The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for ... more The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of large energetic proton events up to hundreds of MeV. The a-Si:H presents an excellent radiation hardness and finds application in harsh radiation environments for medical purposes, for particle beam characterization and in space weather science and applications. The critical flux detection threshold for solar X rays, soft gamma rays, electrons and protons is discussed in detail.
2019 8th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2019
The Compact Muon Solenoid (CMS) detector is operating at the Large Hadron Collider (LHC) with pro... more The Compact Muon Solenoid (CMS) detector is operating at the Large Hadron Collider (LHC) with proton-proton collisions at 13 TeV center-of-mass energy and with 25 ns bunch spacing. The High Luminosity LHC (HL-LHC) will require a significant upgrade of the CMS electromagnetic calorimeter (ECAL) in order to maintain good detector performance in the harsh radiation environment, increasing data rates, and higher level of pile-up events of the HL-LHC. The very front-end (VFE) readout electronics have been completely redesigned, with goals of providing precision timing, low noise, and sampling rate four times higher than the current one. This paper focuses on the LiTE-DTU ASIC that is a fully digital data transmission unit which performs online data selection, online lossless compression, and high-speed serial transmission. I will report on the ASIC architecture, the selected methods for data selection and compression, data format, and techniques for mitigation of radiation damage mitigation.
Proceedings of The XXI International Workshop High Energy Physics and Quantum Field Theory — PoS(QFTHEP 2013), 2014
A precision lepton universality test by measurement of the helicity suppressed ratio of leptonic ... more A precision lepton universality test by measurement of the helicity suppressed ratio of leptonic decay rates of the charged kaon with 10 5 K ± → e ± ν decays collected by the NA62 experiment in 2007-08 is presented. The record accuracy of 0.4% constrains the parameter space of new physics models with extended Higgs sector, a fourth generation of quarks and leptons or sterile neutrinos. An improved upper limit on the rate of the lepton number violating decay K ± → π ∓ µ ± µ ± from the NA48/2 experiment, which probes the resonant enhancement of the rate in the presence of heavy Majorana neutrinos in the 100 MeV range, is also presented.
Proceedings of 50th International Winter Meeting on Nuclear Physics — PoS(Bormio2012), 2012
PANDA is a fixed target experiment with antiproton beam up to 15 GeV/c, that will take place at t... more PANDA is a fixed target experiment with antiproton beam up to 15 GeV/c, that will take place at the future FAIR facility. The PANDA experiment will allow the study of different physics topics, from hadron structure and quark-gluon dynamics to nuclear physics. The Micro-Vertex Detector (MVD) is the detector closest to the interaction point, and it is equipped with pixel and strip detectors. The MVD is designed to reconstruct the secondary vertices of the involved charmed mesons, featuring good spatial resolution, limited material budget, radiation hardness, and PID capability. The peculiar requirement to work in a triggerless environment asks for the capability to handle very high data rates. The hybrid pixel R&D program is in its final stage. Its design is based on thin epitaxial sensors and readout chip developed in 130nm CMOS technology. Here the latest pixel detector R&D achievements are presented.
Proceedings of Topical Workshop on Electronics for Particle Physics — PoS(TWEPP-17), 2018
RD53A is a large scale 65 nm CMOS pixel demonstrator chip that has been developed by the RD53 col... more RD53A is a large scale 65 nm CMOS pixel demonstrator chip that has been developed by the RD53 collaboration for very high rate (3 GHz/cm 2) and very high radiation levels (500 Mrad, possibly 1 Grad) for ATLAS and CMS phase 2 upgrades. It features serial powering operation and design variations in the analog and digital pixel matrix for different testing purposes. The design and verification of RD53A are described together with an outline of the plans to develop final pixel chips for the two experiments.
Proceedings of 9th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors — PoS(RD09), 2010
The hybrid pixel detector is the innermost part of the tracking system of the PANDA experiment. G... more The hybrid pixel detector is the innermost part of the tracking system of the PANDA experiment. Good spatial resolution, capability to manage a huge amount of data, due to the high interaction rate and the absence of the trigger signal, limited material budget, due to the particle momentum starting from few hundreds of MeV/c, particle identification using energy loss measurement and radiation hardness are the major features. To cope with these requests, a complete R&D program is in progress to study and design a custom detector, always based on the standard hybrid technology, but with thin epitaxial silicon sensors and readout developed by 130nm CMOS technology. Dedicated mechanical structures, using new materials, and cooling system are under study too. The detector layout description and results concerning first prototypes are reported. 2
The first study of W boson production in pPb collisions is presented, for bosons decaying to a mu... more The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 nb −1 at a nucleon-nucleon centre-of-mass energy of √ s NN = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV/c, and as a function of the lepton pseudorapidity in the |η lab | < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.
