Physics Commons^™

Neutron Stars With Baryon Number Violation, Probing Dark Sectors, Jeffrey M. Berryman, Susan Gardner, Mohammadreza Zakeri

Physics and Astronomy Faculty Publications

The neutron lifetime anomaly has been used to motivate the introduction of new physics with hidden-sector particles coupled to baryon number, and on which neutron stars provide powerful constraints. Although the neutron lifetime anomaly may eventually prove to be of mundane origin, we use it as motivation for a broader review of the ways that baryon number violation, be it real or apparent, and dark sectors can intertwine and how neutron star observables, both present and future, can constrain them.

Atomistic Engineering Of Phonons In Functional Oxide Heterostructures, Seung Gyo Jeong, Ambrose Seo, Woo Seok Choi

Physics and Astronomy Faculty Publications

Engineering of phonons, that is, collective lattice vibrations in crystals, is essential for manipulating physical properties of materials such as thermal transport, electron-phonon interaction, confinement of lattice vibration, and optical polarization. Most approaches to phonon-engineering have been largely limited to the high-quality heterostructures of III–V compound semiconductors. Yet, artificial engineering of phonons in a variety of materials with functional properties, such as complex oxides, will yield unprecedented applications of coherent tunable phonons in future quantum acoustic devices. In this study, artificial engineering of phonons in the atomic-scale SrRuO₃/SrTiO₃ superlattices is demonstrated, wherein tunable phonon modes are observed …

Comments On The Holographic Description Of Narain Theories, Anatoly Dymarsky, Alfred D. Shapere

Physics and Astronomy Faculty Publications

We discuss the holographic description of Narain U(1)^c × U(1)^c conformal field theories, and their potential similarity to conventional weakly coupled gravitational theories in the bulk, in the sense that the effective IR bulk description includes “U(1) gravity” amended with additional light degrees of freedom. Starting from this picture, we formulate the hypothesis that in the large central charge limit the density of states of any Narain theory is bounded by below by the density of states of U(1) gravity. This immediately implies that the maximal value of the spectral gap for primary fields is ∆₁ = …

The Measure Aspect Of Quantum Uncertainty, Of Entanglement, And The Associated Entropies, Ivan Horváth

Physics and Astronomy Faculty Publications

Indeterminacy associated with the probing of a quantum state is commonly expressed through spectral distances (metric) featured in the outcomes of repeated experiments. Here, we express it as an effective amount (measure) of distinct outcomes instead. The resulting μ-uncertainties are described by the effective number theory whose central result, the existence of a minimal amount, leads to a well-defined notion of intrinsic irremovable uncertainty. We derive μ-uncertainty formulas for arbitrary set of commuting operators, including the cases with continuous spectra. The associated entropy-like characteristics, the μ-entropies, convey how many degrees of freedom are effectively involved in a given …

Awegnn: Auto-Parametrized Weighted Element-Specific Graph Neural Networks For Molecules., Timothy Szocinski, Duc Duy Nguyen, Guo-Wei Wei

Mathematics Faculty Publications

While automated feature extraction has had tremendous success in many deep learning algorithms for image analysis and natural language processing, it does not work well for data involving complex internal structures, such as molecules. Data representations via advanced mathematics, including algebraic topology, differential geometry, and graph theory, have demonstrated superiority in a variety of biomolecular applications, however, their performance is often dependent on manual parametrization. This work introduces the auto-parametrized weighted element-specific graph neural network, dubbed AweGNN, to overcome the obstacle of this tedious parametrization process while also being a suitable technique for automated feature extraction on these internally complex …

The Design Of The N2edm Experiment, N. J. Ayres, G. Ban, L. Bienstman, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, E. Chanel, J. Chen, P.-J. Chiu, B. Clément, C. B. Crawford, M. Daum, B. Dechenaux, C. B. Doorenbos, S. Emmenegger, L. Ferraris-Bouchez, M. Fertl, A. Fratangelo, P. Flaux

Physics and Astronomy Faculty Publications

We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.

