energy sources. Electrochemical nitrogen fixation reaction under mild conditions is a promising alternative to the current H-B process. We have continued nitrogen fixation research using different electrocatalysts and feedstock gases. Palladium (Pd) is used as a cathode, and platinum (Pt) as an anode in a one-pot cell. The Pd nanoparticles in LiOH solution appear to promise a good Faradaic Efficiency (FE). Other intermetallic nanoparticles could be made and screened for electrocatalytic activity. In addition, we have used new analytical techniques to quantitatively measure the production of ammonia, and other nitrogen species of interest.

Vanadium dioxide (VO2) undergoes a reversible insulator-to-metal phase transition (IMT) near room temperature, providing an active tunable platform for photonics devices due to drastic change in VO2 optical properties at IMT. A high-quality VO2 film on a Gallium Arsenide (GaAs) substrate is significant in photonics applications for the development of electrically and thermally tunable devices operating at far-infrared (FIR) spectral range. VO2 film on GaAs will be an attractive platform to develop phonon polaritonic metasurfaces because GaAs support phonon polaritons at its FIR Reststrahlen band (28.5 – 33 µm). In this work, we numerically demonstrate thermally tunable surface phonon polaritonic devices using VO2 films on GaAs, working within GaAs’s Reststrahlen band.  The device consists of 40 nm thick gold grating (periodicity = 1100 nm, gap = 100 nm) on 100 nm thick VO2 on GaAs substrate. The cavity resonance is observed near 30.2 µm and shows redshifts as temperature increases. Furthermore, we explore various grating periods and gaps to control the cavity resonance tuning and its dynamic redshift induced by temperature changes.

Polarimetry is an invaluable tool for investigating material properties under the influence of polarized light. Long-wave infrared polarimetry is often limited due to a lack of polarization-sensitive optical components at mid- and far-infrared (MIR and FIR). Here, we experimentally demonstrate a MIR active and highly efficient polarization-control nanostructure. We measure the polarization rotation and ellipticity induced from gold subwavelength grating structures on top of vanadium dioxide (VO2) film on silicon carbide. The proposed structure has a resonance at 840 cm-1 due to the Fabry-Perot cavity array of coupled surface plasmon-phonon polaritons. The insulator-metal phase transition of VO2 at 55C causes a 25 cm-1 resonance shift. The polarized light parallel to the grating reflects when on resonance, while the light polarized perpendicular to the grating is strongly absorbed. Off resonance, the reflected light gains an additional scattering phase and intensity from the cavity, changing its polarization. A custom, high-resolution polarimetric spectrum microscope was developed to measure the IR polarization spectra of samples as small as 100x100-micron. This work demonstrates a novel polarimetry apparatus, enabling researchers to do precise polarimetric studies of small samples at FIR wavelengths.

During the next LHC long shutdown 3 (2024-2026), the Compact Muon Solenoid (CMS) experiment will replace its current endcaps with a high granularity calorimeter (HGCAL) that comprises ~6M silicon cells and ~400K scintillator tiles. HGCAL will operate at -30 C in order to keep electronics noise low and charge collection efficiency as high as possible. TTU is one of the Module Assembly Centers for these modules. We present the current design, material choices and the details of the assembly process.

Vanadium dioxide (VO2) is famous for the reversible metal-to-insulator transition - from an insulating monoclinic phase to a metallic rutile phase - slightly above room temperature which allows many photonics applications such as optical switching and modulators. Since the metal-to-insulator transition temperature is sensitive to the concentration of substituents, lower or higher the transition temperature by doping chemical substitution expands VO2 application to the lower energy scale. Here, we investigate an optical property of NbxV1-xO2 single crystals (x = 0.4, 0.11, 0.15, 0.24, 0.35, and 0.88) across the metal-to-insulator transition. NbxV1-xO2 alloy will help in resolving the structural and electronic connection among crystal phases. We measured a reflection spectrum at mid-infrared range. We obtained an optical conductivity of NbxV1-xO2 extracted by using Kramers-Kronig analysis. To evaluate the metal-to-insulator or the metal-to-semiconductor transition, we applied an extended Drude model to fit the optical conductivity.

