Nuclear Commons^™

Electron Scattering And Neutrino Physics, A. M. Ankowski, A. Ashkenazi, S. Bacca, J. L. Barrow, M. Betancourt, A. Bodek, M. E. Christy, L. Doria, S. Dytman, A. Friedland, O. Hen, C. J. Horowitz, N. Jachowicz, W. Ketchum, T. Lux, K. Mahn, C. Mariani, J. Newby, V. Pandey, A. Papadopoulou, E. Radicioni, F. Sánchez, C. Sfienti, J. M. Udías, L. Weinstein, L. Alvarez-Ruso, J. E. Amaro, C. A. Argüelles, A. B. Balantekin, S. Bolognesi, V. Brdar, P. Butti, S. Carey, Z. Djurcic, O. Dvornikov, S. Edayath, S. Gardiner, J. Isaacson, W. Jay, K. S. Mcfarland, A. Nikolakopoulos, A. Norrick, S. Pastore, G. Paz, M. H. Reno, I. Ruiz Simo, J. E. Sobczyk, A. Sousa, N. Toro, Y. D. Tsai, M. Wagman, J. G. Walsh, G. Yang

Physics Faculty Publications

A thorough understanding of neutrino–nucleus scattering physics is crucial for the successful execution of the entire US neutrino physics program. Neutrino–nucleus interaction constitutes one of the biggest systematic uncertainties in neutrino experiments—both at intermediate energies affecting long-baseline deep underground neutrino experiment, as well as at low energies affecting coherent scattering neutrino program—and could well be the difference between achieving or missing discovery level precision. To this end, electron–nucleus scattering experiments provide vital information to test, assess and validate different nuclear models and event generators intended to test, assess and validate different nuclear models and event generators intended to be used …

Nuclear Magnetic Quadrupole Moment Of ¹⁷⁵Lu And Parity-Violating Polarization Degree Of Levels In ¹⁷⁵Luoh⁺, Igor Kurchavov, Daniel Maison, Leonid Skripnikov, Matt Grau, Alexander Petrov

Physics Faculty Publications

A calculation is performed of the parity-violating polarizations in the external electric field, which are associated with the electron electric dipole moment (eEDM) and magnetic quadrupole moment (MQM) of the ¹⁷⁵Lu nucleus, as well as the determination of the rovibrational structure for the ¹⁷⁵LuOH⁺ cation. Beyond the bending of the molecule, the slight effect of the stretching of the distance between Lu and OH is taken into account. This study is required for the preparation of the experiment and for the extraction of the eEDM and MQM values of ¹⁷⁵Lu from future measurements.

Measurement Of Spin-Density Matrix Elements In P(770) Production With A Linearly Polarized Photon Beam At E𝛾 = 8.2-8.8 Gev, 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, Et Al., Gluex Collaboration

Physics Faculty Publications

The GlueX experiment at Jefferson Lab studies photoproduction of mesons using linearly polarized 8.5 GeV photons impinging on a hydrogen target which is contained within a detector with near-complete coverage for charged and neutral particles. We present measurements of spin-density matrix elements for the photoproduction of the vector meson ρ(770). The statistical precision achieved exceeds that of previous experiments for polarized photoproduction in this energy range by orders of magnitude. We confirm a high degree of s-channel helicity conservation at small squared four-momentum transfer t and are able to extract the t dependence of natural- and unnatural-parity exchange contributions to …

Liouvillian Dynamics Of The Open Schwinger Model: String Breaking And Kinetic Dissipation In A Thermal Medium, Kyle Lee, James Mulligan, Felix Ringer, Xiaojun Yao

Physics Faculty Publications

Understanding the dynamics of bound state formation is one of the fundamental questions in confining quantum field theories such as Quantum Chromodynamics (QCD). One hadronization mechanism that has garnered significant attention is the breaking of a string initially connecting a fermion and an antifermion. Deepening our understanding of real-time string-breaking dynamics with simpler, lower dimensional models like the Schwinger model can improve our understanding of the hadronization process in QCD and other confining systems found in condensed matter and statistical systems. In this paper, we consider the string-breaking dynamics within the Schwinger model and investigate its modification inside a thermal …

