Physical Sciences and Mathematics Commons^™

Generalized Parton Distributions And Pseudodistributions, Anatoly V. Radyushkin

Physics Faculty Publications

We derive one-loop matching relations for the Ioffe-time distributions (ITDs) related to the pion distribution amplitude (DA) and generalized parton distributions (GPDs). They are obtained from a universal expression for the one-loop correction in an operator form, and will be used in the ongoing lattice calculations of the pion DA and GPDs within the parton pseudodistributions approach.

Parton Distribution Functions From Loffe Time Pseudo-Distributions, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David Richards, Savvas Zafeiropoulos

Physics Faculty Publications

In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two volumes, with lattice spacings a = 0.127 fm and a = 0.094 fm, for a pion mass of roughly 400 MeV. With two lattice spacings and two volumes, both continuum limit and infinite volume extrapolation systematic errors of the PDF are considered. In addition to the x dependence of the PDF, we compute their first two moments and compare them with the pertinent phenomenological determinations.

Consistency Checks For Two-Body Finite-Volume Matrix Elements: Conserved Currents And Bound States, Raúl A. Briceño, Maxwell T. Hansen, Andrew W. Jackura

Physics Faculty Publications

Recently, a framework has been developed to study form factors of two-hadron states probed by an external current. The method is based on relating finite-volume matrix elements, computed using numerical lattice QCD, to the corresponding infinite-volume observables. As the formalism is complicated, it is important to provide nontrivial checks on the final results and also to explore limiting cases in which more straightforward predictions may be extracted. In this work we provide examples on both fronts. First, we show that, in the case of a conserved vector current, the formalism ensures that the finite-volume matrix element of the conserved charge …

Question 1: Electric Cars; Question 2: Chicken Poop, Larry Weinstein

Physics Faculty Publications

How much more electrical energy will the United States need to generate if everyone drives electric cars? How much chicken excrement is produced in the United States every year?. [Extracted from the article]

Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, S. Adhikari, A. Ali, M. J. Amaryan, A. Austregesilo, F. Barbosa, J. Barlow, A. Barnes, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, N. Wickramaarachchi, B. Zihlmann, The Gluex Collaboration

Physics Faculty Publications

We report on the measurement of the beam asymmetry Σ for the reactions →γp→pη and →γp→pη′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer −t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Σ_η to Σ_η′ to these models as …

Pion Valence Structure From Ioffe-Time Parton Pseudodistribution Functions, Bálint Joó, Joseph Karpie, Kostas Orinos, Anatoly V. Radyushkin, David G. Richards, Raza Sabbir Sufian, Savvas Zafeiropoulos

Physics Faculty Publications

We present a calculation of the pion valence quark distribution extracted using the formalism of reduced Ioffe-time pseudodistributions or more commonly known as pseudo-PDFs. Our calculation is carried out on two different 2 + 1 flavor QCD ensembles using the isotropic-clover fermion action, with lattice dimensions 24³ × 64 and 32³ × 96 at the lattice spacing of a = 0.127 fm, and with the quark mass equivalent to a pion mass of m_π ≃ 415 MeV. We incorporate several combinations of smeared-point and smeared-smeared pion source-sink interpolation fields in obtaining the lattice QCD matrix elements using …

Solutions For Fermi Questions, December 2019: Question 1: Electric Cars; Question 2: Chicken Poop, Larry Weinstein

Physics Faculty Publications

How much more electrical energy will the United States need to generate if everyone drives electric cars? B I Answer: i b If we all switch from gasoline-fueled to electricity-fueled cars, then we will need to generate more electrical energy. Thus, if we replace all of our gasoline-fueled cars with electricity-fueled cars, we will need to generate about 30% more electrical energy. [Extracted from the article]

Secondary Infall In The Seyfert's Sextet: A Plausible Way Out Of The Short Crossing Time Paradox, Omar López-Cruz, Héctor Javier Ibarra-Medel, Sebastián F. Sánchez, Mark Birkinshaw, Christopher Añorve, Jorge K. Barrera-Ballesteros, Jesús Falcon-Barroso, Wayne A. Barkhouse, Juan P. Torres-Papaqui

Physics Faculty Publications

We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly available data to investigate the star formation histories of galaxies in the Seyfert's Sextet (SS; HCG 79). The galaxies H79a, H79b, H79c, and H79f have low star formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories, we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turnaround, initially gas-rich galaxies crossed for the first time, consuming …