A search for a massive resonance decaying into a standard-model-like Higgs boson (H) and a W or Z... more A search for a massive resonance decaying into a standard-model-like Higgs boson (H) and a W or Z boson is reported. The analysis is performed on a data sample corresponding to an integrated luminosity of 19.7 fb −1 , collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. Signal events, in which the decay products of Higgs, W, or Z bosons at high Lorentz boost are contained within single reconstructed jets, are identified using jet substructure techniques, including the tagging of b hadrons. This is the first search for heavy resonances decaying into HW or HZ resulting in an all-jet final state, as well as the first application of jet substructure techniques to identify H → WW * → 4q decays at high Lorentz boost. No significant signal is observed and limits are set at 95% confidence level on the production cross sections of W and Z in a model with mass-degenerate charged and neutral spin-1 resonances.
Measurements of the cross sections for top quark pairs produced in association with a W or Z boso... more Measurements of the cross sections for top quark pairs produced in association with a W or Z boson are presented, using 8 TeV pp collision data corresponding to an integrated luminosity of 19.5 fb −1 , collected by the CMS experiment at the LHC. Final states are selected in which the associated W boson decays to a charged lepton and a neutrino or the Z boson decays to two charged leptons. Signal events are identified by matching reconstructed objects in the detector to specific final state particles from ttW or ttZ decays. The ttW cross section is measured to be 382 +117 −102 fb with a significance of 4.8 standard deviations from the background-only hypothesis. The ttZ cross section is measured to be 242 +65 −55 fb with a significance of 6.4 standard deviations from the background-only hypothesis. These measurements are used to set bounds on five anomalous dimension-six operators that would affect the ttW and ttZ cross sections.
ABSTRACT A 64-channel ASIC for TOF PET imaging is presented. The circuit provides time and energy... more ABSTRACT A 64-channel ASIC for TOF PET imaging is presented. The circuit provides time and energy measurements of events produced by a SiPM coupled to a L(Y)SO fast scintillator. This ASIC is developed in the framework of the EndoTOFPETUS collaboration as an option for the readout of external 200×200 mm plate detector, which consists of 3×3×15 mm crystals and 3×3 mm (active area) SiPMs. Using the chip with non-segmented and/or higher light yield crystals is possible. The same applies for photodetectors with different gain, polarity, or even higher dark count rate. The targeted 200 ps timing resolution for the system and the need for a low power consumption have driven the choice of a closed-loop amplifier input stage and a 50 ps time binning TDC based on analogue interpolation. A power consumption between 5 to 10 mW per channel is expected to guarantee a SNR of at least 20 dB for the single photon, using a SiPM with 320 pF terminal capacitance.
The first observation of the Z boson decaying to four leptons in proton-proton collisions is pres... more The first observation of the Z boson decaying to four leptons in proton-proton collisions is presented. The analyzed data set corresponds to an integrated luminosity of 5.02 fb −1 at √ s = 7 TeV collected by the CMS detector at the Large Hadron Collider. A pronounced resonance peak, with a statistical significance of 9.7 σ, is observed in the distribution of the invariant mass of four leptons (electrons and/or muons) with mass and width consistent with expectations for Z boson decays. The branching fraction and cross section reported here are defined by phase space restrictions on the leptons, namely, 80 < m 4 < 100 GeV, where m 4 is the invariant mass of the four leptons, and m > 4 GeV for all pairs of leptons, where m is the two-lepton invariant mass. The measured branching fraction is B(Z → 4) = 4.2 +0.9 −0.8 (stat.) ± 0.2(syst.) × 10 −6 and agrees with the standard model prediction of 4.45 × 10 −6. The measured cross section times branching fraction is σ(pp → Z) B(Z → 4) = 112 +23 −20 (stat.) +7 −5 (syst.) +3 −2 (lumi.) fb, also consistent with the standard model prediction of 120 fb. The four-lepton mass peak arising from Z → 4 decays provides a calibration channel for the Higgs boson search in the H → ZZ → 4 decay mode.
