Takashi Asada
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The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
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Takashi Asada has a total of 318 co-authors. Here are the top co-authors by number of shared publications:
- Andrey Aleksandrov
Sezione INFN di Napoli
9 shared publications - Giovanni De Lellis
Sezione INFN di Napoli
9 shared publications - Valeri Tioukov
Sezione INFN di Napoli
9 shared publications - Adele Lauria
Sezione INFN di Napoli
7 shared publications - A. Fiorillo
Sezione INFN di Napoli
6 shared publications - A. P. Conaboy
Humboldt-Universität zu Berlin, 12489 Berlin, Germany
6 shared publications
Latest Publications
- Open Access
Antiproton Interferometry and Aharonov–Bohm Effect (AIABE)
The Aharonov–Bohm (AB) effect is one of the most striking features of quantum physics, and it is of critical importance to elucidate the role of the electromagnetic potential and its physical meaning. In spite of the fact that it was first proposed in 1949, up to now it has only been demonstrated for electrons and neutrons. We propose the realization of an experiment to study the AB effect for the antiproton, which will have the double feature of being a non-elementary charged particle and at the same time an antiparticle. The experiment will be conducted in collaboration with the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) group at the CERN AD (Antiproton Decelerator), making use of a slow antiproton beam.
Open AccessAntiproton Interferometry and Aharonov–Bohm Effect (AIABE)
The Aharonov–Bohm (AB) effect is one of the most striking features of quantum physics, and it is of critical importance to elucidate the role of the electromagnetic potential and its physical meaning. In spite of the fact that it was first proposed in 1949, up to now it has only been demonstrated for electrons and neutrons. We propose the realization of an experiment to study the AB effect for the antiproton, which will have the double feature of being a non-elementary charged particle and at the same time an antiparticle. The experiment will be conducted in collaboration with the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) group at the CERN AD (Antiproton Decelerator), making use of a slow antiproton beam.
- Open Access
- 13 June 2025
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 134 (23) , 231802
Observation of Collider Neutrinos without Final State Muons with the SND@LHC Experiment
We report the observation of neutrino interactions without final state muons at the LHC, with a significance of 6.4 σ . A dataset of proton-proton collisions at s = 13.6 TeV collected by SND@LHC in 2022 and 2023 is used, corresponding to an integrated luminosity of 68.6 fb − 1 . Neutrino interactions without a reconstructed muon are selected, resulting in an event sample consisting mainly of neutral-current and electron neutrino charged-current interactions in the detector. After selection cuts, 9 neutrino interaction candidate events are observed with an estimated background of 0.32 events.
- 13 June 2025
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 134 (23) , 231802
Open AccessObservation of Collider Neutrinos without Final State Muons with the SND@LHC Experiment
We report the observation of neutrino interactions without final state muons at the LHC, with a significance of 6.4 σ . A dataset of proton-proton collisions at s = 13.6 TeV collected by SND@LHC in 2022 and 2023 is used, corresponding to an integrated luminosity of 68.6 fb − 1 . Neutrino interactions without a reconstructed muon are selected, resulting in an event sample consisting mainly of neutral-current and electron neutrino charged-current interactions in the detector. After selection cuts, 9 neutrino interaction candidate events are observed with an estimated background of 0.32 events.
- Open Access
- 1 December 2024
- Published by IOP Publishing in Journal of Instrumentation
- Vol. 19 (12) , P12002
An integrated flux-symmetric spectrometer-magnet system for the SND@LHC experiment upgrade
The proposed upgrade of the SND@LHC experiment for the High Luminosity phase of the LHC (HL-LHC) will strongly benefit from the presence of a magnetized region, allowing for muon momentum and charge measurement. In this paper we describe an iron core magnet system that is partly integrated with the calorimeter and that is designed to respect the strict constraints from the available space in the experimental cavern, power consumption, and field requirements. Semi-analytical tools are introduced to explore the parameter space, in order to define the primary design options. A full 3-D analysis is then performed in order to validate the optimal choice, and to propose a conceptual design, including sizing of the components, detector performances and stray fields. Several technical options are also discussed, anticipating the design phase.
