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Physics Faculty Publications

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Articles 61 - 90 of 1942

Full-Text Articles in Physical Sciences and Mathematics

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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Modeling A Nb3Sn Cryounit In Gpt At Uitf, Sunil Pokharel, A. S. Hofler, Geoffrey A. Krafft Jan 2023

Modeling A Nb3Sn Cryounit In Gpt At Uitf, Sunil Pokharel, A. S. Hofler, Geoffrey A. Krafft

Physics Faculty Publications

Nb3Sn is a prospective material for future superconducting radio frequency (SRF) accelerator cavities. Compared to conventional niobium, the material can achieve higher quality factors, higher temperature operation, and potentially higher accelerating gradients (Eacc ≈ 96 MV/m). In this work, we performed modeling of the Upgraded Injector Test Facility (UITF) at Jefferson Lab utilizing newly constructed Nb3Sn cavities. We studied the effects of the buncher cavity and varied the gun voltage from 200-500 keV. We have calibrated and optimized the SRF cavity gradients and phases for the Nb3Sn five-cell cavities' energy gains with the …

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Tuning Microwave Losses In Superconducting Resonators, Alex Gurevich Jan 2023

Tuning Microwave Losses In Superconducting Resonators, Alex Gurevich

Physics Faculty Publications

Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials treatments and technological advances. As a result, the niobium cavities have reached the quality factors Q ~ 1011 at 1-2 GHz and 1.5 K and the breakdown radio-frequency (rf) fields H close to the dc superheating eld of the Meissner state. These advances raise the question whether the state-of-the-art cavities are close to the fundamental limits, what these limits actually are, and to what extent the Q and H limits …

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Scattered Spectra From Inverse Compton Sources Operating At High Laser Fields And High Electron Energies, Geoffrey A. Krafft, Balša Terzić, Erik Johnson, G. Wilson Jan 2023

Scattered Spectra From Inverse Compton Sources Operating At High Laser Fields And High Electron Energies, Geoffrey A. Krafft, Balša Terzić, Erik Johnson, G. Wilson

Physics Faculty Publications

As Compton x-ray and gamma-ray sources become more prevalent, to understand their performance in a precise way, it becomes important to be able to compute the distribution of scattered photons precisely. For example, codes have been developed at Old Dominion University which were used to understand the performance of the Dresden Compton Source in detail. An ideal model would (i) include the full Compton effect frequency relations between incident and scattered photons, (ii) allow the field strength to be large enough that nonlinear effects are captured, and (iii) allow the effects of electron beam emittance to be introduced and studied. …

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Non-Singlet Quark Helicity Pdfs Of The Nucleon From Pseudo-Distributions, Robert Edwards, Colin Egerer, Joseph Karpie, Nikhil Karthik, Christopher Monahan, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Raza Sabbir Sufian, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration Jan 2023

Non-Singlet Quark Helicity Pdfs Of The Nucleon From Pseudo-Distributions, Robert Edwards, Colin Egerer, Joseph Karpie, Nikhil Karthik, Christopher Monahan, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David Richards, Eloy Romero, Raza Sabbir Sufian, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration

Physics Faculty Publications

The non-singlet helicity quark parton distribution functions (PDFs) of the nucleon are determined from lattice QCD, by jointly leveraging pseudo-distributions and the distillation spatial smearing paradigm. A Lorentz decomposition of appropriately isolated space-like matrix elements reveals pseudo-distributions that contain information on the leading-twist helicity PDFs, as well as an invariant amplitude that induces an additional z2 contamination of the leading-twist signal. An analysis of the short-distance behavior of the space-like matrix elements using matching coefficients computed to next-to-leading order (NLO) exposes the desired PDF up to this additional z2 contamination. Due to the non-conservation of the axial current, …

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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 …

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Cavity And Cryomodule Developments For Eic, R. A. Rimmer, E. Daly, J. Guo, J. Henry, J. Matalevich, H. Wang, S. Wang, D. Holmes, K. Smith, W. Xu, A. Zaltsman, B. Xiao, Subashini De Silva, Jean R. Delayen Jan 2023