Theoretical Study On Η′ → Π+Π−Π+(0)Π−(0), Ehsan Jafari, Bing An Li

Physics and Astronomy Faculty Publications

The η′ meson is associated with the U(1) anomaly. In this paper, a successful effective chiral theory of mesons has been applied to study the anomalous decays of η′ → π⁺π⁻π⁺⁽⁰⁾π⁻⁽⁰⁾. Contribution of triangle and box diagrams is calculated, which indicates that the box anomaly has a significant contribution to the decay amplitudes.

[Please download the article to see the rest of the abstract.]

Gauge Invariant Target Space Entanglement In D-Brane Holography, Sumit R. Das, Anurag Kaushal, Sinong Liu, Gautam Mandal, Sandip P. Trivedi

Physics and Astronomy Faculty Publications

It has been suggested in arXiv:2004.00613 that in Dp-brane holography, entanglement in the target space of the D-brane Yang-Mills theory provides a precise notion of bulk entanglement in the gravity dual. We expand on this discussion by providing a gauge invariant characterization of operator sub-algebras corresponding to such entanglement. This is achieved by finding a projection operator which imposes a constraint characterizing the target space region of interest. By considering probe branes in the Coloumb branch we provide motivation for why the operator sub-algebras we consider are appropriate for describing a class of measurements carried out with low-energy probes in …

Direct Detection Of 5-Mev Protons By Flexible Organic Thin-Film Devices, Ilaria Fratelli, Andrea Ciavatti, Enrico Zanazzi, Laura Basiricò, Massimo Chiari, Laura Fabbri, John E. Anthony, Alberto Quaranta, Beatrice Fraboni

Chemistry Faculty Publications

The direct detection of 5-MeV protons by flexible organic detectors based on thin films is here demonstrated. The organic devices act as a solid-state detector, in which the energy released by the protons within the active layer of the sensor is converted into an electrical current. These sensors can quantitatively and reliably measure the dose of protons impinging on the sensor both in real time and in integration mode. This study shows how to detect and exploit the energy absorbed both by the organic semiconducting layer and by the plastic substrate, allowing to extrapolate information on the present and past …

Quantum Stabilizer Codes, Lattices, And Cfts, Anatoly Dymarsky, Alfred D. Shapere

Physics and Astronomy Faculty Publications

There is a rich connection between classical error-correcting codes, Euclidean lattices, and chiral conformal field theories. Here we show that quantum error-correcting codes, those of the stabilizer type, are related to Lorentzian lattices and non-chiral CFTs. More specifically, real self-dual stabilizer codes can be associated with even self-dual Lorentzian lattices, and thus define Narain CFTs. We dub the resulting theories code CFTs and study their properties. T-duality transformations of a code CFT, at the level of the underlying code, reduce to code equivalences. By means of such equivalences, any stabilizer code can be reduced to a graph code. We can …

Magnetic Normal Mode Calculations In Big Systems: A Highly Scalable Dynamical Matrix Approach Applied To A Fibonacci-Distorted Artificial Spin Ice, Loris Giovannini, Barry W. Farmer, Justin S. Woods, Ali Frotanpour, Lance E. De Long, Federico Montoncello

Physics and Astronomy Faculty Publications

We present a new formulation of the dynamical matrix method for computing the magnetic normal modes of a large system, resulting in a highly scalable approach. The motion equation, which takes into account external field, dipolar and ferromagnetic exchange interactions, is rewritten in the form of a generalized eigenvalue problem without any additional approximation. For its numerical implementation several solvers have been explored, along with preconditioning methods. This reformulation was conceived to extend the study of magnetization dynamics to a broader class of finer-mesh systems, such as three-dimensional, irregular or defective structures, which in recent times raised the interest among …

Flavor-Dependent Radiative Corrections In Coherent Elastic Neutrino-Nucleus Scattering, Oleksandr Tomalak, Pedro Machado, Vishvas Pandey, Ryan Plestid

