J. Annand

activity

19992026

^{208}

Pb from Coherent Pion Photoproduction

229 citations · 2k across the 69 of their papers we have counts for

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46 papers · 1 filter

nucl-ex2024

First measurement using elliptically polarized photons of the double-polarization observable $E$ for $γ p \to p π^{0}$ and $γ p \to n π^{+}$

A2 Collaboration, F. Afzal, K. Spieker +74

We report the measurement of the helicity asymmetry $E$ for the $p π^{0}$ and $n π^{+}$ final states using, for the first time, an elliptically polarized photon beam in combination with…

nucl-ex2023

Evaluation of the E2/M1 ratio in the $N \to Δ (1232)$ transition from the $γ p \to p π^{0}$ reaction

E. Mornacchi, P. Pedroni, F. Afzal +59

A new data set for the helicity-dependent differential cross section of the single-meson photoproduction reaction $γ p \to p π^{0}$ was obtained for the photon energy interval 150-4…

nucl-ex2023★ 2 cited

Helicity dependent cross sections for the photoproduction of $π^{0} π^{\pm}$ pairs from quasi-free nucleons

A2 Collaboration, D. Ghosal, V. Sokhoyan +71

Photoproduction of $π^{0} π^{\pm}$ -pairs from quasifree nucleons bound in the deuteron has been investigated to study the helicity dependence of this reaction. Measurements with a liq…

nucl-ex2022

Neutron polarisation transfer, $C_{x^{'}}^{n}$ , in $π^{+}$ photoproduction off the proton

M. Bashkanov, D. P. Watts, S. J. D. Kay +63

We report a first measurement of the double-polarisation observable, $C_{x^{'}}$ , in $π^{+}$ photoproduction off the proton. The $C_{x^{'}}$ double-polarisation observable represents the t…

nucl-ex2022★ 3 cited

First measurement of polarisation transfer $C_{x^{'}}^{n}$ in deuteron photodisintegration

M. Bashkanov, D. P. Watts, S. J. D. Kay +66

A first measurement of the polarisation transfer from a circularly-polarised photon to the final state neutron ( $C_{x^{'}}^{n}$ ) in deuterium photodisintegration has been carried out. T…

nucl-ex2022★ 1 cited

Measurement of the helicity dependence for single $π^{0}$ photoproduction from the deuteron

The A2 collaboration, F. Cividini, M. Dieterle +72

The helicity-dependent single $π^{0}$ photoproduction cross section on the deuteron and the angular dependence of the double polarisation observable $E$ for the quasi-free single $…

nucl-ex2021

Measurement of Compton scattering at MAMI for the extraction of the electric and magnetic polarizabilities of the proton

A2 Collaboration, E. Mornacchi, P. P. Martel +65

A precise measurement of the differential cross-sections $d σ / d Ω$ and the linearly polarized photon beam asymmetry $Σ_{3}$ for Compton scattering on the proton below pion threshold ha…

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★ 2 cited

Single $π^{0}$ Production Off Neutrons Bound in Deuteron with Linearly Polarized Photons

C. Mullen, S. Gardner, D. I. Glazier +79

The quasifree $γ d \to π^{0} n (p)$ photon beam asymmetry, $Σ$ , has been measured at photon energies, $E_{γ}$ , from 390 to 610 MeV, corresponding to center of mass energy fr…

nucl-ex2021★ 32 cited

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

M. E. Christy, T. Gautam, L. Ou +167

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q $^{2}$ ) up to 15.75~\gevsq. Combined with existing data, these p…

nucl-ex2020★ 9 cited

Helicity-dependent cross sections for the photoproduction of $π^{0}$ pairs from nucleons

M. Dieterle, L. Witthauer, A. Fix +88

The double-polarization observable $E$ and helicity-dependent cross sections $σ_{1/2}$ , $σ_{3/2}$ have been measured for the photoproduction of $π^{0}$ pairs off quasi-free protons a…

nucl-ex2019★ 20 cited

Signatures of the $d^{*} (2380)$ hexaquark in d( $γ$ , $p n$ )

M. Bashkanov, D. P. Watts, S. J. D. Kay +74

We report a measurement of the spin polarisation of the recoiling neutron in deuterium photodisintegration, utilising a new large acceptance polarimeter within the Crystal Ball at…

nucl-ex2019★ 14 cited

Spin polarizabilities of the proton by measurement of Compton double-polarization observables