Deeply Virtual Compton Scattering Using A Positron Beam In Hall C, V. Berdnikov, A. Camsonne, M. Carmignotto, R. Ent, J. Grames, D. Higinbotham, C. Keppel, M. Mccaughan, P. Paremuzyan, B. Sawatzky, A. Somov, B. Wojtsekhowski, S. Wood, C. Zorn, R. Dupré, M. Ehrhart, M. Guidal, S. Habet, A. Hobart, D. Marchand, C. Muñoz Camacho, S. Niccolai, E. Voutier, M. Mazouz, T. Horn, G. Kalicy, M. Muhoza, I. Pegg, R. Trotta, A. Asaturyan, A. Mkrtchyan, H. Mkrtchyan, V. Tadevosyan, H. Voskanyan, S. Zhamkochyan, M. Amaryan, C. Hyde, M. Kerver, J. Murphy, J. Roche, P. Markowitz, A. Afanasev, W. J. Briscoe, I. Strakovsky, M. Boer, T. Forest, J.R.M. Annand, D. J. Hamilton, B. Mckinnon, D. Day, M. A. I. Fernando, D. Keller, R. Rondon, J. Zhang, K. Brinkmann, S. Diehl, R. Novotny, P. Gueye, V. Bellini, D. Dutta, E. Kinney, P. Nadel-Turonski, G. Niculescu, S. Sirca, I. Albayrak, M. Defurne, Z. Huang, Z. Ye

Physics Faculty Publications

We propose to use the High Momentum Spectrometer of Hall C combined with Neutral Particle Spectrometer (NPS) to perform high precision measurement of the deeply virtual compton scattering (DVCS) cross section using a beam of positrons. The combination of measurements with oppositely charged incident beams is the only unambiguous way to disentange the contribution of the DVCS² term in the photon electroproduction cross section from its interference with the Bethe-Heitler amplitude. This provies a stronger way to constrain the Generalized Parton Distributions of the nucleon. A range of kinematics accessible with an 11 GeV beam off an unpolarized proton target …

Two-Current Transition Amplitudes With Two-Body Final States, Keegan H. Sherman, Feliipe G. Ortega-Gama, Raúl A. Briceño, Andrew W. Jackura

Physics Faculty Publications

We derive the on-shell form of amplitudes containing two external currents with a single hadron in the initial state and two hadrons in the final state, denoted as 1 + J → 2 + J . This class of amplitude is relevant in precision tests of the Standard Model as well as for exploring the structure of excited states in the QCD spectrum. We present a model-independent description of the amplitudes where we sum to all orders in the strong interaction. From this analytic form we are able to extract transition and elastic resonance form factors consistent with previous work …

Partial Muon Capture Rates In A = 3 And A = 6 Nuclei With Chiral Effective Field Theory, G. B. King, S. Pastore, M. Piarulli, Rocco Schiavilla

Physics Faculty Publications

Searches for neutrinoless double-β decay rates are crucial in addressing questions within fundamental symmetries and neutrino physics. The rates of these decays depend not only on unknown parameters associated with neutrinos, but also on nuclear properties. In order to reliably extract information about the neutrino, one needs an accurate treatment of the complex many-body dynamics of the nucleus. Neutrinoless double-β decays take place at momentum transfers on the order of 100MeV /c and require both nuclear electroweak vector and axial current matrix elements. Muon capture, a process in the same momentum transfer regime, has readily available experimental data to validate …

Magnetic Structure Of Few-Nucleon Systems At High Momentum Transfers In A Chiral Effective Field Theory Approach, A. Gnech, R. Schiavilla