Physics and Astronomy Faculty Publications

We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. ⁴⁰Ar and ²⁸Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light masses. …

Ir Finite S-Matrix By Gauge Invariant Dressed States, Hayato Hirai, Sotaro Sugishita

Physics and Astronomy Faculty Publications

Dressed states were proposed to define the infrared (IR) finite S-matrix in QED or gravity. We show that the original Kulish-Faddeev dressed states are not enough to cure the IR divergences. To illustrate this problem, we consider QED with background currents (Wilson lines). This theory is exactly solvable but shares the same IR problems as the full QED. We show that naive asymptotic states lead to IR divergences in the S-matrix and are also inconsistent with the asymptotic symmetry, even if we add the original Kulish-Faddeev dressing operators. We then propose new dressed states which are consistent with …

Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

To evaluate the effects of spallation on ablative material, it is necessary to evaluate the mass loss. To do so, a Lagrangian particle trajectory code is used to reconstruct trajectories that match the experimental data for all kinematic parameters. The results from spallation experiments conducted at the NASA HYMETS facility over a wedge sample were used. A data-driven adaptive methodology was used to adapts the ejection parameters until the numerical trajectory matches the experimental data. The preliminary reconstruction results show that the size of the particles seemed to be correlated with the location of the ejection event. The size of …

Near Conformal Perturbation Theory In Syk Type Models, Sumit R. Das, Animik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

We present a systematic procedure to extract the dynamics of the low energy soft mode in SYK type models with a single energy scale J and emergent reparametrization symmetry in the IR. This is given in the framework of the perturbative scheme of arXiv:1608.07567 based on a specific (off-shell) breaking of conformal invariance in the UV, adjusted to yield the exact large-N saddle point. While this breaking term formally vanishes on-shell, it has a non-trivial effect on correlation functions and the effective action. In particular, it leads to the Schwarzian action with a specific coupling to bi-local matter. The …

Cft Unitarity And The Ads Cutkosky Rules, David Meltzer, Allic Sivaramakrishnan

Physics and Astronomy Faculty Publications

We derive the Cutkosky rules for conformal field theories (CFTs) at weak and strong coupling. These rules give a simple, diagrammatic method to compute the double-commutator that appears in the Lorentzian inversion formula. We first revisit weakly-coupled CFTs in flat space, where the cuts are performed on Feynman diagrams. We then generalize these rules to strongly-coupled holographic CFTs, where the cuts are performed on the Witten diagrams of the dual theory. In both cases, Cutkosky rules factorize loop diagrams into on-shell sub-diagrams and generalize the standard S-matrix cutting rules. These rules are naturally formulated and derived in Lorentzian momentum space, …

Effective Number Theory: Counting The Identities Of A Quantum State, Ivan Horváth, Robert Mendris

Anesthesiology Faculty Publications

Quantum physics frequently involves a need to count the states, subspaces, measurement outcomes, and other elements of quantum dynamics. However, with quantum mechanics assigning probabilities to such objects, it is often desirable to work with the notion of a “total” that takes into account their varied relevance. For example, such an effective count of position states available to a lattice electron could characterize its localization properties. Similarly, the effective total of outcomes in the measurement step of a quantum computation relates to the efficiency of the quantum algorithm. Despite a broad need for effective counting, a well-founded prescription has not …

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …

A Hybrid Achromatic Metalens, Fatih Balli, Mansoor A. Sultan, Sarah K. Lami, J. Todd Hastings

Electrical and Computer Engineering Faculty Publications

Metalenses, ultra-thin optical elements that focus light using subwavelength structures, have been the subject of a number of recent investigations. Compared to their refractive counterparts, metalenses offer reduced size and weight, and new functionality such as polarization control. However, metalenses that correct chromatic aberration also suffer from markedly reduced focusing efficiency. Here we introduce a Hybrid Achromatic Metalens (HAML) that overcomes this trade-off and offers improved focusing efficiency over a broad wavelength range from 1000-1800 nm. HAMLs can be designed by combining recursive ray-tracing and simulated phase libraries rather than computationally intensive global search algorithms. Moreover, HAMLs can be fabricated …

