G. Organtini

Numbers and Non-Numbers Programming Languages Basic Elements in C Programs Logic Elements Basic Data Structures Pointers Functions Numeric Interpolation and Integration Differential Equations Integration More on Differential Equations Pseudo Random Numbers Random Walks Lists, Dictionaries and Percolation Bits and Boolean Variables Recursion and Data Sorting Dynamic Data Structures Graphs and Algorithms on Graphs Optimization Methods Monte Carlo Methods Stochastic Methods.

The X17 particle, the E38 particle, and the anomalous soft photons are anomalous particles because they do not appear to belong to any known Standard Model families. We propose a QED meson description of the anomalous particles as composite systems of a light quark and a light antiquark bound and confined by the compact QED interaction, by combining Polyakov's transverse confinement of opposite electric charges in compact QED in (2+1)D and Schwinger's longitudinal confinement for massless opposite electric charges in QED in (1+1)D. With predicted QED meson masses close to the observed X17 and E38 masses, QED mesons may be good candidates for the description of the anomalous particles.

We report on the construction and test of a lead-scintillating fiber (spaghetti) calorimeter built to fill the gap between endcaps and barrel in the L3 BGO detector. Results from test-beam, as well as MC simulations for the prototypes and for the full detector, are presented.

Correlated measurements of emission spectra, photoluminescence and scintillation decays, thermoluminescence, and light yield were performed on a selected set of undoped and La-doped PbWO4 single crystals. The samples were grown from 5N purity raw powders and show the blue emission component only. Distinct influence of La doping was found in the decays, thermoluminescence and light yield characteristics. It is discussed in the light of the direct influence of La doping on suppressing the creation of point defect centers in the PbWO4 lattice, which are involved in the energy transfer and storage processes in this material.

Arduino is a widely used open-source platform composed of both hardware and software tools that can be very useful in a physics laboratory. Its low price, the large availability of sensors and transducers, its ease of use and its open nature makes it a perfect tool to involve students in active and cooperative learning. In this paper we show a few examples of what can be done using an Arduino and some sensor, and propose a template for documenting activities.

The ordinary and the extraordinary complex refractive index of PbWO4 together with the crystal optical axis orientation are determined on the basis of transmittance and reflectance measurements at normal incidence with polarised light and the measurement of the separation angle between the ordinary and the extraordinary ray at various laser wavelengths. The real part of the extraordinary complex refractive index is lower than the ordinary one (i.e. PbWO4 is a negative uniaxial crystal) and they seem not to be affected by a 30 ppm Nb5+ doping.

We report on the response of microchannel plates (MCPs) to single relativistic particles and to electromagnetic showers. Particle detection by means of secondary emission of electrons at the MCP surface has long been proposed and is used extensively in ion time-of-flight mass spectrometers. What has not been investigated in depth is their use to detect the ionizing component of showers. The time resolution of MCPs exceeds anything that has been previously used in calorimeters and, if exploited effectively, could aid in the event reconstruction at high luminosity colliders. Several prototypes of photodetectors with the amplification stage based on MCPs were exposed to cosmic rays and to 491 MeV electrons at the INFN-LNF Beam-Test Facility. The time resolution and the efficiency of the MCPs are measured as a function of the particle multiplicity, and the results used to model the response to high-energy showers.

The PADME experiment at the DA$\Phi$NE Beam-Test Facility (BTF) aims at searching for invisible decays of the dark photon by measuring the final state missing mass in the process $e^+e^- \to \gamma+ A'$, with $A'$ undetected. The measurement requires the determination of the 4-momentum of the recoil photon, performed using a homogeneous, highly segmented BGO crystals calorimeter. We report the results of the test of a 5$\times$5 crystals prototype performed with an electron beam at the BTF in July 2016.

The PADME experiment is designed to search for a hypothetical dark photon $A^{\prime}$ produced in positron-electron annihilation using a bunched positron beam at the Beam Test Facility of the INFN Laboratori Nazionali di Frascati. The expected sensitivity to the $A^{\prime}$-photon mixing parameter $\epsilon$ is 10$^{-3}$, for $A^{\prime}$ mass $\le$ 23.5 MeV/$c^{2}$ after collecting $\sim 10^{13}$ positrons-on-target. This paper presents the PADME detector status after commissioning in July 2019. In addition, the software algorithms employed to reconstruct physics objects, such as photons and charged particles, and the calibration procedures adopted are illustrated in detail. The results show that the experimental apparatus reaches the design performance, and is able to identify and measure standard electromagnetic processes, such as positron Bremsstrahlung, electron-positron annihilation into two photons.