D. Paudyal, P. P. Martel, G. M. Huber +90

The Compton double-polarization observable $Σ_{2 z}$ has been measured for the first time in the $Δ (1232)$ resonance region using a circularly polarized photon beam incident on a lo…

nucl-ex2019★ 27 cited

Cross Section for $γ n \to π^{0} n$ measured at Mainz/A2

W. J. Briscoe, M. Hadzimehmedovi, A. E. Kudryavtsev +89

The $γ n \to π^{0} n$ differential cross section evaluated for 27 energy bins span the photon-energy range 290-813 MeV (W = 1.195-1.553 GeV) and the pion c.m. polar production angles,…

nucl-ex2019★ 3 cited

Measurement of the beam-helicity asymmetry in photoproduction of $π^{0} η$ pairs on carbon, aluminum, and lead

V. Sokhoyan, S. Prakhov, A. Fix +88

The beam-helicity asymmetry was measured, for the first time, in photoproduction of $π^{0} η$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The result…

nucl-ex2019★ 2 cited

Physics with Positron Beams at Jefferson Lab 12 GeV

A. Afanasev, I. Albayrak, S. Ali +124

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

nucl-ex2018★ 21 cited

Experimental study of the $γ p \to K^{0} Σ^{+}$ , $γ n \to K^{0} Λ$ , and $γ n \to K^{0} Σ^{0}$ reactions at the Mainz Microtron

C. S. Akondi, K. Bantawa, D. M. Manley +78

This work measured $d σ / d Ω$ for neutral kaon photoproduction reactions from threshold up to a c.m.\ energy of 1855MeV, focussing specifically on the $γ p \to K^{0} Σ^{+}$ , $γn\righ…

nucl-ex2018★ 9 cited

First measurement of helicity-dependent cross sections in pi0-eta photoproduction from quasi-free nucleons

A. Käser, M. Dieterle, L. Witthauer +80

The helicity-dependent cross sections for the photoproduction of $π^{0} η$ pairs have been measured for the first time. The experiment was performed at the tagged photon facility of t…

nucl-ex2018★ 20 cited

Deuteron photodisintegration by polarized photons in the region of the $d^{*} (2380)$

M. Bashkanov, S. Kay, D. P. Watts +70

We report the first large-acceptance measurement of the beam-spin asymmetry for deuteron photodisintegration ( $γ d \to p n$ ) in the photon energy range $400 < E_{γ} < 630$ ~MeV. The mea…

nucl-ex2017★ 24 cited

First measurement of the polarization observable $E$ and helicity-dependent cross sections in single $π^{0}$ photoproduction from quasi-free nucleons

M. Dieterle, L. Witthauer, F. Cividini +84

The double-polarization observable $E$ and the helicity-dependent cross sections $σ_{1/2}$ and $σ_{3/2}$ have been measured for the first time for single $π^{0}$ photoproduction fr…

nucl-ex2017★ 55 cited

Study of $η$ and $η^{'}$ photoproduction at MAMI

V. L. Kashevarov, P. Ott, S. Prakhov +87

The reactions $γ p \to η p$ and $γ p \to η^{'} p$ have been measured from their thresholds up to the center-of-mass energy $W = 1.96$ GeV with the tagged-photon facilities at the Mainz Microt…

nucl-ex2016★ 22 cited

Determination of the scalar polarizabilities of the proton using beam asymmetry $Σ_{3}$ in Compton scattering

V. Sokhoyan, E. J. Downie, E. Mornacchi +73

The scalar dipole polarizabilities, $α_{E 1}$ and $β_{M 1}$ , are fundamental properties related to the internal dynamics of the nucleon. The currently accepted values of the proton p…

nucl-ex2016★ 21 cited

Photoproduction ofeta-pi pairs off nucleons and deuterons

A. Kaeser, F. Mueller, J. Ahrens +66

Quasi-free photoproduction of $π η$ -pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.…

nucl-ex2016★ 11 cited

Photon asymmetry measurements of $γ p \to π^{0} p$ for E $_{γ}$ =320 $-$ 650 MeV

S. Gardner, D. Howdle, M. H. Sikora +97

High statistics measurements of the photon asymmetry $Σ$ for the $γ$ p $\to π^{0}$ p reaction have been made in the center of mass energy range W=1214-145…

First measurement using elliptically polarized photons of the double-polarization observable E for γp→pπ0 and γp→nπ+

Evaluation of the E2/M1 ratio in the N→Δ(1232) transition from the γ​p​→pπ0 reaction

Helicity dependent cross sections for the photoproduction of π0π± pairs from quasi-free nucleons

Neutron polarisation transfer, Cx′n​, in π+ photoproduction off the proton

First measurement of polarisation transfer Cx′n​ in deuteron photodisintegration

Measurement of the helicity dependence for single π0 photoproduction from the deuteron

Measurement of Compton scattering at MAMI for the extraction of the electric and magnetic polarizabilities of the proton

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

Single π0 Production Off Neutrons Bound in Deuteron with Linearly Polarized Photons

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

Helicity-dependent cross sections for the photoproduction of π0 pairs from nucleons

Signatures of the d∗(2380) hexaquark in d(γ,pn)