For more information about PhD Thesis Defense presentations, please contact the individual student or advisor.

Graduate Student Kemal Tezgin, Department of Physics, University of Connecticut, "Theoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions ", PhD Dissertation Defense1:00pm
11/18
Graduate Student Kemal Tezgin, Department of Physics, University of Connecticut, "Theoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions ", PhD Dissertation Defense
Wednesday, November 18th, 2020
01:00 PM  03:00 PM
Storrs Campus
Video meetingGraduate Student Kemal Tezgin, Department of Physics,
University of Connecticut
Theoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions
The understanding of the internal structure of the proton and other strongly interacting particles is at the forefront of modern nuclear physics research. Generalized Parton Distribution Functions (GPDs) are a powerful tool to advance the understanding of the hadron structure. In addition to the information about the one dimensional collinear momentum distributions of partons (quarks, antiquarks, and gluons) known from studies of high energy deepinelastic reactions, GPDs also carry information on the distribution of partons in the transverse plane, and allow us in this way to access the threedimensional structure of the nucleon. GPDs can be studied in hardexclusive reactions and contain also information on the energymomentum tensor form factors which will allow us to gain insights on quantities like pressure or angular momentum distribution inside the nucleon. The goal of this thesis is to deepen our understanding of the threedimensional structure of the nucleon. We investigate energymomentum tensor form factors and densities, and all leadingtwist GPDs in the bag model. This quark model provides a consistent theoretical framework to investigate many general concepts that have recently attracted interest, and allows one to study insightful limits like the largeNc limit, heavyquark limit, or the nonrelativistic limit. Another important aspect of this thesis is the discussion of the monopole and quadrupole contributions to the angular momentum density. Finally, the description of pseudoscalar meson production in exclusive processes in terms of GPDs is discussed in the GoloskokovKroll model and implemented in the PARTONS framework, a software development project which will provide direct support for experiments at the Jefferson National Lab and the future ElectronIon Collider.Contact Information: Prof. P. Schweitzer
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Theoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions , Doctoral Dissertation Oral Defense Of Kemal Tezgin1:00pm
11/18
Theoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions , Doctoral Dissertation Oral Defense Of Kemal Tezgin
Wednesday, November 18th, 2020
01:00 PM  02:30 PM
Storrs Campus
ZoomTheoretical and Phenomenological Studies of the Nucleon Structure in High Energy Reactions
In high energy collisions, Parton Distribution Functions (PDFs) are fundamental objects to describe onedimensional collinear momentum distributions of partons (quarks, antiquarks, and gluons) inside the nucleon. In addition to PDFs, Generalized Parton Distribution Functions (GPDs) also carry information on the distribution of partons in the transverse plane to its motion and allow us to access the threedimensional structure of the nucleon. On the other hand, energymomentum tensor (EMT) densities allow us to access the pressure, shear forces, and angular momentum density inside the nucleon. The goal of this thesis is to deepen our understanding of the threedimensional structure of the nucleon. We investigate energymomentum tensor (EMT) form factors and densities, and all leadingtwist GPDs in the bag model, formulated in the largeN_c limit. We also evaluate all leadingtwist chiralodd GPDs of the relativistic nucleon in the bag model. The consistency of this quark model allows us to investigate many general concepts that have recently attracted interest, including pressure, shear forces, and angular momentum density. Another important aspect of this thesis is to discuss that the monopole and quadrupole contributions to the angular momentum density can be generated from each other uniquely in a modelindependent way. The last chapter is dedicated to the phenomenology of GPDs and the GoloskokovKroll model's implementation in the PARTONS framework for pseudoscalar meson production in exclusive processes.Contact Information: kemal.tezgin@uconn.edu
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Graduate Student Benjamin Commeau, Department of Physics, University of Connecticut, "Two Studies on Topological Properties of Organic Superconductors and a new Quantum Dynamical Simulation Algorithm", PhD Dissertation Defense2:00pm
9/25
Graduate Student Benjamin Commeau, Department of Physics, University of Connecticut, "Two Studies on Topological Properties of Organic Superconductors and a new Quantum Dynamical Simulation Algorithm", PhD Dissertation Defense
Friday, September 25th, 2020
02:00 PM  04:00 PM
Storrs Campus
Video meetingGraduate Student Benjamin Commeau, Department of Physics,
University of Connecticut
Two Studies on Topological Properties of Organic Superconductors and a new Quantum Dynamical Simulation Algorithm
In this thesis I investigate two research topics in topological organic superconductors and one research topic in variational algorithms for quantum computation.
