Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 12 of 12

Full-Text Articles in Physics

Gluon Transverse-Momentum-Dependent Distributions From Large-Momentum Effective Theory, Ruilin Zhu, Yao Ji, Jian-Hui Zhang, Shuai Zhao Jan 2023

Gluon Transverse-Momentum-Dependent Distributions From Large-Momentum Effective Theory, Ruilin Zhu, Yao Ji, Jian-Hui Zhang, Shuai Zhao

Physics Faculty Publications

We demonstrate that gluon transverse-momentum-dependent parton distribution functions (TMDPDFs) can be extracted from lattice calculations of appropriate Euclidean correlations in large-momentum effective theory (LaMET). Based on perturbative calculations of gluon unpolarized and helicity TMDPDFs, we present a matching formula connecting them and their LaMET counterparts, where the latter are renormalized in a scheme facilitating lattice calculations and converted to the MS ¯ scheme. The hard matching kernel is given up to one-loop level. We also show that the perturbative result is independent of the prescription used for the pinch-pole singularity in the relevant correlations. Our results offer a guidance for …


Machine Learning-Based Jet And Event Classification At The Electron-Ion Collider With Applications To Hadron Structure And Spin Physics, Kyle Lee, James Mulligan, Mateusz Płoskoń, Felix Ringer, Feng Yuan Jan 2023

Machine Learning-Based Jet And Event Classification At The Electron-Ion Collider With Applications To Hadron Structure And Spin Physics, Kyle Lee, James Mulligan, Mateusz Płoskoń, Felix Ringer, Feng Yuan

Physics Faculty Publications

We explore machine learning-based jet and event identification at the future Electron-Ion Collider (EIC). We study the effectiveness of machine learning-based classifiers at relatively low EIC energies, focusing on (i) identifying the flavor of the jet and (ii) identifying the underlying hard process of the event. We propose applications of our machine learning-based jet identification in the key research areas at the future EIC and current Relativistic Heavy Ion Collider program, including enhancing constraints on (transverse momentum dependent) parton distribution functions, improving experimental access to transverse spin asymmetries, studying photon structure, and quantifying the modification of hadrons and jets in …


Basics Of Factorization In A Scalar Yukawa Field Theory, F. Aslan, L. Gamberg, J.O. Gonzalez-Hernandez, T. Rainaldi, T. C. Rogers Jan 2023

Basics Of Factorization In A Scalar Yukawa Field Theory, F. Aslan, L. Gamberg, J.O. Gonzalez-Hernandez, T. Rainaldi, T. C. Rogers

Physics Faculty Publications

The factorization theorems of QCD apply equally well to most simple quantum field theories that require renormalization but where direct calculations are much more straightforward. Working with these simpler theories is convenient for stress testing the limits of the factorization program and for examining general properties of the parton density functions or other correlation functions that might be necessary for a factorized description of a process. With this view in mind, we review the steps of factorization in a real scalar Yukawa field theory for both deep inelastic scattering and semi-inclusive deep inelastic scattering cross sections. In the case of …


Neutrino-Tagged Jets At The Electron Ion Collider, Miguel Arratia, Zhong-Bo Kang, Sebouh J. Paul, Alexei Prokudin, Felix Ringer, Fanyi Zhao Jan 2023

Neutrino-Tagged Jets At The Electron Ion Collider, Miguel Arratia, Zhong-Bo Kang, Sebouh J. Paul, Alexei Prokudin, Felix Ringer, Fanyi Zhao

Physics Faculty Publications

We explore the potential of jet observables in charged-current deep inelastic scattering events at the future Electron-Ion Collider. Tagging jets with a recoiling neutrino, which can be identified by the event’s missing transverse momentum, will allow for flavor-sensitive measurements of transverse momentum dependent parton distribution functions. We present the first predictions for transverse-spin asymmetries in azimuthal neutrino-jet correlations and hadron-in-jet measurements. We study the kinematic reach and the precision of these measurements and explore their feasibility using parametrized detector simulations. We conclude that jet production in charged-current deep inelastic scattering, while challenging in terms of luminosity requirements, will complement the …


Resolution To The Problem Of Consistent Large Transverse Momentum In Tmds, J. O. Gonzalez-Hernandez, Tommaso Rainaldi, Ted Rogers Jan 2023

Resolution To The Problem Of Consistent Large Transverse Momentum In Tmds, J. O. Gonzalez-Hernandez, Tommaso Rainaldi, Ted Rogers

