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Physics Faculty Publications

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Articles 1 - 30 of 376

Full-Text Articles in Elementary Particles and Fields and String Theory

Studying 𝜋⁺𝜋⁻ Photoproduction Beyond Pomeron Exchange, Łukasz Bibrzycki, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alex Akridge, César Fernández-Ramirez, Gloria Montaña, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Daniel Winney, Adam P. Szczepaniak Jan 2025

Studying 𝜋⁺𝜋⁻ Photoproduction Beyond Pomeron Exchange, Łukasz Bibrzycki, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alex Akridge, César Fernández-Ramirez, Gloria Montaña, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Daniel Winney, Adam P. Szczepaniak

Physics Faculty Publications

Forward photoproduction of 𝜋⁺𝜋⁻ pairs with invariant mass of the order of 𝑚𝜌 ∼770  MeV is traditionally attributed to Pomeron exchange. Based on a detailed analysis of the CEBAF Large Acceptance Spectrometer photoproduction data collected at photon energies below 4 GeV, it is shown from a study of the angular moments that the dynamics of two-pion photoproduction for |𝑡|≳0.5  GeV² cannot be explained by Pomeron exchange alone. This motivates the development of a new theoretical model of two-pion photoproduction which incorporates both two-pion and pion-nucleon resonant contributions. After fitting free parameters, the model provides an excellent description of the low …

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Nonperturbative Aspects Of The Electromagnetic Pion Form Factor At High Energies, K. Quirion, C. Fernandez-Ramirez, V. Mathieu, G. Montaña, R. J. Perry, A. Pilloni, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak, D. Winney Jan 2025

Nonperturbative Aspects Of The Electromagnetic Pion Form Factor At High Energies, K. Quirion, C. Fernandez-Ramirez, V. Mathieu, G. Montaña, R. J. Perry, A. Pilloni, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak, D. Winney

Physics Faculty Publications

The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct a model that simultaneously accounts for the pion wave function, gluonic exchanges, and quark Reggeization. In particular, we find that quark Reggeization can be investigated at high energies by studying scaling violation of the form factor.

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Nonlocal Nucleon Matrix Elements In The Rest Frame, Joe Karpie, Christopher Monahan, Anatoly Radyushkin Jan 2025

Nonlocal Nucleon Matrix Elements In The Rest Frame, Joe Karpie, Christopher Monahan, Anatoly Radyushkin

Physics Faculty Publications

Extracting parton structure from lattice quantum chromodynamics (QCD) calculations requires studying the coordinate scale 𝑧3 dependence of the matrix elements of bilocal operators. The most significant contribution comes from the 𝑧3 dependence induced by ultraviolet (UV) renormalization of the Wilson line. We demonstrate that the next-to-leading order perturbative calculations of the renormalization factor can describe, to a few percent accuracy, the logarithm of the lattice QCD rest frame matrix elements with separations up to distances of 0.6 fm on multiple lattice spacings. The residual discrepancies can be modeled by a leading effect from the structure of the nucleon.

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Qcd Factorization With Multihadron Fragmentation Functions, T. C. Rogers, M. Radici, A. Courtoy, T. Rainaldi Jan 2025

Qcd Factorization With Multihadron Fragmentation Functions, T. C. Rogers, M. Radici, A. Courtoy, T. Rainaldi

Physics Faculty Publications

Important aspects of quantum chromodynamics (QCD) factorization theorems are the properties of the objects involved that can be identified as universal. One example is that the definitions of parton densitiesand fragmentation functions for different types of hadrons differ only in the identity of the nonperturbative states that form the matrix elements, but are otherwise the same. This leads to independence of perturbativecalculations on nonperturbative details of external states. It also lends support to interpretations ofcorrelation functions as encapsulations of intrinsic nonperturbative properties. These characteristics have usually been presumed to still hold true in fragmentation functions even when the observed nonperturbative …

