arXiv subjects

M. Bomben

Publications and source records attributed to M. Bomben.

At least 19 recordsLinked to original sources

arXiv2026

Comparison of Silvaco and Synopsys TCAD Predictions Including the Perugia Radiation Damage Model in Silicon Pixel Detectors for the HL-LHC

At the High Luminosity Large Hadron Collider (HL-LHC), silicon pixel detectors will be exposed to radiation fluences about 5 to 10 times larger than those experienced by the current innermost pixel layers up to today. Due to radiation damage to bulk of pixel detectors, leakage current and depletion voltage will increase significantly over time, posing severe constraints on operating conditions, with important modifications to the electric field profile due to radiation induced deep defects in silicon bulk. It is important to have reliable predictions for all observables - such as leakage current level and breakdown voltage - after irradiation, in order to estimate operational voltage values. In this paper, the predictions of Silvaco and Synopsys TCAD device simulations are compared when the surface and bulk defects and traps of the ``New University of Perugia radiation damage model'' are included by studying observables like leakage current, depletion and breakdown voltage, along with electric field and trap occupancy profiles. The results are quite promising regarding leakage current, depletion voltage, electric field and trap statistics, at two distinct reference temperatures and fluences.

physics.ins-det↗

arXiv2024

Impact of extreme ultraviolet radiation on the scintillation of pure and xenon-doped liquid argon

The Xenon-Argon Technology (X-ArT) collaboration presents a study on the dynamics of pure and xenon-doped liquid argon (LAr) scintillation. Using two types of silicon photomultipliers sensitive to different wavelength ranges, we provide evidence in favor of a contribution from long-lived (>10 $\mu$s) extreme ultraviolet (EUV) lines emitted from argon atomic states, which enhances the light yield. This component is present in both pure and xenon-doped LAr, becoming more pronounced at higher xenon concentrations, where it complements the traditional collisional energy transfer process. To explain this mechanism, we develop a comprehensive model of the Xe-doped LAr scintillation process that integrates both collisional and radiative contributions. Additionally, we investigate how xenon doping affects LAr scintillation light yield and pulse shape discrimination. Finally, we hypothesize that the EUV component may explain the emission of spurious electrons, a known challenge in light dark matter searches using noble liquids. By characterizing the scintillation dynamics in Xe-doped LAr, identifying the long-lived EUV component, and exploring the potential origin of spurious electrons, this work lays the groundwork for optimizing detector performance and advancing the design and sensitivity of future noble liquid particle detectors.

hep-ex↗

arXiv2022

Simulations of Silicon Radiation Detectors for High Energy Physics Experiments

Silicon radiation detectors are an integral component of current and planned collider experiments in high energy physics. Simulations of these detectors are essential for deciding operational configurations, for performing precise data analysis, and for developing future detectors. In this white paper, we briefly review the existing tools and discuss challenges for the future that will require research and development to be able to cope with the foreseen extreme radiation environments of the High Luminosity runs of the Large Hadron Collider and future hadron colliders like FCC-hh and SPPC.

physics.ins-det↗

arXiv2022

Solid State Detectors and Tracking for Snowmass

Tracking detectors are of vital importance for collider-based high energy physics (HEP) experiments. The primary purpose of tracking detectors is the precise reconstruction of charged particle trajectories and the reconstruction of secondary vertices. The performance requirements from the community posed by the future collider experiments require an evolution of tracking systems, necessitating the development of new techniques, materials and technologies in order to fully exploit their physics potential. In this article we summarize the discussions and conclusions of the 2022 Snowmass Instrumentation Frontier subgroup on Solid State and Tracking Detectors (Snowmass IF03).

physics.ins-det↗

arXiv2019

Performance of Thin Planar \textit{n-on-p} silicon pixels after HL-LHC radiation fluences

The tracking detector of ATLAS, one of the experiments at the Large Hadron Collider (LHC), will be upgraded in 2024-2026 to cope with the challenging environment conditions of the High Luminosity LHC (HL-LHC). The LPNHE, in collaboration with FBK and INFN, has produced 130~$μ$m thick $n-on-p$ silicon pixel sensors which can withstand the expected large particle fluences at HL- LHC, while delivering data at high rate with excellent hit efficiency. Such sensors were tested on beam before and after irradiation both at CERN-SPS and at DESY, and their performances are presented in this paper. Beam test data indicate that these detectors are suited for all the layers where planar sensors are foreseen in the future ATLAS tracker: hit-efficiency is greater than 97\% for fluences $Φ\lesssim 7\times10^{15}\rm{n_{eq}/cm^2}$ and module power consumption is within the specified limits. Moreover, at a fluence $Φ= 1.3\times10^{16}\rm{n_{eq}/cm^2}$, hit-efficiency is still as high as 88\% and charge collection efficiency is about 30\%.