Measurement Of The Cross Sections For Inclusive Electron Scattering In The E12-14-012 Experiment At Jefferson Lab, M. Murphy, H. Dai, D. Abrams, A. M. Ankowski, B. Aljawrneh, S. Alsalmi, J. Bane, S. Barcus, O. Benhar, V. Bellini, J. Bericic, D. Biswas, A. Camsonne, J. Castellanos, J.-P. Chen, M. E. Christy, K. Craycraft, R. Cruz-Torres, D. Day, S.-C. Dusa, E. Fuchey, T. Gautam, C. Giusti, J. Gomez, C. Gu, T. Hague, J.-O. Hanson, F. Hauenstein, D. W. Higinbotham, C. E. Hyde, C. M. Jen, C. Keppel, S. Li, R. Lindgren, H. Liu, C. Mariani, R. E. Mcclellan, D. Meekins, R. Michaels, M. Mihovilovic, D. Nguyen, M. Nycz, L. Ou, B. Pandey, V. Pandey, K. Park, G. Perera, A. J. R. Puckett, S. N. Santiesteban, S. Širca, T. Su, L. Tang, Y. Tian, N. Ton, B. Wojtsekhowski, S. Wood, Z. Ye, J. Zhang, The Jefferson Lab Hall A Collaboration

Physics Faculty Publications

The E12-14-012 experiment performed at Jefferson Lab Hall A has collected inclusive electron-scattering data for different targets at the kinematics corresponding to beam energy 2.222 GeV and scattering angle 15.54°. Here we present a comprehensive analysis of the collected data and compare the double-differential cross sections for inclusive scattering of electrons, extracted using solid targets (aluminum, carbon, and titanium) and a closed argon-gas cell. The data extend over broad range of energy transfer, where quasielastic interaction, Δ-resonance excitation, and inelastic scattering yield contributions to the cross section. The double-differential cross sections are reported with high precision (∼3%) for all targets …

Collinear Factorization In Wide-Angle Hadron Pair Production In E + E − Annihilation, E. Moffat, T. C. Rogers, N. Sato, A. Signori

Physics Faculty Publications

We compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of e+ e− annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with …

Validating The Water Vapor Variance Similarity Relationship In The Interfacial Layer Using Observations And Large-Eddy Simulations, M. K. Osman, D. D. Turner, Thijs Heus, V. Wulfmeyer

Physics Faculty Publications

In previous work, the similarity relationship for the water vapor variance in the interfacial layer (IL) at the top of the convective boundary layer (CBL) was proposed to be proportional to the convective velocity scale and the gradients of the water vapor mixing ratio and the Brunt‐Vaisala frequency in the entrainment zone. In the presence of wind shear in the IL, the similarity relationship was hypothesized to also include a dependence on the gradient Richardson number. Simultaneous measurements of the surface buoyancy flux, wind‐shear profiles from a radar wind profiler, water vapor mixing ratio and temperature measurements and their gradients …

Aerosol Particle And Black Carbon Emission Factors Of Vehicular Fleet In Manila, Philippines, Leizel Madueño, Simonas Kecorius, Wolfram Birmili, Thomas Müller, James Bernard Simpas, Edgar Vallar, Maria Cecilia Galvez, Mylene Cayetano, Alfred Wiedensohler

Physics Faculty Publications

Poor air quality has been identified as one of the main risks to human health, especially in developing regions, where the information on physical chemical properties of air pollutants is lacking. To bridge this gap, we conducted an intensive measurement campaign in Manila, Philippines to determine the emission factors (EFs) of particle number (PN) and equivalent black carbon (BC). The focus was on public utility jeepneys (PUJ), equipped with old technology diesel engines, widely used for public transportation. The EFs were determined by aerosol physical measurements, fleet information, and modeled dilution using the Operational Street Pollution Model (OSPM). The results …

Complete Matching For Quasidistribution Functions In Large Momentum Effective Theory, Wei Wang, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu

Physics Faculty Publications

We complete the procedure of extracting parton distribution functions (PDFs) using large momentum effective theory at leading power accuracy in the hadron momentum. We derive a general factorization formula for the quasi-PDFs in the presence of mixing and give the corresponding hard matching kernel at O(α_s), both for the unpolarized and for the polarized quark and gluon quasi-PDFs. Our calculation is performed in a regularization-independent momentum subtraction scheme. The results allow us to match the nonperturbatively renormalized quasi-PDFs to normal PDFs in the presence of mixing and therefore can be used to extract flavor-singlet quark PDFs as well …

Numerical Exploration Of Three Relativistic Particles In A Finite Volume Including Two-Particle Resonances And Bound States, Fernando Romero-López, Stephen R. Sharpe, Tyler D. Blanton, Raúl A. Briceño, Maxwell T. Hansen

Physics Faculty Publications

In this work, we use an extension of the quantization condition, given in ref. [1], to numerically explore the finite-volume spectrum of three relativistic particles, in the case that two-particle subsets are either resonant or bound. The original form of the relativistic three-particle quantization condition was derived under a technical assumption on the two-particle K matrix that required the absence of two-particle bound states or narrow two-particle resonances. Here we describe how this restriction can be lifted in a simple way using the freedom in the definition of the K-matrix-like quantity that enters the quantization condition. With this in hand, …

Comparing Proton Momentum Distributions In A = 2 And 3 Nuclei Via 2H 3H And 3He (E,E′P) Measurements, R. Cruz-Torres, F. Hauenstein, A. Schmidt, D. Nguyen, D. Abrams, H. Albataineh, S. Alsalmi, D. Androic, K. Aniol, W. Armstrong, J. Arrington, H. Atac, D. Bulumulla, C. E. Hyde, V. Khachatryan, M. N.H. Rashad, L. B. Weinstein, Z. Y. Ye, J. Zhang, Jefferson Lab Hall A Tritium Collaboration

Physics Faculty Publications

We report the first measurement of the (e, e' p) reaction cross-section ratios for Helium-3 (³He), Tritium (³H), and Deuterium (d). The measurement covered a missing momentum range of 40 ≤ p_miss ≤ 550 MeV/c, at large momentum transfer ({Q²} ≈ 1.9 (GeV/c)²) and x_B > 1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with planewave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for ³He/d and ³H/d extend to just above the typical …

Nuclear Theory And Event Generators For Charge-Changing Neutrino Reactions, J. W. Van Orden, T. W. Donnelly

Physics Faculty Publications

Semi-inclusive CCν cross sections based on factorized cross sections are studied for a selection of spectral function models with the objective of facilitating the choice of models for use as input into event generators. The basic formalism for such cross sections is presented along with an introduction to constructing spectral functions for simple models based on the independent-particle shell model, the relativistic Fermi gas model (RFG), and a local density approximation (LDA) based on the RFG. Spectral functions for these models are shown for 16O along with a more sophisticated model which includes nucleon-nucleon interactions [AlvarezRuso et al., Prog. …

Laser Irradiation Of Mung Bean (Vigna Radiata L.) At Two Wavelengths For Enhanced Seedling Development, Rayno Vic B. Janayon, Raphael A. Guerrero

Physics Faculty Publications

Two laser sources operating at wavelengths of 632.8 nm (He-Ne) and 488 nm (Ar+

) are used in examining the effects of coherent, low-power, continuous wave exposure on the development of Vigna radiata L. Presowing laser irradiation of seeds leads to an improvement of mung bean seedling characteristics, with increased values of hypocotyl length (an increase of up to 22.5%), root length (an increase of up to 28.8%), and seedling mass (a maximum increase of 29.2%). Measured parameters between seedlings from laser-irradiated seeds and from control samples are statistically different at a level of significance equal to 0.05. For both …

Muon Capture In Nuclei: An Ab Initio Approach Based On Green's Function Monte Carlo Methods, A. Lovato, N. Rocco, Rocco Schiavilla

Physics Faculty Publications

An ab initio Green’s function Monte Carlo (GFMC) method is introduced for calculating total rates of muon weak capture in light nuclei with mass number A ≤ 12. As a first application of the method, we perform a calculation of the rate in ³H and ⁴He in a dynamical framework based on realistic two- and three-nucleon interactions and realistic nuclear charge-changing weak currents. The currents include one- and two-body terms induced by π-and ρ-meson exchange, and N-to-Δ excitation, and are constrained to reproduce the empirical value of the Gamow-Teller matrix element in tritium. We investigate the sensitivity of …