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Measurement Of Spin-Density Matrix Elements In Δ⁺⁺ (1232) Photoproduction, F. Ayzal, C. S. Akondi, M. Albrecht, M. Amaryan, S. Arrigo, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barringa, R. Barsotti, D. Barton, V. Baturin, V. V. Berdnikov, T. Black, W. Boeglin, M. Boer, W. J. Briscoe, T. Britton, S. Cao, E. Chudakov, G. Chung, P. L. Cole, O. Cortes, V. Crede, M. M. Dalton, D. Darulis, A. Deur, S. Dobbs, A. Dolgolenko, M. Dugger, R. Dzhygadlo, D. Ebersole, M. Edo, H. Egiyan, T. Erbora, P. Eugenio, A. Fabrizi, C. Fanelli, S. Fang, J. Fitches, A. M. Foda, S. Furletov, L. Gan, H. Gao, A. Gardener, A. Gasparian, D. I. Glazier, C. Gleason, V. S. Goryachev, B. Grube, J. Guo, L. Guo, J. Hernandez, K. Hernandez, N. D. Hoffman, D. Hornidge, G. Hou, P. Hurck, A. Hurley, W. Imoehl, D. G. Ireland, M. M. Ito, I. Jaegle, N. S. Jarvis, T. Jeske, M. Jing, R. T. Jones, V. Kakoyan, G. Kalicy, V. Khachatryan, C. Kourkoumelis, A. Laduke, I. Larin, D. Lawrence, D. I. Lersch, H. Li, B. Liu, K. Livingston, G. J. Lolos, L. Lorenti, V. Lyubovitskij, R. Ma, D. Mack, A. Mahmood, H. Marukyan, V. Matveev, M. Mccaughan, M. Mccracken, C. A. Meyer, R. Miskimen, R. E. Mitchell, K. Mizutani, V. Neelamana, L. Ng, E. Nissen, S. Oreśić, A. I. Ostrovidov, Z. Papandreou, C. Paudel, R. Pedroni, L. Pentchev, K. J. Peters, E. Prathr, S. Rakshit, J. Reinhold, A. Remington, B. G. Ritchie, J. Ritman, G. Rodriguez, D. Romanov, K. Saldana, C. Salgado, S. Schadmand, A. M. Schertz, K. Scheuer, A. Schick, A. Schmidt, R. A. Schumacher, J. Schwiening, N. Septian, P. Sharp, X. Shen, M. R. Shepherd, J. Sikes, A. Smith, E. S. Smith, D. I. Sober, A. Somov, S. Somov, J. R. Stevens, I. I. Strakovsky, B. Sumner, K. Suresh, V.V. Tarasov, S. Taylor, A. Teymurazyan, A. Thiel, T. Viducic, T. Whitlatch, N. Wickramaarachchi, Y. Wunderlich, B. Yu, J. Zarling, Z. Zhang, X. Zhou, B. Zihlmann Jan 2025

Measurement Of Spin-Density Matrix Elements In Δ⁺⁺ (1232) Photoproduction, F. Ayzal, C. S. Akondi, M. Albrecht, M. Amaryan, S. Arrigo, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barringa, R. Barsotti, D. Barton, V. Baturin, V. V. Berdnikov, T. Black, W. Boeglin, M. Boer, W. J. Briscoe, T. Britton, S. Cao, E. Chudakov, G. Chung, P. L. Cole, O. Cortes, V. Crede, M. M. Dalton, D. Darulis, A. Deur, S. Dobbs, A. Dolgolenko, M. Dugger, R. Dzhygadlo, D. Ebersole, M. Edo, H. Egiyan, T. Erbora, P. Eugenio, A. Fabrizi, C. Fanelli, S. Fang, J. Fitches, A. M. Foda, S. Furletov, L. Gan, H. Gao, A. Gardener, A. Gasparian, D. I. Glazier, C. Gleason, V. S. Goryachev, B. Grube, J. Guo, L. Guo, J. Hernandez, K. Hernandez, N. D. Hoffman, D. Hornidge, G. Hou, P. Hurck, A. Hurley, W. Imoehl, D. G. Ireland, M. M. Ito, I. Jaegle, N. S. Jarvis, T. Jeske, M. Jing, R. T. Jones, V. Kakoyan, G. Kalicy, V. Khachatryan, C. Kourkoumelis, A. Laduke, I. Larin, D. Lawrence, D. I. Lersch, H. Li, B. Liu, K. Livingston, G. J. Lolos, L. Lorenti, V. Lyubovitskij, R. Ma, D. Mack, A. Mahmood, H. Marukyan, V. Matveev, M. Mccaughan, M. Mccracken, C. A. Meyer, R. Miskimen, R. E. Mitchell, K. Mizutani, V. Neelamana, L. Ng, E. Nissen, S. Oreśić, A. I. Ostrovidov, Z. Papandreou, C. Paudel, R. Pedroni, L. Pentchev, K. J. Peters, E. Prathr, S. Rakshit, J. Reinhold, A. Remington, B. G. Ritchie, J. Ritman, G. Rodriguez, D. Romanov, K. Saldana, C. Salgado, S. Schadmand, A. M. Schertz, K. Scheuer, A. Schick, A. Schmidt, R. A. Schumacher, J. Schwiening, N. Septian, P. Sharp, X. Shen, M. R. Shepherd, J. Sikes, A. Smith, E. S. Smith, D. I. Sober, A. Somov, S. Somov, J. R. Stevens, I. I. Strakovsky, B. Sumner, K. Suresh, V.V. Tarasov, S. Taylor, A. Teymurazyan, A. Thiel, T. Viducic, T. Whitlatch, N. Wickramaarachchi, Y. Wunderlich, B. Yu, J. Zarling, Z. Zhang, X. Zhou, B. Zihlmann