High-Temperature Optical Properties Of Indium Tin Oxide Thin-Films, Jiwoong Kim, Sujan Shrestha, Maryam Souri, John G. Connell, Sungkyun Park, Ambrose Seo

Physics and Astronomy Faculty Publications

Indium tin oxide (ITO) is one of the most widely used transparent conductors in optoelectronic device applications. We investigated the optical properties of ITO thin films at high temperatures up to 800 °C using spectroscopic ellipsometry. As temperature increases, amorphous ITO thin films undergo a phase transition at ~ 200 °C and develop polycrystalline phases with increased optical gap energies. The optical gap energies of both polycrystalline and epitaxial ITO thin films decrease with increasing temperature due to electron-phonon interactions. Depending on the background oxygen partial pressure, however, we observed that the optical gap energies exhibit reversible changes, implying that …

Effect Of Thomas Rotation On The Lorentz Transformation Of Electromagnetic Fields, Lakshya Malhotra, Robert Golub, Eva Kraegeloh, Nima Nouri, Bradley R. Plaster

Physics and Astronomy Faculty Publications

A relativistic particle undergoing successive boosts which are non collinear will experience a rotation of its coordinate axes with respect to the boosted frame. This rotation of coordinate axes is caused by a relativistic phenomenon called Thomas Rotation. We assess the importance of Thomas rotation in the calculation of physical quantities like electromagnetic fields in the relativistic regime. We calculate the electromagnetic field tensor for general three dimensional successive boosts in the particle's rest frame as well as the laboratory frame. We then compare the electromagnetic field tensors obtained by a direct boost [Formula: see text] and successive boosts [Formula: …

Analysis Of Magnetization Directions Of Lunar Swirls, Lillie Cole

Lewis Honors College Capstone Collection

Lunar Swirls are high albedo markings on the Moon that exist in the regions of some crustal magnetic anomalies. The precise mechanism responsible for the swirl features is unknown but a prevailing theory is solar wind standoff, where the magnetic field from subsurface magnetized sources protects the lunar surface from solar wind ions, leading to their lesser maturation and brighter appearance. If this theory is correct, the magnetic field of the anomalies should heavily influence the appearance of the swirl. To better understand the cause of swirls, the magnetization direction of the source creating the field is analyzed. This study …

A Csi Detector Array For The Ndtgamma Test Measurement, Diana V. Sahibnazarova

Oswald Research and Creativity Competition

No abstract provided.

Hyperfine Splitting In Muonium: Accuracy Of The Theoretical Prediction, Michael I. Eides

Physics and Astronomy Faculty Publications

In the last twenty years, the theory of hyperfine splitting in muonium developed without any experimental input. Finally, this situation is changing and a new experiment on measuring hyperfine splitting in muonium is now in progress at J-PARC. The goal of the MuSEUM experiment is to improve by an order of magnitude experimental accuracy of the hyperfine splitting and muon-electron mass ratio. Uncertainty of the theoretical prediction for hyperfine splitting will be crucial for comparison between the forthcoming experimental data and the theory in search of a possible new physics. In the current literature estimates of the error bars of …

Dressed States From Gauge Invariance, Hayato Hirai, Sotaro Sugishita

Physics and Astronomy Faculty Publications

The dressed state formalism enables us to define the infrared finite S-matrix for QED. In the formalism, asymptotic charged states are dressed by clouds of photons. The dressed asymptotic states are originally obtained by solving the dynamics of the asymptotic Hamiltonian in the far past or future region. However, there was an argument that the obtained dressed states are not gauge invariant. We resolve the problem by imposing a correct gauge invariant condition. We show that the dressed states can be obtained just by requiring the gauge invariance of asymptotic states. In other words, Gauss’s law naturally leads to …