In the first chapter we investigate the structural and electronic properties of the three structural phases alpha, beta and kappa of (BEDTTTF)2I3, by performing state of the art ab initio calculations in the framework of density functional theory. We furthermore report about the irreducible representations of the corresponding electronic band structures, symmetry of their crystal structure, and discuss the origin of band crossings.
Additionally, we discuss the chemically induced strain in kappa(BEDTTTF)2I3 achieved by replacing the iodine layer with other Halogens: Fluorine, Bromine and Chlorine. In the case of kappa(BEDTTTF)2F3, we identify topologically protected crossings within the band structure. These crossings are forced to occur due to the nonsymmorphic nature of the crystal. In the second chapter, we performed structural optimization and electronic structure calculations in the framework of density functional theory, incorporating, first, the recently developed strongly constrained and appropriately normed semilocal density functional SCAN, and, second, van der Waals corrections to the PBE exchange correlation functional by means of the dDsC dispersion correction method.
In the case of alpha(BEDTTTF)2F3 the formation of overtilted DiractypeII nodes within the quasi 2dimensional Brillouin zone can be found.
For kappa(BEDTTTF)2F3, the recently reported topological transition within the electronic band structure cannot be revealed. In the third chapter, we propose a new algorithm called Variational Hamiltonian Diagonalization (VHD), which approximately transforms a given Hamiltonian into a diagonal form that can be easily exponentiated. VHD allows for fast forwarding, and removes Trotterization error and allows simulation of the entire Hilbert space. We prove an operational meaning for the VHD cost function in terms of the average simulation fidelity. Moreover, we prove that the VHD cost function does not exhibit a shallowdepth barren plateau. Our numerical simulations verify that VHD can be used for fastforwarding dynamics.
Zoom Link: https://harvard.zoom.us/j/92203325795?pwd=T2VoYzNPNkwvZW1GWFlhQk9Ga1lwUT09Contact Information: Prof. S. Yelin
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Graduate Student Saman Bastami, Department of Physics, University of Connecticut, "Studies on Hadron Structure through TransverseMomentumDependent Parton Distribution Functions", PhD Dissertation Defense1:15pm
9/11
Graduate Student Saman Bastami, Department of Physics, University of Connecticut, "Studies on Hadron Structure through TransverseMomentumDependent Parton Distribution Functions", PhD Dissertation Defense
Friday, September 11th, 2020
01:15 PM  03:15 PM
Storrs Campus
Video meetingGraduate Student Saman Bastami, Department of Physics,
University of Connecticut
Studies on Hadron Structure through TransverseMomentumDependent Parton Distribution Functions
The detailed description of hadrons in terms of quarks and gluons, the fundamental degrees of freedom of Quantum Chromodynamics, is an open problem. Important aspects of hadron structure can be studied in certain deepinelastic highenergy processes which have revealed important insights about the longitudinal momentum distributions of quarks and gluons inside hadrons. Our knowledge of the threedimensional structure is still very limited. Transverse momentum dependent parton distribution functions (TMDs) are one of the main tools to study the transverse structure of hadrons through processes such as semiinclusive deep inelastic scattering SIDIS) or the DrellYan process. This dissertation is dedicated to phenomenological and model studies of TMDs.
All spin and azimuthal asymmetries of the leptonnucleon SIDIS are calculated at leading and subleading twist exploring the socalled "WandzuraWilczektype" approximation which consists in a systematic neglect quarkgluon correlations. The results are obtained using available phenomenological information on TMDs as well as constraints from stateoftheart lattice QCD calculations, and compared to the experimental data from HERMES, COMPASS and Jefferson Lab.
The asymmetries of the pioninduced DrellYan process with polarized protons are studied at leading twist. The information about TMDs is taken from nonperturbative calculations in the lightfront constituent quark model, the spectator model and, where available, phenomenological extractions of TMDs. The results are compared to recent data from the first polarized pionnucleon DrellYan experiment performed by the COMPASS Collaboration at CERN, and predictions for future experiments are made.