Physics Faculty Publications

We measure the spin-density matrix elements (SDMEs) of the Δ⁺⁺ (1232) in the photoproduction reaction 𝛾p→π−Δ⁺⁺(1232) with the GlueX experiment in Hall D at Jefferson Lab. The measurement uses a linearly–polarized photon beam with energies from 8.2 to 8.8 GeV and the statistical precision of the SDMEs exceeds the previous measurement by three orders of magnitude for the momentum transfer squared region below 1.4 GeV². The data are sensitive to the previously undetermined relative sign between couplings in existing Regge-exchange models. Linear combinations of the extracted SDMEs allow for a decomposition into natural and unnatural–exchange amplitudes. We find that the …

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Beam Spin Asymmetry Measurements Of Deeply Virtual Π⁰ Production With Clas12, The Clas Collaboration, A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J. S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, M. Zureck, Et Al. Jan 2024

Beam Spin Asymmetry Measurements Of Deeply Virtual Π⁰ Production With Clas12, The Clas Collaboration, A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J. S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, M. Zureck, Et Al.

Physics Faculty Publications

The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive π0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2and the Bjorken scaling variable 𝓍B in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions …

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A Formalism For Extracting Track Functions From Jet Measurements, Kyle Lee, Ian Moult, Felix Ringer, Wouter J. Waalewijn Jan 2024

A Formalism For Extracting Track Functions From Jet Measurements, Kyle Lee, Ian Moult, Felix Ringer, Wouter J. Waalewijn

Physics Faculty Publications

The continued success of the jet substructure program will require widespread use of tracking information to enable increasingly precise measurements of a broader class of observables. The recent reformulation of jet substructure in terms of energy correlators has simplified the incorporation of universal non-perturbative matrix elements, so called “track functions”, in jet substructure calculations. These advances make it timely to understand how these universal non-perturbative functions can be extracted from hadron collider data, which is complicated by the use jet algorithms. In this paper we introduce a new class of jet functions, which we call (semi-inclusive) track jet functions, which …

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Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao Jan 2024

Counting Linearly Polarized Gluons With Lattice Qcd, Shuai Zhao

Physics Faculty Publications

We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we propose calculating a Euclidean version of the degree of polarization for a fast-moving hadron on the lattice, which is ultraviolet finite, and no soft function subtraction is needed. It indicates a practical way to explore the distribution of the linearly polarized gluons in a proton and the linearly polarized gluon effects in hadron collisions on the lattice.

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Gluon Helicity From Global Analysis Of Experimental Data And Lattice Qcd Ioffe Time Distributions, J. Karpie, R. M. Whitehill, W. Melnitchouk, C. Monahan, K. Orginos, J.-W. Qui, D. G. Richards, N. Sato, S. Zafeiropoulos, Jefferson Lab Angular Momentum And Hadstruc Collaboration Jan 2024

Gluon Helicity From Global Analysis Of Experimental Data And Lattice Qcd Ioffe Time Distributions, J. Karpie, R. M. Whitehill, W. Melnitchouk, C. Monahan, K. Orginos, J.-W. Qui, D. G. Richards, N. Sato, S. Zafeiropoulos, Jefferson Lab Angular Momentum And Hadstruc Collaboration

Physics Faculty Publications

We perform a new global analysis of spin-dependent parton distribution functions with the inclusion of Ioffe time pseudodistributions computed in lattice QCD (LQCD), which are directly sensitive to the gluon helicity distribution, Δg. These lattice data have an analogous relationship to parton distributions as do experimental cross sections, and can be readily included in global analyses. We focus in particular on the constraining capability of current LQCD data on the sign of Δg at intermediate parton momentum fractions x, which was recently brought into question by analysis of data in the absence of parton positivity constraints. …

