Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

This 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

PANDA Phase One - PANDA collaboration

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P¯ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper

Irradiation effects on Gd3_{3}AI3_{3}Ga3_{3}O12_{12} scintillators prospective for application in harsh irradiation environments

We provide evidences that multicomponent garnet-type Ce-doped crystal GAGG (Gd$_{3}$AI$_{3}$Ga$_{3}$O$_{12}$) is a promising scintillator to be applied in harsh irradiation environments, particularly, in high-energy physics experiments and reactor research facilities, where long-term operation is mandatory. Applicability of this scintillator for the upgrade of the detectors at future accelerators with high luminosity like High luminosity LHC is considered and GAGG:Ce with different codopings is compared with Ce-doped oxyorthosilicate crystals, which are currently also strong candidates for such applications. It is shown that the irradiation with 24 GeV protons at a fluence of $5 \times 10^{14}$ p/cm$^2$ has no significant effect on optical absorption in the spectral range of the scintillator emission. The contribution of radioisotopes formed in the material by irradiation with protons to the noise pedestal and the noise energy equivalent due to harmful radio-luminescence excited by the radionuclides remains negligible at short gates in collider experiments. Moreover, we show that the irradiation-generated color centers absorb outside the spectral range of Ce luminescence. These centers do not significantly affect the dynamics of nonequilibrium carriers, which is responsible for the timing properties of the scintillator. The density of free carriers decays with a characteristic time of 2 ps, while the decay constant for trapped carriers is ∼50 ns both before and after irradiation

Multipurpose Ce-doped Ba-Gd silica glass scintillator for radiation measurements

A new inorganic scintillation material based on Ba-Gd silica glass doped with cerium (BGS) is fabricated and studied. With the highest light yield among heavy glasses at the level of 2500 ph/MeV and fast scintillation response, the new scintillator ensures a good coincidence time resolution of < 230 ps FWHM for 511 keV  γ -quanta from a $^{22}$Na source and SiPM readout. In addition to good performance in  γ -quanta detection, the material demonstrates capability for efficient detection of low-energetic​ neutrons. The scintillator is produced by exploiting the standard industrial glass technology, which allows for an unlimited scaling up the conversion of raw material into a high-quality scintillator at a high rate. The glass can be casted in application-specific molds, so minimizing the material losses. The presented glass scintillator has potential for further improvement of its light output and scintillation response time

Study of excited Ξ baryons with the P¯ ANDA detector

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯ANDA will provide direct access to final states containing a Ξ¯ Ξ pair, for which production cross sections up to μb are expected in p¯p reactions. With a luminosity of L= 10 31 cm- 2 s- 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼106events/day. With a nearly 4 π detector acceptance, P¯ANDA will thus be a hyperon factory. In this study, reactions of the type p¯p → Ξ¯ +Ξ∗ - as well as p¯p → Ξ¯ ∗ +Ξ- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking

Study of Excited Ξ\Xi Baryons with the PANDA Detector

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards $N^*$ and $\Delta$ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the $N^*$ and $\Delta$ spectra. The future antiproton experiment PANDA will provide direct access to final states containing a $\bar{\Xi}\Xi$ pair, for which production cross sections up to $\mu$b are expected in $\bar{p}p$ reactions. With a luminosity of $L=10^{31}\,cm^{-2}s^{-1}$ in the first phase of the experiment, the expected cross sections correspond to a production rate of $\sim 10^6$ events$/$day. With a nearly $4\pi$ detector acceptance, PANDA will thus be a hyperon factory. In this study, reactions of the type $\bar{p}p\rightarrow \bar{\Xi}^+ \Xi^{*-}$ as well as $\bar{p}p\rightarrow \bar{\Xi}^{*+} \Xi^{-}$ with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between $3\,\%$ and $5\,\%$. This allows high statistics data to be collected within a few weeks of data taking

Study of excited

The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards $$N^*$$ and $$\varDelta$$ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the $$N^*$$ and $$\varDelta$$ spectra. The future antiproton experiment $$\overline{\text{ P }}$$ANDA will provide direct access to final states containing a $${\overline{\varXi }}\varXi$$ pair, for which production cross sections up to $$\mu \text{ b }$$ are expected in $$\bar{\text{ p }}$$p reactions. With a luminosity of $$L=10^{31}$$ cm$$^{-2}$$ s$$^{-1}$$ in the first phase of the experiment, the expected cross sections correspond to a production rate of $$\sim 10^6\, \text{ events }/\text{day }$$. With a nearly $$4\pi$$ detector acceptance, $$\overline{\text{ P }}$$ANDA will thus be a hyperon factory. In this study, reactions of the type $$\bar{\text{ p }}$$p $$\rightarrow$$$${\overline{\varXi }}^{+}$$$$\varXi ^{*-}$$ as well as $$\bar{\text{ p }}$$p $$\rightarrow$$$${\overline{\varXi }}^{*+}$$$$\varXi ^{-}$$ with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking

The potential of Λ and Ξ- studies with PANDA at FAIR

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA