Z. Ahmed

activity

20122025

most citedNew Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei

59 citations · 798 across the 41 of their papers we have counts for

collaborators

42 papers

hep-ex2025

New high-statistics measurement of the $π^{0} \to e^{+} e^{-} γ$ Dalitz decay at the Mainz Microtron

S. Prakhov, L. Heijkenskjöld, S. Abt +69

The Dalitz decay $π^{0} \to e^{+} e^{-} γ$ has been measured with the highest statistical accuracy obtained so far in the $γ p \to π^{0} p$ reaction with the A2 tagged-photon facility at the M…

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★ 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…

hep-ex2022

Target and beam-target asymmetries for the $γ p \to π^{0} π^{0} p$ reaction

S. Garni, V. L. Kashevarov, A. Fix +81

Background: Photoproduction of pion pairs allows to study sequential decays of nucleon resonances via excited intermediate states. Such decays are important e.g. for states which i…

nucl-ex2022

First Measurement of the EMC Effect in $^{10}$ B and $^{11}$ B

A. Karki, D. Biswas, F. A. Gonzalez +94

The nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in $^{10}$ B and $^{11}$ B. Previous measure…

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

Constraints on the onset of color transparency from quasi-elastic $^{12}$ C $(e, e^{'} p)$ up to $Q^{2} = 14.2$ (GeV $/ c)^{2}$

D. Bhetuwal, J. Matter, H. Szumila-Vance +87

Quasi-elastic scattering on $^{12}$ C $(e, e^{'} p)$ was measured in Hall C at Jefferson Lab for space-like 4-momentum transfer squared $Q^{2}$ in the range of 8--14.2\,(GeV/ $c$ ) $^{2}$ with p…

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 $…

hep-ph2022★ 36 cited

Deeply virtual Compton scattering cross section at high Bjorken $x_{B}$

F. Georges, M. N. H. Rashad, A. Stefanko +159

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 Generaliz…

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…

hep-ph2021

Deeply virtual Compton scattering off the neutron

M. Benali, C. Desnault, M. Mazouz +96

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scatt…

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…

hep-ex2020★ 18 cited

Deep exclusive electroproduction of $π^{0}$ at high $Q^{2}$ in the quark valence regime

The Jefferson Lab Hall A Collaboration, M. Dlamini, B. Karki +159

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of $x_{B}$ (0.36, 0.48 and 0.60) and $Q^{2}$ (3.1 to 8.4 GeV $^{2}$ ) obtai…

nucl-ex2020★ 35 cited

Ruling out color transparency in quasi-elastic $^{12}$ C(e,e'p) up to $Q^{2}$ of 14.2 (GeV/c) $^{2}$

D. Bhetuwal, J. Matter, H. Szumila-Vance +87

Quasielastic $^{12}$ C $(e, e^{'} p)$ scattering was measured at space-like 4-momentum transfer squared $Q^{2}$ ~=~8, 9.4, 11.4, and 14.2 (GeV/c) $^{2}$ , the highest ever achieved to date. Nucl…

nucl-ex2020★ 16 cited

Probing the Deuteron at Very Large Internal Momenta

Carlos Yero

$^{2} H (e, e^{'} p) n$ cross sections have been measured at 4-momentum transfers of $Q^{2} = 4.5 \pm 0.5$ (GeV/c) $^{2}$ over a range of neutron recoil momenta, $p_{r}$ ,…

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-ex2020★ 23 cited

Novel observation of isospin structure of short-range correlations in calcium isotopes

D. Nguyen, Z. Ye, P. Aguilera +101

Short Range Correlations (SRCs) have been identified as being responsible for the high momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of n…

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

Probing for high momentum protons in $^{4}$ He via the $^{4} H e (e, e^{'} p) X$ reaction

S. Iqbal, F. Benmokhtar, M. Ivanov +107

Experimental cross sections for the $^{4} H e (e, e^{'} p) X$ reaction up to a missing momentum of 0.632 GeV/ $c$ at $x_{B} = 1.24$ and $Q^{2}$ =2(GeV/ $c$ ) $^{2}$ are reported. The data are compared to…

New high-statistics measurement of the π0→e+e−γ Dalitz decay at the Mainz Microtron

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

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

Target and beam-target asymmetries for the γp→π0π0p reaction

First Measurement of the EMC Effect in 10B and 11B

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

Constraints on the onset of color transparency from quasi-elastic 12C(e,e′p) up to Q2=14.2(GeV/c)2

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

Deeply virtual Compton scattering cross section at high Bjorken xB​