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Search For Axion-Like Particles Through Nuclear Primakoff Production Using The Gluex Detector, J. R. Pybus, T. Kolar, B. Devkota, P. Sharp, B. Yu, O. Hen, E. Piasetzky, S. N. Santiesteban, A. Schmidt, A. Somov, Y. Soreq, H. Szumila-Vance, S. Adhikari, C. S. Akondi, C. Ayerbe Gayoso, V. V. Berdnikov, H. Bhatt, D. Bhetuwal, M. M. Dalton, A. Deur, R. Dotel, C. Fanelli, J. Guo, T. J. Hague, D. W. Higinbotham, N. D. Hoffman, P. Hurck, I. Jaegle, A. Karki, W. Li, V. Lyubovitskij, H. Marukyan, M. D. Mccaughan, M. E. Mccracken, S. Oresic, Z. Papandreou, C. Paudel, S. Ratliff, E. M. Seroka, S. Somov, I. Strakovsky, K. Suresh, A. Thiel, B. Zihlmann Jan 2024

Search For Axion-Like Particles Through Nuclear Primakoff Production Using The Gluex Detector, J. R. Pybus, T. Kolar, B. Devkota, P. Sharp, B. Yu, O. Hen, E. Piasetzky, S. N. Santiesteban, A. Schmidt, A. Somov, Y. Soreq, H. Szumila-Vance, S. Adhikari, C. S. Akondi, C. Ayerbe Gayoso, V. V. Berdnikov, H. Bhatt, D. Bhetuwal, M. M. Dalton, A. Deur, R. Dotel, C. Fanelli, J. Guo, T. J. Hague, D. W. Higinbotham, N. D. Hoffman, P. Hurck, I. Jaegle, A. Karki, W. Li, V. Lyubovitskij, H. Marukyan, M. D. Mccaughan, M. E. Mccracken, S. Oresic, Z. Papandreou, C. Paudel, S. Ratliff, E. M. Seroka, S. Somov, I. Strakovsky, K. Suresh, A. Thiel, B. Zihlmann

Physics Faculty Publications

We report on the results of the first search for the production of axion-like particles (ALPs) via Primakoff production on nuclear targets, ᵧA → aA, in the "SRC-CT" experiment using the GlueX detector at Jefferson Lab. This search uses an integrated luminosity of 100 pb-1 center dot nucleon on a C-12 target with a real photon beam of energies 6 < Eᵧ < 10.8 GeV, and explores the mass region of 200 < m(a) < 450 MeV via the decay a → ᵧᵧ. This mass range is between the pi0 and η meson masses, which enables the use of the measured η meson production rate to obtain absolute bounds on the ALP production with reduced sensitivity to …

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Tmd Phenomenology With The Hso Approach, Tommaso Rainaldi, M. Boglione, J. O. Gonzalez-Hernandez, Ted C. Rogers Jan 2024

Tmd Phenomenology With The Hso Approach, Tommaso Rainaldi, M. Boglione, J. O. Gonzalez-Hernandez, Ted C. Rogers

Physics Faculty Publications

Transverse momentum dependent (TMD) observables are typically classified in terms of their contributions coming from different regions in transverse momentum. The low transverse momentum behavior is often ascribed to intrinsic nonperturbative properties of the hadron described by TMD factorization, while the large transverse momentum region can be computed using fixed order collinear perturbation theory. Combining both pictures in a consistent way presents challenges, for practical calculations as well as the interpretation of results. We discuss a recent approach that is designed to retain a physical interpretation in terms of hadron structure while alleviating tension with techniques used at much higher …

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Solving The Homogeneous Bethe-Salpeter Equation With A Quantum Annealer, Filippo Fornetti, Alex Gnech, Tobias Frederico, Francesco Pederiva, Matteo Rinaldi, Alessandro Roggero, Giovanni Salmè, Sergio Scopetta, Michele Viviani Jan 2024

Solving The Homogeneous Bethe-Salpeter Equation With A Quantum Annealer, Filippo Fornetti, Alex Gnech, Tobias Frederico, Francesco Pederiva, Matteo Rinaldi, Alessandro Roggero, Giovanni Salmè, Sergio Scopetta, Michele Viviani

Physics Faculty Publications

The homogeneous Bethe-Salpeter equation (hBSE), describing a bound system in a genuinely relativistic quantum-field theory framework, was solved for the first time by using a D-Wave quantum annealer. After applying standard techniques of discretization, the hBSE, in ladder approximation, can be formally transformed in a generalized eigenvalue problem (GEVP), with two square matrices: one symmetric and the other nonsymmetric. The latter matrix poses the challenge of obtaining a suitable formal approach for investigating the nonsymmetric GEVP by means of a quantum annealer, i.e., to recast it as a quadratic unconstrained binary optimization problem. A broad numerical analysis of the proposed …

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The Continuous Electron Beam Accelerator Facility At 12 Gev, P. A. Adderly, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. Bastaninejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, Y. Zhang, Et Al. Jan 2024

The Continuous Electron Beam Accelerator Facility At 12 Gev, P. A. Adderly, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. Bastaninejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, Y. Zhang, Et Al.