Abstract During 2022 data taking (Run III) PADME searched for a resonant production and a visible decay of the X17 particle into e + e - . A precise knowledge within 1% uncertainty of the number of positrons was required for the observation. To that purpose, an array of 2 × 6 Timepix3 (total of 512 × 1536 pixels) hybrid pixel detectors operated in data-streaming mode with ToA resolution of 1.56 ns for every pixel was employed. Two methods for data acquisition were developed. A frame-based method, integrating the number of hits for each individual pixel for a predefined period of time served for monitoring the beam conditions and to provide a rough estimation of the beam distribution and number of positrons. A data streaming mode exploiting the nanosecond time resolution of Timepix3 detector was used for precise characterization of the transverse beam profile and the distribution of the incident positrons within each bunch of ∼ 200 ns duration.

Abstract The PADME experiment at LNF-INFN employs positron-on-target-annihilation to search for new light particles. Crucial parts of the experiment are the charged particle detectors, composed of plastic scintillator bars with light transmitted by wavelength shifting fibers to silicon photomultipliers (SiPMs). The location of the detector — close to a turbomolecular pump, inside a vacuum tank, and exposed to 0.5 T magnetic field — has driven the design of custom modular SiPM front-end and power supply electronics. The design of the system and its performance, confirming the desired sub-ns resolution on the reconstructed particle flying times, is shown and discussed.

Abstract Classical physics results are often taught purely from the theoretical side. Key results, especially in electromagnetism, are typically not explored experimentally, and in applications students are then expected to leap straight into more complex scenarios that make use of these principles in electronics, sensors and instrumentation. This is unfortunate because not all individuals are equally able to learn well purely from the mathematical angle, and even those who do are not exposed to exploring the magnitude of competing effects, for example isolating a particular magnetic field signal from the background of the Earth’s field. An experiment is presented here to test Ampère’s law with a setup that can be assembled out of everyday materials with minimal components—a smartphone, a DC power supply, wires—in a procedure that can be completed in just a few hours. The data from the three magnetic field sensors of the phones, together with the gyroscope sensors providing position, are recorded and numerically integrated. The experiment is also demonstrated using sensors collected by an Arduino board instead of a smartphone. The experiment allows to measure the net current carried by wires inside the closed path over which the magnetic field is integrated, i.e. Ampère’s law. This experimental approach to exploring Ampère’s Law can be adapted towards high school or university demonstrations, depending on the level of accuracy and detail that one aims to pursue.