physics.ins-det↗

arXiv2019

LPNHE scientific perspectives for the European Strategy for Particle Physics

This note summarizes the activities and the scientific and technical perspectives of the Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE) at Sorbonne University, Paris. Although the ESPP is specifically aimed at particle physics, we discuss in this note in parallel the three scientific lines developed at LPNHE (Particle Physics, Astroparticles, Cosmology), first with the current scientific activities, then for the future activities. However, our conclusions and recommendations are focused on the particle physics strategy.

hep-ph↗

arXiv2018

Beam test measurements of Low Gain Avalanche Detector single pads and arrays for the ATLAS High Granularity Timing Detector

For the high luminosity upgrade of the LHC at CERN, ATLAS is considering the addition of a High Granularity Timing Detector (HGTD) in front of the end cap and forward calorimeters at |z| = 3.5 m and covering the region 2.4 < |η| < 4 to help reducing the effect of pile-up. The chosen sensors are arrays of 50 μm thin Low Gain Avalanche Detectors (LGAD). This paper presents results on single LGAD sensors with a surface area of 1.3x1.3 mm2 and arrays with 2x2 pads with a surface area of 2x2 mm^2 or 3x3 mm^2 each and different implant doses of the p+ multiplication layer. They are obtained from data collected during a beam test campaign in Autumn 2016 with a pion beam of 120 GeV energy at the CERN SPS. In addition to several quantities measured inclusively for each pad, the gain, efficiency and time resolution have been estimated as a function of the position of the incident particle inside the pad by using a beam telescope with a position resolution of few μm. Different methods to measure the time resolution are compared, yielding consistent results. The sensors with a surface area of 1.3x1.3 mm^2 have a time resolution of about 40 ps for a gain of 20 and of about 27 ps for a gain of 50 and fulfill the HGTD requirements. Larger sensors have, as expected, a degraded time resolution. All sensors show very good efficiency and time resolution uniformity.

physics.ins-det↗

arXiv2018

Production and Integration of the ATLAS Insertable B-Layer

During the shutdown of the CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between the existing Pixel detector of the ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new pixel layer, the Insertable B-Layer (IBL), was to maintain or improve the robustness and performance of the ATLAS tracking system, given the higher instantaneous and integrated luminosities realised following the shutdown. Because of the extreme radiation and collision rate environment, several new radiation-tolerant sensor and electronic technologies were utilised for this layer. This paper reports on the IBL construction and integration prior to its operation in the ATLAS detector.

physics.ins-det↗

arXiv2018

Measurement of $\cos{2β}$ in $B^{0} \to D^{(*)} h^{0}$ with $D \to K_{S}^{0} π^{+} π^{-}$ decays by a combined time-dependent Dalitz plot analysis of BaBar and Belle data

We report measurements of $\sin{2β}$ and $\cos{2β}$ from a time-dependent Dalitz plot analysis of $B^{0} \to D^{(*)} h^{0}$ with $D \to K_{S}^{0} π^{+} π^{-}$ decays, where the light unflavored and neutral hadron $h^{0}$ is a $π^{0}$, $η$, or $ω$ meson. The analysis is performed with a combination of the final data sets of the \babar\ and Belle experiments containing $471 \times 10^{6}$ and $772 \times 10^{6}$ $B\bar{B}$ pairs collected at the $Υ\left(4S\right)$ resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure $\sin{2β} = 0.80 \pm 0.14 \,(\rm{stat.}) \pm 0.06 \,(\rm{syst.}) \pm 0.03 \,(\rm{model})$ and $\cos{2β} = 0.91 \pm 0.22 \,(\rm{stat.}) \pm 0.09 \,(\rm{syst.}) \pm 0.07 \,(\rm{model})$. The result for the direct measurement of the angle is $β= \left( 22.5 \pm 4.4 \,(\rm{stat.}) \pm 1.2 \,(\rm{syst.}) \pm 0.6 \,(\rm{model}) \right)^{\circ}$. The last quoted uncertainties are due to the composition of the $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decay amplitude model, which is newly established by a Dalitz plot amplitude analysis of a high-statistics $e^{+}e^{-} \to c\bar{c}$ data sample as part of this analysis. We find the first evidence for $\cos2β>0$ at the level of $3.7$ standard deviations. The measurement excludes the trigonometric multifold solution $π/2 - β= (68.1 \pm 0.7)^{\circ}$ at the level of $7.3$ standard deviations and therefore resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. The hypothesis of $β= 0^{\circ}$ is ruled out at the level of $5.1$ standard deviations, and thus CP violation is observed in $B^{0} \to D^{(*)} h^{0}$ decays.