Physics Faculty Publications

The five low-energy constants (LECs) in the electromagnetic current derived in chiral effective field theory (χEFT) up to one loop are determined by a simultaneous fit to the A=2−3 nuclei magnetic moments and to the deuteron magnetic form factor and threshold electrodisintegration at backward angles over a wide range of momentum transfers. The resulting parametrization then yields predictions for the ³He/³H magnetic form factors in excellent accord with the experimental values for momentum transfers ranging up to ≈0.8 GeV/c, beyond the expected regime of validity of the χEFT approach. The calculations are based on last-generation two-nucleon interactions …

Cross-Section Measurement Of Virtual Photoproduction Of Iso-Triplet Three-Body Hypernucleus, ⋀Nn, T. Gogami, K. N. Suzuki, B. Pandey, K. Itabashi, S. Nagao, K. Okuyama, S. N. Nakamura, L. Tang, D. Abrams, T. Akiyama, D. Androic, K. Aniol, C. Ayerbe Gayoso, J. Bane, S. Barcus, J. Barrow, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, A. Camsonne, J. Castellanos, J-P. Chen, J. Chen, S. Covrig, D. Chrisman, R. Cruz-Torres, R. Das, E. Fuchey, K. Gnanvo, F. Garibaldi, T. Gautam, J. Gomez, P. Gueye, T.J. Hague, O. Hansen, W. Henry, F. Hauenstein, D. W. Higinbotham, C. E. Hyde, M. Kaneta, C. Keppel, T. Kutz, N. Lashley-Colthirst, S. Li, H. Liu, J. Mammei, P. Markowitz, R. E. Mcclellan, F. Meddi, D. Meekins, R. Michaels, M. Mihovilovic, A. Moyer, D. Nguyen, M. Nycz, V. Owen, C. Palatchi, S. Park, T. Petkovic, S. Premathilake, P.E. Reimer, J. Reinhold, S. Riordan, V. Rodriguez, C. Samanta, S. N. Santiesteban, B. Sawatzky, S. Širca, K. Slifer, T. Su, Y. Tian, Y. Toyama, K. Uehara, G. M. Urciuoli, D. Votaw, J. Williamson, B. Wojtsekhowski, S. A. Wood, B. Yale, Z. Ye, J. Zhang, X. Zheng

Physics Faculty Publications

Missing-mass spectroscopy with the ³H(e, e′K⁺) reaction was carried out at Jefferson Lab’s (JLab) Hall A in Oct–Nov, 2018. The differential cross section for the ³H(γ^∗, K⁺)Λnn was deduced at ω = Ee − E_e′ = 2.102 GeV and at the forward K⁺-scattering angle (0^° ≤ θ_γ∗K ≤ 5^°) in the laboratory frame. Given typical predicted energies and decay widths, which are (B_Λ, Γ) = (−0.25, 0.8) and (−0.55, 4.7) MeV, the cross sections were found …

Searching For An Enhanced Signal Of The Onset Of Color Transparency In Baryons With D(E,E′P)N Scattering, Shujie Li, Carlos Yero, Jennifer Rittenhouse West, Clare Bennett, Wim Cosyn, Douglas Higinbotham, Misak Sargsian, Holly Szumila-Vance

Physics Faculty Publications

Observation of the onset of color transparency in baryons would provide a new means of studying the nuclear strong force and would be the first clear evidence of baryons transforming into a color-neutral point-like size in the nucleus as predicted by quantum chromodynamics. Recent C (e, e′p) results from electron-scattering did not observe the onset of color transparency (CT) in protons up to spacelike four-momentum transfers squared, Q² = 14.2 GeV ² . The traditional methods of searching for CT in (e, e′p) scattering use heavy targets favoring kinematics with already initially reduced final state interactions (FSIs) such that …

Collinear Factorization At Subasymptotic Kinematics And Validation In A Diquark Spectator Model, Juan V. Guerrero, Alberto Accardi

Physics Faculty Publications

We revisit the derivation of collinear factorization for Deep Inelastic Scattering at subasymptotic values of the four-momentum transfer squared, where the masses of the particles participating in the interaction cannot be neglected. By using an inclusive jet function to describe the scattered quark final state, we can restrict the needed parton kinematic approximations just to the four-momentum conservation of the hard scattering process, and explicitly expand the rest of the diagram in powers of the unobserved parton transverse momenta rather than neglecting those. This procedure provides one with more flexibility in fixing the virtuality of the scattered and recoiling partons …