The "covariant parton model", an effective hadronic model based on the intuitive parton model concept, is extended and formalized. This allows one to compute all timereversaleven TMDs of leading and subleading twist in a systematic way. This model naturally supports the WandzuraWilczektype approximations and predicts several nontrivial relations between TMDs, many of which are supported in other model frameworks and can be tested in experiments. Applications and limitations of the model are discussed.
Meeting video link: https://zoom.us/j/96866754697?pwd=NEM1WUt3VkxhbVdQQWdacVVubHNvQT09Contact Information: Prof. P. Schweitzer
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Doctoral Dissertation Oral Defense of Saman Bastami1:30pm
9/7
Doctoral Dissertation Oral Defense of Saman Bastami
Monday, September 7th, 2020
01:30 PM  03:00 PM
Other
ZoomStudies on Hadron Structure through Transverse Momentum Dependent Parton Distribution FunctionsContact Information: saman.bastami@uconn.edu
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Graduate Student Brandon A. Clary, Department of Physics, University of Connecticut, "Exclusive Phi Production Beam Spin Asymmetry Measurements with CLAS12", PhD Dissertation Defense9:30am
8/21
Graduate Student Brandon A. Clary, Department of Physics, University of Connecticut, "Exclusive Phi Production Beam Spin Asymmetry Measurements with CLAS12", PhD Dissertation Defense
Friday, August 21st, 2020
09:30 AM  11:30 AM
Storrs Campus
Video meetingGraduate Student Brandon A. Clary, Department of Physics,
University of Connecticut
Exclusive Phi Production Beam Spin Asymmetry Measurements with CLAS12
Measurements of the beam spin asymmetry (BSA) of the exclusive electroproduction of the vector phi(1020) meson through its decay into charged Kaons have been performed. The data set used was based on the RGA run period from the recently upgraded CEBAF Large Acceptance Spectrometer (CLAS12) in Hall B at Jefferson National Lab (JLab). The run period used a 10.6 GeV longitudinally polarized electron beam and an unpolarized hydrogen target. The available statistics collected allow for detailed studies of the W, t, xB, and Q2 dependencies of the BSA amplitudes from vector phi meson production. The BSA measurements will shed light on the exchange mechanisms responsible for phi production at JLab energies. In this dissertation, a nonzero BSA is observed, which suggests a possible enhancement of pseudoscalar exchange mechanism near phi production threshold. Therefore, the nonzero BSA may be a result of the interference of the pseudoscalar exchange mechanism with a scalar one. Ultimately, information on the dominant exchange mechanism will aid in the development of a Generalized Parton Distribution (GPD) based description of these processes in the context of hard to soft transition.
Webex link: https://uconncmr.webex.com/uconncmr/j.php?MTID=m0844eee0d13477ad76f35797ae8467dbContact Information: Prof. K. Joo
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Graduate Student Daniel McNeel, Department of Physics, University of Connecticut, "Shape Coexistence in \(^{28}\)Mg: Structure of a Transitional Nucleus", PhD Dissertation Defense1:00pm
6/11
Graduate Student Daniel McNeel, Department of Physics, University of Connecticut, "Shape Coexistence in \(^{28}\)Mg: Structure of a Transitional Nucleus", PhD Dissertation Defense
Thursday, June 11th, 2020
01:00 PM  03:00 PM
Storrs Campus
Video meetingGraduate Student Daniel McNeel, Department of Physics,
University of Connecticut
Shape Coexistence in \(^{28}\)Mg: Structure of a Transitional Nucleus
The structure of nuclei outside the region of stability is an area of ongoing experimental research. Recent investigations in the region around \(^{32}\)Mg have discovered inversions in the usual ordering of shell model states. From these discoveries, theories of the evolution towards this "island of inversion" predict lowlying deformed intruder states for several nuclei in the region. One such nucleus, which exists in the region of transition between the normal and inverted hierarchies, is \(^{28}\)Mg. In this nucleus the ground state is expected to be mixed, i.e. it is a superposition of nearby \(0^+\) neutron pairing configurations. An excited intruder \(0^+\) state will have a different configuration and shape than surrounding states, a property known as shape coexistence.