Physics Faculty Publications

This review paper describes the energy-upgraded Continuous Electron Beam Accelerator Facility (CEBAF) accelerator. This superconducting linac has achieved 12 GeV beam energy by adding 11 new high-performance cryomodules containing 88 superconducting cavities that have operated cw at an average accelerating gradient of 20 MV/m. After reviewing the attributes and performance of the previous 6 GeV CEBAF accelerator, we discuss the upgraded CEBAF accelerator system in detail with particular attention paid to the new beam acceleration systems. In addition to doubling the acceleration in each linac, the upgrade included improving the beam recirculation magnets, adding more helium cooling capacity to …

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Analytic Solutions Of The Dglap Evolution And Theoretical Uncertainties, A. Simonelli Jan 2024

Analytic Solutions Of The Dglap Evolution And Theoretical Uncertainties, A. Simonelli

Physics Faculty Publications

The energy dependence for the singlet sector of Parton Distributions Functions (PDFs) is described by an entangled pair of ordinary linear differential equations. Although there are no exact analytic solutions, it is possible to provide approximated results depending on the assumptions and the methodology adopted. These results differ in their sub-leading, neglected terms and ultimately they are associated with different treatments of the theoretical uncertainties. In this work, a novel analytic approach in Mellin space is presented and a new methodology for obtaining closed and exponentiated analytic solutions is devised. Different results for the DGLAP evolution at Next-Leading-Order are compared, …

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Event Generators For High-Energy Physics Experiments, J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. Höche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreaopoulos, A. M. Ankowski, E.C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. Van Beekveld, G. Beswick, S. Bhattacharya, K. Zapp, Et Al. Jan 2024

Event Generators For High-Energy Physics Experiments, J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. Höche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreaopoulos, A. M. Ankowski, E.C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. Van Beekveld, G. Beswick, S. Bhattacharya, K. Zapp, Et Al.

Physics Faculty Publications

We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these …

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Dual-Energy Electron Storage Ring, B. Dhital, Y. S. Derbenev, A. Hutton, H. Zhang, G. A. Krafft, Y. Zhang, F. Lin, V. S. Morozov Jan 2024

Dual-Energy Electron Storage Ring, B. Dhital, Y. S. Derbenev, A. Hutton, H. Zhang, G. A. Krafft, Y. Zhang, F. Lin, V. S. Morozov

Physics Faculty Publications

A dual-energy electron storage ring is a novel concept initially proposed to cool hadron beams at high energies. The design consists of two closed rings operating at significantly different energies: the low-energy ring and the high-energy ring. These two rings are connected by an energy recovery linac (ERL) that provides the necessary energy difference. The ERL features superconducting radio-frequency (SRF) cavities that first accelerate the beam from the low energy EL to the high energy EH and then decelerate the beam from EH to EL in the next pass. The different SRF cavities in the ERL …

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Phenomenology Of Tmd Parton Distributions In Drell-Yan And Z⁰ Boson Production In A Hadron Structure Oriented Approach, F. Aslan, M. Boglione, J. O. Gonzalez-Hernandez, T. Rainaldi, T. C. Rogers, A. Simonelli Jan 2024

Phenomenology Of Tmd Parton Distributions In Drell-Yan And Z⁰ Boson Production In A Hadron Structure Oriented Approach, F. Aslan, M. Boglione, J. O. Gonzalez-Hernandez, T. Rainaldi, T. C. Rogers, A. Simonelli

Physics Faculty Publications

We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to transverse momentum dependent (TMD) phenomenology applied to Drell-Yan-like processes, including lepton pair production at moderate Q² and Z⁰ boson production. We compare and contrast general features of our methodology with other common practices and emphasize aspects that we view as improvements. Separately, we discuss the importance of treatments that preserve various theoretical properties of the nonperturbative parts of TMD parametrizations for future applications that have the extraction of hadron structure as a primary goal. These include the HSO’s preservation of a basic TMD parton-model-like …