An Update To C12-21-004: Semi-Inclusive Deep Inelastic Scattering Measurements Of A = 3 Nuclei With Clas12 In Hall B, D. Gaskell, D. W. Higinbotham, C. Keith, C. Keppel, J. Maxwell, A. Tadepalli, D. Meekins, D. Nguyen, S. Stepanyan, H. Szumila-Vance, A. Denniston, O. Hen, J. Kahlbow, T. Kutz, J. R. Pybus, E. P. Segarra, C. Ayerbe-Gayoso, H. Bhatt, B. Devkota, J. Dunne, D. Dutta, L. El Fassi, A. Karki, M. Amarian, C. Fogler, F. Hauenstein, C. Hyde, G. Gavalian, L. B. Weinstein, S. Li, R. Cruz Torres, J. Rittenhouse West, Z. G. Xiao, Y. Wang, J. H. Xu, Z. H. Ye, Y. P. Zhang, K. Griffioen, P. Bosted, A. Bianconi, G. Costantini, M. Leali, S. Migliorati, L. Venturelli, V. Mascagna, A. Boyer, F. Benmokhtar, A. Gadsby, A. Parker, L. Baashen, B. Raue, W. J. Briscoe, S. Ratliff, A. Schmidt, E. Seroka, P. Sharp, P. G. Solazzo, I. I. Strakovsky, K. Adhikari, G. Niculescu, K.-T. Brinkmann, S. Diehl, A. Kripko, Sheren Alsalmi, Tyler J. Hague, A. Beck, S. Beck, E. Cohen, I. Korover, G. Johansson, C. Neuburger, E. Piasetzky, Michael Nycz, R. Capobianco, T. Haywars, F.-X. Girod, K. Joo, A. Kim, V. Klimenko, R. Santos, U. Shrestha, P. Simmerling, J. Richard, N. Trotta, B. Mckinnon, W. Brooks

Physics Faculty Publications

We propose to measure precision ratios of charged pion electroproduction in 10.6 GeV Semi-Inclusive Deep Inelastic Scattering from ²D, ³He and ³H targets in CLAS12 over a wide range of xB to test the flavor dependence of the EMC effect in the valence quark region. This trio of targets minimizes hadron attenuation effects while maximizing nuclear asymmetry and takes advantage of the tritium target that will be developed for the approved quasi-elastic experiment E12-20-005 [1]. The experiment will focus on z = En/v ≥ 0.3 to maximize the connection between the struck quark and the detected π±. Double ratios of …

X17 Boson And The ³H(P, E⁺E⁻) ⁴He And ³He(N,E⁺E⁻) ⁴He Processes: A Theoretical Analysis, M. Viviani, E. Filandri, C. Gustavino, A. Kievsky, L. E. Marcucci, Rocco Schiavilla

Physics Faculty Publications

The present work deals with e⁺−e⁻ pair production in the four-nucleon system. We first analyze the process as a purely electromagnetic one in the context of a state-of-the-art approach to nuclear strong-interaction dynamics and nuclear electromagnetic currents, derived from chiral effective field theory (χEFT). Next, we examine how the exchange of a hypothetical low-mass boson would impact the cross section for such a process. We consider several possibilities, that this boson is either a scalar, pseudoscalar, vector, or axial particle. The ab initio calculations use exact hyperspherical-harmonics methods to describe the bound state and low-energy spectrum of …

Beam-Spin Asymmetry Σ For Σ⁻ Hyperon Photoproduction Off The Neutron, N. Zachariou, E. Munevar, B. L. Berman, P. Bydžovský, A. Cieplý, G. Feldman, Y. Ilieva, P. Nadel-Turonski, D. Skoupil, A. V. Sarantsev, D. P. Watts B, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, Et Al.