The Two Temperature Model predicts temporal and spatial electron and lattice temperatures by solving a coupled set of differential equations. This understanding of the electronic and lattice temperature is necessary for understanding carrier dynamics. In our simulation, we use a Python library called NTMpy; we can then  predict the temperature of the electronic system and the lattice of the material of interest as well as the substrate by using variables such as, the depth of the material, the heat capacity, specific heat, coupling term between the electronic system and the lattice, the temporal profile of the incoming energy source, fluence and polarization. The purpose of using this simulation is to show electron scattering processes, by spectroscopy, in the femtosecond to picosecond regime, often times called Ultrafast Spectroscopy. The combination of the simulation with lab data allows us to not only study the scattering processes happening, but also the time of thermalization. In Ferromagnetic Nickel we were able to accurately reproduce lab data and show that the electronic system reaches temperatures on the order of 700K and thermalizes within the range of 10-15 ps.

The large hadron collider (LHC) situated at CERN, Geneva is the world's most powerful accelerator which is used to study particle physics through proton-proton collisions at energy scale of TeV. The inelastic proton collisions produce other elementary particles which are studied through specialized detectors. The Hadron Calorimeter (HCAL) is one such detector designed to detect hadrons and measure their energy. Hadrons are the bound states of quarks. High energy quarks produce an avalanche of such hadrons, which are collectively called jets. The formation and detection of jets, working of HCAL, and the study of raw pulses received by HCAL will be presented.

The standard model of particle physics has been successful in explaining decades of experimental observations. The discovery of Higgs boson at the LHC verified one of the key predictions of the theory while opening doors to new questions. The mass of the Higgs boson was expected to have large, divergent quantum corrections, yet the latest measurements revealed the Higgs boson mass to be 125.11 GeV with 0.1% uncertainity. This paradox is commonly referred to as the hierarchy problem. Supersymmetry (SUSY) is the leading candidate that can explain the above discrepancy. A strategy to search for the signatures for SUSY and the current status of the work will be presented.

XTE J1946+274 is a Be/X-ray binary (BeXRB) that was first discovered in September 1998, when 15.8s pulsations were detected using RXTE All-Sky Monitor and BATSE. This High Mass X-Ray Binary underwent a Type II outburst in June 2018 and was observed by the Chinese satellite Insight-HXMT at a flux of ~4.27 × 10-9 erg cm-2 s-1 in the range of 1 to 80 keV. The source was observed for a duration of 150 ks. This source was observed to have a spin period of 15.756 seconds. The pulse profile shows strong energy dependence with a double-peaked structure at low energies while evolving into a single-peaked structure at higher energies. The spectral continuum is described using a model consisting of a double component power-law and a black body component. We find the presence of a broad absorption-like feature at 48.3 keV and are probing to see if this is a cyclotron resonance scattering feature. 

We use the Insight-HXMT Data Analysis software hxmtsoftv2.05, CALDB 2.06, and heasoft-6.30 to analyze the observations and extract scientific products.

Supersymmetric models provide explanations for the relic abundance of dark matter, resolve the higgs boson hierarchy problem, and predict that gauge couplings will unify at high energies. It also predicts a new particle for each Standard Model (SM) particle. Considering the number of states these models predict, there can be more than 100 free parameters in a supersymmetric theory. To facilitate experimental investigation, these theories are often constrained by allowing only a few masses to vary and assuming new states decay through a single process limiting the predicted particles that can be generated by an event. A relevant example of this is the Simplified Model Spectra (SMS) used in many predictions tested by the Compact Muon Solenoid (CMS) experiment. In this work, we present a study testing the robustness of assumptions made by CMS in producing mass exclusion limits of superpartners using SMS. Using a theoretical framework published in 2020, we computed the expected limits of neutralinos and charginos, and those from the SMS assumptions in order to see how robust the CMS results are with respect to different parameterizations of superpartners’ properties. We elected to focus on a high energy diboson jet plus missing energy search, as it is a distinct final state that is rarely seen in SM interactions. Our data showed that, despite the increased complexity of the model we used, the upper limit was either not significantly changed, or improved by around a factor of two, depending on the values of the mass parameters. This leads us to the conclusion that, at least for parameterization studied here, applying a more complex framework to simulation may not be necessary.