physica status solidi (a)Volume 164, Issue 2 p. R9-R10 Research Letter Radiation Damage and Thermoluminescence of Gd-Doped PbWO4 S. Baccaro, S. Baccaro ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorP. Bohacek, P. Bohacek Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorB. Borgia, B. Borgia INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorA. Cecilia, A. Cecilia ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorS. Croci, S. Croci INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this authorI. Dafinei, I. Dafinei INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorM. Diemoz, M. Diemoz INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorP. Fabeni, P. Fabeni IROE del CNR, Via Panciatichi 64, 50127 Firenze, ItalySearch for more papers by this authorM. Ishii, M. Ishii SIT, Shonan Institute of Technology, Fujisawa 251, JapanSearch for more papers by this authorM. Kobayashi, M. Kobayashi KEK, National Laboratory for High Energy Physics, Tsukuba 305, JapanSearch for more papers by this authorM. Martini, M. Martini INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this authorM. Montecchi, M. Montecchi ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorM. Nikl, M. Nikl Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorK. Nitsch, K. Nitsch Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorG. Organtini, G. Organtini INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma III., 00146 Roma, ItalySearch for more papers by this authorG. P. Pazzi, G. P. Pazzi IROE del CNR, Via Panciatichi 64, 50127 Firenze, ItalySearch for more papers by this authorY. Usuki, Y. Usuki Furukawa Co., Yoshima, Iwaki 970-11, JapanSearch for more papers by this authorA. Vedda, A. Vedda INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this author S. Baccaro, S. Baccaro ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorP. Bohacek, P. Bohacek Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorB. Borgia, B. Borgia INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorA. Cecilia, A. Cecilia ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorS. Croci, S. Croci INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this authorI. Dafinei, I. Dafinei INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorM. Diemoz, M. Diemoz INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma “La Sapienza”, 00185 Roma, ItalySearch for more papers by this authorP. Fabeni, P. Fabeni IROE del CNR, Via Panciatichi 64, 50127 Firenze, ItalySearch for more papers by this authorM. Ishii, M. Ishii SIT, Shonan Institute of Technology, Fujisawa 251, JapanSearch for more papers by this authorM. Kobayashi, M. Kobayashi KEK, National Laboratory for High Energy Physics, Tsukuba 305, JapanSearch for more papers by this authorM. Martini, M. Martini INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this authorM. Montecchi, M. Montecchi ENEA-INN/TEC, Via Anguillarese 301, S.Maria di Galeria, 00060 Roma, ItalySearch for more papers by this authorM. Nikl, M. Nikl Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorK. Nitsch, K. Nitsch Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague, Czech RepublicSearch for more papers by this authorG. Organtini, G. Organtini INFN, Sez. di Roma, Dipt. di Fisica, Universita di Roma III., 00146 Roma, ItalySearch for more papers by this authorG. P. Pazzi, G. P. Pazzi IROE del CNR, Via Panciatichi 64, 50127 Firenze, ItalySearch for more papers by this authorY. Usuki, Y. Usuki Furukawa Co., Yoshima, Iwaki 970-11, JapanSearch for more papers by this authorA. Vedda, A. Vedda INFM, DIP. di Scienza dei Materiali, Universita di Milano, 20126 Milano, ItalySearch for more papers by this author First published: 16 November 2001 https://doi.org/10.1002/1521-396X(199712)164:2<R9::AID-PSSA99999>3.0.CO;2-ZCitations: 35AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume164, Issue2December 1997Pages R9-R10 RelatedInformation

The PADME experiment, at the Laboratori Nazionali di Frascati (LNF), in Italy, will search for invisible decays of the hypothetical dark photon via the process e+e−→γA′, where the A′ escapes detection. The dark photon mass range sensitivity in a first phase will be 1 to 24 MeV. We report here on performance measurements and simulation studies of a prototype of the Small-Angle Calorimeter, a component of PADME’s detector dedicated to rejecting 2- and 3-gamma backgrounds. The crucial requirement is a timing resolution of less than 200 ps, which is satisfied by the choice of PbF2 crystals and the newly released Hamamatsu R13478UV photomultiplier tubes (PMTs). We find a timing resolution of 81 ps (with double-peak separation resolution of 1.8 ns) and a single-crystal energy resolution of 10% at 550 MeV with light yield of 2.05 photo-electrons per MeV, using 100 to 400 MeV electrons at the Beam Test Facility of LNF. We also propose the investigation of a two-PMT solution coupled to a single PbF2 crystal for higher-energy applications, which has potentially attractive features.

Cerium-doped Lutetium-Yttrium Oxyorthosilicate (LYSO:Ce)is one of the most widely used Cerium-doped Lutetium based scintillation crystals. Initially developed for medical detectors it rapidly became attractive for High Energy Particle Physics (HEP) applications, especially in the frame of high luminosity particle colliders. In this paper, a comprehensive and systematic study of LYSO:Ce ($[Lu_{(1-x)}Y_x]_2SiO_5$:$Ce$) crystals is presented. It involves for the first time a large number of crystal samples (180) of the same size from a dozen of producers.The study consists of a comparative characterization of LYSO:Ce crystal products available on the market by mechanical, optical and scintillation measurements and aims specifically, to investigate key parameters of timing applications for HEP.