Cavity And Cryomodule Developments For Eic, R. A. Rimmer, E. Daly, J. Guo, J. Henry, J. Matalevich, H. Wang, S. Wang, D. Holmes, K. Smith, W. Xu, A. Zaltsman, B. Xiao, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The EIC is a major new project under construction at BNL in partnership with JLab. It relies upon a number of new SRF cavities at 197 MHz, 394 MHz, 591 MHz and 1773 MHz to pre-bunch, accelerate, cool and crab the stored beams. R&D is focusing on the 591 MHz elliptical cavity and 197 MHz crab cavity first as these are the most challenging. Preliminary designs of these cavities are presented along with an R&D status report. To avoid developing multiple different cryostats a modular approach is adopted using a high degree of commonality of parts and systems. This approach …

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Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky Jan 2023

Rapidity-Only Tmd Factorization At One Loop, Ian Balitsky

Physics Faculty Publications

Typically, a production of a particle with a small transverse momentum in hadron-hadron collisions is described by CSS-based TMD factorization at moderate Bjorken xB ~ 1 and by kT-factorization at small xB. A uniform description valid for all xB is provided by rapidity-only TMD factorization developed in a series of recent papers at the tree level. In this paper the rapidity-only TMD factorization for particle production by gluon fusion is extended to the one-loop level.

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Development Of A Prototype Superconducting Radio-Frequency Cavity For Conduction Cooled Accelerators, Gianluigi Ciovati, J. Anderson, S. Balachandran, G. Cheng, B. Coritron, E. Daly, P. Dhakal, Alex Gurevich, F. Hannon, K. Harding, L. Holland, F. Marhauser, K. Mclaughlin, D. Packard, T. Powers, U. Pudasaini, J. Rathke, R. Rimmer, T. Schultheiss, H. Vennekate, D. Vollmer Jan 2023

Development Of A Prototype Superconducting Radio-Frequency Cavity For Conduction Cooled Accelerators, Gianluigi Ciovati, J. Anderson, S. Balachandran, G. Cheng, B. Coritron, E. Daly, P. Dhakal, Alex Gurevich, F. Hannon, K. Harding, L. Holland, F. Marhauser, K. Mclaughlin, D. Packard, T. Powers, U. Pudasaini, J. Rathke, R. Rimmer, T. Schultheiss, H. Vennekate, D. Vollmer

Physics Faculty Publications

The higher efficiency of superconducting radio-frequency (SRF) cavities compared to normal -conducting ones enables the development of high-energy continuous-wave linear accelerators (linacs). Recent progress in the development of high-quality Nb3Sn film coatings along with the availability of cryocoolers with high cooling capacity at 4 K makes it feasible to operate SRF cavities cooled by thermal conduction at relevant accelerating gradients for use in accelerators. A possible use of conduction-cooled SRF linacs is for environmental applications, requiring electron beams with energy of 1-10 MeV and 1 MW of power. We have designed a 915 MHz SRF linac for such …

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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, …

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First Clas12 Measurement Of Deeply Virtual Compton Scattering Beam-Spin Asymmetries In The Extended Valence Region, G. Christiaens, M. Defurne, D. Sokhan, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Zurek, Et Al., Clas Collaboration Jan 2023

First Clas12 Measurement Of Deeply Virtual Compton Scattering Beam-Spin Asymmetries In The Extended Valence Region, G. Christiaens, M. Defurne, D. Sokhan, P. Achenbach, Z. Akbar, M. J. Amaryan, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Zurek, Et Al., Clas Collaboration

Physics Faculty Publications

Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarized protons. The results greatly extend the Q2 and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.

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Two-Point Correlator Of Twist-2 Light-Ray Operators In N=Sym In Bfkl Approximation, Ian Balitsky, Vladimir Kazakov, Evgeny Sobko Jan 2023

Two-Point Correlator Of Twist-2 Light-Ray Operators In N=Sym In Bfkl Approximation, Ian Balitsky, Vladimir Kazakov, Evgeny Sobko

Physics Faculty Publications

We generalize local operators of the leading twist-2 of 𝒩 = SYM theory to the case of complex Lorentz spin j using principal series representation of sl(2, R). We give the direct computation of correlation function of two such non-local operators in the BFKL regime when j → 1. The correlator appears to have the expected conformal coordinate dependence governed by the anomalous dimension of twist-2 operator in NLO BFKL approximation predicted by Kotikov and Lipatov.