- 1 December 2024
- Published by IOP Publishing in Journal of Instrumentation
- Vol. 19 (12) , P12002
Open AccessAn integrated flux-symmetric spectrometer-magnet system for the SND@LHC experiment upgrade
The proposed upgrade of the SND@LHC experiment for the High Luminosity phase of the LHC (HL-LHC) will strongly benefit from the presence of a magnetized region, allowing for muon momentum and charge measurement. In this paper we describe an iron core magnet system that is partly integrated with the calorimeter and that is designed to respect the strict constraints from the available space in the experimental cavern, power consumption, and field requirements. Semi-analytical tools are introduced to explore the parameter space, in order to define the primary design options. A full 3-D analysis is then performed in order to validate the optimal choice, and to propose a conceptual design, including sizing of the components, detector performances and stray fields. Several technical options are also discussed, anticipating the design phase.
- Open Access
Results and Perspectives from the First Two Years of Neutrino Physics at the LHC by the SND@LHC Experiment
After rapid approval and installation, the SND@LHC Collaboration was able to gather data successfully in 2022 and 2023. Neutrino interactions from νμs originating at the LHC IP1 were observed. Since muons constitute the major background for neutrino interactions, the muon flux entering the acceptance was also measured. To improve the rejection power of the detector and to increase the fiducial volume, a third Veto plane was recently installed. The energy resolution of the calorimeter system was measured in a test beam. This will help with the identification of νe interactions that can be used to probe charm production in the pseudo-rapidity range of SND@LHC (7.2 < η < 8.4). Events with three outgoing muons have been observed and are being studied. With no vertex in the target, these events are very likely from muon trident production in the rock before the detector. Events with a vertex in the detector could be from trident production, photon conversion, or positron annihilation. To enhance SND@LHC’s physics case, an upgrade is planned for HL-LHC that will increase the statistics and reduce the systematics. The installation of a magnet will allow the separation of νμ fromOpen AccessResults and Perspectives from the First Two Years of Neutrino Physics at the LHC by the SND@LHC Experiment
After rapid approval and installation, the SND@LHC Collaboration was able to gather data successfully in 2022 and 2023. Neutrino interactions from νμs originating at the LHC IP1 were observed. Since muons constitute the major background for neutrino interactions, the muon flux entering the acceptance was also measured. To improve the rejection power of the detector and to increase the fiducial volume, a third Veto plane was recently installed. The energy resolution of the calorimeter system was measured in a test beam. This will help with the identification of νe interactions that can be used to probe charm production in the pseudo-rapidity range of SND@LHC (7.2 < η < 8.4). Events with three outgoing muons have been observed and are being studied. With no vertex in the target, these events are very likely from muon trident production in the rock before the detector. Events with a vertex in the detector could be from trident production, photon conversion, or positron annihilation. To enhance SND@LHC’s physics case, an upgrade is planned for HL-LHC that will increase the statistics and reduce the systematics. The installation of a magnet will allow the separation of νμ from - Top Cited PapersOpen Access
- 1 May 2024
- Published by IOP Publishing in Journal of Instrumentation
- Vol. 19 (05) , P05067
SND@LHC: the scattering and neutrino detector at the LHC
SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the pseudo-rapidity region of 7.2 < η < 8.4. The experiment is located 480 m downstream of the ATLAS interaction point, in the TI18 tunnel. The detector is composed of a hybrid system based on an 830 kg target made of tungsten plates, interleaved with emulsion and electronic trackers, also acting as an electromagnetic calorimeter, and followed by a hadronic calorimeter and a muon identification system. The detector is able to distinguish interactions of all three neutrino flavours, which allows probing the physics of heavy flavour production at the LHC in the very forward region. This region is of particular interest for future circular colliders and for very high energy astrophysical neutrino experiments. The detector is also able to search for the scattering of Feebly Interacting Particles. In its first phase, the detector is ready to operate throughout LHC Run 3 and collect a total of 250 fb-1.
- 1 May 2024
- Published by IOP Publishing in Journal of Instrumentation
- Vol. 19 (05) , P05067
Top Cited PapersOpen AccessSND@LHC: the scattering and neutrino detector at the LHC
SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the pseudo-rapidity region of 7.2 < η < 8.4. The experiment is located 480 m downstream of the ATLAS interaction point, in the TI18 tunnel. The detector is composed of a hybrid system based on an 830 kg target made of tungsten plates, interleaved with emulsion and electronic trackers, also acting as an electromagnetic calorimeter, and followed by a hadronic calorimeter and a muon identification system. The detector is able to distinguish interactions of all three neutrino flavours, which allows probing the physics of heavy flavour production at the LHC in the very forward region. This region is of particular interest for future circular colliders and for very high energy astrophysical neutrino experiments. The detector is also able to search for the scattering of Feebly Interacting Particles. In its first phase, the detector is ready to operate throughout LHC Run 3 and collect a total of 250 fb-1.