Dual Superconformal Symmetry Of N = 2 Chern-Simons Theory With Fundamental Matter At Large N, Karthik Inbasekar, Sachin Jain, Sucheta Majumdar, Pranjal Nayak, Turmoli Neogi, Ritam Sinha, Tarun Sharma, V. Umesh

Physics and Astronomy Faculty Publications

Dual conformal symmetry and Yangian symmetry are symmetries of amplitudes that have aided the study of scattering amplitudes in highly supersymmetric theories like N = 4 SYM and ABJM. However, in general such symmetries are absent from the theories with lesser or no supersymmetry. In this paper, we show that the tree level 2 → 2 scattering amplitude in the 3d N = 2 Chern-Simons theory coupled to a fundamental chiral multiplet is dual superconformal invariant. In the ’t Hooft large N limit, the 2 → 2 scattering amplitude in this theory has been shown to be tree-level exact in …

Charting The Space Of 3d Cfts With A Continuous Global Symmetry, Anatoly Dymarsky, Joao Penedones, Emilio Trevisani, Alessandro Vichi

Physics and Astronomy Faculty Publications

We study correlation functions of a conserved spin-1 current J_μ in three dimensional Conformal Field Theories (CFTs). We investigate the constraints imposed by permutation symmetry and current conservation on the form of three point functions ⟨J_μJ_νO_Δ,ℓ⟩ and the four point function ⟨J_μJ_νJ_ρJ_σ⟩ and identify the minimal set of independent crossing symmetry conditions. We obtain a recurrence relation for conformal blocks for generic spin-1 operators in three dimensions. In the process, we improve several technical points, facilitating the use of recurrence relations. By applying …

Exact Generalized Partition Function Of 2d Cfts At Large Central Charge, Anatoly Dymarsky, Kirill Pavlenko

Physics and Astronomy Faculty Publications

We discuss generalized partition function of 2d CFTs on thermal cylinder decorated by higher qKdV charges. We propose that in the large central charge limit qKdV charges factorize such that generalized partition function can be rewritten in terms of auxiliary non-interacting bosons. The explicit expression for the generalized free energy is readily available in terms of the boson spectrum, which can be deduced from the conventional thermal expectation values of qKdV charges. In other words, the picture of the auxiliary non-interacting bosons allows extending thermal one-point functions to the full non-perturbative generalized partition function. We verify this conjecture for the …

Intercomparison Of Small Unmanned Aircraft System (Suas) Measurements For Atmospheric Science During The Lapse-Rate Campaign, Lindsay Barbieri, Stephan T. Kral, Sean C. C. Bailey, Amy E. Frazier, Jamey D. Jacob, Joachim Reuder, David Brus, Phillip B. Chilson, Christopher Crick, Carrick Detweiler, Abhiram Doddi, Jack Elston, Hosein Foroutan, Javier González-Rocha, Brian R. Greene, Marcelo I. Guzman, Adam L. Houston, Ashraful Islam, Osku Kemppinen, Dale Lawrence, Elizabeth A. Pillar-Little, Shane D. Ross, Michael P. Sama, David G. Schmale Iii, Travis J. Schuyler, Ajay Shankar, Suzanne W. Smith, Sean Waugh, Cory Dixon, Steve Borenstein, Gijs De Boer

Chemistry Faculty Publications

Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and …

Rate Of Cluster Decomposition Via Fermat-Steiner Point, Alexander Avdoshkin, Lev Astrakhantsev, Anatoly Dymarsky, Michael Smolkin

Physics and Astronomy Faculty Publications

In quantum field theory with a mass gap correlation function between two spatially separated operators decays exponentially with the distance. This fundamental result immediately implies an exponential suppression of all higher point correlation functions, but the predicted exponent is not optimal. We argue that in a general quantum field theory the optimal suppression of a three-point function is determined by total distance from the operator locations to the Fermat-Steiner point. Similarly, for the higher point functions we conjecture the optimal exponent is determined by the solution of the Euclidean Steiner tree problem. We discuss how our results constrain operator spreading …