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Characterization Of Dissipative Regions Of A N-Doped Superconducting Radio-Frequency Cavity, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Lavarone Jan 2023

Characterization Of Dissipative Regions Of A N-Doped Superconducting Radio-Frequency Cavity, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Lavarone

Physics Faculty Publications

We report radio-frequency measurements of quality factors and temperature mapping of a nitrogen doped Nb superconducting RF cavity. Cavity cutouts of hot and cold spots were studied with low temperature scanning tunneling microscopy and spectroscopy, X-ray photoelectron spectroscopy and secondary electron microscopy. Temperature mapping revealed a substantial reduction of the residual resistance upon cooling the cavity with a greater temperature gradient and hysteretic losses at the quench location, pointing to trapped vortices as the dominant source of residual surface resistance.Analysis of the tunneling spectra in the framework of a proximity effect theory shows that hot spots have a reduced pair …

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First Measurement Of Hard Exclusive 𝛑⁻Δ⁺⁺ Electroproduction Beam-Spin Asymmetries Off The Proton, S. Diehl, N. Trotta, K. Joo, P. Achenbach, Z. Akbar, W. R. Armstrong, H. Atac, H. Avakian, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A. S. Biselli, F. Bossù, K.-T. Brinkman, M. Zurek, Et Al., Clas Collaboration Jan 2023

First Measurement Of Hard Exclusive 𝛑⁻Δ⁺⁺ Electroproduction Beam-Spin Asymmetries Off The Proton, S. Diehl, N. Trotta, K. Joo, P. Achenbach, Z. Akbar, W. R. Armstrong, H. Atac, H. Avakian, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A. S. Biselli, F. Bossù, K.-T. Brinkman, M. Zurek, Et Al., Clas Collaboration

Physics Faculty Publications

The polarized cross-section ratio σLT′/σ0 from hard exclusive π−Δ++ electroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using a 10.2  GeV/10.6  GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. The study, which provides the first observation of this channel in the deep-inelastic regime, focuses on very forward-pion kinematics in the valence regime, and photon virtualities ranging from 1.5  GeV2 up to 7  GeV2. The reaction provides a novel access to the d-quark content of the nucleon and to p→Δ++ transition generalized parton …

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Searching For Prompt And Long-Lived Dark Photons In Electroproduced E⁺ E⁻ Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, P. Butti, V. D. Burkert, D. Calvo, T. Cao, M. Carpinelli, A. Celentano, G. Charles, L. Colaneri, W. Cooper, D. Crowe, C. Cuevas, A. D'Angelo, N. Dashyan, B. Wojtsekhowski, Et Al. Jan 2023

Searching For Prompt And Long-Lived Dark Photons In Electroproduced E⁺ E⁻ Pairs With The Heavy Photon Search Experiment At Jlab, P. H. Adrian, N. A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, S. Bueltmann, P. Butti, V. D. Burkert, D. Calvo, T. Cao, M. Carpinelli, A. Celentano, G. Charles, L. Colaneri, W. Cooper, D. Crowe, C. Cuevas, A. D'Angelo, N. Dashyan, B. Wojtsekhowski, Et Al.

Physics Faculty Publications

The heavy photon search experiment (HPS) at the Thomas Jefferson National Accelerator Facility searches for electroproduced dark photons. We report results from the 2016 engineering run consisting of 10 608  nb−1 of data for both the prompt and displaced vertex searches. A search for a prompt resonance in the e+e− invariant mass distribution between 39 and 179 MeV showed no evidence of dark photons above the large QED background, limiting the coupling of ε2≳10−5, in agreement with previous searches. The search for displaced vertices showed no evidence of excess signal over background …

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Surface Properties And Rf Performance Of Vapor Diffused Nb₃Sn On Nb After Sequential Anneals Below 1000 °C, Jayendrika K. Tiskumara, Jean R. Delayen, U. Pudasaini, G. Eremeev Jan 2023

