Roberto Ammendola

Roberto Ammendola
INFN - Istituto Nazionale di Fisica Nucleare | INFN · Rome II

Physicist - Computer Scientist
APECAST - APEIRON - NA62 - CSES-Limadou - SPAN

About

122
Publications
13,403
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1,393
Citations
Citations since 2016
70 Research Items
1161 Citations
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2016201720182019202020212022050100150200250

Publications

Publications (122)
Article
Full-text available
A bstract A sample of 2 . 8 × 10 ⁴ K ⁺ → π ⁺ μ ⁺ μ − candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017–2018. The model-independent branching fraction is measured to be (9 . 15 ± 0 . 08) × 10 − 8 , a factor three more precise than previous measurements. The decay form factor is presented as a function...
Preprint
Full-text available
In the field of High Performance Computing, communications among processes represent a typical bottleneck for massively parallel scientific applications. Object of this research is the development of a network interface card with specific offloading capabilities that could help large scale simulations in terms of communication latency and scalabili...
Article
In the near future, Exascale systems will need to bridge three technology gaps to achieve high performance while remaining under tight power constraints: energy efficiency and thermal control; extreme computation efficiency via HW acceleration and new arithmetic; methods and tools for seamless integration of reconfigurable accelerators in heterogen...
Article
Full-text available
The second China Seismo-Electromagnetic Satellite (CSES-02) will be equipped with the new electric field detector (EFD-02), to measure the ionospheric electric field components at a Low Earth Orbit (LEO) over a wide frequency band (DC - 3.5 MHz) and with a high sensitivity (~ 1μV /m). EFD-02 will measure the voltages between different pairs of prob...
Article
Searches for lepton number violating K+→π−e+e+ and K+→π−π0e+e+ decays have been performed using the complete dataset collected by the NA62 experiment at CERN in 2016–2018. Upper limits of 5.3×10−11 and 8.5×10−10 are obtained on the decay branching fractions at 90% confidence level. The former result improves by a factor of four over the previous be...
Preprint
Full-text available
A new FPGA-based low-level trigger processor has been installed at the NA62 experiment. It is intended to extend the features of its predecessor due to a faster interconnection technology and additional logic resources available on the new platform. With the aim of improving trigger selectivity and exploring new architectures for complex trigger co...
Preprint
Full-text available
The APEnet+ board delivers a point-to-point, low-latency, 3D torus network interface card. In this paper we describe the latest generation of APEnet NIC, APEnet v5, integrated in a PCIe Gen3 board based on a state-of-the-art, 28 nm Altera Stratix V FPGA. The NIC features a network architecture designed following the Remote DMA paradigm and tailored...
Article
Full-text available
Searches for the lepton number violating K^{+}→π^{-}μ^{+}e^{+} decay and the lepton flavor violating K^{+}→π^{+}μ^{-}e^{+} and π^{0}→μ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K...
Conference Paper
Full-text available
To achieve high performance and high energy efficiency on near-future exascale computing systems, three key technology gaps needs to be bridged. These gaps include: energy efficiency and thermal control; extreme computation efficiency via HW acceleration and new arithmetics; methods and tools for seamless integration of reconfigurable accelerators...
Article
Full-text available
A bstract The NA62 experiment reports the branching ratio measurement $$ \mathrm{BR}\left({K}^{+}\to {\pi}^{+}\nu \overline{\nu}\right)=\left({10.6}_{-3.4}^{+4.0}\left|{}_{\mathrm{stat}}\right.\pm {0.9}_{\mathrm{syst}}\right)\times {10}^{-11} $$ BR K + → π + ν ν ¯ = 10.6 − 3.4 + 4.0 stat ± 0.9 syst × 10 − 11 at 68% CL, based on the observation of 2...
Article
Full-text available
A bstract A search for the K ⁺ → π ⁺ X decay, where X is a long-lived feebly interacting particle, is performed through an interpretation of the K ⁺ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ analysis of data collected in 2017 by the NA62 experiment at CERN. Two ranges of X masses, 0–110 MeV /c ² and 154–260 MeV /c ² , and lifetimes above 100 ps...