- Open Access
- 27 January 2024
- Published by Springer Nature in The European Physical Journal C
- Vol. 84 (1) , 1-10
Measurement of the muon flux at the SND@LHC experiment
The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between 100 GeV and 1 TeV. It covers a previously unexplored pseudo-rapidity range of $$7.2<\eta <8.4$$ . The detector is located 480 m downstream of the ATLAS interaction point in the TI18 tunnel. It comprises a veto system, a target consisting of tungsten plates interleaved with nuclear emulsion and scintillating fiber (SciFi) trackers, followed by a muon detector (UpStream, US and DownStream, DS). In this article we report the measurement of the muon flux in three subdetectors: the emulsion, the SciFi trackers and the DownStream Muon detector. The muon flux per integrated luminosity through an 18 $$\times $$ 18 cm $$^{2}$$ area in the emulsion is: $$\begin{aligned} 1.5 \pm 0.1(\text {stat}) \times 10^4\,\text {fb/cm}^{2}. \end{aligned}$$ The muon flux per integrated luminosity through a 31 $$\times $$ 31 cm $$^{2}$$ area in the centre of the SciFi is: $$\begin{aligned} 2.06\pm 0.01(\text {stat})\pm 0.12(\text {sys}) \times 10^{4} \text {fb/cm}^{2} \end{aligned}$$ The muon flux per integrated luminosity through a 52 $$\times $$ 52 cm $$^{2}$$ area in the centre of the downstream muon system is: $$\begin{aligned} 2.35\pm 0.01(\text {stat})\pm 0.10(\text {sys}) \times 10^{4}\,\text {fb/cm}^{2} \end{aligned}$$ The total relative uncertainty of the measurements by the electronic detectors is 6 $$\%$$ for the SciFi and 4 $$\%$$ for the DS measurement. The Monte Carlo simulation prediction of these fluxes is 20–25 $$\%$$ lower than the measured values.- 27 January 2024
- Published by Springer Nature in The European Physical Journal C
- Vol. 84 (1) , 1-10
Open AccessMeasurement of the muon flux at the SND@LHC experiment
The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between 100 GeV and 1 TeV. It covers a previously unexplored pseudo-rapidity range of $$7.2<\eta <8.4$$ . The detector is located 480 m downstream of the ATLAS interaction point in the TI18 tunnel. It comprises a veto system, a target consisting of tungsten plates interleaved with nuclear emulsion and scintillating fiber (SciFi) trackers, followed by a muon detector (UpStream, US and DownStream, DS). In this article we report the measurement of the muon flux in three subdetectors: the emulsion, the SciFi trackers and the DownStream Muon detector. The muon flux per integrated luminosity through an 18 $$\times $$ 18 cm $$^{2}$$ area in the emulsion is: $$\begin{aligned} 1.5 \pm 0.1(\text {stat}) \times 10^4\,\text {fb/cm}^{2}. \end{aligned}$$ The muon flux per integrated luminosity through a 31 $$\times $$ 31 cm $$^{2}$$ area in the centre of the SciFi is: $$\begin{aligned} 2.06\pm 0.01(\text {stat})\pm 0.12(\text {sys}) \times 10^{4} \text {fb/cm}^{2} \end{aligned}$$ The muon flux per integrated luminosity through a 52 $$\times $$ 52 cm $$^{2}$$ area in the centre of the downstream muon system is: $$\begin{aligned} 2.35\pm 0.01(\text {stat})\pm 0.10(\text {sys}) \times 10^{4}\,\text {fb/cm}^{2} \end{aligned}$$ The total relative uncertainty of the measurements by the electronic detectors is 6 $$\%$$ for the SciFi and 4 $$\%$$ for the DS measurement. The Monte Carlo simulation prediction of these fluxes is 20–25 $$\%$$ lower than the measured values. - Open Access
- 19 July 2023
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 131 (3) , 031802
Observation of Collider Muon Neutrinos with the SND@LHC Experiment
We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of . The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of , inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed signal.- 19 July 2023
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 131 (3) , 031802
Open AccessObservation of Collider Muon Neutrinos with the SND@LHC Experiment
We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of . The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of , inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed signal. - 10 January 2023
- Published by American Physical Society (APS) in Physical Review C
- Vol. 107 (1) , 014608
Environmental sub-MeV neutron measurement at the Gran Sasso surface laboratory with a super-fine-grained nuclear emulsion detector