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Towards Unpolarized Gpds From Pseudo-Distributions, Hervé Dutrieux, Robert G. Edwards, Colin Egerer, Joseph Karpie, Christopher Monahan, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Savvas Zafeiropoulos Jan 2024

Towards Unpolarized Gpds From Pseudo-Distributions, Hervé Dutrieux, Robert G. Edwards, Colin Egerer, Joseph Karpie, Christopher Monahan, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Savvas Zafeiropoulos

Physics Faculty Publications

We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) Hu−d(x, ξ, t) and Eu−d(x, ξ, t) in the pseudo-distribution formalism using distillation. Taking advantage of the large kinematic coverage made possible by this approach, we present results on the moments of GPDs up to the order x3 — including their skewness dependence — at a pion mass mπ = 358 MeV and a lattice spacing a = 0.094 fm.

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Revisiting Gauge Invariance And Reggeization Of Pion Exchange, Glòria Montaña, Daniel Winney, Łukasz Bibrzycki, César Fernández-Ramirez, Giorgio Foti, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Adam P. Szczepaniak Jan 2024

Revisiting Gauge Invariance And Reggeization Of Pion Exchange, Glòria Montaña, Daniel Winney, Łukasz Bibrzycki, César Fernández-Ramirez, Giorgio Foti, Nadine Hammoud, Vincent Mathieu, Robert J. Perry, Alessandro Pilloni, Arkaitz Rodas, Vanamali Shastry, Wyatt A. Smith, Adam P. Szczepaniak

Physics Faculty Publications

The Reggeized pion is expected to provide the main contribution to the forward cross section in light meson photoproduction reactions with charge exchange at high energies. We discuss the Reggeization of pion exchange in charged pion photoproduction with an emphasis on consistency with current conservation. We show that the gauge-invariant amplitude for the exchange of a particle with a generic even spin J ≥ 2 in the t channel is analytic at J = 0 and that it can be interpreted in terms of the nucleon electric current. This enables us to reconcile the dynamics in the s and u …

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Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers Jan 2024

Definition Of Fragmentation Functions And The Violation Of Sum Rules, John Collins, Ted C. Rogers

Physics Faculty Publications

We point out a problem with the formulation and derivations of sum rules for quark fragmentation functions that impacts their validity in QCD, but which potentially points toward an improved understanding of final states in inclusive hard processes. Fragmentation functions give the distribution of final-state hadrons arising from a parton exiting a hard scattering, and the sum rules for momentum, electric charge, etc. express conservation of these quantities. The problem arises from a mismatch between the quark quantum numbers of the initial quark and the fact that all observed final-state hadrons are confined bound states with color zero. We point …

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Mass And Isospin Breaking Effects In The Skyrme Model And In Holographic Qcd, Lorenzo Bartolini, Stefano Bolognesi, Sven Bjarke Gudnason, Tommaso Rainaldi Jan 2024

Mass And Isospin Breaking Effects In The Skyrme Model And In Holographic Qcd, Lorenzo Bartolini, Stefano Bolognesi, Sven Bjarke Gudnason, Tommaso Rainaldi

Physics Faculty Publications

We discuss how the quark masses and their mass splitting affect the baryons in the Skyrme model as well as the Witten-Sakai-Sugimoto (WSS) model. In both cases, baryons are described by solitonic objects, i.e., Skyrmions and instantons, respectively. After the quantization of their zero modes, the nucleons become quantum states of a rotor. We show how the quark mass affects the moment of inertia and we provide a semianalytic approach valid in the small-mass limit. Additionally, we show how the two lightest quarks’ mass splitting affects the moments of inertia of the Skyrmion and induces an isospin breaking effect. This …

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1/Q² Power Corrections To Tmd Factorization For Drell-Yan Hadronic Tensor, I. Balitsky Jan 2024

1/Q² Power Corrections To Tmd Factorization For Drell-Yan Hadronic Tensor, I. Balitsky

Physics Faculty Publications

I calculate 1/Q2 power corrections to unpolarized Drell-Yan hadronic tensor for electromagnetic (EM) current at large N-c and demonstrate the EM gauge invariance at this level.

