85 research outputs found
Experimental results of the dE/dx resolution measurement in PANDA-type Straw Tube Tracker
No full textStraw tubes are known as excellent tools for particle tracking. A multilayer, densely packed ensemble of about 5000 straw tubes - so called Straw Tube Trackers (STT) is considered as an option for the central tracker of the future PANDA@FAIR experiment. Simulations indicate that the energy loss of particles traversing several layers of straw tubes can in addition result in a decisive contribution to particle discrimination in the momentum range up to 1.5 GeV/c. Experimental investigation of the energy resolution in prototype of the PANDA-type STT have been undertaken in Research Center Jülich (Germany). The experimental setup, readout electronics, method of data treatment and the encouraging results are presented
A straw tube detector for the PANDA experiment
No full textThe PANDA experiment will be built at the FAIR facility in Darmstadt
(Germany) to perform accurate tests of the strong interaction through pp and
pA annihilations. This paper will address the design issue of the Straw Tube Tracker
(STT), one of the two options proposed for the PANDA Central Tracker
Synchrotron oscillation effects on an rf-solenoid spin resonance
No full textNew measurements are reported for the time dependence of the vertical polarization of a 0: 97 GeV/c deuteron beam circulating in a storage ring and perturbed by an rf solenoid. The storage ring is the cooler synchrotron (COSY) located at the Forschungszentrum Julich. The beam polarization was measured continuously using a 1.5 cm thick carbon target located at the edge of the circulating deuteron beam and the scintillators of the EDDA detector. An rf solenoid mounted on the ring was used to generate fields at and near the frequency of the 1 - G gamma spin resonance. Measurements were made of the vertical beam polarization as a function of time with the operation of the rf solenoid in either fixed or continuously variable frequency mode. Using rf-solenoid strengths as large as 2.66 x 10(-5) revolutions/turn, slow oscillations (similar to 1 Hz) were observed in the vertical beam polarization. When the circulating beam was continuously electron cooled, these oscillations completely reversed the polarization and showed no sign of diminishing in amplitude. But for the uncooled beam, the oscillation amplitude was damped to nearly zero within a few seconds. A simple spin-tracking model without the details of the COSY ring lattice was successful in reproducing these oscillations and demonstrating the sensitivity of the damping to the magnitude of the synchrotron motion of the beam particles. The model demonstrates that the characteristic features of measurements made in the presence of large synchrotron oscillations are distinct from the features of such measurements when made off resonance. These data were collected in preparation for a study of the spin coherence time, a beam property that needs to become long to enable a search for an electric dipole moment using a storage ring
Influence of electron cooling on the polarization lifetime of a horizontally polarized storage ring beam
No full textA previous publication has shown that the in-plane polarization (IPP) component of a polarized 0.97-GeV/c deuteron beam in the COSY storage ring may acquire a polarization half-life in excess of 1000 s through a combination of beam bunching, electron cooling (prior to any spin manipulation), sextupole field adjustment, and a limitation of the beam intensity. This paper documents further tests pointing to additional gains in the IPP lifetime if cooling is active throughout the beam store
Measurement of Spin Observables in the ~p ~d Breakup Reaction
No full textWe update our Letter-of-Intent 202 for Measurement of Spin Observables in the
~p ~d Breakup Reaction. An estimate of the overall beam time needed for completing
the measurements is specied and a timeline in view of the planned PAX experiments
is presented.
The proposal aims at a study of the three nucleon continuum in proton deuteron
breakup reactions, between 30 and 50 MeV proton beam energies, an energy range
where there have been few and limited measurements. The large coverage of the PAX
detection setup and the energy range chosen will provide essential new data intended
as a laboratory for chiral eective eld theory, the modern theory for nuclear forces
relevant at low and intermediate energies.
Vector and tensor analyzing powers and spin correlation coecients will be measured
and evaluated over large kinematical areas in the ve parameter phase space of
the nal state containing three nucleons. For the analysis the sampling method will
be used, a technique developed specically for the complex analysis of three particle
nal states, providing a direct comparison between experiment and theory
Feasibility studies for the measurement of time-like proton electromagnetic form factors from p ̄ p→ μ+μ- at P ̄ ANDA at FAIR
No full textThis paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p ̄ p→ μ+μ- reaction at P ̄ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ̄ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p ̄ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented
Feasibility study for the measurement of transition distribution amplitudes at ANDA in
No full textInternational audienceThe exclusive charmonium production process in p¯p annihilation with an associated π0 meson p¯p→J/ψπ0 is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/ψ→e+e- decay channel with the AntiProton ANnihilation at DArmstadt (P¯ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the p¯p→π+π-π0 and p¯p→J/ψπ0π0 reactions are performed with PandaRoot, the simulation and analysis software framework of the P¯ANDA experiment. It is shown that the measurement can be done at P¯ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity
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