A model is suggested to interpret nucleon electromagnetic form factors both in space and time-like regions and to describe the existing data. It implies quarks to be colorless in the region of high ...intensity chromo-electromagnetic gluon field inside the nucleon.
Tests of optical glues for the PANDA electromagnetic calorimeter Dbeyssi, A.; Tomasi-Gustafsson, E.; Hennino, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2013, Letnik:
722
Journal Article
Recenzirano
This paper reports on the results of tests for low temperature applications of two commercial optical glues in the electromagnetic calorimeter of PANDA at FAIR. Mechanical, thermal and optical ...properties are presented, as well as radiation hardness to photon and proton radiation.
Radiative corrections to the annihilation of proton–antiproton into electron–positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the ...time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.
Radiative corrections to the annihilation of proton–antiproton into electron–positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the ...time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.
Model independent expressions for all polarization observables in μ+p→μ+p elastic scattering are obtained, taking into account the lepton mass and including the two-photon exchange contribution. The ...spin structure of the matrix element is parametrized in terms of six independent complex amplitudes, functions of two independent kinematical variables. General statements about the influence of the two-photon-exchange terms on the differential cross section and on polarization observables are given. Polarization effects have been investigated for the case of a longitudinally polarized lepton beam and polarized nucleon in the final state.
We extend previous calculations of polarization observables for the annihilation reaction p¯+p→ℓ−+ℓ+ to the case of heavy leptons, such as the μ- and τ-leptons. We consider the case when the beam ...and/or the target are polarized, as well as when the outgoing leptons are polarized. We give the dependence of the unpolarized cross section, angular asymmetry, and various polarization observables on the relevant kinematical variables in the center of mass and in the laboratory system, paying particular attention to the effect of the mass induced terms.
The singly Cabibbo-suppressed decay D+s → K + π + π − π 0 is observed by using a data set corresponding to an integrated luminosity of 6.32 fb − 1 recorded by the BESIII detector at the ...centre-of-mass energies between 4.178 and 4.226 GeV. The first amplitude analysis of D+s → K + π + π − π 0 reveals the sub-structures in this decay and determines the fractions and relative phases of different intermediate processes. The dominant intermediate process is D+s → K *0 ρ + , with a fit fraction of (40 . 5 ± 2 . 8 stat . ± 1 . 5 syst . )%. With the detection efficiency based on our amplitude analysis, the absolute branching fraction for D+s → K + π + π − π 0 is measured to be (9 . 75 ± 0 . 54 stat . ± 0 . 17 syst . ) × 10 − 3 .
Using data collected with the BESIII detector in e(+)e(-) collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32 fb(-1) of integrated luminosity, we report the ...amplitude analysis and branching-fraction measurement of the D-s(+) -> pi(+)pi(0)eta' decay. We find that the dominant intermediate process is D-s(+) -> rho(+)eta' and the significances of other resonant and nonresonant processes are all less than 3 sigma. The upper limits on the branching fractions of S-wave and P-wave nonresonant components are set to 0.10% and 0.74% at the 90% confidence level, respectively. In addition, the branching fraction of the D-s(+) -> pi(+)pi(0)eta' decay is measured to be (6.15 +/- 0.25(stat.) +/- 0.18(syst.))%, which receives significant contribution only from D-s(+) -> rho(+)eta' according to the amplitude analysis.