The measurement of environmental neutrons is particularly important in the search for new physics, such as dark matter particles, because neutrons constitute an often irreducible background source. The measurement of the neutron energy spectra in the sub-MeV scale is technically difficult because it requires a very good energy resolution and a very high -ray rejection power. In this study, we used a super-fine-grained nuclear emulsion, called nano imaging tracker, as a neutron detector. The main target of neutrons is the hydrogen (proton) content of emulsion films. Through a topological analysis, proton recoils induced by neutron scattering can be detected as tracks with submicrometric accuracy. This method shows an extremely high -ray rejection power, at the level of , which is equivalent to five years accumulation of environmental rays, and a very good energy and direction resolution even in the sub-MeV energy region. In order to carry out this measurement with sufficient statistics, we upgraded the automated scanning system to achieve a speed of 250 g/(year machine). We calibrated the detector performance of this system with 880 keV monochromatic neutrons: a very good agreement with the expectation was found for all the relevant kinematic variables. The application of the developed method to a sample exposed at the INFN Gran Sasso surface laboratory provided the first measurement of sub-MeV environmental neutrons with a flux of in the proton energy range between 0.25 and 1 MeV (corresponds to neutron energy range between 0.25 and 10 MeV), consistent with the prediction. The neutron energy and direction distributions also show a good agreement.- 10 January 2023
- Published by American Physical Society (APS) in Physical Review C
- Vol. 107 (1) , 014608
Environmental sub-MeV neutron measurement at the Gran Sasso surface laboratory with a super-fine-grained nuclear emulsion detector
The measurement of environmental neutrons is particularly important in the search for new physics, such as dark matter particles, because neutrons constitute an often irreducible background source. The measurement of the neutron energy spectra in the sub-MeV scale is technically difficult because it requires a very good energy resolution and a very high -ray rejection power. In this study, we used a super-fine-grained nuclear emulsion, called nano imaging tracker, as a neutron detector. The main target of neutrons is the hydrogen (proton) content of emulsion films. Through a topological analysis, proton recoils induced by neutron scattering can be detected as tracks with submicrometric accuracy. This method shows an extremely high -ray rejection power, at the level of , which is equivalent to five years accumulation of environmental rays, and a very good energy and direction resolution even in the sub-MeV energy region. In order to carry out this measurement with sufficient statistics, we upgraded the automated scanning system to achieve a speed of 250 g/(year machine). We calibrated the detector performance of this system with 880 keV monochromatic neutrons: a very good agreement with the expectation was found for all the relevant kinematic variables. The application of the developed method to a sample exposed at the INFN Gran Sasso surface laboratory provided the first measurement of sub-MeV environmental neutrons with a flux of in the proton energy range between 0.25 and 1 MeV (corresponds to neutron energy range between 0.25 and 10 MeV), consistent with the prediction. The neutron energy and direction distributions also show a good agreement.- 18 June 2015
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electromagnetic Compatibility
- Vol. 57 (5) , 1164-1167
Representation of a Straight Thin Wire in a Lossy Medium and an Oblique Thin Wire in Air for FDTD Simulations
An improved representation of a straight thin wire for a 3-D finite-difference time-domain simulation has been applied to the transient analysis of a straight thin wire in a lossy medium, and its validity has been shown. In this representation, a straight wire having a specified radius is simulated by a straight wire having the equivalent radius 0.199Δs, where Δs is the lateral side length of cubic cells employed, embedded in an artificial parallelepiped medium having modified conductivity (only if it is in a lossy medium), modified relative permittivity, and modified relative permeability. Also, the equivalent radius of a staircase-approximated oblique wire in air has been evaluated, and its thin-wire representation has been discussed.
- 18 June 2015
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electromagnetic Compatibility
- Vol. 57 (5) , 1164-1167
Representation of a Straight Thin Wire in a Lossy Medium and an Oblique Thin Wire in Air for FDTD Simulations
An improved representation of a straight thin wire for a 3-D finite-difference time-domain simulation has been applied to the transient analysis of a straight thin wire in a lossy medium, and its validity has been shown. In this representation, a straight wire having a specified radius is simulated by a straight wire having the equivalent radius 0.199Δs, where Δs is the lateral side length of cubic cells employed, embedded in an artificial parallelepiped medium having modified conductivity (only if it is in a lossy medium), modified relative permittivity, and modified relative permeability. Also, the equivalent radius of a staircase-approximated oblique wire in air has been evaluated, and its thin-wire representation has been discussed.