Unitarity Of The Infinite-Volume Three-Particle Scattering Amplitude Arising From A Finite-Volume Formalism, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe, Adam P. Szczepaniak

Physics Faculty Publications

Hansen and Sharpe [Phys. Rev. D 92, 114509 (2015)] derived a relation between the scattering amplitude of three identical bosons,M₃, and a real function referred to as the divergence-free K matrix and denoted K_df;3. The result arose in the context of a relation between finite-volume energies and K_df;3, derived to all orders in the perturbative expansion of a generic low-energy effective field theory. In this work we set aside the role of the finite volume and focus on the infinite-volume relation between K_df;3 and M₃. We show that, for any …

Factorization Of Jet Cross Sections In Heavy-Ion Collisions, Jian-Wei Qiu, Felix Ringer, Nobuo Sato, Pia Zurita

Physics Faculty Publications

We propose a new phenomenological approach to establish QCD factorization of jet cross sections in the heavy-ion environment. Starting from a factorization formalism in proton-proton collisions, we introduce medium modified jet functions to capture the leading interaction of jets with the hot and dense QCD medium. A global analysis using a Monte Carlo sampling approach is performed in order to reliably determine the new jet functions from the nuclear modification factor of inclusive jets at the LHC. We find that gluon jets are significantly more suppressed due to the presence of the medium than quark jets. In addition, we observe …

Power-Law Scaling In The Internal Variability Of Cumulus Cloud Size Distributions Due To Subsampling And Spatial Organization, R. A. J. Neggers, P. J. Griewank, Thijs Heus

Physics Faculty Publications

In this study, the spatial structure of cumulus cloud populations is investigated using three-dimensional snapshots from large-domain LES experiments. The aim is to understand and quantify the internal variability in cloud size distributions due to subsampling effects and spatial organization. A set of idealized shallow cumulus cases is selected with varying degrees of spatial organization, including a slowly organizing marine precipitating case and five more quickly organizing diurnal cases over land. A subdomain analysis is applied, yielding cloud number distributions at sample sizes ranging from severely undersampled to nearly complete. A strong power-law scaling is found in the relation between …

Luminosity-Luminosity Correlations In Flux-Limited Multiwavelength Data, J. Singal, V. Petrosian, J. Haider, S. Malik

Physics Faculty Publications

We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with …

Silicene-Like Domains On Irsi3 Crystallites, Dylan Nicholls, Fnu Fatima, Deniz Cakir, Nuri Oncel

Physics Faculty Publications

Recently, silicene, the graphene equivalent of silicon, has attracted a lot of attention due to its compatibility with Si-based electronics. So far, silicene has been epitaxy grown on various crystalline surfaces such as Ag(110), Ag(111), Ir(111), ZrB2(0001) and Au(110) substrates. Here, we present a new method to grow silicene via high temperature surface reconstruction of hexagonal IrSi3 nanocrystals. The h-IrSi3 nanocrystals are formed by annealing thin Ir layers on Si(111) surface. A detailed analysis of the STM images shows the formation of silicene like domains on the surface of some of the IrSi3 crystallites. We studied both morphology and electronic …

Taller In The Saddle: Constraining Cmb Physics Using Saddle Points, Jow L. Dylan, Dagoberto Contreras, Douglas Scott, Emory F. Bunn

Physics Faculty Publications

The statistics of extremal points in the cosmic microwave background (CMB) temperature (hot and cold spots) have been well explored in the literature, and have been used to constrain models of the early Universe. Here, we extend the study of critical points in the CMB to the set that remains after removing extrema, namely the saddle points. We perform stacks of temperature and polarization about temperature saddle points in simulations of the CMB, as well as in data from the Plancksatellite. We then compute the theoretical profile of saddle-point stacks, given the underlying power spectra of the CMB. As an …

Studying The Interface Between Croconic Acid Thin Films And Substrates Using A Slow Positron Beam, Dean Peterson, Jiandang Liu, Jonas Etzweiler, Gabriel Sontoyo, Sara J. Callori, Kimberley R. Cousins, Timothy Usher, Renwu Zhang