Multinucleon transfer is known to be sensitive to the static deformation of a nucleus. It is also sensitive to both the amplitude and phase of configuration mixed states, and enhances transfer to those states which are similar to the ground state of the target plus two nucleons in single particle orbitals. This makes it a valuable tool to investigate the properties of \(^{28}\)Mg. The twoneutron adding reaction \(^{26}\)Mg(t,p)\(^{28}\)Mg has been used to study the properties of the ground state and excited \(0^+\) states. This experiment was carried out at Argonne National Laboratory using the HELIcal Orbit Spectrometer (HELIOS). HELIOS was designed to overcome the difficulties of measuring reactions in inverse kinematics. Experiments in inverse kinematics consist of a heavy particle, in this case \(^{26}\)Mg, incident on the light particle (\(^3\)H).
Because multinucleon transfers are more complex than single particle transfers, a calculation of the nuclear structure must guide the understanding of which configurations will be strongly populated. Shell model calculations have been used to evaluate the structure related transfer amplitudes, which were used as input into Distorted Wave Born Approximation (DWBA) calculations for the reaction. The results of this analysis are the relative contributions of different configurations to the ground state and excited \(0^+\) states, which provide a stringent test of the theoretical prediction of shape coexistence and intruder states.
Video link: https://uconncmr.webex.com/meet/dgm14002Contact Information: Prof. A. Wuosmaa
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Graduate Student Matthew Phelps, Department of Physics, University of Connecticut, "Cosmological Fluctuations in Standard and Conformal Gravity", PhD Dissertation Defense10:00am
6/2
Graduate Student Matthew Phelps, Department of Physics, University of Connecticut, "Cosmological Fluctuations in Standard and Conformal Gravity", PhD Dissertation Defense
Tuesday, June 2nd, 2020
10:00 AM  12:00 PM
Storrs Campus
Video meetingGraduate Student Matthew Phelps, Department of Physics,
University of Connecticut
Cosmological Fluctuations in Standard and Conformal Gravity
In the theory of cosmological perturbations, extensive methods of simplifying the equations of motion and eliminating nonphysical gauge modes are required in order to construct the perturbative solutions. One approach, standard within modern cosmology, is to decompose the metric perturbation into a basis of scalars, vectors, and tensors defined according to their transformation behavior under threedimensional rotations (the S.V.T. decomposition). By constructing a projector formalism to define the basis components, we show that such a decomposition is intrinsically nonlocal and necessarily incorporates spatially asymptotic boundary conditions. We continue application of the S.V.T. decomposition and solve the fluctuation equations exactly within standard cosmologies as applied to both Einstein gravity and conformal gravity, finding that in general the various S.V.T. gaugeinvariant combinations only decouple at a higherderivative level. To match the underlying transformation group of General Relativity and thus provide a manifestly covariant formalism, we introduce an alternate scalar, vector, tensor basis with components defined according to general fourdimensional coordinate transformations. In this basis, the fluctuation equations greatly simplify, where one can again decouple them into separate gaugeinvariant sectors at the higherderivative level. In the context of conformal gravity, we use similar constructions to solve the fluctuation equations exactly within any geometry that is conformal to flat and show that in a radiation era RobertsonWalker cosmology, fluctuations grow as \(t^4\).