hep-ex↗

arXiv2018

First evidence for $\cos 2β>0$ and resolution of the CKM Unitarity Triangle ambiguity by a time-dependent Dalitz plot analysis of $B^{0} \to D^{(*)} h^{0}$ with $D \to K_{S}^{0} π^{+} π^{-}$ decays

We present first evidence that the cosine of the CP-violating weak phase $2β$ is positive, and hence exclude trigonometric multifold solutions of the CKM Unitarity Triangle using a time-dependent Dalitz plot analysis of $B^{0} \to D^{(*)} h^{0}$ with $D \to K_{S}^{0} π^{+} π^{-}$ decays, where $h^{0} \in \{π^{0}, η, ω\}$ denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BaBar and Belle experiments collected at the $Υ(4S)$ resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain $( 471 \pm 3 )\times 10^6\, B\bar{B}$ pairs recorded by the BaBar detector and $( 772 \pm 11 )\times 10^6\, B\bar{B}$ pairs recorded by the Belle detector. The results of the measurement are $\sin{2β} = 0.80 \pm 0.14 \,(\rm{stat.}) \pm 0.06 \,(\rm{syst.}) \pm 0.03 \,(\rm{model})$ and $\cos{2β} = 0.91 \pm 0.22 \,(\rm{stat.}) \pm 0.09 \,(\rm{syst.}) \pm 0.07 \,(\rm{model})$. The result for the direct measurement of the angle $β$ of the CKM Unitarity Triangle is $β= \left( 22.5 \pm 4.4 \,(\rm{stat.}) \pm 1.2 \,(\rm{syst.}) \pm 0.6 \,(\rm{model}) \right)^{\circ}$. The quoted model uncertainties are due to the composition of the $D^{0} \to K_{S}^{0} π^{+} π^{-}$ decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics $e^{+}e^{-} \to c\bar{c}$ data sample. CP violation is observed in $B^{0} \to D^{(*)} h^{0}$ decays at the level of $5.1$ standard deviations. The significance for $\cos{2β}>0$ is $3.7$ standard deviations. The trigonometric multifold solution $π/2 - β= (68.1 \pm 0.7)^{\circ}$ is excluded at the level of $7.3$ standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.

hep-ex↗

arXiv2015

First Observation of CP Violation in B0->D(*)CP h0 Decays by a Combined Time-Dependent Analysis of BaBar and Belle Data

We report a measurement of the time-dependent CP asymmetry of B0->D(*)CP h0 decays, where the light neutral hadron h0 is a pi0, eta or omega meson, and the neutral D meson is reconstructed in the CP eigenstates K+ K-, K0S pi0 or K0S omega. The measurement is performed combining the final data samples collected at the Y(4S) resonance by the BaBar and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain ( 471 +/- 3 ) x 10^6 BB pairs recorded by the BaBar detector and ( 772 +/- 11 ) x 10^6, BB pairs recorded by the Belle detector. We measure the CP asymmetry parameters -eta_f S = +0.66 +/- 0.10 (stat.) +/- 0.06 (syst.) and C = -0.02 +/- 0.07 (stat.) +/- 0.03 (syst.). These results correspond to the first observation of CP violation in B0->D(*)CP h0 decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations.

hep-ex↗

arXiv2013

Performance of Irradiated Thin Edgeless N-on-P Planar Pixel Sensors for ATLAS Upgrades

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. Because of its radiation hardness and cost effectiveness, the n-on-p silicon technology is a promising candidate for a large area pixel detector. The paper reports on the joint development, by LPNHE and FBK of novel n-on-p edgeless planar pixel sensors, making use of the active trench concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, a complete overview of the electrical characterization of several irradiated samples will be discussed. Some comments about detector modules being assembled will be made and eventually some plans will be outlined.

physics.ins-det↗

arXiv2013

Electrical Characterization of a Thin Edgeless N-on-p Planar Pixel Sensors For ATLAS Upgrades