A Higgs particle produced in association with a Z boson and decaying into two photons is searched for in the data collected by the L3 experiment at LEP. All possible decay modes of the Z boson are investigated. No signal is observed in 447.5 pb^-1 of data recorded at centre-of-mass energies up to 209 GeV. Limits on the branching fraction of the Higgs boson decay into two photons as a function of the Higgs mass are derived. A lower limit on the mass of a fermiophobic Higgs boson is set at 105.4 GeV at 95% confidence level.

A method to determine the photopeak position of the γ absorption spectrum of radioactive sources in low light yield scintillators as lead tungstate is discussed. The method is based on the parametrization of both the Compton and photoelectric contributions to the spectrum and it is proven to be reliable and to give stable and precise results.

Further tests of lead tungstate crystal matrices made in high-energy electron beams in 1996, using new crystals, new APDs and an improved test setup confirm that an energy resolution of better than 0.6% at 100 GeV can be obtained when the longitudinal uniformity of the struck crystal is adequate. Light loss measurements under low dose irradiation are reported. It is shown that there is no loss of energy resolution after irradiation and it is demonstrated that the calibration change due to light loss can be tracked with a precision monitoring system. Successful tests with a preshower device, equipped with a silicon strip detector readout, are also described.

The PADME experiment at the LNF Beam Test Facility searches for dark photons produced in the annihilation of positrons with the electrons of a fix target. The strategy is to look for the reaction $e^{+}+e^{-}\rightarrow \gamma+A'$, where $A'$ is the dark photon, which cannot be observed directly or via its decay products. The electromagnetic calorimeter plays a key role in the experiment by measuring the energy and position of the final-state $\gamma$. The missing four-momentum carried away by the $A'$ can be evaluated from this information and the particle mass inferred. This paper presents the design, construction, and calibration of the PADME's electromagnetic calorimeter. The results achieved in terms of equalisation, detection efficiency and energy resolution during the first phase of the experiment demonstrate the effectiveness of the various tools used to improve the calorimeter performance with respect to earlier prototypes.

Undergraduate Texts in Physics (UTP) publishes authoritative texts covering topics encountered in a physics undergraduate syllabus.Each title in the series is suitable as an adopted text for undergraduate courses, typically containing practice problems, worked examples, chapter summaries, and suggestions for further reading.

A bstract The PADME experiment at the DAΦNE Beam-Test Facility (BTF) of the INFN Laboratory of Frascati is designed to search for invisible decays of dark sector particles produced in electron-positron annihilation events with a positron beam and a thin fixed target, by measuring the missing mass of single-photon final states. The presence of backgrounds originating from beam halo particles can significantly reduce the sensitivity of the experiment. To thoroughly understand the origin of the beam background contribution, a detailed G eant 4-based Monte Carlo simulation has been developed, containing a full description of the detector together with the beam line and its optical elements. This simulation allows the full interactions of each particle to be described, both during beam line transport and during detection, a possibility which represents an innovative way to obtain reliable background predictions.

A measurement of the inclusive cross section of in-flight electron-positron annihilation to photons, e+e−→γγ, is presented using the PADME detector at the Laboratori Nazionali di Frascati. A beam of 430 MeV positrons, corresponding to a center-of-mass energy of 20 MeV, strikes a thin diamond target. The two photons produced in the interaction are detected by an electromagnetic calorimeter made of BGO crystals. The measurement is the first based on direct detection of the photon pair and one of the most precise for positron energies below 1 GeV. It represents an intermediate step in the ultimate PADME goal of searching for dark sector particles and mediators weakly coupled to photons and electrons, with masses ranging from 1 to 20 MeV. The final value, σe+e−→γγ=(1.977±0.018(stat)±0.119(syst)) mb, agrees with next-to-leading-order QED predictions within the 6% experimental uncertainty.6 MoreReceived 8 November 2022Accepted 20 December 2022DOI:https://doi.org/10.1103/PhysRevD.107.012008Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle interactionsTotal cross sectionsGeneral PhysicsParticles & Fields

We report on measurements of mass and total decay width of the W boson and of triple-gauge-boson couplings, γWW and ZWW, with the L3 detector at LEP. W-pair events produced in e+e− interactions between 161 GeV and 172GeV centre-of-mass energy are selected in a data sample corresponding to a total luminosity of 21.2 pb−1. The mass and total decay width of the W boson are determined to be MW = 80.75−0.27+0.26(exp.) ± 0.03 (LEP) GeV and ΓW = 1.74−0.78+0.88(stat.) ± 0.25(syst.)GeV, respectively. Limits on anomalous triple-gauge-boson couplings, γWW and ZWW, are determined, in particular −1.5 < δZ < 1.9 (95% CL), excluding vanishing ZWW coupling at more than 95% confidence level.

