scholarly journals Effects of light-by-light scattering in the Lamb shift and hyperfine structure of muonic hydrogen

2019 ◽  
Vol 222 ◽  
pp. 03010 ◽  
Author(s):  
A. E. Dorokhov ◽  
A. P. Martynenko ◽  
F. A. Martynenko ◽  
A. E. Radzhabov
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Lamb Shift ◽  
Axial Vector ◽  
Muonic Hydrogen ◽  
Meson Exchange ◽  
Interaction Operator ◽  
Two Photon ◽  
Meson Coupling ◽  
Precise Experimental Data

We calculate the meson exchange contribution to the interaction operator of muon and proton, which is determined by the meson coupling with two photon state. For the construction of transition form factor Meson → γγ we use the existing parametrizations based on experimental data including the monopole parametrization over photon four-momenta. For an estimate of the form factor value atzero photon four-momenta squared we use experimental data on the decay width ΓMeson→γγ. It is shown that scalar, pseudoscalar, axial vector and tensor mesons exchanges give significant contribution to the Lamb shift (LS) and hyperfine splitting (HFS) in muonic hydrogen which should be taken into account for a comparison with precise experimental data.

scholarly journals The sigma-meson exchange contribution to the muonic hydrogen Lamb shift

2019 ◽  
Vol 212 ◽  
pp. 07003 ◽  
Author(s):  
A.E. Dorokhov ◽  
A.P. Martynenko ◽  
F.A. Martynenko ◽  
A.E. Radzhabov
Keyword(s):  
Experimental Data ◽  
Lamb Shift ◽  
Scalar Meson ◽  
Muonic Hydrogen ◽  
Meson Exchange ◽  
Exchange Contribution ◽  
Meson Coupling ◽  
Decay Widths ◽  
Precise Experimental Data ◽  
Sigma Meson

The sigma(ξ)meson exchange contribution to the potential of the muon-proton interactionin muonichydrogen inducedbythe ξ-meson coupling to two photons is estimated. The transition form factor ξ → γγ is deduced from the quark model and experimental data on the decay widths Γσγγ. It is shown that scalar meson exchange contribution to the Lamb shift in muonic hydrogen, △ELs(2P−2S ),is rather large and relevant for a comparison with coming precise experimental data.

scholarly journals Hadronic contribution of light by light scattering in the energy spectrum of muonic hydrogen

2019 ◽  
Vol 204 ◽  
pp. 05008 ◽  
Author(s):  
A. E. Dorokhov ◽  
A. P. Martynenko ◽  
F. A. Martynenko ◽  
A. E. Radzhabov
Keyword(s):  
Experimental Data ◽  
Scalar Meson ◽  
Muonic Hydrogen ◽  
Meson Exchange ◽  
Exchange Contribution ◽  
Photon State ◽  
Two Photon ◽  
Meson Coupling ◽  
Precise Experimental Data ◽  
Gamma S

The contribution from scalar meson (S) exchange to the potential of the muon-proton interaction in muonic hydrogen induced by the scalar meson coupling to the two photon state is calculated. An estimate of transition form factor S → γγ is given on the basis of the quark model and experimental data on the decay widths $${\Gamma _{S\gamma \gamma }}$$. It is shown that scalar meson exchange contribution to the Lamb shift in muonic hydrogen ∆ELs(2P – 2S) is large and important for a comparison with precise experimental data.

scholarly journals The proton size puzzle: experiment vs theory.

2018 ◽  
Vol 191 ◽  
pp. 04001 ◽  
Author(s):  
A. E. Dorokhov ◽  
A. P. Martynenko ◽  
F. A. Martynenko ◽  
A. E. Radzhabov
Keyword(s):  
Charge Radius ◽  
Axial Vector ◽  
Muonic Hydrogen ◽  
Current Status ◽  
Interaction Operator ◽  
Two Photon ◽  
Proton Charge ◽  
Proton Charge Radius ◽  
Points Of View ◽  
Precise Experimental Data

Current status of the proton size puzzle from experimental and theoretical points of view is briefly discussed. The interest to these studies is primarily related to experiments conducted by the CREMA collaboration (Charge Radius Experi- ments with Muonic Atoms) with muonic hydrogen and deuterium by methods of laser spectroscopy. As a result a more accurate value of the proton charge radius was found to be rp = 0:84184(67) fm, which is different from the value recommended by CODATA for 7σ. In the second part we discuss recent calculations of the contribution of light pseudoscalar (PS) and axial-vector (AV) mesons to the interaction operator of a muon and a proton in muonic hydrogen atom, with the coupling of mesons to the muon being via two-photon intermediate state. Numerical estimates of the contributions to the hyperfine structure of the spectrum of the S and P levels are presented. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is rather important for a comparison with precise experimental data.

scholarly journals TWO-PHOTON ANNIHILATION INTO PROTON-ANTIPROTON IN A QUARK-DIQUARK SCHEME

1989 ◽  
Vol 04 (19) ◽  
pp. 5213-5234 ◽  
Author(s):  
M. ANSELMINO ◽  
F. CARUSO ◽  
P. KROLL ◽  
W. SCHWEIGER
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Cross Section ◽  
Electromagnetic Form Factor ◽  
Wave Functions ◽  
Proton Antiproton ◽  
Unpolarized Cross Section ◽  
Two Photon ◽  
Photon Annihilation ◽  
Good Agreement

We consider [Formula: see text] in the framework of the Brodsky-Farrar-Lepage scheme allowing for (scalar) diquarks as quasi-elementary constituents. We compute the unpolarized cross section using different proton wave functions. Their normalization is fixed by computing the electromagnetic form factor of the proton in the same framework. Good agreement with the experimental data can be obtained. Two-photon annihilation into other baryons is also discussed.

Optimal information for the pion form factor from analyticity and experimental data

1973 ◽  
Vol 63 ◽  
pp. 285-300 ◽  
Author(s):  
G. Nenciu ◽  
I. Raszillier ◽  
W. Schmidt ◽  
H. Schneider
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Pion Form Factor ◽  
Optimal Information

scholarly journals η′transition form factor from space- and timelike experimental data

2016 ◽  
Vol 94 (5) ◽  
Author(s):  
R. Escribano ◽  
S. Gonzàlez-Solís ◽  
P. Masjuan ◽  
P. Sanchez-Puertas
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Transition Form Factor ◽  
Transition Form
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