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. Because of its radiation hardness and cost effectiveness, the n-on-p silicon technology is a promising candidate for a large area pixel detector. The paper reports on the joint development, by LPNHE and FBK of novel n-on-p edgeless planar pixel sensors, making use of the active trench concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, and presenting some sensors' simulation results, a complete overview of the electrical characterization of the produced devices will be given.

physics.ins-det↗

arXiv2013

Development of Edgeless Silicon Pixel Sensors on p-type substrate for the ATLAS High-Luminosity Upgrade

In view of the LHC upgrade for the High Luminosity Phase (HL-LHC), the ATLAS experiment is planning to replace the Inner Detector with an all-Silicon system. The n-in-p bulk technology represents a valid solution for the modules of most of the layers, given the significant radiation hardness of this option and the reduced cost. The large area necessary to instrument the outer layers will demand to tile the sensors, a solution for which the inefficient region at the border of each sensor needs to be reduced to the minimum size. This paper reports on a joint R&D project by the ATLAS LPNHE Paris group and FBK Trento on a novel n-in-p edgeless planar pixel design, based on the deep-trench process available at FTK.

physics.ins-det↗

arXiv2013

Development of Edgeless n-on-p Planar Pixel Sensors for future ATLAS Upgrades

The development of n-on-p "edgeless" planar pixel sensors being fabricated at FBK (Trento, Italy), aimed at the upgrade of the ATLAS Inner Detector for the High Luminosity phase of the Large Hadron Collider (HL-LHC), is reported. A characterizing feature of the devices is the reduced dead area at the edge, achieved by adopting the "active edge" technology, based on a deep etched trench, suitably doped to make an ohmic contact to the substrate. The project is presented, along with the active edge process, the sensor design for this first n-on-p production and a selection of simulation results, including the expected charge collection efficiency after radiation fluence of $1 \times 10^{15} {\rm n_{eq}}/{\rm cm}^2$ comparable to those expected at HL-LHC (about ten years of running, with an integrated luminosity of 3000 fb$^{-1}$) for the outer pixel layers. We show that, after irradiation and at a bias voltage of 500 V, more than 50% of the signal should be collected in the edge region; this confirms the validity of the active edge approach.

physics.ins-det↗

arXiv2013

Novel Silicon n-on-p Edgeless Planar Pixel Sensors for the ATLAS upgrade

In view of the LHC upgrade phases towards HL-LHC, the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. We report on the development of novel n-in-p edgeless planar pixel sensors fabricated at FBK (Trento, Italy), making use of the "active edge" concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology and fabrication process, we present device simulations (pre- and post-irradiation) performed for different sensor configurations. First preliminary results obtained with the test-structures of the production are shown.

physics.ins-det↗

arXiv2012

Planar Pixel Sensors for the ATLAS Upgrade: Beam Tests results

Results of beam tests with planar silicon pixel sensors aimed towards the ATLAS Insertable B-Layer and High Luminosity LHC (HL-LHC) upgrades are presented. Measurements include spatial resolution, charge collection performance and charge sharing between neighbouring cells as a function of track incidence angle for different bulk materials. Measurements of n-in-n pixel sensors are presented as a function of fluence for different irradiations. Furthermore p-type silicon sensors from several vendors with slightly differing layouts were tested. All tested sensors were connected by bump-bonding to the ATLAS Pixel read-out chip. We show that both n-type and p-type tested planar sensors are able to collect significant charge even after integrated fluences expected at HL-LHC.

physics.ins-det↗

arXiv2011

Recent progress of the ATLAS Planar Pixel Sensor R&D Project

The foreseen luminosity upgrade for the LHC (a factor of 5-10 more in peak luminosity by 2021) poses serious constraints on the technology for the ATLAS tracker in this High Luminosity era (HL-LHC). In fact, such luminosity increase leads to increased occupancy and radiation damage of the tracking detectors. To investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Planar Pixel Sensor R&D Project was established comprising 17 institutes and more than 80 scientists. Main areas of research are the performance of planar pixel sensors at highest fluences, the exploration of possibilities for cost reduction to enable the instrumentation of large areas, the achievement of slim or active edge designs to provide low geometric inefficiencies without the need for shingling of modules and the investigation of the operation of highly irradiated sensors at low thresholds to increase the efficiency. In the following I will present results from the group, concerning mainly irradiated-devices performance, together with studies for new sensors, including detailed simulations.

physics.ins-det↗