Physics Faculty Publications

We report a new measurement of the beam-spin asymmetry, Σ, for the ^→𝛾n → K⁺Σ⁻ reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with …

The Cross-Section Measurement For The 3H (E, E', K+) Nnλ Reaction, K. N. Suzuki, T. Gogami, B. Pandey, Florian Hauenstein, Charles E. Hyde, Z. Ye, J. Zhang, X. Zheng, Et Al.

Physics Faculty Publications

The small binding energy of the hypertriton leads to predictions of the non-existence of bound hypernuclei for isotriplet three-body systems such as nnΛ. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound nnΛ state. The nnΛ state was sought by missing-mass spectroscopy via the (e, e′K+) reaction at Jefferson Lab’s experimental Hall A. The present experiment has higher sensitivity to the nnΛ-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for …

Polarized Structure Function ΣLt' From 𝜋⁰P Electroproduction Data In The Resonance Region At 0.2 Gev² < Q² < 1.0 Gev², E. L. Isupov, V. D. Burkert, A. A. Golubenko, K. Joo, N. S. Markov, V. I. Mokeev, L. C. Smith, N. Zachariou, W. R. Armstrong, H. Atac, Et Al

Physics Faculty Publications

The first results on the σ_LT′ structure function in exclusive π⁰p electroproduction at invariant masses of the final state of 1.5GeV < W < 1.8 GeV and in the range of photon virtualities 0.4 GeV² < Q² < 1.0 GeV² were obtained from data on beam spin asymmetries and differential cross sections measured with the CLAS detector at Jefferson Lab. The Legendre moments determined from the σ_LT′ structure function have demonstrated sensitivity to the contributions from the nucleon resonances in the second and third resonance regions. These new data on the beam spin asymmetries in π⁰p electroproduction extend the opportunities for the extraction of the nucleon resonance electro-excitation amplitudes in …

Neutrino Energy Reconstruction From Semi-Inclusive Samples, R. González-Jiménez, M. B. Barbaro, J. A. Caballero, T. W. Donnelly, N. Jachowicz, G.D. Megias, K. Niewczas, A. Nikolakopoulos, J.W. Van Orden, J. M. Udías

Physics Faculty Publications

We study neutrino-nucleus charged-current reactions on finite nuclei for the situation in which an outgoing muon and a proton are detected in coincidence; i.e., we focus on semi-inclusive cross sections. We limit our attention to one-body current interactions (quasielastic scattering) and assess the impact of different nuclear effects in the determination of the neutrino energy. We identify the regions in phase space where the neutrino energy can be reconstructed relatively well and study whether the cross section in those regions is significant. Our results indicate that it is possible to filter more than 50% of all events according to the …

Measurement Of Charged-Pion Production In Deep-Inelastic Scattering Off Nuclei With The Clas Detector, Clas Collaboration, S. Morán, R. Dupre, H. Hakobyan, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, Florian Hauenstein, Sebastian Kuhn, Pushpa Pandey, Jiwan Poudel, Yelena Prok, Lawrence B. Weinstein, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al.

Physics Faculty Publications

Background: Energetic quarks in nuclear deep-inelastic scattering propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimulated gluon bremsstrahlung and intranuclear interactions of forming hadrons. More data are required to gain a more complete understanding of these effects.

Purpose: To test the theoretical models of parton transport and hadron formation, we compared their predictions for the nuclear and kinematic dependence of pion production in nuclei.

Methods: We have measured charged-pion production in semi-inclusive deep-inelastic scattering off D, C, Fe, and Pb using the CLAS detector and the CEBAF 5.014-GeV electron beam. …

Spectroscopic Study Of A Possible Λ𝑛𝑛 Resonance And A Pair Of (E, E'K⁺) Reaction With A Tritium Target, Hall A Collaboration, B. Pandey, L. Tang, T. Gogami, Florian Hauenstein, Charles Hyde, Z. Ye, J. Zhang, X. Zheng, Et Al.