2019 15th Conference on Ph.D Research in Microelectronics and Electronics (PRIME)
The High Luminosity LHC (HL-LHC), the foreseen LHC upgrade, will entail higher levels of instanta... more The High Luminosity LHC (HL-LHC), the foreseen LHC upgrade, will entail higher levels of instantaneous luminosity by about a factor of 5 from current levels.The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid detector (CMS) will experience a challenging environment during the HL-LHC phase. As a matter of fact higher event pileup, increasing data rates and harsher radiation environment are some of the expected conditions.A complete redesign of the ECAL on-detector readout electronics have been performed in order to obtain precision timing, noise mitigation and increased sampling rate. As a result a high-resolution, high-speed ADC has been designed to convert the signal from the front-end Trans-Impedance Amplifier (TIA) stage. Each readout channel will produce a large amount of data which will require fast data processing circuitry and high speed serial links. A new digital architecture has been developed in order to decrease the data bandwidth by means of lossless data compression. These functions has been integrated in two ASICs: CATIA and LiTE-DTU, designed in commercial CMOS 130 nm and 65 nm technology, respectively.
CERN-LHC. Measurement of the cross sections for Upsilon(1s), Upsilon(2S) and Upsilon(3S) producti... more CERN-LHC. Measurement of the cross sections for Upsilon(1s), Upsilon(2S) and Upsilon(3S) production in proton-proton collisions at a centre of mass energy of 7 TeV. The data sample, with an integrated luminosity of 35.8+-1.4 pb-1 covers the PT range 0-50 GeV/c and |rapidity| < 2.4. The Upsilon resonances are identified through their decay to di-muons and the data are uncorrected for the branching ratio. Fiducial as well as acceptance-corrected cross sections are tabulated. The effects of the polarization on the acceptance corrected cross section are given for the following extreme scenarios: HX_ T - fully transverse in the helicity frame HX_ L - fully longitudinal in the helicity frame CS_ T - fully transverse in the Collins-Soper frame CS_ L - fully longitudinal in the Collins-Soper frame.
The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for ... more The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of large energetic proton events up to hundreds of MeV. The a-Si:H presents an excellent radiation hardness and finds application in harsh radiation environments for medical purposes, for particle beam characterization and in space weather science and applications. The critical flux detection threshold for solar X rays, soft gamma rays, electrons and protons is discussed in detail.
2019 8th International Conference on Modern Circuits and Systems Technologies (MOCAST), 2019
The Compact Muon Solenoid (CMS) detector is operating at the Large Hadron Collider (LHC) with pro... more The Compact Muon Solenoid (CMS) detector is operating at the Large Hadron Collider (LHC) with proton-proton collisions at 13 TeV center-of-mass energy and with 25 ns bunch spacing. The High Luminosity LHC (HL-LHC) will require a significant upgrade of the CMS electromagnetic calorimeter (ECAL) in order to maintain good detector performance in the harsh radiation environment, increasing data rates, and higher level of pile-up events of the HL-LHC. The very front-end (VFE) readout electronics have been completely redesigned, with goals of providing precision timing, low noise, and sampling rate four times higher than the current one. This paper focuses on the LiTE-DTU ASIC that is a fully digital data transmission unit which performs online data selection, online lossless compression, and high-speed serial transmission. I will report on the ASIC architecture, the selected methods for data selection and compression, data format, and techniques for mitigation of radiation damage mitigation.
Proceedings of The XXI International Workshop High Energy Physics and Quantum Field Theory — PoS(QFTHEP 2013), 2014
A precision lepton universality test by measurement of the helicity suppressed ratio of leptonic ... more A precision lepton universality test by measurement of the helicity suppressed ratio of leptonic decay rates of the charged kaon with 10 5 K ± → e ± ν decays collected by the NA62 experiment in 2007-08 is presented. The record accuracy of 0.4% constrains the parameter space of new physics models with extended Higgs sector, a fourth generation of quarks and leptons or sterile neutrinos. An improved upper limit on the rate of the lepton number violating decay K ± → π ∓ µ ± µ ± from the NA48/2 experiment, which probes the resonant enhancement of the rate in the presence of heavy Majorana neutrinos in the 100 MeV range, is also presented.