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Inclusive Reactions From Finite Minkowski Spacetime Correlation Functions, Marco A. Carrillo, Raúl A. Briceño, Alexandru M. Sturzu Jan 2024

Inclusive Reactions From Finite Minkowski Spacetime Correlation Functions, Marco A. Carrillo, Raúl A. Briceño, Alexandru M. Sturzu

Physics Faculty Publications

The need to determine scattering amplitudes of few-hadron systems for arbitrary kinematics expands a broad set of subfields of modern-day nuclear and hadronic physics. In this work, we expand upon previous explorations on the use of real-time methods, like quantum computing or tensor networks, to determine few-body scattering amplitudes. Such calculations must be performed in a finite Minkowski spacetime, where scattering amplitudes are not well defined. Our previous work presented a conjecture of a systematically improvable estimator for scattering amplitudes constructed from finite-volume correlation functions. Here we provide further evidence that the prescription works for larger kinematic regions than previously …

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Conformal Bk Equation At Qcd Wilson-Fisher Point, I. Balitsky, G. A. Chirilli Jan 2024

Conformal Bk Equation At Qcd Wilson-Fisher Point, I. Balitsky, G. A. Chirilli

Physics Faculty Publications

High-energy scattering in pQCD in the Regge limit is described by the evolution of Wilson lines governed by the BK equation [1, 2]. In the leading order, the BK equation is conformally invariant and the eigenfunctions of the linearized BFKL equation are powers. It is a common belief that at d ≠ 4 the BFKL equation is useless since unlike d = 4 case it cannot be solved by usual methods. However, we demonstrate that at critical Wilson-Fisher point of QCD the relevant part of NLO BK restores the conformal invariance so the solutions are again powers. As a check …

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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 …

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Prospects For 𝛾*𝛾* → 𝜋𝜋 Via Lattice Qcd, Raúl Briceño, Andrew W. Jackura, Arkaitz Rodas, Juan V. Guerrero Jan 2023

Prospects For 𝛾*𝛾* → 𝜋𝜋 Via Lattice Qcd, Raúl Briceño, Andrew W. Jackura, Arkaitz Rodas, Juan V. Guerrero

Physics Faculty Publications

The 𝛾*𝛾* → 𝜋𝜋 scattering amplitude plays a key role in a wide range of phenomena, including understanding the inner structure of scalar resonances as well as constraining the hadronic contributions to the anomalous magnetic moment of the muon. In this work, we explain how the infinite-volume Minkowski amplitude can be constrained from finite-volume Euclidean correlation functions. The relationship between the finite-volume Euclidean correlation functions and the desired amplitude holds up to energies where 3𝜋 states can go on shell, and is exact up to exponentially small corrections that scale like 𝒪(e−m𝜋L), where L is the spatial extent …

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A Multidimensional Study Of The Structure Function Ratio Σlt'/ Σ₀ From Hard Exclusive ��⁺ Electro-Production Off Protons In The Gpd Regime, S. Diehl, A. Kim, K. Joo, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avagyan, C. Ayerbe Gayoso, L. Baashen, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinsky, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Bondi, W.A. Booth, M. Zurek, Et Al. Jan 2023

A Multidimensional Study Of The Structure Function Ratio Σlt'/ Σ₀ From Hard Exclusive ��⁺ Electro-Production Off Protons In The Gpd Regime, S. Diehl, A. Kim, K. Joo, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avagyan, C. Ayerbe Gayoso, L. Baashen, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinsky, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Bondi, W.A. Booth, M. Zurek, Et Al.

Physics Faculty Publications

A multidimensional extraction of the structure function ratio from the hard exclusive →ep → e'n��+ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime (t/Q2≪ 1) with a wide kinematic range of in the valence regime (0.17 < ��B < 0.55), and virtualities ranging from 1.5 GeV2 up to 6 GeV2. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd …

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Exclusive 𝝅⁻ Electroproduction Off The Neutron In Deuterium In The Resonance Region, Y. Tian, R. W. Gothe, V. I. Mokeev, G. Hollis, M. J. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. Biselli, F. Bossù, S. Boiarinov, M. Bondì, J. Zhang, Et Al., The Clas Collaboration Jan 2023

Exclusive 𝝅⁻ Electroproduction Off The Neutron In Deuterium In The Resonance Region, Y. Tian, R. W. Gothe, V. I. Mokeev, G. Hollis, M. J. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. Biselli, F. Bossù, S. Boiarinov, M. Bondì, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

New results for the exclusive and quasifree cross sections off neutrons bound in deuterium 𝛾vn(p) → pπ− (p) are presented over a wide final state hadron angle range with a kinematic coverage of the invariant mass (W) up to 1.825 GeV and the four-momentum transfer squared (Q2) from 0.4 to 1.0 GeV2. The exclusive structure functions were extracted and their Legendre moments were obtained. Final-state-interaction contributions have been kinematically separated from the extracted quasifree cross sections off bound neutrons solely based on the analysis of the experimental data. These new results will serve as …