Article
The NA62 experiment at CERN reports searches for K+→μ+N and K+→μ+νX decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O(10−8) of the neutrino mixing parameter |Uμ4|2 for N masses in the range 200–384 MeV/c2 and...
Article
Full-text available
A bstract The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 10 ⁹ tagged π ⁰ mesons from K ⁺ → π ⁺ π ⁰ ( γ ), searching for the decay of the π ⁰ to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4 . 4 × 10 − 9 is set on the branching ratio at 90% confidence level,...
Article
Full-text available
The aim of this work is to validate the China Seismo-Electromagnetic Satellite 01 (CSES-01) Electric Field Detector (EFD) measurements through the analysis of the instrument response to various inputs: (a) geomagnetic field variations, (b) plasma density depletions, and (c) electromagnetic signals from natural and artificial sources such as Schuman...
Article
Full-text available
A bstract The NA62 experiment reports an investigation of the $$ {K}^{+}\to {\pi}^{+}\nu \overline{\nu} $$ K + → π + ν ν ¯ mode from a sample of K ⁺ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of (0 . 389 ± 0 . 024) × 10 − 10 , corresponding to 2.2 events assuming the Standard Model branching rat...
Article
Full-text available
A search for heavy neutral lepton (N) production in K+→e+N decays using the data sample collected by the NA62 experiment at CERN in 2017–2018 is reported. Upper limits of the extended neutrino mixing matrix element |Ue4|2 are established at the level of 10−9 over most of the accessible heavy neutral lepton mass range 144–462 MeV/c2, with the assump...
Article
Full-text available
The L0TP+ initiative is aimed at the upgrade of the FPGA-based Level-0 Trigger Processor (L0TP) of the NA62 experiment at CERN for the post-LS2 data taking, which is expected to happen at 100% of design beam intensity, corresponding to about 3.3 × 10 ¹² protons per pulse on the beryllium target used to produce the kaons beam. Although tests perform...
Poster
Full-text available
An electric field detector (EFD), suitable to investigate electromagnetic phenomena in the near Earth environment, such as ionosphere-magnetosphere transition zone, has been developed in the context of the Chinese-Italian CSES collaboration in order to be installed on the second satellite. The instrument consists of four identical probes located at...
Article
Full-text available
The NA62 experiment at CERN reports a search for the lepton number violating decays K+→π−e+e+ and K+→π−μ+μ+ using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of 2.2×10−10 and 4.2×10−11 are obtained, respectively, at 90% confidence level. These upper limits improve on previous...
Article
Full-text available
A bstract The results of a search for π ⁰ decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of 4.12 × 10 ⁸ tagged π ⁰ mesons, no signal is observed. Assuming a kinetic-mixing interaction, limits are set on the dark photon coupling to the ordinary photon as a function of the dar...
Article
Full-text available
The Three Dimensional Fast Fourier Transform (3D-FFT) is commonly used to solve the partial differential equations describing the system evolution in several physical phenomena, such as the motion of viscous fluids described by the Navier-Stokes equations. Simulation of such problems requires the use of a parallel High-Performance Computing archite...
Article
Full-text available
The integrated low-level trigger and data acquisition (TDAQ) system of the NA62 experiment at CERN is described. The requirements of a large and fast data reduction in a high-rate environment for a medium-scale, distributed ensemble of many different sub-detectors led to the concept of a fully digital integrated system with good scaling capabilitie...
Article
Full-text available
The NA62 experiment at the CERN SPS reports the first search for K ⁺ →π ⁺ νν¯ using the decay-in-flight technique, based on a sample of 1.21×10 ¹¹ K ⁺ decays collected in 2016. The single event sensitivity is 3.15×10 ⁻¹⁰ , corresponding to 0.267 Standard Model events. One signal candidate is observed while the expected background is 0.152 events. T...
Preprint
Full-text available
We profile the impact of computation and inter-processor communication on the energy consumption and on the scaling of cortical simulations approaching the real-time regime on distributed computing platforms. Also, the speed and energy consumption of processor architectures typical of standard HPC and embedded platforms are compared. We demonstrate...