Physics Faculty Publications

A mass spectroscopy experiment with a pair of nearly identical high-resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e′K⁺) reaction, enhancements, which may correspond to a possible Λnn resonance and a pair of ΣNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A = 3 and 4 Σ hypernuclei have …

Probing For High-Momentum Protons In ⁴He Via The ⁴He (E, E'P) X Reactions, Jefferson Lab Hall A Collaboration, S. Iqbal, F. Benmokhtar, M. Ivanov, L. B. Weinstein, X. Zheng, P. Zhu, R. Zielinski, Et Al

Physics Faculty Publications

Experimental cross sections for the ⁴He(e,e′p) X reactions in the missing energy range from 0.017 to 0.022 GeV and up to a missing momentum of 0.632 GeV/c at x_B = 1.24 and Q² = 2 (GeV/c)² are reported. The data are compared to relativistic distorted-wave impulse approximation calculations for the ⁴He(e,e′p)³H channel. Significantly more events are observed for p_m ≥ 0.45 GeV/c than are predicted by the theoretical model, and striking fluctuations in the ratio of data to the theoretical model around p_m = 0.3GeV/c are possible signals of initial-state multinucleon …

Determination Of The Argon Spectral Function From (E, E'P) Data, Jefferson Lab Hall A Collaboration, L. Jiang, A.M. Ankowski, D. Abrams, Florian Hauenstein, Charles Hyde, S. Wood, Z. Ye, J. Zhang, Et Al.

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 argon target. Here, we report the full results of the analysis of the data set corresponding to beam energy 2.222 GeV, and spanning the missing momentum and missing energy range 15 ≲ pm ≲ 300  MeV /c and 12 ≲ Em ≲ 80  MeV. The reduced cross section, determined as a function of p_m and E_m with ≈ 4% accuracy, has been fitted using the results of Monte Carlo simulations involving a model spectral function and …

Rapidity Evolution Of Tmds With Running Coupling, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

The scale of a coupling constant for rapidity-only evolution of transverse-momentum dependent (TMD) operators in the Sudakov kinematic region is calculated using the Brodsky-Lepage-Mackenzie optimal scale setting [S. J. Brodsky et al., Phys. Rev. D 28, 228 (1983).]. The effective argument of a coupling constant is halfway in the logarithmical scale between the transverse momentum and energy of TMD distribution. The resulting rapidity-only evolution equation is solved for quark and gluon TMDs.

Measurement Of The Nucleon FN₂/FP₂ Structure Function Ratio By The Jefferson Lab Marathon Tritium/Helium-3 Deep Inelastic Scattering Experiment, D. Abrams, H. Albataineh, B. S. Aljawrneh, S. Alsalmi, D. Androic, K. Aniol, W. Armstrong, J. Arrington, H. Atac, T. Averett, C. Ayerbe Gayoso, X. Bai, J. Bane, J. Barcus, A. Beck, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, D. Blyth, W. Boeglin, D. Bulumulla, Et Al.

Physics Faculty Publications

The ratio of the nucleon F₂ structure functions, Fⁿ₂/F^p₂, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ³H and ³He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken …

New Measurements Of The Beam-Normal Single Spin Asymmetry In Elastic Electron Scattering Over A Range Of Spin-0 Nuclei, Prex And Crex Collaborations, D. Adhikari, H. Albataineh, D. Androic, F. Hauenstein, M.N.H. Rashad, W. Zhang, J. Zhang, X. Zheng, Et Al.

Physics Faculty Publications

We report precision determinations of the beam-normal single spin asymmetries (A_n) in the elastic scattering of 0.95 and 2.18 GeV electrons off ¹²C, ⁴⁰Ca, ⁴⁸Ca, and ²⁰⁸Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_n for ⁴⁰Ca and ⁴⁸Ca are found to be similar to that of ¹²C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z ≤ 20. We also report A_n for ²⁰⁸Pb at two …

Deeply Virtual Compton Scattering Cross Section At High Bjorken 𝓍B, F. Georges, M.N.H. Rashad, A. Stefanko, J. Zhang, Y. Zhao, P. Zhu, Et Al.