In 1999, the construction of the electromagnetic calorimeter of the Compact Muon Solenoid (CMS) experiment started. Half of the barrel calorimeter made of 61200 lead tungstate (PWO) crystals will be assembled and tested in the Regional Centre of INFN-ENEA in Rome, Italy. Before assembling, all 30600 PWO crystals will be qualified for scintillation and radiation hardness characteristics by a specially built Automatic Crystal Control System. The measuring techniques for crystal qualification and performances of the automatic system will be discussed in this work.

The influence of Gd3+ doping on the optical properties of PbWO4 has been investigated by radio- and thermoluminescence, photoluminescence time decay, optical absorption and light yield measurements. The samples were grown by the Czochralski method and the concentration of Gd in the melt was in the range 0 to 135 mol. ppm. The results demonstrate that a dopant concentration of around 100 ppm in the crystal appears as the best one in order to optimise the scintillation performance of the material.

G. OrgantiniF. AmeliG. CavotoE. Di MarcoF. PiacentiniS. MorgantiE. PasqualucciA. PolimeniM. RescignoF. Safai TehraniG. SalméP. ViciniR. Faccini

The CMS Electromagnetic Calorimeter (ECAL) is made of about 75 000 lead tungstate crystals. The 61 200 crystals of the barrel part are read by Avalanche Photodiodes (APD) with internal amplification of the signal. Since the gain strongly depends on the bias voltage, the APDs require a very stable power supply system. To preserve the high energy resolution of the calorimeter, a stability of the bias voltage of the order of 10-4 is required over several months, a typical interval between absolute calibrations of the full read-out chain with physics events. This paper describes the high voltage power supply system developed for CMS ECAL and its performances as measured in laboratory tests and during test-beam operations of several modules of the calorimeter.

Hundreds of concurrent collisions per bunch crossing are expected at future hadron colliders. Precision timing calorimetry has been advocated as a way to mitigate the pileup effects and, thanks to their excellent time resolution, microchannel plates (MCPs) are good candidate detectors for this goal. We report on the response of MCPs, used as secondary emission detectors, to single relativistic particles and to electromagnetic showers. Several prototypes, with different geometries and characteristics, were exposed to particle beams at the INFN-LNF Beam Test Facility and at CERN. Their time resolution and efficiency are measured for single particles and as a function of the multiplicity of particles. Efficiencies between 50% and 90% to single relativistic particles are reached, and up to 100% in presence of a large number of particles. Time resolutions between 20 ps and 30 ps are obtained.

We have measured the probability, n(g->cc~), of a gluon splitting into a charm-quark pair using 1.7 million hadronic Z decays collected by the L3 detector. Two independent methods have been applied to events with a three-jet topology. One method relies on tagging charmed hadrons by identifying a lepton in the lowest energy jet. The other method uses a neural network based on global event shape parameters. Combining both methods, we measure n(g->cc~)= [2.45 +/- 0.29 +/- 0.53]%.

A sampling calorimeter using cerium fluoride scintillating crystals as active material, interleaved with heavy absorber plates, and read out by wavelength-shifting (WLS) fibers is being studied as a calorimeter option for detectors at the upgraded High-Luminosity LHC (HL-LHC) collider at CERN. A prototype has been exposed to electron beams of different energies at the INFN Frascati (Italy) Beam Test Facility. This paper presents results from the studies performed on the prototype, such as signal amplitudes, light yield and energy resolution.

