Measurement of recoil proton polarizations in the electrodisintegration of deuterium by polarized electrons

Barkhuff, D.; Armstrong, Christopher; Bertozzi, W.; Chen, J.P.; Dale, D.; Dodson, G.; Epstein, M. B.; Farkhondeh, M.; Finn, John M.; Gilad, S.; Jones, M. K.; Joo, K.; Kelly, James; Kowalski, S.; Liu, D.; Lourie, R.; McIntyre, Justin I.; Madey, R.; Margaziotis, D. J.; Markowitz, P.; Mertz, C.; Milbrath, Brian D.; Mitchell, J.; Mukhopadhyay, S.; Perdrisat, C. F.; Punjabi, V.; Qin, L.; Rutt, P. M.; Sarty, A. J.; Tieger, D.; Tschalaer, C.; Turchinetz, W.; Ulmer, P. E.; Verst, S.P. Van; Vellidis, C.; Warren, G.; Weinstein, Lawrence; Woo, R. J.

doi:10.1016/s0370-2693(99)01294-0

Cited by 16 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the neutron side, the pioneering experiment of Madey et al performed the first recoil polarization measurement of G En at a Q 2 -value of 0.255 GeV 2 in 1994 [36] at the MIT BATES Linear Accelerator; and the first double polarization measurement of the proton form factor ratio, G Ep /G Mp , was also carried out at the same lab in 1994-1995 by measuring the two polarization transfer components P ℓ and P t , at Q 2 -values of 0.38 to 0.50 GeV 2 [37,38,39].…”

Section: History Of Elastic Electron Scattering On the Nucleonmentioning

confidence: 99%

“…In his review paper Hofstadter [4] discussed in detail the extraction of proton charge and magnetization radii between 0.72 and 0.80 fm using different models. Almost sixty years after the work of Hofstadter [4], the question of whether the proton radius is 0.8775 (51) fm, the CODATA [5] value from ep elastic scattering, or is 0.84087 (39) fm [6], the muonic hydrogen value, which is a difference of seven standard deviations, is being discussed intensely.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The structure of the nucleon: Elastic electromagnetic form factors

et al. 2015

Self Cite

View full text Add to dashboard Cite

Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discuss the outlook for the future.PACS. PACS-key 13.40.Gp -PACS-key 13.85.Dz

show abstract

Section: History Of Elastic Electron Scattering On the Nucleonmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The structure of the nucleon: Elastic electromagnetic form factors

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Polarization transfer from a polarized electron to a proton in an elastic scattering reaction has become a recognized method to measure the ratio of the proton's elastic electromagnetic form factors G E /G M [1][2][3][4][5][6][7][8][9]. For a proton initially at rest, assuming the one-photon exchange approximation, the ratio of the transverse (P x ) to longitudinal (P z ) polarization-transfer components, with respect to the momentum transfer q, is proportional to G E /G M [10]:…”

Section: Introductionmentioning

confidence: 99%

“…where k 0 , k 0 are respectively the initial and final electron energies, θ k,k is the electron scattering angle in the lab Measuring the ratio of the components of the polarization transfer to a knock-out proton in quasi-free kinematics on nuclei, which is sensitive to the electromagnetic FF ratio, has been suggested as a method to study differences between free and bound protons [4,5]. As such it can be used as a tool to identify medium modifications in the bound proton's internal structure [12], reflected in the FFs and thereby in the polarization transfer.…”

Section: Introductionmentioning

confidence: 99%

The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic e→p and quasi-elastic e
Paul
¹
,
Brecelj
²
,
Arenhövel
³

et al. 2019
Physics Letters B
6
1
17
0
View full text Add to dashboard Cite

A comparison between polarization-transfer to a bound proton in quasi-free kinematics by the A( e, e p) knockout reaction and that in elastic scattering off a free proton can provide information on the characteristics of the bound proton. In the past the reported measurements have been compared to those of a free proton with zero initial momentum. We introduce, for the first time, expressions for the polarization-transfer components when the proton is initially in motion and compare them to the 2 H data measured at the Mainz Microtron (MAMI). We show the ratios of the transverse (P x ) and longitudinal (P z ) components of the polarization transfer in 2 H( e, e p)n, to those of elastic scattering off a "moving proton", assuming the proton's initial (Fermi-motion) momentum equals the negative missing momentum in the measured reaction. We found that the correction due to the proton motion is up to 20% at high missing momentum. However the effect on the double ratio (Px/Pz) A (Px/Pz) 1 H is largely canceled out, as shown for both 2 H and 12 C data. This implies that the difference between the restingand the moving-proton kinematics is not the primary cause for the deviations between quasi-elastic and elastic scattering reported previously.

show abstract

“…Polarization transfer from a polarized electron to a proton in elastic scattering has become a recognized method to measure the ratio of the proton's elastic electromagnetic form factors, G E /G M [1][2][3][4][5][6][7][8][9]. Assuming the one-photon exchange approximation, the ratio of the transverse (P x ) to longitudinal (P z ) polarization-transfer components is proportional to G E /G M [10].…”

Section: Introductionmentioning

confidence: 99%

Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics

Paul¹,

Izraeli²,

Brecelj³

et al. 2019

Physics Letters B

View full text Add to dashboard Cite

We present measurements of the polarization-transfer components in the 2 H( e, e p) reaction, covering a previously unexplored kinematic region with large positive (anti-parallel) missing momentum, p miss , up to 220 MeV/c, and Q 2 = 0.65 (GeV/c) 2 . These measurements, performed at the Mainz Microtron (MAMI), were motivated by theoretical calculations which predict small final-state interaction (FSI) effects in these kinematics, making them favorable for searching for medium modifications of bound nucleons in nuclei. We find in this kinematic region that the measured polarization-transfer components P x and P z and their ratio agree with the theoretical calculations, which use free-proton form factors. Using this, we establish upper limits on possible medium effects that modify the bound proton's form factor ratio G E /G M at the level of a few percent. We also compare the measured polarization-transfer components and their ratio for 2 H to those of a free (moving) proton. We find that the universal behavior of 2 H, 4 He and 12 C in the double ratio (Px/Pz) A (Px/Pz) 1 H is maintained in the positive missing-momentum region.

show abstract

Measurement of recoil proton polarizations in the electrodisintegration of deuterium by polarized electrons

Cited by 16 publications

References 17 publications

The structure of the nucleon: Elastic electromagnetic form factors

The structure of the nucleon: Elastic electromagnetic form factors

The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic e→p and quasi-elastic e
Paul
¹
,
Brecelj
²
,
Arenhövel
³

et al. 2019
Physics Letters B
6
1
17
0
View full text Add to dashboard Cite

Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics

Contact Info

Product

Resources

About

Measurement of recoil proton polarizations in the electrodisintegration of deuterium by polarized electrons

Cited by 16 publications

References 17 publications

The structure of the nucleon: Elastic electromagnetic form factors

The structure of the nucleon: Elastic electromagnetic form factors

The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic e→p and quasi-elastic ePaul1, Brecelj2, Arenhövel3 et al. 2019Physics Letters B61170View full textAdd to dashboardCite

Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics

Contact Info

Product

Resources

About

The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic e→p and quasi-elastic e
Paul
¹
,
Brecelj
²
,
Arenhövel
³

et al. 2019
Physics Letters B
6
1
17
0
View full text Add to dashboard Cite