A. Hobart

activity

20202026

most citedAn experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

45 citations · 272 across the 36 of their papers we have counts for

collaborators

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24 papers · 1 filter

nucl-ex2026

First measurement of polarized spin-density matrix elements and differential cross sections d $σ$ /d $t$ in $ω$ ~photoproduction off the proton for $2.7 < E_{γ} < 5.2$ GeV using CLAS at Jefferson Lab

T. Hu, Z. Akbar, V. Crede +147

We report on the differential cross sections d $σ$ /d $t$ , the unpolarized spin-density matrix elements $ρ_{00}^{0}$ , $ρ_{1 - 1}^{0}$ , Re\, $ρ_{10}^{0}$ , and the first extraction of the polari…

nucl-ex2025

Threshold $J / ψ$ Photoproduction as a Probe of Nuclear Gluon Structure

J. R. Pybus, D. Dutta, H. Gao +83

The nuclear EMC effect is the observation that quark distributions in bound nucleons experience significant modification at large $x$ relative to free nucleons. Despite decades of…

nucl-ex2025

Measurement of Beam-Recoil Observables $C_{x}$ and $C_{z}$ for $K^{+} Λ$ Photoproduction

CLAS Collaboration, S. Adhikari, B. A. Raue +154

Exclusive photoproduction of $K^{+} Λ$ final states off a proton target has been an important component in the search for missing nucleon resonances and our understanding of the prod…

nucl-ex2025

Recoil Polarization in $K^{+} Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

D. S. Carman, A. D'Angelo, L. Lanza +127

Hyperon recoil polarization measurements for the exclusive electroproduction of $K^{+} Λ$ and $K^{+} Σ^{0}$ final states from an unpolarized proton target have been carried out using the C…

nucl-ex2025

Measurement of single- and double-polarization observables in the photoproduction of $π^{+} π^{-}$ ~meson pairs off the proton using CLAS at Jefferson Laboratory

P. Roy, S. Cao, V. Crede +141

The photoproduction of $π^{+} π^{-}$ meson pairs off the proton has been studied in the reaction $γ p \to p π^{+} π^{-}$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-sp…

nucl-ex2024

Photoproduction of two charged pions off protons in the resonance region

A. V. Sarantsev, E. Klempt, K. V. Nikonov +4

Photoproduction of charged pions pairs off protons is studied within the invariant masses of the final state hadrons from 1.6 to 2.4 GeV at the Thomas Jefferson National Accelerato…

nucl-ex2024★ 2 cited

Measurement of the nucleon spin structure functions for 0.01< $Q^{2}$ <1 GeV $^{2}$ using CLAS

A. Deur, S. E. Kuhn, M. Ripani +147

The spin structure functions of the proton and the deuteron were measured during the EG4 experiment at Jefferson Lab in 2006. Data were collected for longitudinally polarized elect…

nucl-ex2024

Dihadron Azimuthal Correlations in Deep-Inelastic Scattering Off Nuclear Targets

CLAS Collaboration

We measured the nuclear dependence of the di-pion azimuthal correlation function in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) and a 5 GeV…

nucl-ex2023★ 1 cited

Beam Charge Asymmetries for Deeply Virtual Compton Scattering on the Proton at CLAS12

E. Voutier, V. Burkert, S. Niccolai +76

The parameterization of the nucleon structure through Generalized Parton Distributions (GPDs) shed a new light on the nucleon internal dynamics. For its direct interpretation, Deep…

nucl-ex2023★ 19 cited

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

A. Accardi, P. Achenbach, D. Adhikari +441

This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a…

nucl-ex2023

Measurement of the helicity asymmetry $E$ for the $γ p \to p π^{0}$ reaction in the resonance region

K. Chan, N. Zachariou, M. Bashkanov +9

The double-spin-polarization observable $E$ for $γ p \to p π^{0}$ has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies $E_{γ}$ …

nucl-ex2022

First Measurement of $Λ$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

T. Chetry, L. El Fassi, W. K. Brooks +151

We report results of $Λ$ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Contin…

nucl-ex2022★ 9 cited

Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei

S. J. Paul, S. Moran, M. Arratia +142

We present the first measurement of di-hadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident o…

nucl-ex2022★ 1 cited

Exclusive $π^{-}$ Electroproduction off the Neutron in Deuterium in the Resonance Region

Y. Tian, R. W. Gothe, V. I. Mokeev +140

New results for the exclusive and quasi-free cross sections off neutrons bound in deuterium $γ_{v} n (p) \to p π^{-} (p)$ are presented over a wide final state hadron angle rang…

nucl-ex2022★ 13 cited

Beam-Recoil Transferred Polarization in $K^{+} Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

D. S. Carman, A. D'Angelo, L. Lanza +138

Beam-recoil transferred polarizations for the exclusive electroproduction of $K^{+} Λ$ and $K^{+} Σ^{0}$ final states from an unpolarized proton target have been measured using the CLAS12…

nucl-ex2021

Polarized Structure Function $σ_{L T^{'}}$ from $π^{0} p$ Electroproduction Data in the Resonance Region at $0.4$ GeV $^{2} < Q^{2} < 1.0$ GeV $^{2}$

E. L. Isupov, V. D. Burkert, A. A. Golubenko +138

The first results on the $σ_{L T^{'}}$ structure function in exclusive $π^{0} p$ electroproduction at invariant masses of the final state of 1.5 GeV $<$ $W$ $<$ 1.8 GeV and in the range o…

nucl-ex2021★ 28 cited

Measurement of charged-pion production in deep-inelastic scattering off nuclei with the CLAS detector