Surface Properties And Rf Performance Of Vapor Diffused Nb₃Sn On Nb After Sequential Anneals Below 1000 °C, Jayendrika K. Tiskumara, Jean R. Delayen, U. Pudasaini, G. Eremeev

Physics Faculty Publications

Nb₃Sn is a next-generation superconducting material that can be used for future superconducting radiofrequency (SRF) accelerator cavities, promising better performance, cost reduction, and higher operating temperature than Nb. The Sn vapor diffusion method is currently the most preferred and successful technique to coat niobium cavities with Nb₃Sn. Among post-coating treatments to optimize the coating quality, higher temperature annealing without Sn is known to degrade Nb₃Sn because of Sn loss. We have investigated Nb₃Sn/Nb samples briefly annealed at 800-1000 °C, for 10 and 20 minutes to potentially improve the surface to enhance the performance of Nb₃Sn-coated cavities. Following the sample studies, …

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Magnetic Field Mapping Of A Large-Grain 1.3 Ghz Single-Cell Cavity, Ishwari Prasad Parajuli, Jean R. Delayen, Alex V. Gurevich, Gianluigi Ciovati Jan 2023

Magnetic Field Mapping Of A Large-Grain 1.3 Ghz Single-Cell Cavity, Ishwari Prasad Parajuli, Jean R. Delayen, Alex V. Gurevich, Gianluigi Ciovati

Physics Faculty Publications

A new magnetic field mapping system for 1.3 GHz single-cell cavities was developed in order to reveal the impact of ambient magnetic field and temperature gradients during cool-down on the flux trapping phenomenon. Measurements were done at 2 K for different cool-down conditions of a large-grain cavity before and after 120 °C bake. The fraction of applied magnetic field trapped in the cavity walls was ~ 50% after slow cool-down and ~ 20% after fast cool-down. The results showed a weak correlation between between trapped flux locations and hot-spots causing the high-field Q-slope. The results also showed an increase of …

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Development And Performance Of Rfd Crab Cavity Prototypes For Hl-Lhc Aup, L. Listori, P. Berrutti, M. Narduzzi, A. Castilla, S. U. De Silva, J. R. Delayen, N. A. Huque, Z. Li, A. Ratti Jan 2023

Development And Performance Of Rfd Crab Cavity Prototypes For Hl-Lhc Aup, L. Listori, P. Berrutti, M. Narduzzi, A. Castilla, S. U. De Silva, J. R. Delayen, N. A. Huque, Z. Li, A. Ratti

Physics Faculty Publications

The US will be contributing to the HL-LHC upgrade at CERN with the fabrication and qualification of RFD crabbing cavities in the framework of the HL-LHC Accelerator Upgrade Project (AUP) managed by Fermilab. AUP received Critical Decision 3 (CD-3) approval by DOE in December 2020 launching the project into the production phase. The electro-magnetic design of the cavity was inherited from the LHC Accelerator Research Program (LARP) but needed to be revised to meet new project requirements and to prevent issues encountered during beam tests performed at CERN in the R&D phase. Two prototype cavities were manufactured in industry and …

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Fabrication And Testing Of A Prototype Rf-Dipole Crabbing Cavity, S. U. De Silva, J. R. Delayen, H. Park Jan 2023

Fabrication And Testing Of A Prototype Rf-Dipole Crabbing Cavity, S. U. De Silva, J. R. Delayen, H. Park

Physics Faculty Publications

Crabbing cavities are essential in particle colliders to compensate the luminosity degradation due to beam collision at a crossing angle. The 952.6 MHz 2-cell rf-dipole crabbing cavity system was proposed for the Jefferson Lab Electron-Ion Collider to restore the head-on collisions of electron and proton bunches at the interaction point. A prototype cavity was designed and developed to demonstrate the performance of multi-cell rf-dipole structures. This paper presents the fabrication process and cold test results of the first 2-cell rf-dipole prototype cavity.