Calorimetry is one of the principal tools for investigating nature in the field of high-energy physics. This 
process operates by colliding particles on a calorimeter, a specialized detector designed to fully absorb the 
incoming particles. This collision initiates a cascade of particles, forming a shower that emits charge or light as 
it traverses the calorimeter material. This transfer of energy from particle momenta to charge or light signals
allows for the precise calculation of the shower’s total energy. 
The effectiveness of a calorimeter hinges on the type of material that is chosen. On one hand, it needs to be 
dense enough to stop the particles fully. On the other hand, a material that releases too many baryons from a 
collision can introduce noise and ‘invisible’ energy that eludes detection. This study centers on the intricate 
interplay between incoming particles and calorimeter materials. 
Employing Monte Carlo simulations with GEANT4 (a particle physics simulation toolkit), we subjected an 
array of particles to various calorimeter materials, unveiling some of the mechanisms behind baryon 
production. Our analysis reveals that the primary source of baryon production stems from the “evaporation” of 
the calorimeter material nucleus upon collision, liberating protons and neutrons. This happens at relatively low 
beam energies of around 5 GeV. A much smaller effect is the pair production of baryons in inelastic collisions. 
We also found the unaccounted “invisible” energy in the calorimeter to be proportional to the number of 
baryons produced. This suggests that at least part of this invisible energy arises from the binding energy in the 
nucleus being overcome as the nucleus evaporates into its substituent parts. This binding energy then does not 
appear as light or charge signals in the calorimeter, justifying the name ‘invisible’ energy.
Extending our investigations across various materials, including Copper, liquid Hydrogen, Uranium, and Lead, 
we found the Baryon production to increase notably with the atomic number of the material. This is consistent 
with the proton and neutron production through nucleus evaporation described above.
Though these findings may not introduce revelations in high-energy physics, they offer valuable insights into 
common processes during high-energy collisions. Documenting and archiving such simulations provide a 
valuable resource for particle physicists, aiding in informed decisions regarding calorimeter materials and 
advancing the field.

Silicon nitride photonic chips have emerged as a promising platform for a variety of applications, ranging from communication to sensing. However, their integration with other physical systems, such as microfluidics and atomic vapor cells, remains challenging due to the modal size difference between photonics and these domains. Here, we address this issue by optimizing subwavelength grating metalens for on-chip Gaussian beam generation. We focus on in-plane beam generation, which allows easier integration and alignment with other systems. Our approach involves engineering the modal beam size by arranging metamaterial subwavelength gratings, transforming modal sizes from hundreds of micrometers to a few micrometers. The device is designed on a simple monolithic scheme, which can be readily fabricated by well-established complementary metal-oxide-semiconductor (CMOS) processes. Our device is readily integrable with photonic chips and has the potential to advance various chip-scale photonic applications, including biochemical sensing and atomic wavelength referencing.

Improving the reconstruction of hadronic shower with similar precision as electromagnetic particles in high-energy physics calorimeters has been a longstanding quest. The dual-readout method (DREAM) measuring the scintillation and Cherenkov light simultaneously has shown the significant improvement of the energy reconstruction for hadronic showers over the traditional simple signal sum method. We simulated a finely-segmented Cherenkov fiber calorimeter using GEANT4 and used neural network to reconstruct the energy. We compare its performance to the dual-readout method and discuss how the neural networks (graph neural networks) improve the energy reconstruction of hadronic shower.

Light-matter coupling underlies many fundamental quantum mechanical process, as well as being foundational to quantum informational platforms. While the study of coupling to two-state systems is extensive, work on many-body systems coupled to light is select. In this work we study radiation from a finite-sized one-dimensional electron system coupled to light. We consider how an exited state of the system relaxes via the emission of photons. We find that despite the seemingly trivial florescence, the electronic states exhibit entanglement and superradiance, analogous to the Dicke model. In general, we find that the decay processes involve a ‘competition’ between superradiance and Pauli blocking.  This work made extensive use of the bosonization and representation theory. Future work involves studying a number of quantum critical systems making use of conformal field theory (CFT) such as Majorana chains, spin chains and certain fractional quantum Hall edge states.

The D-Wave machine is an annealer built with a superconducting circuit infrastructure. The extent to which D-Wave’s operation is quantum mechanical rather than classical has garnered considerable interest. Recently, a D-Wave system was used to simulate the quench dynamics of a one-dimensional Ising spin chain and it was found that the defect density followed a power law in the annealing time. This power law is consistent with Kibble-Zurek scaling and the predictions of quantum mechanics. However, this does not rule out a classical explanation---any phenomenon without an energy scale, whether it be classical or quantum, will exhibit power law behavior.  Here, we consider a modified version of the Ising spin chain in which the ferromagnet couplings alternate in strength. This introduces a gap and thus an energy scale to the problem. We are currently studying the quench dynamics of this system to determine whether they offer more direct evidence of coherent quantum behavior and here present our preliminary results.