At the high luminosity LHC (HL-LHC) about 200 concurrent interactions are expected, with a spread between the interaction vertices of few centimeters in the beam direction and 200 ps in the collision time. A time of flight resolution of the order of 30 ps would be able to reduce neutral particles pile-up contamination at the calorimeter level of about one order of magnitude, restoring pile-up conditions similar to what is routinely sustained in the current run of the LHC . Micro-channel plates have been used in PMT configuration as fast charged particles detector (resolution of better than 20 ps have been achieved with commercial devices), however they are not particularly radiation tolerant, mostly due to the ion feedback on the photocathode. The possibility of using micro-channel plates without a photocathode (i-MCP) has been studied in several test beams. Different MCP geometries are compared with the goal to identify the optimal configuration. Efficiency of more then 70% with a time resolution of better than 40 ps are achieved for single charged particles, leading to an efficiency close to 100% for EM shower after few radiation lengths. This open the possibility to use i-MCPs as a timing layer in a sampling calorimeter or to use it in a pre-shower device independent from the calorimeter technology.

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In this paper we outline a lecture given to undergraduate students to explain why physicists are so interested in the Higgs boson. The lecture was conceived for students not yet familiar with advanced physics and is suitable for those studying several other disciplines. The Higgs mechanism is introduced through semi-classical arguments mimicking basic field-theory concepts, assuming the validity of a symmetry principle in the expression of the energy of particles in a classical field. The lecture is divided into two parts. The first, suitable even for high-school students, shows how the mass of a particle results from a dynamical effect caused by interaction between a massless particle and a field (as in the Higgs mechanism). The audience for the second, much more technical part consists mainly of teachers and university students from disciplines other than physics.

A prototype for a sampling calorimeter made out of cerium fluoride crystals interleaved with tungsten plates, and read out by wavelength-shifting fibres, has been exposed to beams of electrons with energies between 20 and 150 GeV, produced by the CERN Super Proton Synchrotron accelerator complex. The performance of the prototype is presented and compared to that of a Geant4 simulation of the apparatus. Particular emphasis is given to the response uniformity across the channel front face, and to the prototype׳s energy resolution.

The Higgs mechanism gives mass to particles as a result of the interaction between massless particles and a scalar field. In this version it is reformulated in a purely classical form, using a simple formalism suitable for undergraduate students. The need for the Higgs field is justified with arguments following from a review of the concept of energy and from special relativity. While most of the popularisations of the Higgs mechanism relies on analogies with friction, the proposed explanation appears to be at the same time formally coherent and simple enough to be proposed to undergraduate students, the prerequisites being just the knowledge of the energy density of electric and magnetic fields.

The barrel part of the CMS electromagnetic calorimeter consists of about 75 000 Lead Tungstate (PbWO4) crystals arranged in 36×4 modules which are assembled in two Regional Centres, in Rome and at CERN. Two automatic machines have been designed to check the crystal quality before assembly. The main crystal characteristics are compared to a set of specifications included in the contract with the crystal producers. The measurement stability and cross-calibration between the two machines is a fundamental issue, which has to be monitored throughout the construction phase. This paper describes comparisons between measurements made at the two regional centres to ensure a consistent and reliable crystal quality control.

In classical mechanics matter and fields are completely separated. Matter interacts with fields. For particle physicists this is not the case. Both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this paper we explain why particle physicists believe in such a picture, introducing the technique of Feynman diagrams starting from very basic and popular analogies with classical mechanics, making the physics of elementary particles comprehensible even to high school students, the only prerequisite being the knowledge of the conservation of mechanical energy.

Transmittance and luminescence measurements of Bi-doped and Nb-doped PbWO4 crystals after vacuum annealing were performed. Annealing effect on the optical and scintillation properties of the crystals was detected at various annealing temperatures. The gamma radiation damage is presented at different absorbed doses to investigate radiation resistance after annealing.

This paper describes a cost effective and safe device to perform realistic experiments about the physics of radioactivity in classrooms. It can be used to study both $\alpha-$ and $\beta-$radioactivity as well as $\gamma-$emitters and shows an extremely realistic behaviour. The device, in the form of a Geiger-M\"uller tube, was tested during a public lecture and it deceived many people, even among physicists and teachers.

