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

Precision resonance energy scans with the PANDA experiment at FAIR: Sensitivity study for width and line shape measurements of the X(3872)

This paper summarises a comprehensive Monte Carlo simulation study for precision resonance energy scan measurements. Apart from the proof of principle for natural width and line shape measurements of very narrow resonances with PANDA, the achievable sensitivities are quantified for the concrete example of the charmonium-like X(3872) state discussed to be exotic, and for a larger parameter space of various assumed signal cross-sections, input widths and luminosity combinations. PANDA is the only experiment that will be able to perform precision resonance energy scans of such narrow states with quantum numbers of spin and parities that differ from J P C = 1 - -

Machine learning on FPGA for event selection

Real-time data processing is a frontier field in experimental particle physics. The application of FPGAs at the trigger level is used by many current and planned experiments (CMS, LHCb, Belle2, PANDA). Usually they use conventional processing algorithms. LHCb has implemented Machine Learning (ML) elements for real-time data processing with a triggered readout system that runs most of the ML algorithms on a computer farm. The work described in this article aims to test the ML-FPGA algorithms for streaming data acquisition. There are many experiments working in this area and they have a lot in common, but there are many specific solutions for detector and accelerator parameters that are worth exploring further. This report describes the purpose of the work and progress in evaluating the ML-FPGA application

Development and characterization of a 4 × 4mm 2 pixel neutron scintillation detector using digital SiPMs

This work describes the development of the first demonstrator device for neutron detection based on a 6Li-glass as a scintillator and silicon photomultipliers (SiPM) as photodetector. For the first characterization, the scintillator was pixelated with a one to one correspondence between scintillator and SiPM pixels, and optical cross-talk between pixels was minimized. Measurements in a high luminosity neutron beam show the functionality of the device and allow for partial characterization. The position resolution is 4 × 4mm2 and the detection efficiency of neutrons is 91(6)% relative to the active area. The device is linear up to at least 600 kcps

Improved Rise Approximation Method for Pulse Arrival Timing

This paper describes the deduction of pulse arrivaltimes from digital waveforms recorded with a multichannel data-acquisition (DAQ) system. A linear rise approximation (LRA)arrival timing method provides restricted timing resolution forpulses with nonlinear rise. It reaches 1/20th of the samplingperiod, if the relation between signal shaping and sampling rate isoptimized. We introduce a nonlinear rise approximation (nLRA),which reduces the sampling phase error (SPE) down to lessthan 1/100th of the sampling period. The proposed timingalgorithm uses a single free parameter that can easily be adjustedfor various radiation detectors. The technique permits using arather slow pulse shaping and low sampling rates, thus stronglyreducing power consumption and the costs of the system. A high-density DAQ system integrating over 2000 channels inside anOpenVPX crate is presented. A prototype has been tested in theproton beam at cooler synchrotron (COSY) at Jülich ResearchCenter (Germany)

PET Scintillator Arrangement on digital SiPMs

The common way to build a PET detector is to place an array of scintillator elements on top of a photo detector. In order to achieve high spatial resolution the scintillator footprints are often smaller than the pixel size of the photodetector. This requires light sharing and some kind of algorithm like Anger-Logic in order to identify the correct scintillator element in which the event took place. The digital Silicon Photomultiplier DPC3200-22-44 (Philips Digital Photon Counting) is a fully digital photo sensor device [1]. Each pixel consists of 3200 individual micro cells which are charged and read out under digital control. The device (Tile) is organized as an array of 8 by 8 pixels each of 3.9x3.9 mm2 size and is realized as a PCB equipped with 16 dice. One die provides four pixels together with the corresponding triggering, validation and readout electronics. Depending on the configuration the detection of an event on one die can cause the other dice to transmit their data as well (neighbor logic). The obvious solution of using neighbor logic and a scintillator matrix with light guide covering the whole tile shows some drawbacks. After each event all 16 dice will be busy and all pixels need to be read out. This results in increased dead time and a lot of data. Furthermore it turned out that sometimes pixels are missing because dice were already busy and could not transmit data when the event was detected. This will complicate the identification of the event position. A better performance can be obtained when the light is shared only within the four pixels of each die and the dice work independent from each other. We investigated the positioning capability of different scintillator matrices and light guides. These are arranged in such a way, that a single die can only receive the light from a 4 by 4 array of LYSO crystals which covers exactly the die dimensions. The results show that clear crystal identification can be achieved with such an arrangement. [1] Haemisch et al., Physics Procedia 37 (2012) 154

PET scintillator arrangement on digital SiPMs

A typical high resolution PET detector consists of a matrix of scintillator elements which are connected to a light guide in order to spread the light onto the pixels of a photo detector. In this work we introduce a matrix that works without light guide but has defined internal light leaks in order to allow controlled light sharing between the individual scintillator elements. This is especially useful when used together with the Philips digital SiPM DPC 3200. We show that better position determination is achieved and in addition higher count rates should be possible compared to a classical light guide solution