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Measurement Of The J/𝛹 Photoproduction Cross Section Over The Full Near-Threshold Kinematic Region, S. Adhikari, F. Afzal, C.S. Akondi, M. Albrecht, M. Amaryan, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, W. Boeglin, W. J. Briscoe, T. Britton, B. Zihlmann Jan 2023

Measurement Of The J/𝛹 Photoproduction Cross Section Over The Full Near-Threshold Kinematic Region, S. Adhikari, F. Afzal, C.S. Akondi, M. Albrecht, M. Amaryan, V. Arroyave, A. Asaturyan, A. Austregesilo, Z. Baldwin, F. Barbosa, J. Barlow, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, W. Boeglin, W. J. Briscoe, T. Britton, B. Zihlmann

Physics Faculty Publications

We report the total and differential cross sections for J/ψ photoproduction with the large acceptance GlueX spectrometer for photon beam energies from the threshold at 8.2 GeV up to 11.44 GeV and over the full kinematic range of momentum transfer squared, t. Such coverage facilitates the extrapolation of the differential cross sections to the forward (t=0) point beyond the physical region. The forward cross section is used by many theoretical models and plays an important role in understanding J/ψ photoproduction and its relation to the J/ψ-proton interaction. These measurements of J/ψ photoproduction near threshold are also crucial inputs to theoretical …

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Three-Body Scattering And Quantization Conditions From S-Matrix Unitarity, Andrew W. Jackura Jan 2023

Three-Body Scattering And Quantization Conditions From S-Matrix Unitarity, Andrew W. Jackura

Physics Faculty Publications

Two methodologies have been presented in the literature which connect relativistic three-particle scattering amplitudes with lattice QCD spectra—the “relativistic effective field theory” approach and the “finite-volume unitarity” method. While both methods have been shown to be equivalent in various works, it has not been shown how to arrive at the relativistic effective field theory results directly from S-matrix unitarity. In this work, we provide a simple proof of the relativistic effective field theory form of the scattering equations directly from unitarity. Motivated by the finite-volume unitarity approach, we then postulate a set of quantization conditions which relate the finite-volume energy …

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Analytic Continuation Of The Relativistic Three-Particle Scattering Amplitudes, Sebastian M. Dawid, Md Habib E. Islam, Raúl A. Briceño Jan 2023

Analytic Continuation Of The Relativistic Three-Particle Scattering Amplitudes, Sebastian M. Dawid, Md Habib E. Islam, Raúl A. Briceño

Physics Faculty Publications

We investigate the relativistic scattering of three identical scalar bosons interacting via pair-wise interactions. Extending techniques from the nonrelativistic three-body scattering theory, we provide a detailed and general prescription for solving and analytically continuing integral equations describing the three-body reactions. We use these techniques to study a system with zero angular momenta described by a single scattering length leading to a bound state in a two-body subchannel. We obtain bound-state-particle and three-particle amplitudes in the previously unexplored kinematical regime; in particular, for real energies below elastic thresholds and complex energies in the physical and unphysical Riemann sheets. We extract positions …

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Eic 197 Mhz Crab Cavity Rf Optimization, Zenghai Li, Subashini U. De Silva, Jean R. Delayen, Robert A. Rimmer, Qiong Wu, Binping Xiao, Wencan Xu Jan 2023

Eic 197 Mhz Crab Cavity Rf Optimization, Zenghai Li, Subashini U. De Silva, Jean R. Delayen, Robert A. Rimmer, Qiong Wu, Binping Xiao, Wencan Xu

Physics Faculty Publications

Crab cavities, operating at 197 MHz and 394 MHz respectively, will be used to compensate the loss of luminosity due to a 25 mrad crossing angle at the interaction point in the Electron Ion Collider (EIC). Both crab cavities are of the RF Dipole (RFD) shape. To meet the machine design requirements, there are a few important cavity design considerations that need to be addressed. First, to achieve stable cavity operation at the design voltages, cavity geometry details must be optimized to suppress potential multipacting. Incorporating strong HOM damping in the cavity design is required for the beam stability and …

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Temperature, Rf Field, And Frequency Dependence Performance Evaluation Of Superconducting Niobium Half-Wave Coaxial Cavity, N. K. Raut, G. Ciovati, S. U. De Silva, J. R. Delayen, P. Dhakal, B. D. Khanal, J. K. Tiskumara Jan 2023

Temperature, Rf Field, And Frequency Dependence Performance Evaluation Of Superconducting Niobium Half-Wave Coaxial Cavity, N. K. Raut, G. Ciovati, S. U. De Silva, J. R. Delayen, P. Dhakal, B. D. Khanal, J. K. Tiskumara

Physics Faculty Publications

Recent advancement in superconducting radio frequency cavity processing techniques, with diffusion of impurities within the RF penetration depth, resulted in high quality factor with increase in quality factor with increasing accelerating gradient. The increase in quality factor is the result of a decrease in the surface resistance as a result of nonmagnetic impurities doping and change in electronic density of states. The fundamental understanding of the dependence of surface resistance on frequency and surface preparation is still an active area of research. Here, we present the result of RF measurements of the TEM modes in a coaxial half-wave niobium cavity …

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Crab Cavities For Ilc, P. A. Mcintosh, S. A. Belomestnykh, G. Burt, R. Calaga, S. U. De Silva, J. R. Delayen, I. V. Gonin, T. N. Khabiboulline, A. Lunin, T. Okugi, Y. M. Orlov, S. Verdú-Andrés, B. P. Xiao, V. P. Yakovlev, A. Yamamoto Jan 2023

Crab Cavities For Ilc, P. A. Mcintosh, S. A. Belomestnykh, G. Burt, R. Calaga, S. U. De Silva, J. R. Delayen, I. V. Gonin, T. N. Khabiboulline, A. Lunin, T. Okugi, Y. M. Orlov, S. Verdú-Andrés, B. P. Xiao, V. P. Yakovlev, A. Yamamoto

Physics Faculty Publications

For the 14 mrad crossing angle proposed, crab cavity systems are fundamentally anticipated for the viable operation of the International Linear Collider (ILC), in order to maximise its luminosity performance. Since 2021, a specialist development team have been defining optimum crab cavity technologies which can fulfil the operational requirements for ILC, both for its baseline centre-of-mass energy of 250 GeV, but also extending those requirements out to higher beam collision intensities. Five design teams have established crab cavity technology solutions, which have the capability to also operate up to 1 TeV centre-of-mass. This presentation showcases the key performance capabilities of …

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Constraints On The Onset Of Color Transparency From Quasielastic ¹²C(E, E′P) Up To Q² = (14.2 Gev /C)², D. Bhetuwal, J. Matter, H. Szumila-Vance, C. Ayerbe Gayoso, M. L. Kabir, D. Dutta, R. Ent, D. Abrams, Z. Ahmed, B. Aljawrneh, S. Alsalmi, R. Ambrose, D. Androic, W. Armstrong, A. Asaturyan, K. Assumin-Gyimah, A. Bandari, S. Basnet, V. Berdnikov, J. Zhang, Et Al., Hall C. Collaboration Jan 2023

Constraints On The Onset Of Color Transparency From Quasielastic ¹²C(E, E′P) Up To Q² = (14.2 Gev /C)², D. Bhetuwal, J. Matter, H. Szumila-Vance, C. Ayerbe Gayoso, M. L. Kabir, D. Dutta, R. Ent, D. Abrams, Z. Ahmed, B. Aljawrneh, S. Alsalmi, R. Ambrose, D. Androic, W. Armstrong, A. Asaturyan, K. Assumin-Gyimah, A. Bandari, S. Basnet, V. Berdnikov, J. Zhang, Et Al., Hall C. Collaboration

Physics Faculty Publications

Quasielastic scattering on 12C(e,e′p) was measured in Hall C at Jefferson Lab for spacelike four-momentum transfer squared Q2 in the range of 8–14.2(GeV/c)2 with proton momenta up to 8.3GeV/c. The experiment was carried out in the upgraded Hall C at Jefferson Lab. It used the existing high-momentum spectrometer and the new super-high-momentum spectrometer to detect the scattered electrons and protons in coincidence. The nuclear transparency was extracted as the ratio of the measured yield to the yield calculated in the plane wave impulse approximation. Additionally, the transparency of the 1s1/2 and 1p3/2 shell …