Physics Faculty Publications

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable 𝓍_B. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of 𝓍_B, while systematically including helicity flip amplitudes. …

Observation Of Azimuth-Dependent Suppression Of Hadron Pairs In Electron Scattering Off Nuclei, S. J. Paul, S. Morán, M. Arratia, A. El Alaoui, H. Hakobyan, W. Brooks, M. J. Amaryan, W. R. Armstrong, H. Atac, L. Baashen, N. A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, K.-Th. Brinkmann, W. J. Briscoe, D. Bulumulla, V. D. Burkert, R. Capobianco, D. S. Carman, A. Celentano, V. Chesnokov, T. Chetry, G. Ciullo, P. L. Cole, M. Contalbrigo, G. Constantini, A. D' Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Dilks, C. Djalali, R. Dupre, H. Egiyan, L. El Fassi, P. Eugenio, S. Fegan, A. Filippi, G. Gavalian, Y. Ghandilyan, G. P. Gilfoyle, A. A. Golubenko, G. Gosta, R. W. Gothe, K. A. Griffioen, M. Guidal, M. Hattawy, T. B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D. G. Ireland, E. L. Isupov, H. S. Jo, R. Johnston, K. Joo, S. Joosten, D. Keller, A. Khanal, M. Khandaker, W. Kim, A. Kripko, V. Kubarovsky, V. Lagerquist, L. Lanza, M. Leali, S. Lee, P. Lenisa, X. Li, K. Livingston, I.J.D. Macgregor, D. Marchand, V. Mascagna, B. Mckinnon, Z. E. Meziani, S. Migliorati, R. G. Milner, T. Mineeva, M. Mirazita, V. I. Mokeev, P. Moran, C. Munoz Camacho, K. Neupane, D. Nguyen, S. Niccolai, G. Niculescu, M. Osipenko, A. I. Ostrovidov, P. Pandey, M. Paolone, L. L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, N. Pilleux, D. Pocanic, O. Pogorelko, M. Pokhrel, J. Poudel, J. W. Price, Y. Prok, B. A. Raue, T. Reed, M. Ripani, G. Rosner, F. Sabatié, C. Salgado, A. Schmidt, R. A. Schumacher, Y. G. Sharabian, E. V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, S. Stepanyan, I. I. Strakovsky, S. Strauch, J. A. Tan, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, X. Wei, R. Wishart, M. H. Wood, N. Zachariou, Z. W. Zhao, V. Ziegler, M. Zurek

Physics Faculty Publications

We present the first measurement of dihadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the gibuu model, which suggests that hadrons form near the nuclear surface and undergo multiple scattering in nuclei. These results show …

Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data, R. Weiss, A. W. Denniston, J. R. Pybus, O. Hen, E. Piasetzky, A. Schmidt, L. B. Weinstein, N. Barnea

Physics Faculty Publications

The extraction of the relative abundances of short-range correlated (SRC) nucleon pairs from inclusive electron scattering is studied using the generalized contact formalism (GCF) with several nuclear interaction models. GCF calculations can reproduce the observed scaling of the cross-section ratios for nuclei relative to deuterium at high x_B and large Q², a₂ = (σ_A/A)/(σ_d/2). In the nonrelativistic instant-form formulation, the calculation is very sensitive to the model parameters and only reproduces the data using parameters that are inconsistent with ab initio many-body calculations. Using a light-cone GCF formulation significantly decreases this sensitivity …

Short-Range Correlations And The Nuclear Emc Effect In Deuterium And Helium-3, E. P. Segarra, J. R. Pybus, F. Hauenstien, D. W. Higinbotham, G. A. Miller, E. Piasetzky, A. Schmidt, M. Strikman, L. B. Weinstein, O. Hen