Article
Optical wavelength multiplexing is a widely used technique in Information and Communication Technology to increase maximum data transmission bandwidth on a single optical fiber. We propose wavelength multiplexing/demultiplexing using optical Ring Resonators (RR) on a silicon photonics circuit for fast timing highly segmented detectors readout. A ca...
Article
Full-text available
The use of GPUs to implement general purpose computational tasks, known as GPGPU since fifteen years ago, has reached maturity. Applications take advantage of the parallel architectures of these devices in many different domains. Over the last few years several works have demonstrated the effectiveness of the integration of GPU-based systems in the...
Preprint
Full-text available
K^{+}\rightarrow\pi^{+}\nu\overline{\nu}$ is one of the theoretically cleanest meson decay where to look for indirect effects of new physics complementary to LHC searches. The NA62 experiment at CERN SPS is designed to measure the branching ratio of this decay with 10\% precision. NA62 took data in pilot runs in 2014 and 2015 reaching the final des...
Poster
We propose to use wavelength multiplexing on a silicon photonics circuit for highly segmented pixel detectors readout. Many front-end channels can be encoded and transmitted on the same common optical line and subsequently decoded by the back-end optical demultiplexer chip.
Article
The ExaNeSt project started on December 2015 and is funded by EU H2020 research framework (call H2020-FETHPC-2014, n. 671553) to study the adoption of low-cost, Linux-based power-efficient 64-bit ARM processors clusters for Exascale-class systems. The ExaNeSt consortium pools partners with industrial and academic research expertise in storage, inte...
Article
Full-text available
The deployment of the next generation computing platform at ExaFlops scale requires to solve new technological challenges mainly related to the impressive number (up to 10^6) of compute elements required. This impacts on system power consumption, in terms of feasibility and costs, and on system scalability and computing efficiency. In this perspect...
Article
Full-text available
Efficient brain simulation is a scientific grand challenge, a parallel/distributed coding challenge and a source of requirements and suggestions for future computing architectures. Indeed, the human brain includes about 10^15 synapses and 10^11 neurons activated at a mean rate of several Hz. Full brain simulation poses Exascale challenges even if s...
Article
Full-text available
We measured the impact of long-range exponentially decaying intra-areal lateral connectivity on the scaling and memory occupation of a distributed spiking neural network simulator compared to that of short-range Gaussian decays. While previous studies adopted short-range connectivity, recent experimental neurosciences studies are pointing out the r...
Article
Full-text available
A search for heavy neutral lepton production in K+ decays using a data sample collected with a minimum bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10−7 to 10−6 level are established on the elements of the extended neutrino mixing matrix |Ue4|2 and |Uμ4|2 for heavy neutral lepton mass in the ranges 170–448 Me...
Article
We present the prototype of an Electric Field Detector (EFD) for space applications, that has been developed in the framework of the Chinese-Italian collaboration on the CSES (China Seismo-Electromagnetic Satellite) forthcoming missions. In particular CSES-1 will be placed in orbit in the early 2018. The detector consists of spherical probes design...
Article
Full-text available
In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL) with data collected by NA48/2 (2003-2004), NA62-RK (2007) and NA62 (2015) CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. I...
Article
Full-text available
In this paper we present the status of the 3rd generation design of the APEnet board (V5) built upon the 28nm Altera Stratix V FPGA; it features a PCIe Gen3 x8 interface and enhanced embedded transceivers with a maximum capability of 12.5Gbps each. The network architecture is designed in accordance to the Remote DMA paradigm. The APEnet+ V5 prototy...
Article
Full-text available
With processor architecture evolution, the HPC market has undergone a paradigm shift. The adoption of low-cost, Linux-based clusters extended the reach of HPC from its roots in modelling and simulation of complex physical systems to a broader range of industries, from biotechnology, cloud computing, computer analytics and big data challenges to man...
Article
Full-text available
NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. Such measurements, like the branching fraction of the K⁺ → π⁺ ν decay, have the potential to bring significant insights into new physics processes when comparison is made with precise theoretical predictions. For this purpose, innovative techniques have...
Article
Full-text available
The NA62 experiment at the CERN SPS aims at measuring the branching ratio of the very rare kaon decay K⁺ → π⁺ ν (expected 10⁻¹⁰) with a 10% background. Since an high-intensity kaon beam is required to collect enough statistics, the Level-0 trigger plays a fundamental role in both the background rejection and in the particle identification. The calo...
Article
Among the meson decays, K→πνν‾ are the cleanest environment, from the theoretical point of view, where to search for new physics effects. The NA62 Experiment at CERN SPS aims to measure the BR(K+→π+νν‾) with a 10% precision by the end of 2018. It has been commissioned with technical runs in 2014 and 2015, and some preliminary results of the detecto...
Article
Full-text available
The NA62 experiment at CERN SPS has started its data-taking. Its aim is to measure the branching ratio of the ultra-rare decay K⁺ → π⁺ν ν̅ . In this context, rejecting the background is a crucial topic. One of the main background to the measurement is represented by the K⁺ → π⁺π⁰ decay. In the 1-8.5 mrad decay region this background is rejected by...
Article
NaNet is a framework for the development of FPGA-based PCI Express (PCIe) Network Interface Cards (NICs) with real-time data transport architecture that can be effectively employed in TRIDAQ systems. Key features of the architecture are the flexibility in the configuration of the number and kind of the I/O channels, the hardware offloading of the n...
Article
This project aims to exploit the parallel computing power of a commercial Graphics Processing Unit (GPU) to implement fast pattern matching in the Ring Imaging Cherenkov (RICH) detector for the level 0 (L0) trigger of the NA62 experiment. In this approach, the ring-fitting algorithm is seedless, being fed with raw RICH data, with no previous inform...
Article
The parallel computing power of commercial Graphics Processing Units (GPUs) is exploited to perform real-time ring fitting at the lowest trigger level using information coming from the Ring Imaging Cherenkov (RICH) detector of the NA62 experiment at CERN. To this purpose, direct GPU communication with a custom FPGA-based board has been used to redu...
Article
Full-text available
A commercial Graphics Processing Unit (GPU) is used to build a fast Level 0 (L0) trigger system tested parasitically with the TDAQ (Trigger and Data Acquisition systems) of the NA62 experiment at CERN. In particular, the parallel computing power of the GPU is exploited to perform real-time fitting in the Ring Imaging CHerenkov (RICH) detector. Dire...
Article
Full-text available
We describe a White Rabbit Facility for time synchronization we are preparing for the future Cherenkov Telescope Array observatory
Article
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The CSES satellite, developed by Chinese (CNSA) and Italian (ASI) space Agencies, will investigate iono-magnetospheric disturbances (induced by seismicity and electromagnetic emissions of tropospheric and anthropogenic origin); will monitor the temporal stability of the inner Van Allen radiation belts and will study the solar-terrestrial coupling b...
Article
Full-text available
Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiment...
Article
Full-text available
A GPU-based low level (L0) trigger is currently integrated in the experimental setup of the RICH detector of the NA62 experiment to assess the feasibility of building more refined physics-related trigger primitives and thus improve the trigger discriminating power. To ensure the real-time operation of the system, a dedicated data transport mechanis...
Article
Full-text available
The NA62 experiment at the CERN SPS aims at measuring the branching ratio of the very rare kaon decay K+ → π+ ν (expected 10−10) with a 10% background. Since an high-intensity kaon beam is required to collect enough statistics, the Level-0 trigger plays a fundamental role in both the background rejection and in the particle identification. The calo...
Article
Full-text available
The KM3NeT-Italia underwater neutrino detection unit, the tower, consists of 14 floors. Each floor supports 6 Optical Modules containing front-end electronics needed to digitize the PMT signal, format and transmit the data and 2 hydrophones that reconstruct in real-time the position of Optical Modules, for a maximum tower throughput of more than 60...
Article
General-purpose computing on GPUs is emerging as a new paradigm in several fields of science, although so far applications have been tailored to employ GPUs as accelerators in offline computations. With the steady decrease of GPU latencies and the increase in link and memory throughputs, time is ripe for real-time applications using GPUs in high-en...