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Determination Of The Titanium Spectral Function From (E, E'P) Data, L. Jiang, A.M. Ankowski, D. Abrams, L. Gu, B. Aljawrneh, S. Alsalmi, J. Bane, A. Batz, S. Barcus, M. Barroso, V. Bellini, O. Benhar, J. Bericic, D. Biswas, A. Camsonne, J. Castellanos, J. -P. Chen, M. E. Christy, K. Craycraft, R. Cruz-Torres, H. Dai, D. Day, A. Dirican, S. -C. Dusa, E. Fuchey, T. Gautam, C. Giusti, J. Gomez, C. Gu, T. J. Hague, J. -O. Hansen, F. Hauenstein, D. W. Higinbotham, C. Hyde, Z. Jerzyk, A. M. Johnson, C. Keppel, C. Lanham, S. Li, R. Lindgren, H. Liu, C. Mariani, R. E. Mcclellan, D. Meekins, R. Michaels, M. Mihovilovic, M. Murphy, D. Nguyen, M. Nycz, L. Ou, B. Pandey, V. Pandey, K. Park, G. Perera, A.J.R. Puckett, S.N. Santiesteban, S. Ŝirca, T. Su, L. Tang, Y. Tian, N. Ton, B. Wojsekhowski, S. Wood, Z. Ye, J. Zhang Jan 2023

Determination Of The Titanium Spectral Function From (E, E'P) Data, L. Jiang, A.M. Ankowski, D. Abrams, L. Gu, B. Aljawrneh, S. Alsalmi, J. Bane, A. Batz, S. Barcus, M. Barroso, V. Bellini, O. Benhar, J. Bericic, D. Biswas, A. Camsonne, J. Castellanos, J. -P. Chen, M. E. Christy, K. Craycraft, R. Cruz-Torres, H. Dai, D. Day, A. Dirican, S. -C. Dusa, E. Fuchey, T. Gautam, C. Giusti, J. Gomez, C. Gu, T. J. Hague, J. -O. Hansen, F. Hauenstein, D. W. Higinbotham, C. Hyde, Z. Jerzyk, A. M. Johnson, C. Keppel, C. Lanham, S. Li, R. Lindgren, H. Liu, C. Mariani, R. E. Mcclellan, D. Meekins, R. Michaels, M. Mihovilovic, M. Murphy, D. Nguyen, M. Nycz, L. Ou, B. Pandey, V. Pandey, K. Park, G. Perera, A.J.R. Puckett, S.N. Santiesteban, S. Ŝirca, T. Su, L. Tang, Y. Tian, N. Ton, B. Wojsekhowski, S. Wood, Z. Ye, J. Zhang

Physics Faculty Publications

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e,e′p) cross section in parallel kinematics using a natural titanium target. In this paper, we report the analysis of the dataset obtained in different kinematics for our solid natural titanium target. Data were obtained in a range of missing momentum and missing energy between 15 ≲ pm ≲ 250  MeV/c and 12 ≲ Em ≲ 80  MeV, respectively, and using an electron beam energy of 2.2 GeV. We measured the reduced cross section with ∼7% accuracy as a function of both missing momentum and missing energy. …

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Observation Of Correlations Between Spin And Transverse Momenta In Back-To-Back Dihadron Production At Clas12, H. Avakian, T.B. Hayward, A. Kotzinian, W.R. Armstrong, H. Atac, C. Ayerbe Gayoso, L. Baashen, N.A. Balzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. S. Biselli, M. Bondi, S. Boiarinov, M. Zurek, Et Al. Jan 2023

Observation Of Correlations Between Spin And Transverse Momenta In Back-To-Back Dihadron Production At Clas12, H. Avakian, T.B. Hayward, A. Kotzinian, W.R. Armstrong, H. Atac, C. Ayerbe Gayoso, L. Baashen, N.A. Balzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. S. Biselli, M. Bondi, S. Boiarinov, M. Zurek, Et Al.

Physics Faculty Publications

We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction in the deep inelastic scattering process. In this reaction, two hadrons are produced in opposite hemispheres along the z axis in the virtual photon-target nucleon center-of-mass frame, with the first hadron produced in the current-fragmentation region and the second in the target-fragmentation region. The data were taken with longitudinally polarized electron beams of 10.2 and 10.6 GeV incident on an unpolarized liquid-hydrogen target using the CLAS12 spectrometer at Jefferson Lab. Observed nonzero sinΔϕ modulations in ep→e'pπ+ X events, where Δϕ is the difference …

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