S. Moran, R. Dupre, H. Hakobyan +141

Background: Energetic quarks in nuclear DIS propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimul…

nucl-ex2021

Beam-spin asymmetry $Σ$ for $Σ^{-}$ hyperon photoproduction off the neutron

Nicholas Zachariou, Edwin Munevar, Barry Berman +8

We report a new measurement of the beam-spin asymmetry $Σ$ for the $γ n \to K^{+} Σ^{-}$ reaction using quasi-free neutrons in a liquid-deuterium target. The new…

nucl-ex2021

Deeply virtual Compton scattering using a positron beam in Hall-C at Jefferson Lab

A. Afanasev, I. Albayrak, S. Ali +71

We propose to use the High Momentum Spectrometer of Hall C combined with the Neutral Particle Spectrometer (NPS) to perform high precision measurements of the Deeply Virtual Compto…

nucl-ex2021★ 21 cited

Beam charge asymmetries for deeply virtual Compton scattering off the proton

V. Burkert, L. Elouadrhiri, F. -X. Girod +57

The unpolarized and polarized Beam Char\-ge Asymmetries (BCAs) of the $\vv{e}^{\pm}p \to e^{\pm}p γ$ process off unpolarized hydrogen are discussed. The measurement of BCAs with th…

nucl-ex2021★ 17 cited

Measurement of deeply virtual Compton scattering off Helium-4 with CLAS at Jefferson Lab

R. Dupré, M. Hattawy, N. A. Baltzell +138

We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off $^{4}$ He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab us…

nucl-ex2021★ 25 cited

Measurement of the proton spin structure at long distances

X. Zheng, A. Deur, H. Kang +148

Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long di…

nucl-ex2020★ 45 cited

An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

A. Accardi, A. Afanasev, I. Albayrak +227

Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context…

nucl-ex2020★ 11 cited

First measurement of direct photoproduction of the $a_{2} (1320)^{0}$ meson on the proton

A. Celentano, M. Battaglieri, R. De Vita +4

We present the first measurement of the exclusive reaction $γ p \to a_{2} (1320)^{0} p$ in the photon energy range $3.5$ - $5.5$ GeV and four-momentum transfer squared $0.2<-t<2…

First measurement of polarized spin-density matrix elements and differential cross sections dσ/dt in ω~photoproduction off the proton for 2.7<Eγ​<5.2 GeV using CLAS at Jefferson Lab

Threshold J/ψ Photoproduction as a Probe of Nuclear Gluon Structure

Measurement of Beam-Recoil Observables Cx​ and Cz​ for K+Λ Photoproduction

Recoil Polarization in K+Y Electroproduction in the Nucleon Resonance Region with CLAS12

Measurement of single- and double-polarization observables in the photoproduction of π+π−~meson pairs off the proton using CLAS at Jefferson Laboratory

Photoproduction of two charged pions off protons in the resonance region

Measurement of the nucleon spin structure functions for 0.01<Q2<1 GeV2 using CLAS

Dihadron Azimuthal Correlations in Deep-Inelastic Scattering Off Nuclear Targets

Beam Charge Asymmetries for Deeply Virtual Compton Scattering on the Proton at CLAS12

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

Measurement of the helicity asymmetry E for the γ​p​→pπ0 reaction in the resonance region

First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei

Exclusive π− Electroproduction off the Neutron in Deuterium in the Resonance Region

Beam-Recoil Transferred Polarization in K+Y Electroproduction in the Nucleon Resonance Region with CLAS12

Polarized Structure Function σLT′​ from π0p Electroproduction Data in the Resonance Region at 0.4 GeV2<Q2<1.0 GeV2

Measurement of charged-pion production in deep-inelastic scattering off nuclei with the CLAS detector

Beam-spin asymmetry Σ for Σ− hyperon photoproduction off the neutron

Deeply virtual Compton scattering using a positron beam in Hall-C at Jefferson Lab

Beam charge asymmetries for deeply virtual Compton scattering off the proton

Measurement of deeply virtual Compton scattering off Helium-4 with CLAS at Jefferson Lab

Measurement of the proton spin structure at long distances

An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

First measurement of direct photoproduction of the a2​(1320)0 meson on the proton

First measurement of polarized spin-density matrix elements and differential cross sections d $σ$ /d $t$ in $ω$ ~photoproduction off the proton for $2.7 < E_{γ} < 5.2$ GeV using CLAS at Jefferson Lab

Threshold $J / ψ$ Photoproduction as a Probe of Nuclear Gluon Structure

Measurement of Beam-Recoil Observables $C_{x}$ and $C_{z}$ for $K^{+} Λ$ Photoproduction

Recoil Polarization in $K^{+} Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

Measurement of single- and double-polarization observables in the photoproduction of $π^{+} π^{-}$ ~meson pairs off the proton using CLAS at Jefferson Laboratory

Measurement of the nucleon spin structure functions for 0.01< $Q^{2}$ <1 GeV $^{2}$ using CLAS

Measurement of the helicity asymmetry $E$ for the $γ p \to p π^{0}$ reaction in the resonance region

First Measurement of $Λ$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Exclusive $π^{-}$ Electroproduction off the Neutron in Deuterium in the Resonance Region

Beam-Recoil Transferred Polarization in $K^{+} Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

Polarized Structure Function $σ_{L T^{'}}$ from $π^{0} p$ Electroproduction Data in the Resonance Region at $0.4$ GeV $^{2} < Q^{2} < 1.0$ GeV $^{2}$

Beam-spin asymmetry $Σ$ for $Σ^{-}$ hyperon photoproduction off the neutron

First measurement of direct photoproduction of the $a_{2} (1320)^{0}$ meson on the proton