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A. Balla

Publications and source records attributed to A. Balla.

8 recordsLinked to original sources

Performance of the LHCb muon detector in Run 3

In Run 3 of the LHC, the instantaneous luminosity at the LHCb interaction point has been increased by a factor of five, from $4\times 10^{32}\rm{cm}^{-2}\rm{s}^{-1}$ to $2\times 10^{33}\rm{cm}^{-2}\rm{s}^{-1}$. Several hardware interventions, including a complete overhaul of the readout electronics, have been carried out on the muon detector. The muon identification algorithms in the software trigger were improved with the aim of ensuring Run 2 performance under a higher particle rate. The operation and calibration of the upgraded muon detector are presented. The muon detection efficiency and muon identification performance are evaluated on data calibration samples collected during the year 2024. A muon identification efficiency above 90\% with sub-percent hadron misidentification probability is achieved by exploiting the pattern of hits in the muon detector.

hep-ex

The LHCb upgrade I

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software.

hep-ex

SHADOWS (Search for Hidden And Dark Objects With the SPS)

We propose a new beam-dump experiment, SHADOWS, to search for a large variety of feebly-interacting particles possibly produced in the interactions of a 400 GeV proton beam with a high-Z material dump. SHADOWS will use the 400 GeV primary proton beam extracted from the CERN SPS currently serving the NA62 experiment in the CERN North area and will take data off-axis when the P42 beam line is operated in beam-dump mode. SHADOWS can accumulate up to a ~2 x10^19 protons on target per year and expand the exploration for a large variety of FIPs well beyond the state-of-the-art in the mass range of MeV-GeV in a parameter space that is allowed by cosmological and astrophysical observations. So far the strongest bounds on the interaction strength of new feebly-interacting light particles with Standard Model particles exist up to the kaon mass; above this threshold the bounds weaken significantly. SHADOWS can do an important step into this still poorly explored territory and has the potential to discover them if they have a mass between the kaon and the beauty mass. If no signal is found, SHADOWS will push the limits on their couplings with SM particles between one and four orders of magnitude in the same mass range, depending on the model and scenario.

hep-ex

Performance of scintillating tiles with direct silicon-photomultiplier (SiPM) readout for application to large area detectors

The light yield, the time resolution and the efficiency of different types of scintillating tiles with direct Silicon Photomultiplier readout and instrumented with a customised front-end electronics have been measured at the Beam Test Facility of Laboratori Nazionali di Frascati and several test stands. The results obtained with different configurations are presented. A time resolution of the order of 300 ps, a light yield of more than 230 photo-electrons, and an efficiency better than 99.8 $\%$ are obtained with $\sim 225$ cm$^2$ large area tiles. This technology is suitable for a wide range of applications in high-energy physics, in particular for large area muon and timing detectors.

physics.ins-det

Low resource FPGA-based Time to Digital Converter

Time to Digital Converters (TDCs) are very common devices in particles physics experiments. A lot of "off-the-shelf" TDCs can be employed but the necessity of a custom DAta acQuisition (DAQ) system makes the TDCs implemented on the Field-Programmable Gate Arrays (FPGAs) desirable. Most of the architectures developed so far are based on the tapped delay lines with precision down to 10 ps, obtained with high FPGA resources usage and non-linearity issues to be managed. Often such precision is not necessary; in this case TDC architectures with low resources occupancy are preferable allowing the implementation of data processing systems and of other utilities on the same device. In order to reconstruct gamma-gamma physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a 32 channel TDC with a precision of 255 ps and low non-linearity effects along with an embedded data acquisition systems and the interface to the online FARM of KLOE-2.

physics.ins-det

FPGA-based Time to Digital Converter and Data Acquisition system for High Energy Tagger of KLOE-2 experiment

In order to reconstruct gamma-gamma physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a Time to Digital Converter (TDC) with 625 ps resolution (LSB) along with an embedded data acquisition system and the interface to the online FARM of KLOE-2. We will describe briefly the architecture of the TDC and of the Data AcQuisition (DAQ) system. Some more details will be provided about the zero-suppression algorithm used to reduce the data throughput.

physics.ins-det

Status of the Cylindical-GEM project for the KLOE-2 Inner Tracker

The status of the R&D on the Cylindrical-GEM (CGEM) detector foreseen as Inner Tracker for KLOE-2, the upgrade of the KLOE experiment at the DAFNE phi-factory, will be presented. The R&D includes several activities: i) the construction and complete characterization of the full-size CGEM prototype, equipped with 650 microns pitch 1-D longitudinal strips; ii) the study of the 2-D readout with XV patterned strips and operation in magnetic field (up to 1.5T), performed with small planar prototypes in a dedicated test at the H4-SPS beam facility; iii) the characterization of the single-mask GEM technology for the realization of large-area GEM foils.

physics.ins-det