Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userProduction and electromagnetic decay of hyperons: a feasibility study with HADES as a Phase-0 experiment at FAIR
137
0
0.0
(
0
)
Authors
J. Adamczewski-Musch
Ask ChatGPT about the research
No Arabic abstract
A feasibility study has been performed in order to investigate the performance of the HADES detector to measure the electromagnetic decays of the hyperon resonances $Sigma(1385)^0$, $Lambda(1405)$ and $Lambda{Lambda}(1520)$ as well as the production of double strange baryon systems $Xi^-$ and $LambdaLambda$ in p+p reactions at a beam kinetic energy of 4.5 GeV. The existing HADES detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized.
rate research
Read More
Currently, the HADES spectrometer undergoes un upgrade program to be prepared for measurements at the upcoming SIS-100 synchrotron at FAIR. We describe the current status of the HADES di-electron measurements at the SIS-18 and our future plans for SIS-100.
The possibility of measuring the proton electromagnetic form factors in the time-like region at FAIR with the PANDA detector is discussed. Detailed simulations on signal efficiency for the annihilation of $bar p +p $ into a lepton pair as well as for the most important background channels have been performed. It is shown that precision measurements of the differential cross section of the reaction $bar p +p to e^++ e^-$ can be obtained in a wide angular and kinematical range. The individual determination of the moduli of the electric and magnetic proton form factors will be possible up to a value of momentum transfer squared of $q^2simeq 14$ (GeV/c)$^2$. The total $bar p +pto e^++e^-$ cross section will be measured up to $q^2simeq 28$ (GeV/c)$^2$. The results obtained from simulated events are compared to the existing data. Sensitivity to the two photons exchange mechanism is also investigated.
The TRB hardware module is a multi-purpose Trigger and Readout Board with on-board DAQ functionality developed for the upgrade of the HADES experiment. It contains a single computer chip (Etrax) running Linux as a well as a 100 Mbit/s Ethernet interface. It has been orginally designed to work as a 128-channel Time to Digital Converter based on the HPTDC chip from CERN. The new version contains a 2 Gbit/s optical link and an interface connector (15 Gbit/s) in order to realize an add-on card concept which makes the hardware very flexible. Moreover, an FPGA chip (Xilinx, Virtex 4 LX 40) and a TigerSharc DSP provide new computing resources which can be used to run on-line analysis algorithms. The TRB is proposed as a prototype for new modules for the planned detector systems PANDA and CBM at the future FAIR facility at GSI-Darmstadt.
This paper reports results on simultaneous measurements of the reaction channels pp -> pK+Lambda and pp -> pK+Sigma^0 at excess energies of 204, 239, and 284 MeV (Lambda) and 127, 162, and 207 MeV (Sigma^0). Total and differential cross sections are given for both reactions. It is concluded from the measured total cross sections that the high energy limit of the cross section ratio is almost reached at an excess energy of only about 200 MeV. From the differential distributions observed in the overall CMS as well as in the Jackson and helicity frames, a significant contribution of interfering nucleon resonances to the Lambda production mechanism is concluded while resonant Sigma^0-production seems to be of lesser importance and takes place only through specific partial waves of the entrance channel. The data also indicate that kaon exchange plays a minor role in the case of Lambda- but an important role for Sigma^0-production. Thus the peculiar energy dependence of the Lambda-to-Sigma^0 cross section ratio appears in a new light as its explanation requires more than mere differences between the pLambda and the pSigma^0 final state interaction. The data provide a benchmark for theoretical models already available or yet to come.
Simulation results for future measurements of electromagnetic proton form factors at PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $bar p p to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $textit{i.e.}$ $bar p p to pi^+ pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