Physics Faculty Publications

Parametrizing TMD parton densities and fragmentation functions in ways that consistently match their large transverse-momentum behavior in standard collinear factorization has remained notoriously difficult. We show how the problem is solved in a recently introduced set of steps for combining perturbative and nonperturbative transverse momentum in TMD factorization. Called a “bottom-up” approach in a previous article, here we call it a “hadron structure oriented” (HSO) approach to emphasize its focus on preserving a connection to the TMD parton model interpretation. We show that the associated consistency constraints improve considerably the agreement between parametrizations of TMD functions and their large-kT behavior, …


Short-Distance Structure Of Unpolarized Gluon Pseudodistributions, Ian Balitsky, Wayne Morris, Anatoly Radyushkin Jan 2022

Short-Distance Structure Of Unpolarized Gluon Pseudodistributions, Ian Balitsky, Wayne Morris, Anatoly Radyushkin

Physics Faculty Publications

We present the results that form the basis for calculations of the unpolarized gluon parton distributions (PDFs) using the pseudo-PDF approach. We give the results for the most complicated box diagram both for gluon bilocal operators with arbitrary indices and for combinations of indices corresponding to three matrix elements that are most convenient to extract the twist-2 invariant amplitude. We also present detailed results for the gluon-quark transition diagram. The additional results for the box diagram and the gluon-quark contribution may be used for extractions of the gluon PDF from different matrix elements, with a possible cross-check of the results …


Renormalization And Mixing Of Staple-Shaped Wilson Line Operators On The Lattice Revisited, Yao Ji, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu Jan 2021

Renormalization And Mixing Of Staple-Shaped Wilson Line Operators On The Lattice Revisited, Yao Ji, Jian-Hui Zhang, Shuai Zhao, Ruilin Zhu

Physics Faculty Publications

Transverse-momentum-dependent parton distribution functions and wave functions (TMDPDFs/TMDWFs) can be extracted from lattice calculations of appropriate Euclidean matrix elements of staple-shaped Wilson line operators. We investigate the mixing pattern of such operators under lattice renormalization using symmetry considerations. We perform an analysis for operators with all Dirac structures, which reveals mixings that are not present in one-loop lattice perturbation theory calculations. We also present the relevant one-loop matching in a renormalization scheme that does not introduce extra nonperturbative effects at large distances, both for the TMDPDFs and for the TMDWFs. Our results have the potential to greatly facilitate numerical calculations …


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 Dec 2019

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 mπ ≃ 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 …


Exploring The Structure Of The Bound Proton With Deeply Virtual Compton Scattering, M. Hattawy, N. A. Baltzell, R. Dupré, S. Bültmann, B. Torayev, G. Gavalian, F. Hauenstein, S. E. Kuhn, M. Khachatryan, M. Mayer, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao, Clas Collaboration Jan 2019

Exploring The Structure Of The Bound Proton With Deeply Virtual Compton Scattering, M. Hattawy, N. A. Baltzell, R. Dupré, S. Bültmann, B. Torayev, G. Gavalian, F. Hauenstein, S. E. Kuhn, M. Khachatryan, M. Mayer, J. Poudel, Y. Prok, L. B. Weinstein, J. Zhang, Z. W. Zhao, Clas Collaboration

Physics Faculty Publications

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering …


Conformal Invariance Of Transverse-Momentum Dependent Parton Distributions Rapidity Evolution, Ian Balitsky, Giovanni A. Chirilli Jan 2019

Conformal Invariance Of Transverse-Momentum Dependent Parton Distributions Rapidity Evolution, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

We discuss conformal properties of TMD operators and present the result of the conformal rapidity evolution of TMD operators in the Sudakov region.


Quark Pseudodistributions At Short Distances, A. V. Radyushkin Jan 2018

Quark Pseudodistributions At Short Distances, A. V. Radyushkin

Physics Faculty Publications

We perform a one-loop study of the small-z2 3 behavior of the Ioffe-time distribution (ITD) M(ν, z2 3), the basic function that may be converted into parton pseudo- and quasi-distributions. We calculate the corrections on the operator level, so that our results may be also used for pseudo-distribution amplitudes and generalized parton pseudodistributions. We separate two sources of the z2 3-dependence at small z2 the reduced ITD given by the ratio M(ν, z2 due to ln z2 3)/M(0, z2 3. One is related to the ultraviolet (UV) singularities generated by the gauge link. Our …


Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration Jan 2015

Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration

Physics Faculty Publications

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for e p → e'p'ɣ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t, and ɸ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into …