Release_Note

This release note is an excerpt of my PhD thesis which was submitted on July 21th this year.

Release note for the hyperon spin observables programme. Simulations were carried out by Sophie Grape and Erik Thome. More details can be found in their respective theses.

The feasibility of measuring pi0+J/psi production in pbar+p reaction in PANDA is investigated. The study is based on a TDA model for the description of the signal and uses a combination of available data and established hadronic event generator DPM for the description of the background. Events generated using these two approaches were simulated and reconstructed using PANDAroot, and the output was analyzed to check if the input spectra can be reconstructed with the currently proposed PANDA. Results on the s/b ratio and expected accuracy on differential cross-section measurements are given.

This note reports on the latest status of the feasibility studies for the measurement
of time-like, proton electromagnetic form factors (TL EM FFs) at the PANDA
experiment at FAIR. Electromagnetic FFs are fundamental quantities parameterizing
the electric and magnetic structure of hadrons. In the time-like region proton
FFs can be accessed experimentally with the aid of annihilation processes of the type
pbar p -> l+l− (l = e, μ), assuming that the interaction takes place through the exchange of
one virtual photon. The individual determination of the time-like electric and magnetic
proton FFs was limited in the past by the low luminosity available at colliders. In frame
of the PANDARoot software, which encompasses full detector simulation and event reconstruction,
the statistical precision at which the proton FFs will be determined at
PANDA is estimated for the signal channel pbar p -> μ+μ-. The signal identification and suppression
of the main background process (pbar p -> π+π−) is studied. Different methods have
been used to generate and analyse the processes of interest. The results show that TL EM FFs can be measured at PANDA with unprecedented statistical accuracy.

The results of simulations for future measurements of electromagnetic form factors at PANDA
(FAIR) in frame of the PANDARoot software are reported. The statistical precision at which the proton form factors can be determined is estimated. The suppression of the main background (pbar p -> pi+pi-) process versus the signal (pbar p -> e+e-) efficiency, the extraction of the information from the relevant spectra and the evaluation of the statistical errors on the extracted proton form factors from the events of the reaction pbar p -> e+e- have been done on the basis of two different but consistent procedures. The procedure developed here will be directly applied to the experimental data. The comparison with older predictions based on old framework shows consistency of the results and a slightly better precision achieved in a large range of momentum transfer, assuming the nominal conditions of beam and detector performances.

This is the analysis note on the physics chapter of my PhD thesis, which I submitted two weeks ago. As for the current publication rules, the content of the chapter needs to be reviewed internally before I can show any results on conferences (which I intend to do e.g. at EuNPC).

I leave the publication date as the current date, as I don't know anything further.

The treatment of radiative decays in the tensor formalism is subtle.On the example of radiative J/psi decays the procedure is developed,discussing several methods to construct the amplitudes.In the appendices,spin wave functions,different gauges and form factors for radiative dcays are adressed.

Formulae for the differential cross sections for antiproton proton -> omega pi0, with omega decaying into pi+ pi- pi0 and into pi0 gamma, are derived using the tensor formalism(Rarita-Schwinger)

A recipe is given how to construct the decay amplitude for 1 -> 2 + 3 ;2 -> 4 +
5; 3 -> 6 + 7 in tensor formalism(Rarita-Schwinger)for arbitrary integral spins.

Taking the process antiproton proton to omega pi0,omega to pi0 gamma as example the rho matrix of the final state is derived in the helicity formalism taking into account P- and C-conservation.The differential cross section and the gamma polarization observables are calculated using Mathematica.A comparison with similar calculations for the decay omega to pi+ pi+ pi0 is performed.