Proceedings of 50th International Winter Meeting on Nuclear Physics — PoS(Bormio2012), 2012
PANDA is a fixed target experiment with antiproton beam up to 15 GeV/c, that will take place at t... more PANDA is a fixed target experiment with antiproton beam up to 15 GeV/c, that will take place at the future FAIR facility. The PANDA experiment will allow the study of different physics topics, from hadron structure and quark-gluon dynamics to nuclear physics. The Micro-Vertex Detector (MVD) is the detector closest to the interaction point, and it is equipped with pixel and strip detectors. The MVD is designed to reconstruct the secondary vertices of the involved charmed mesons, featuring good spatial resolution, limited material budget, radiation hardness, and PID capability. The peculiar requirement to work in a triggerless environment asks for the capability to handle very high data rates. The hybrid pixel R&D program is in its final stage. Its design is based on thin epitaxial sensors and readout chip developed in 130nm CMOS technology. Here the latest pixel detector R&D achievements are presented.
Proceedings of Topical Workshop on Electronics for Particle Physics — PoS(TWEPP-17), 2018
RD53A is a large scale 65 nm CMOS pixel demonstrator chip that has been developed by the RD53 col... more RD53A is a large scale 65 nm CMOS pixel demonstrator chip that has been developed by the RD53 collaboration for very high rate (3 GHz/cm 2) and very high radiation levels (500 Mrad, possibly 1 Grad) for ATLAS and CMS phase 2 upgrades. It features serial powering operation and design variations in the analog and digital pixel matrix for different testing purposes. The design and verification of RD53A are described together with an outline of the plans to develop final pixel chips for the two experiments.
Proceedings of 9th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors — PoS(RD09), 2010
The hybrid pixel detector is the innermost part of the tracking system of the PANDA experiment. G... more The hybrid pixel detector is the innermost part of the tracking system of the PANDA experiment. Good spatial resolution, capability to manage a huge amount of data, due to the high interaction rate and the absence of the trigger signal, limited material budget, due to the particle momentum starting from few hundreds of MeV/c, particle identification using energy loss measurement and radiation hardness are the major features. To cope with these requests, a complete R&D program is in progress to study and design a custom detector, always based on the standard hybrid technology, but with thin epitaxial silicon sensors and readout developed by 130nm CMOS technology. Dedicated mechanical structures, using new materials, and cooling system are under study too. The detector layout description and results concerning first prototypes are reported. 2
The first study of W boson production in pPb collisions is presented, for bosons decaying to a mu... more The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 nb −1 at a nucleon-nucleon centre-of-mass energy of √ s NN = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV/c, and as a function of the lepton pseudorapidity in the |η lab | < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.
A search for a massive resonance decaying into a standard-model-like Higgs boson (H) and a W or Z... more A search for a massive resonance decaying into a standard-model-like Higgs boson (H) and a W or Z boson is reported. The analysis is performed on a data sample corresponding to an integrated luminosity of 19.7 fb −1 , collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. Signal events, in which the decay products of Higgs, W, or Z bosons at high Lorentz boost are contained within single reconstructed jets, are identified using jet substructure techniques, including the tagging of b hadrons. This is the first search for heavy resonances decaying into HW or HZ resulting in an all-jet final state, as well as the first application of jet substructure techniques to identify H → WW * → 4q decays at high Lorentz boost. No significant signal is observed and limits are set at 95% confidence level on the production cross sections of W and Z in a model with mass-degenerate charged and neutral spin-1 resonances.
Measurements of the cross sections for top quark pairs produced in association with a W or Z boso... more Measurements of the cross sections for top quark pairs produced in association with a W or Z boson are presented, using 8 TeV pp collision data corresponding to an integrated luminosity of 19.5 fb −1 , collected by the CMS experiment at the LHC. Final states are selected in which the associated W boson decays to a charged lepton and a neutrino or the Z boson decays to two charged leptons. Signal events are identified by matching reconstructed objects in the detector to specific final state particles from ttW or ttZ decays. The ttW cross section is measured to be 382 +117 −102 fb with a significance of 4.8 standard deviations from the background-only hypothesis. The ttZ cross section is measured to be 242 +65 −55 fb with a significance of 6.4 standard deviations from the background-only hypothesis. These measurements are used to set bounds on five anomalous dimension-six operators that would affect the ttW and ttZ cross sections.