Physics Faculty Publications

The EMC effect in deuterium and helium-3 is studied using a convolution formalism that allows isolating the impact of high-momentum nucleons in short-ranged correlated (SRC) pairs. We assume that the modification of the structure function of bound nucleons is given by a universal (i.e., nucleus independent) function of their virtuality, and find that the effect of such modifications is dominated by nucleons in SRC pairs. This SRC-dominance of nucleon modifications is observed despite the fact that the bulk of the nuclear inelastic scattering cross-section comes from interacting with low-momentum nucleons. These conclusions are found to be robust to model details …

Semi-Inclusive Deep Inelastic Scattering Measurements Of A = 3 Nuclei With Clas12 In Hall B, S. Li, R. Cruz Torres, J. Rittenhouse West, F. Yuan, A. Denniston, O. Hen, J. Kahlbow, T. Kutz, J. R. Pybus, E. P. Segarra, C. Ayerbe-Gayoso, H. Bhatt, D. Bhetuwal, T. Chetry, B. Devkota, J. Dunne, D. Dutta, L. El Fassi, T. Gaballah, A. Karki, M. Amarian, C. Fogler, F. Hauenstein, C. Hyde, G. Gavalian, L. B. Weinstein, D. Gaskell, D. W. Higinbotham, C. Keith, C. Keppel, J. Maxwell, A. Tadepalli, D. Meekins, D. Nguyen, S. Stepanyan, H. Szumila-Vance, Z. G. Xiao, Y. Wang, Z. H. Ye, Y. P. Zhang, K. Griffioen, P. Bosted, A. Bianconi, G. Costantini, M. Leali, S. Migliorati, L. Venturelli, V. Mascagna, A Boyer, F. Benmokhtar, A. Gadsby, A. Parker, L. Baashen, B. Raue, W. J. Briscoe, S. Ratliff, A. Schmidt, E. Seroka, P. Sharp, P. G. Solazzo, I. I. Strakovsky, K. Adhikari, G. Niculescu, K.-T. Brinkmann, S. Diehl, A. Kripko, Sheren Alsalmi, Tyler J. Hague, A. Beck, S. Beck, E. Cohen, I. Korover, G. Johansson, C. Neuburger, E. Piasetzky, Michael Nycz, R. Capobianco, T. Haywars, F.-X. Girod, K. Joo, A. Kim, V. Klimenko, R. Santos, U. Shrestha, P. Simmerling, J. Richard, N. Trotta, B. Mckinnon, W. Brooks

Physics Faculty Publications

We propose to measure precision ratios of charged pion electroproduction in Semi-Inclusive Deep Inelastic Scattering from ²D, ³He and ³H targets to test the flavor dependence of the EMC effect in the valence quark region. This trio of targets has been chosen to minimize hadron attenuation effects while maximizing nuclear asymmetry. The standard configuration CLAS12 detector will be used in the experiment to detect scattered electrons and knocked-out pions. A new, dedicated, tritium target that will be developed for the approved quasi-elastic experiment, E12-20-005 [1], will be used. The experiment will measure semi-inclusive production of charged pions over a wide …

Exploring Fundamental Properties Of ³He Through The ³He(E, E'D) Process In Clas12, D. W. Higinbotham, C. Keppel, J. Maxwell, D. Nguyen, A. S. Tadepalli, H. Szumila-Vance, S. Širca, M. Mihovilovič, A. Denniston, O. Hen, J. Kahlbow, R. Milner, J. R. Pybus, E. P. Segarra, C. Fogler, F. Hauenstein, C. Hyde, L. B. Weinstein, G. Johansson, E. Piasetzky, A. Beck, S. Beck, E. O. Cohen, I. Korover, A. Biselli, A. Schmidt

Physics Faculty Publications

Recent double-polarization measurements of (e,e'p) and (e,e'd) quasi-elastic processes on ³He have revealed deficiencies in our understanding of three-body system. With the limited kinematic coverage of these low-acceptance spectrometer experiments, it has been impossible to disentangle which aspects of the theoretical description are problematic. While resolving these uncertainties is interesting from a pure few-body physics point of view, it is also of critical importance to our interpretation of deep-inelastic data from polarized ³He which is often used as an effective polarized neutron target: as precision has improved over time, small effects like the net proton polarization end up being significant …