scholarly journals Vacuum polarization effects in elastic scattering of protons by nuclei

1987 ◽  
Vol 197 (4) ◽  
pp. 493-496 ◽  
Author(s):  
N. Ottenstein ◽  
S.J. Wallace ◽  
J.A. Tjon
Keyword(s):  
Elastic Scattering ◽  
Vacuum Polarization ◽  
Polarization Effects

Measurements of differential cross sections and polarization effects in pion-proton elastic scattering in the momentum range 875 to 1579 MeV/ c

1966 ◽  
Vol 289 (1419) ◽  
pp. 449-462 ◽  
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Pulse Height ◽  
Magnetic Core ◽  
Differential Cross Sections ◽  
Liquid Hydrogen Target ◽  
Hydrogen Target ◽  
Momentum Range ◽  
Polarization Effects

In this paper we discuss some measurements that have been made at Nimrod of differential cross sections and polarization effects in πp elastic scattering. The principal aims of this work were to determine the spins and parities of the N * 1/2 (1688) and the N* 3/2 (1920) isobars and to examine the behaviour of the π+p elastic scattering cross section at momenta around 950MeV/ c where a shoulder exists in the total cross sections. Table 1 gives the values of the momenta at which the measurements were made and figure 1 illustrates their relation to other work that has been done in or near this region. A schematic diagram of the experimental arrangement for measuring the differential cross sections is shown in figure 2. An array of scintillation counters, used in conjunction with a coincidence matrix detected particles scattered from a 4 in. long liquid hydrogen target. All events were accepted in which two and only two outgoing particles were detected in coincidence by any combination of two counters on opposite sides of the beam. The number of counts for each combination was stored in the magnetic core store of a 512 channel pulse height analyser

scholarly journals Enhancement of vacuum polarization effects in a plasma

2007 ◽  
Vol 14 (3) ◽  
pp. 032102 ◽  
Author(s):  
A. Di Piazza ◽  
K. Z. Hatsagortsyan ◽  
C. H. Keitel
Keyword(s):  
Vacuum Polarization ◽  
Polarization Effects

The elastic scattering of slow electrons by neon and argon

1966 ◽  
Vol 294 (1437) ◽  
pp. 160-174 ◽  
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Energy Range ◽  
Orbital Method ◽  
Polarization Effects ◽  
Polarization Contribution ◽  
Slow Electrons ◽  
Good Agreement

The theory of the scattering of electrons by neon and argon in the energy range 0 to 13.6 eV is worked out with allowance for both exchange and polarization effects. The polarized orbital method introduced by Temkin has been used to estimate the polarization contribution and good agreement is obtained with the experimental data, right down to the lowest energies. Inclusion of exchange alone is not sufficient.

scholarly journals Muon g – 2 theory: The hadronic part

2018 ◽  
Vol 166 ◽  
pp. 00022 ◽  
Author(s):  
Fred Jegerlehner
Keyword(s):  
Light Scattering ◽  
Energy Range ◽  
Lattice Qcd ◽  
Vacuum Polarization ◽  
Recent Progress ◽  
Axial Vector ◽  
Status Report ◽  
Leading Order ◽  
Future Prospects ◽  
Polarization Effects

I present a status report of the hadronic vacuum polarization effects for the muon g–2, to be considered as an update of [1]. The update concerns recent new inclusive R measurements from KEDR in the energy range 1.84 to 3.72 GeV. For the leading order contributions I find [see formula in PDF] based on e+e- data [incl. τ data], [see formula in PDF] (NLO) and [see formula in PDF] (NNLO). Collecting recent progress in the hadronic light-by-light scattering I adopt π0, η, η' [95 ± 12] + axial-vector [8 ± 3] + scalar [-6 ± 1] + π, K loops [-20 ± 5] + quark loops [22 ± 4] + tensor [1 ± 0] + NLO [3 ± 2] which yields [see formula in PDF]. With these updates I find [see formula in PDF] a 4.1 σ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.

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