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First Measurement Of The Emc Effect In ¹⁰B And ¹¹B, A. Karki, D. Biswas, F. A. Gonzalez, W. Henry, C. Morean, A. Nadeeshani, A. Sun, D. Abrams, Z. Ahmed, B. Aljawrneh, S. Alsalmi, R. Ambrose, D. Androic, W. Armstrong, J. Arrington, D. Asaturyan, K. Assumin-Gyimah, C. Ayerbe Gayoso, A. Bandari, J. Zhang, Et Al., Hall C. Collaboration Jan 2023

First Measurement Of The Emc Effect In ¹⁰B And ¹¹B, A. Karki, D. Biswas, F. A. Gonzalez, W. Henry, C. Morean, A. Nadeeshani, A. Sun, D. Abrams, Z. Ahmed, B. Aljawrneh, S. Alsalmi, R. Ambrose, D. Androic, W. Armstrong, J. Arrington, D. Asaturyan, K. Assumin-Gyimah, C. Ayerbe Gayoso, A. Bandari, J. Zhang, Et Al., Hall C. Collaboration

Physics Faculty Publications

The nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in 10B and 11B. Previous measurements of the EMC effect in A ≤ 12 nuclei showed an unexpected nuclear dependence; 10B and 11B were measured to explore the EMC effect in this region in more detail. Results are presented for 9Be, 10B, 11B, and 12C at an incident beam energy of 10.6 GeV. The EMC effect in the boron isotopes was found to be similar to …

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First Use Of A Longitudinally Polarized Target With Clas12, C. D. Keith, J. Brock, C. Carlin, T. Kageya, V. Lagerquist, J. Maxwell, P. Pandey Jan 2023

First Use Of A Longitudinally Polarized Target With Clas12, C. D. Keith, J. Brock, C. Carlin, T. Kageya, V. Lagerquist, J. Maxwell, P. Pandey

Physics Faculty Publications

Run Group C comprises eight experiments utilizing the CLAS12 detector system in Hall B at Jefferson Lab to study the multidimensional partonic structure of nucleons. The experiments scatter electrons from polarized protons and neutrons in samples of solid NH3 and ND3, dynamically polarized at a temperature of 1 K in a 5 T magnetic field. After a brief description of the target system, the current status of the target and preliminary results of its performance in the experiment are presented.

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Measurement Of The Helicity Asymmetry E For The 𝛾p → P𝛑⁰ Reaction In The Resonance Region, C. W. Kim, N. Zachariou, M. Bashkanov, W. J. Briscoe, S. Fegan, V. L. Kashevarov, K. Nikonov, A. Sarantsev, A. Schmidt, I. I. Strakovsky, D. P. Watts, R. L. Workman, P. Achenbach, Z. Akbar, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, L. Baashen, M. Zurek, Et Al., The Clas Collaboration Jan 2023

Measurement Of The Helicity Asymmetry E For The 𝛾p → P𝛑⁰ Reaction In The Resonance Region, C. W. Kim, N. Zachariou, M. Bashkanov, W. J. Briscoe, S. Fegan, V. L. Kashevarov, K. Nikonov, A. Sarantsev, A. Schmidt, I. I. Strakovsky, D. P. Watts, R. L. Workman, P. Achenbach, Z. Akbar, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, L. Baashen, M. Zurek, Et Al., The Clas Collaboration

Physics Faculty Publications

The double-spin-polarization observable E for 𝛾→ p→ → p𝛑⁰ has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies E𝛾 from 0.367 to 2.173 GeV (corresponding to center-of-mass energies from 1.240 to 2.200 GeV) for pion center-of-mass angles, cos θc.m.𝛑⁰, between - 0.86 and 0.82. These new CLAS measurements cover a broader energy range and have smaller uncertainties compared to previous CBELSA data and provide an important independent check on systematics. These measurements are compared to predictions as well as new global fits from The George Washington University, Mainz, and Bonn-Gatchina …

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