Session PM: Undergraduate Research IV

Quantifying the uncertainty on the location of the holographic critical point

In Quantum Chromodynamics (QCD), we study the behavior of strongly interacting matter made up of quarks and gluons. The transition between the confined and low-energy phase called hadron gas and the deconfined and hot quark gluon plasma phase is a smooth crossover at vanishing density. However, it has been conjectured the crossover must evolve into a line of first order phase transition with a critical end point. By using an Einstein-Maxwell-Dilaton (EMD) model, fixed to reproduce the Lattice-QCD equation of state at vanishing chemical potential, we predict the location of a critical end point in the phase diagram. Two free functions in the EMD model are fixed to reproduce the lattice equation of state, a scalar dilation potential, and another corresponding to the coupling between the Maxwell and dilation fields. By modifying these free functions, we study a possible change in the predicted location of the critical point in the phase diagram.   

Light Yield Measurement of SiPM-on-tile with Cosmic Rays

Silicon Photomultipliers (SiPM) are increasingly being used to detect photons in particle and nuclear physics experiments. In this talk, I will describe work related to the use of SiPM for particle detectors in future experiments on the Electron-Ion Collider, which is under construction in the Brookhaven National Laboratory.  I focus on the technique called "SiPM on tile", which involves a  SiPM coupled to a plastic scintillator tile. Charged particles such as those from cosmic rays are capable of causing a photoelectron to be emitted from scintillators upon ionization, which can be measured with a SiPM in the form of a change of voltage. In order to ensure a cosmic ray has been captured, threefold coincidence experiments need to be performed. I will describe a systematic study of measurements of "light yield" using various configurations of reflective wrapping and paint on the scintillator tiles. Such experiments will be used to inform the design of future particle-detector systems at the EIC.

This work is supported by DOE-NP traineeship program DE-SC0022526   

Studies of Scintillators with Wavelength-Shifting Fiber Readout

The future Electron-Ion Collider (EIC) is the next-generation facility for Nuclear Physics research that will enable us to explore the structure of the proton like never before. In this discussion, I will detail research in prototyping particle detectors using scintillating materials for the future EIC. It will entail three main tasks, discussing fiber polishing, error analysis and development of new techniques to solve experimental problems, and experimental design and construction of said prototypes. Work will primarily focus on scintillating bars, Wave-Length Shifting (WLS) fibers, and calorimeters. Using a combination of 3D modeling software, Sketchup, and data analysis, a polished WLS Fiber was joined with a scintillating bar to construct a cosmic particle detector. This bar plus fiber was used in tandem with two Silicon Photomultipliers (SiPMs) to test and run two-fold coincidence experiments. Analysis of threshold test will also be discussed. Further research will be on data analysis and learning how to fit simulated data using python, pyRoot, and Jupyter Notebook. This work is supported by DOE-NP traineeship program DE-SC0022526

    

Waveform Analysis of Sipm Readout

The Electron Ion Collider is the next-generation facility for Nuclear Physics experiments that will seek to unravel the inner workings of matter. Particle detectors that measure energy of particles in collider experiments, called calorimeters, will be crucial for these experiments. Some of these calorimeters will be based on Silicon Photomultiplier (SiPM) technology, which has been improving subtantially in recent years. In this talk, I will present measurements that characterize the performance for SiPMs used for calorimeters at the future EIC. Using DRS4, Sipm single pulse of voltage waveform is recorded individually into data files that contain the time and voltage. Each waveform shows the background, rising, and falling slopes that the Sipm have when a single photon contacts the diode at Avalanche mode. This presentation shows the use of Python curve fit coding to identify the peak to peak voltages that is required to plot out the average intensity, that is observed by the Sipm at a given position and constant intensity input. The data output is furthermore being studied by a graduate student in the lab for the characterization of Sipms underneath a scintillating tile, while using step motors and UV lights at different positions for the Sipm readouts. (Other studies will be conducted between now and the event date)   

Optical Characterization of Fresnel Lens and Aerogel of mRICH Detector for Electron Ion Collider Experiments

The recent announcement of the construction of an Electron Ion Collider (EIC) at Brookhaven National Laboratory by the U.S. Department of Energy makes the long-sought experimental effort to explore the structure and properties of proton and nuclei in unprecedented precision and broad kinematic coverage a reality. Particle identification (PID) of the final state hadrons is an essential requirement for EIC. In order to meet the challenge of the limited space in the electron endcap in EIC experiments, a compact, projective, and modular ring imaging Cherenkov (mRICH) detector is proposed for K/π separation from 3 up to 10 GeV/c. The mRICH detector consists of an Aerogel radiator block, a Fresnel lens, a four-sided mirror-wall and a photosensor plane. An optical characterization setup is currently being developed at Georgia State University for measuring the uniformity and photon transmission of the Fresnel lens and the Aerogel block. In this poster, we will present the design, construction, and testing of the setup. A GEANT4-based simulation study of Fresnel lens and Aerogel properties will also be presented.   

sPHENIX Jet Performance Studies

The sPHENIX detector at the Relativistic Heavy Ion Collider is designed to measure high transverse momentum probes of the quark-gluon plasma to study the small-scale structure of the QGP. Jets, the spray of particles created from a high momentum parton produced early in the collision, are an ideal probe as they experience the full evolution of the QGP. In order to understand the jet reconstruction in sPHENIX ahead of data taking, the performance is studied in simulation. Both effects from the detector as well as the performance and optimization of the subtraction of energy from the QGP underlying event are presented. In addition, the status of the detector assembly and testing are reported.   

Calibrations of the sPHENIX Calorimeter System for Jet Reconstruction

sPHENIX, which is scheduled to begin collecting data at the Relativistic Heavy Ion Collider in February 2023, is composed of tracking detectors and calorimeters. The calorimeters are designed to precisely measure the energy of jets which are sprays of particles resulting from an energetic quark or gluon produced early in the collision. Detailed studies of the modification to these jets in heavy ion collisions are excellent probes of the quark gluon plasma produced in such collisions. The sPHENIX calorimeters include an electromagnetic calorimeter, an inner and outer hadronic calorimeter located inside and outside the solenoid magnet respectively. In preparation for data collection, initial calibrations have been determined and strategies for the calibrating the individual systems have been developed. This talk will focus on the later stages of the calibration process that ensures the combined jet energy is properly calibrated. In addition, this talk will report on hardware work related to these calibrations.