Video Meeting URL: https://uconncmr.webex.com/meet/map14010Contact Information: Prof. P. Mannheim
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Graduate Student Lukasz Kuna, Department of Physics, University of Connecticut, "Mesoscale Studies of Nanostructured MultiFunctional Materials", PhD Dissertation Defense10:00am
4/16
Graduate Student Lukasz Kuna, Department of Physics, University of Connecticut, "Mesoscale Studies of Nanostructured MultiFunctional Materials", PhD Dissertation Defense
Thursday, April 16th, 2020
10:00 AM  12:00 PM
Storrs Campus
Video meetingGraduate Student Lukasz Kuna,
Department of Physics,
University of Connecticut
Mesoscale Studies of Nanostructured MultiFunctional Materials
In this dissertation, multiple studies centered around functional properties of materials for applications in devices and novel technologies are carried out utilizing a mesoscale modeling approach. The studies involve simulating the properties of dielectric nano/microstructures with coupled polar and elastic degrees of freedom and developing a greater understanding of their dependence on the structure size, morphology and applied external conditions. Of particular focus in this work are optical properties of electroactive materials including zero and onedimensional structures such as nanoparticles and nanowires, as well as mesoscopic functional properties of larger structures such as polycrystalline ceramics (with submicron grain sizes) and ferroelectric mesa structures. The first two research topics are focused on the band gap properties of 1D semiconductors and modeling of ferroelectric mesa structures, each study serving as an important tool in progressing the understanding of these materials for functional applications. The final topic, comprising the larger portion of the work, presents a novel approach for studying transmission in nanocrystalline ceramics based upon wavetrain theory, that is then utilized to predict light transmission in polycrystalline ceramics. In particular, simulations examining the optical properties modulation under different applied mechanical and electrical boundary conditions predict large changes to transmission, including switching from full transparency to opacity in some instances. The results presented in this dissertation highlight an extraordinary promise of functional nano and microceramics for a wide range of advanced engineering applications.Contact Information: Prof. S. Nakhmanson
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Graduate Student Cheng Tu, Department of Physics, University of Connecticut, "Study HVP and HLbL contribution to the muon g  2 using Lattice QCD ", PhD Dissertation Defense3:00pm
12/10
Graduate Student Cheng Tu, Department of Physics, University of Connecticut, "Study HVP and HLbL contribution to the muon g  2 using Lattice QCD ", PhD Dissertation Defense
Tuesday, December 10th, 2019
03:00 PM  05:00 PM
Storrs Campus
GS117Graduate Student Cheng Tu,
Department of Physics,
University of Connecticut
Study HVP and HLbL contribution to the muon g  2 using Lattice QCD
The hadronic vacuum polarization (HVP) contribution and longdistance hadronic lightbylight (HLbL) scattering contribution to the muon anomalous magnetic moment are evaluated by using lattice QCD. The HVP calculations are performed with 2 + 1 + 1 flavors of HISQ fermions at the physical pion mass from three ensembles, generated by the MILC collaboration. In the longdistance part of the HLbL contribution, we replace the QCD, fourcurrent connected Green's function from previous HLbL study with the product of two independent πγγ amplitudes, which are joined by an analytic, position space pion propagator. The calculations are performed with near physical pion mass on four different lattice ensembles, which are generated by RBC/UKQCD Collaboration.Contact Information: Prof. T. Blum
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Graduate Student Razib Obaid, Department of Physics, University of Connecticut, "Single and multiphoton induced ionization in atoms and molecules", PhD Dissertation Defense10:00am
12/5
Graduate Student Razib Obaid, Department of Physics, University of Connecticut, "Single and multiphoton induced ionization in atoms and molecules", PhD Dissertation Defense
Thursday, December 5th, 2019
10:00 AM  12:00 PM
Storrs Campus
GS117Graduate Student Razib Obaid,
Department of Physics,
University of Connecticut
Single and multiphoton induced ionization in atoms and molecules
The response of atomic and molecular species to photoionization is being studied for decades now. These atoms and molecules respond characteristically upon absorption of photons. The interesting question is: how is the energy deposited into the atoms and molecules by absorption of photons ultimately dissipated? The advent and development of Xray synchrotrons, freeelectron lasers and the strong field optical lasers keep ushering new dimensions into this question in terms of the ability of following rapid sequence of events, and, otherwise, identifying hidden relaxation mechanisms.
Through the means of resonant excitation of valence and inner shell electrons of simple atom, such as neon, and clusterlike complex molecular system such as fullerene and endohedral fullerene, we investigated their relaxation mechanisms by absorption of single and multiple photons. At excitation above their characteristic resonances, we observed hitherto unknown time delayed relaxation mechanisms in the structural change of fullerene, interatomic Coulombic decay and incomplete charge transfer processes in endohedral fullerene, and two photon absorption in neon through observation of fluorescence. Furthermore, we also investigated the fragmentation and hydrogen migration dynamics in hydrocarbons to explore the energy dissipation question for biologically relevant systems. The work is worthwhile in that it contributes to the understanding of the ultrafast intrinsic dynamics of various processes and systems relevant to physics, chemistry, and biology.Contact Information: Prof. N. Berrah
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