arXiv subjects

N. Agrawal

Publications and source records attributed to N. Agrawal.

9 recordsLinked to original sources

arXiv2026

ePIC Early Science Report

This Early Science Report from the ePIC Collaboration outlines the compelling physics program achievable during the first years of operation of the Electron-Ion Collider (EIC), prior to the establishment of the full design luminosity and energy range. The analyses are based on realistic early-running beam configurations and detailed Geant4 ePIC detector simulations, hit digitization and data reconstruction. The projected studies from the physics working groups of ePIC span inclusive, semi-inclusive, exclusive, diffractive and tagging, as well as jet and heavy flavor measurements in both electron-proton and electron-ion collisions. Even before the collider reaches its full design performance, these measurements will constrain parton distribution functions in nucleons and nuclei, access transverse-momentum-dependent and spin-dependent observables, probe gluon dynamics in nuclei, and initiate a program of imaging of quarks and gluons. Each measurement is directly connected to the core science pillars of the EIC, identified in the 2018 report by the National Academy of Sciences: understanding the origin of the nucleon mass, unraveling the spin structure of the nucleon, and exploring the emergent properties of dense gluonic matter. The results presented here provide examples that demonstrate that the early years of EIC running with ePIC will deliver novel world-leading insights into Quantum Chromodynamics. In addition, the early science program will establish measurement and analysis methodologies that will pave the way to the subsequent full EIC physics program.

nucl-ex↗

arXiv2026

Radiation tolerance tests on key components of the ePIC-dRICH readout card

The dual-radiator RICH (dRICH) detector of the ePIC experiment will employ over 300000 SiPM pixels as photosensors, organized into more than 1000 Photon Detection Units. Each PDU is a compact module, approximately 5x5x12 cm^3 in size, including four custom ASICs connected to 256 SiPMs and an FPGA-based readout card (RDO) responsible for data acquisition and control. Considering the moderately harsh radiation environment expected in the dRICH detector, this study reports on proton irradiation tests performed on key components of the RDO card to assess their tolerance to cumulative Total Ionizing Dose (TID) and Single Event Effects (SEE). All tested components demonstrated radiation tolerance beyond the TID levels expected for the dRICH environment, with the exception of the ATtiny817 microcontroller, which showed destructive failure. Furthermore, as expected, the observed Single Event Upset (SEU) rates call for appropriate mitigation strategies in the final system design.

physics.ins-det↗

arXiv2026

Electron identification and hadron discrimination using Cherenkov radiation in air and SiPMs

This paper presents a method to identify electrons using the Cherenkov light emitted when a charged particle travels in air and photons are detected with a Silicon PhotoMultiplier (SiPM). The analysis is based on a photon-counting approach using SPAD cells and uses data collected during a test beam at CERN PS. The results are well described by a simple Monte Carlo simulation, which further demonstrates that a very good electron identification and a strong pion/hadron rejection could be obtained over a wide momentum range.

hep-ex↗

arXiv2025

Measurements of efficiency, timing and response to irradiation for direct detection of charged particles with SiPMs

In this paper the efficiency of direct charged particle detection with different Silicon PhotoMultiplier (SiPM) sensors has been measured to be close to 100%. Time resolution of about 20 ps has also been confirmed for sensors with an active area of around 3x3 mm$^\text{2}$ and a single-cell area of 40 $\mu$m$^\text{2}$. In addition, the SiPM performance after irradiation, in terms of timing response and dark count rate, has been evaluated for sensors with a 1x1 mm$^\text{2}$ area, demonstrating that SiPMs can maintain excellent timing capabilities and a low dark count rate when an appropriate threshold is applied to the signal.

physics.ins-det↗

arXiv2023

Measurements of the Cherenkov effect in direct detection of charged particles with SiPMs

In this paper, different Silicon PhotoMultiplier (SiPM) sensors have been tested with charged particles to characterize the Cherenkov light produced in the sensor protection layer. A careful position scan of the SiPM response has been performed with different prototypes, confirming the large number of firing cells and proving almost full efficiency, with the SiPM filling factor essentially negligible. This study also allowed us to study the time resolution of such devices as a function of the number of firing cells, reaching values below 20 ps. These measurements provide significant insight into the capabilities of SiPM sensors in direct detection of charged particles and their potential for several applications.

physics.ins-det↗

arXiv2022

Understanding the direct detection of charged particles with SiPMs

In this paper evidence that the increased response of SiPM sensors to the passage of charged particles is related mainly to Cherenkov light produced in the protection layer is reported. The response and timing properties of sensors with different protection layers have been studied.

physics.ins-det↗

arXiv2022

ATHENA Detector Proposal -- A Totally Hermetic Electron Nucleus Apparatus proposed for IP6 at the Electron-Ion Collider

ATHENA has been designed as a general purpose detector capable of delivering the full scientific scope of the Electron-Ion Collider. Careful technology choices provide fine tracking and momentum resolution, high performance electromagnetic and hadronic calorimetry, hadron identification over a wide kinematic range, and near-complete hermeticity. This article describes the detector design and its expected performance in the most relevant physics channels. It includes an evaluation of detector technology choices, the technical challenges to realizing the detector and the R&D required to meet those challenges.

physics.ins-det↗

arXiv2022

Direct detection of charged particles with SiPMs

The direct response of Silicon PhotoMultipliers being traversed by a MIP charged particle have been studied in a systematic way for the first time. Using beam test data, time resolution and the crosstalk probability have been measured. A characterization of the SiPM by means of a laser beam is also reported. The results obtained for different sensors indicate a measured time resolution around 40-70 ps. Although particles are expected to traverse only one SPAD per event, crosstalk measurements on different sensors indicate an unexpected higher value with respect to the one related to the sensor noise.

physics.ins-det↗

arXiv2021

Design and Implementation of Low Complexity Reconfigurable Filtered-OFDM based LDACS

L-band Digital Aeronautical Communication System (LDACS) aims to exploit vacant spectrum in L-band via spectrum sharing, and orthogonal frequency division multiplexing (OFDM) is the currently accepted LDACS waveform. Recently, various works dealing with improving the spectrum utilization of LDACS via filtering/windowing are being explored. In this direction, we propose an improved and low complexity reconfigurable filtered OFDM (LRef-OFDM) based LDACS using novel interpolation and masking based multi-stage digital filter. The proposed filter is designed to meet the stringent non-uniform spectral attenuation requirements of LDACS standard. It offers significantly lower complexity as well as higher transmission bandwidth than state-of-the-art approaches. We also integrate the proposed filter in our end-to-end LDACS testbed realized using Zynq System on Chip and analyze the performance in the presence of $L$-band legacy user interference as well as LDACS specific wireless channels. Via extensive experimental results, we demonstrate the superiority of the proposed LRef-OFDM over OFDM and Filtered-OFDM based LDACS in terms of power spectral density, bit error rate, implementation complexity, and group delay parameters.

eess.SP↗