BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Determination of the proton charge radius from the study of the hy
 drogen S-energy levels
DTSTART;VALUE=DATE-TIME:20201006T143500Z
DTEND;VALUE=DATE-TIME:20201006T145000Z
DTSTAMP;VALUE=DATE-TIME:20260518T061734Z
UID:indico-contribution-2137@cern.ch
DESCRIPTION:Speakers: Fedor Martynenko ()\nAt present\, four complementary
  methods are used to obtain the charge radii of light nuclei: an elastic s
 cattering of electrons by nuclei\, elastic scattering of muons by nuclei\,
  spectroscopy of electron atoms\, and high-precision laser spectroscopy in
  muonic atoms. Traditionally\, elastic electron scattering was the first m
 ethod to determine the internal structure of a proton. Elastic scattering 
 of leptons by a target nucleus is described by form factors included in th
 e theoretical expression for the scattering cross-section. A proton or oth
 er light nucleus is a compound particle\, and its size is determined by th
 e charge radius. It is related to the slope of the electric form factor of
  the proton $ G_{pE} (q) $ at $ q^2 = 0 $. Over the past two decades\, ato
 mic laser spectroscopy has proven to be a powerful tool for determining th
 e charge radii of light nuclei. Atomic spectroscopy of hydrogen is an indi
 rect way of determining the charge radius $ r_{pE} $ of a proton from pres
 ision measurements of certain energy intervals. While electron scattering 
 and spectroscopy of electron atoms have been available for a long time\, m
 uon spectroscopy became available only in 2010 due to the work of the CREM
 A collaboration. As a result of the first CREMA experiments in 2010\, the 
 value $ r_{pE} = 0.84184 (67) $ fm was obtained\, which was 10 times more 
 accurate than all previous values from experiments with electronic systems
 . Moreover\, this value was significantly less than the CODATA value\, $ r
 _{pE} = 0.8768 (69) $ fm. This difference is called the "puzzle" of the pr
 oton radius. In this work\, a precision study of the structure of energy l
 evels of S-states of hydrogen in quantum electrodynamics is carried out ta
 king into account corrections for vacuum polarization\, nuclear structure\
 , relativism\, as well as complex combined corrections that include the ab
 ove. The frequency of the transition between the levels of S-states is cal
 culated\, which is necessary for comparison with the corresponding experim
 ental data.\n\nhttps://indico.particle.mephi.ru/event/35/contributions/213
 7/
LOCATION:Zoom HEP Theory
URL:https://indico.particle.mephi.ru/event/35/contributions/2137/
END:VEVENT
END:VCALENDAR