ABSTRACT A 64-channel ASIC for TOF PET imaging is presented. The circuit provides time and energy... more ABSTRACT A 64-channel ASIC for TOF PET imaging is presented. The circuit provides time and energy measurements of events produced by a SiPM coupled to a L(Y)SO fast scintillator. This ASIC is developed in the framework of the EndoTOFPETUS collaboration as an option for the readout of external 200×200 mm plate detector, which consists of 3×3×15 mm crystals and 3×3 mm (active area) SiPMs. Using the chip with non-segmented and/or higher light yield crystals is possible. The same applies for photodetectors with different gain, polarity, or even higher dark count rate. The targeted 200 ps timing resolution for the system and the need for a low power consumption have driven the choice of a closed-loop amplifier input stage and a 50 ps time binning TDC based on analogue interpolation. A power consumption between 5 to 10 mW per channel is expected to guarantee a SNR of at least 20 dB for the single photon, using a SiPM with 320 pF terminal capacitance.
The first observation of the Z boson decaying to four leptons in proton-proton collisions is pres... more The first observation of the Z boson decaying to four leptons in proton-proton collisions is presented. The analyzed data set corresponds to an integrated luminosity of 5.02 fb −1 at √ s = 7 TeV collected by the CMS detector at the Large Hadron Collider. A pronounced resonance peak, with a statistical significance of 9.7 σ, is observed in the distribution of the invariant mass of four leptons (electrons and/or muons) with mass and width consistent with expectations for Z boson decays. The branching fraction and cross section reported here are defined by phase space restrictions on the leptons, namely, 80 < m 4 < 100 GeV, where m 4 is the invariant mass of the four leptons, and m > 4 GeV for all pairs of leptons, where m is the two-lepton invariant mass. The measured branching fraction is B(Z → 4) = 4.2 +0.9 −0.8 (stat.) ± 0.2(syst.) × 10 −6 and agrees with the standard model prediction of 4.45 × 10 −6. The measured cross section times branching fraction is σ(pp → Z) B(Z → 4) = 112 +23 −20 (stat.) +7 −5 (syst.) +3 −2 (lumi.) fb, also consistent with the standard model prediction of 120 fb. The four-lepton mass peak arising from Z → 4 decays provides a calibration channel for the Higgs boson search in the H → ZZ → 4 decay mode.
2019 15th Conference on Ph.D Research in Microelectronics and Electronics (PRIME)
The High Luminosity LHC (HL-LHC), the foreseen LHC upgrade, will entail higher levels of instanta... more The High Luminosity LHC (HL-LHC), the foreseen LHC upgrade, will entail higher levels of instantaneous luminosity by about a factor of 5 from current levels.The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid detector (CMS) will experience a challenging environment during the HL-LHC phase. As a matter of fact higher event pileup, increasing data rates and harsher radiation environment are some of the expected conditions.A complete redesign of the ECAL on-detector readout electronics have been performed in order to obtain precision timing, noise mitigation and increased sampling rate. As a result a high-resolution, high-speed ADC has been designed to convert the signal from the front-end Trans-Impedance Amplifier (TIA) stage. Each readout channel will produce a large amount of data which will require fast data processing circuitry and high speed serial links. A new digital architecture has been developed in order to decrease the data bandwidth by means of lossless data compression. These functions has been integrated in two ASICs: CATIA and LiTE-DTU, designed in commercial CMOS 130 nm and 65 nm technology, respectively.
CERN-LHC. Measurement of the cross sections for Upsilon(1s), Upsilon(2S) and Upsilon(3S) producti... more CERN-LHC. Measurement of the cross sections for Upsilon(1s), Upsilon(2S) and Upsilon(3S) production in proton-proton collisions at a centre of mass energy of 7 TeV. The data sample, with an integrated luminosity of 35.8+-1.4 pb-1 covers the PT range 0-50 GeV/c and |rapidity| < 2.4. The Upsilon resonances are identified through their decay to di-muons and the data are uncorrected for the branching ratio. Fiducial as well as acceptance-corrected cross sections are tabulated. The effects of the polarization on the acceptance corrected cross section are given for the following extreme scenarios: HX_ T - fully transverse in the helicity frame HX_ L - fully longitudinal in the helicity frame CS_ T - fully transverse in the Collins-Soper frame CS_ L - fully longitudinal in the Collins-Soper frame.
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Papers by Giovanni Mazza