Physics Faculty Publications

Croconic acid (CA) is the first organic ferroelectric with a spontaneous polarity in bulk samples comparable to its inorganic counterparts. As a natural extension of study, ultrathin CA films (∼nm scale) were investigated to reveal ferroelectric effects in films on different substrates for their fundamental and industrial significance. However, the void defect at the interface between the film and substrate is presumed to interfere with surface effects. In this work, a non-invasive technique, a slow positron beam, coupled with Doppler broadening energy spectroscopy (DBES), is applied to study the void defects within the interfacial layer between CA films and Si …

Waveband Luminosity Correlations In Flux-Limited Multiwavelength Data, Jack Singal, V. Petrosian, Sami Malik, Jibran Haider

Physics Faculty Publications

We explore the general question of correlations among different waveband luminosities in a flux-limited multiband observational data set. Such correlations, often observed for astronomical sources, may be either intrinsic or induced by the redshift evolution of the luminosities and the data truncation due to the flux limits. We first address this question analytically. We then use simulated flux-limited data with three different known intrinsic luminosity correlations and prescribed luminosity functions and evolution similar to the ones expected for quasars. We explore how the intrinsic nature of luminosity correlations can be deduced, including exploring the efficacy of partial correlation analysis with …

Testing For Directionality In The Planck Polarization And Lensing Data, Majd Ghrear, Emory F. Bunn, Dagoberto Contreras, Douglas Scott

Physics Faculty Publications

In order to better analyse the polarization of the cosmic microwave background (CMB), which is dominated by emission from our Galaxy, we need tools that can detect residual foregrounds in cleaned CMB maps. Galactic foregrounds introduce statistical anisotropy and directionality to the polarization pseudo-vectors of the CMB, which can be investigated by using the D statistic of Bunn and Scott. This statistic is rapidly computable and capable of investigating a broad range of data products for directionality. We demonstrate the application of this statistic to detecting foregrounds in polarization maps by analysing the uncleaned Planck 2018 frequency maps. For the …

Multi-Band Optical And Near-Infrared Properties Of Faint Submillimeter Galaxies With Serendipitous Alma Detections, Pallavi Patil, Kristina Nyland, Mark Lacy, Duncan Farrah, José Afonso, Wayne A. Barkhouse, Jason Surace

Physics Faculty Publications

We present a catalog of 26 faint submillimeter galaxies (SMGs) in the XMM Large Scale Structure (XMM-LSS) field identified by cross-matching serendipitously detected sources in archival pre–Atacama Large Millimeter Array (ALMA) band 6 and 7 data with multiband near-infrared (NIR) and optical data from the Spitzer Extragalactic Representative Volume Survey, the VISTA Deep Extragalactic Survey, the Canada–France–Hawaii Telescope Legacy Large Survey, and the Hyper Suprime-Cam Subaru Strategic Program. Of the 26 SMGs in our sample, 15 are identified here for the first time. The majority of the sources in our sample (16/26) have faint submillimeter fluxes (0.1 mJy < S 1mm …

First Results On Nucleon Resonance Photocouplings From The Γp → Π+Π−P Reaction, E. Golovatch, V. D. Burkert, D. S. Carman, R. W. Gothe, K. Hicks, M. J. Amaryan, M. Khachatryan, A. Klein, Y. Prok, Clas Collaboration

Physics Faculty Publications

We report the first experimental measurements of the nine 1-fold differential cross sections for the γ p → π⁺π⁻p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV < W < 2.0 GeV. For the first time the photocouplings of all prominent nucleon resonances in this mass range have been extracted from this exclusive channel. Photoproduction of two charged pions is of particular importance for the evaluation of the photocouplings for the Δ (1620)1/2⁻, Δ (1700)3/2⁻, N(1720)3/2⁺, and Δ (1905)5/2⁺ resonances, which have dominant decays into the π π N final states rather than the more extensively studied single meson decay channels.

Drift Chamber Calibration And Particle Identification In The P-349 Experiment, D. Alfs, A. Asaturyan, M. Carmignotto, M. Diermaier, W. Eyrich, B. Glowacz, D. Grzonka, Florian Hauenstein, T. Horn, K. Kilian, D. Lersch, S. Malbrunot-Ettenauer, A. Mkrtchyan, H. Mkrtchyan, P. Moskal, P. Nadel-Turonski, W. Oelert, J. Ritman, T. Sefzick, V. Tadevosyan, E. Widmann, M. Wolke, S. Zhamkochyan, M. Zieliński, A. Zink, J. Zmeskal

Physics Faculty Publications

The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.