The CRISTAL (Cooperating Repositories and an Information System for Tracking Assembly Lifecycles) project is delivering a software system to facilitate the management of the engineering data collected at each stage of production of CMS. CRISTAL captures all the physical characteristics of CMS components as each sub-detector is tested and assembled. These data are retained for later use in areas such as detector slow control, calibration and maintenance. CRISTAL must, therefore, support different views onto its data dependent on the role of the user. These data viewpoints are investigated in this paper. In the recent past two CMS Notes have been written about CRISTAL. The first note, CMS 1996/003, detailed the requirements for CRISTAL, its relationship to other CMS software, its objectives and reviewed the technology on which it would be based. CMS 1997/104 explained some important design concepts on which CRISTAL is and showed how CRISTAL integrated the domains of product data man- agement and workflow management. This note explains, through the use of diagrams, how CRISTAL can be established for detector production and used as the information source for analyses, such as calibration and slow controls, carried out by physicists. The reader should consult the earlier CMS Notes and conference papers for technical detail on CRISTAL - this note concentrates on issues surrounding the practical use of the CRISTAL software.

In introductory physics textbooks, diodes working principles are usually well described in a relatively simple manner. According to our experience, they are well understood by students. Even when no formal derivation of the physics laws governing the current flow through a diode is given, the use of this device as a check valve is easily accepted. This is not true for transistors. In most textbooks the behavior of a transistor is given without formal explanation. When the amplification is computed, for some reason, students have difficulties in identifying the basic physical mechanisms that give rise to such an effect. In this paper we give a simple and captivating illustration of the working principles of a transistor as an amplifier, tailored to high school students even with almost no background in electronics nor in modern physics. We assume that the target audience is familiar with the idea that a diode works as a check valve for currents. The lecture emphasis is on the illustration of physics principles governing the behavior of a transistor, rather than on a formal description of the processes leading to amplification.

Today the investigation of dark matter nature, its origin, and the way it interacts with ordinary matter plays a crucial role in fundamental science. Several particle physics experiments at accelerators are searching for hidden particles signals to contribute setting more stringent limits on the characteristics of dark matter. The Positron Annihilation into Dark Matter Experiment (PADME), ongoing at the Laboratori Nazionali di Frascati of INFN, is looking for hidden particle signals by studying the missing-mass spectrum of single photon final states resulting from positrons annihilation on the electrons of a fixed target. PADME is expected to reach a sensitivity of up to 10$^{-6}$ on $\epsilon^2$ (kinetic mixing coefficient) representing the coupling of a low-mass dark photon (m< 23.7MeV) with ordinary photons. By measuring the cross-section of the process e$^+$ e$^-$$\rightarrow \gamma \gamma$ at √s=21 MeV and comparing it with SM expectation, it is also possible to set limits on hidden particles decays to photon pairs. In this talk details on the PADME measurement of two-photon annihilation cross-section will be illustrated with its implication to the dark matter studies.

The Positron Annihilation to Dark Matter Experiment (PADME) was designed and constructed to search for dark photons ($A'$) in the process $e^+e^-\rightarrow\gamma A'$, using the positron beam at the Beam Test Facility (BTF) at the National Laboratories of Frascati (LNF). Since the observation of an anomalous spectra in internal pair creation decays of nuclei seen by the collaboration at the ATOMKI institute, the PADME detector has been modified and a new data-taking run has been undertaken to probe the existance of the so-called ``X17" particle

The Positron Annihilation to Dark Matter Experiment (PADME) uses the positron beam of the DA \Phi <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Φ</mml:mi></mml:math> NE Beam-Test Facility, at the Laboratori Nazionali di Frascati (LNF) to search for a Dark Photon A’. The search technique studies the missing mass spectrum of single-photon final states in e^+e^-\rightarrow A'\gamma <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>A</mml:mi><mml:mi>′</mml:mi><mml:mi>γ</mml:mi></mml:mrow></mml:math> annihilation in a positron-on-thin-target experiment. This approach facilitates searches for new particles such as long lived Axion-Like-Parti-cles, protophobic X bosons and Dark Higgs. This talk illustrated the scientific program of the experiment and its first physics results. In particular, the measurement of the cross-section of the SM process e^+e^-\rightarrow \gamma\gamma <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi></mml:mrow></mml:math> at \sqrt{s} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> =21 MeV was shown.

This article describes the reform of a physics undergraduate lab course by introducing new technologies such as Arduino microcontroller and smartphone, to help students experience a more authentic lab experience. This paper outlines the structure of the lab activities and presents findings from pre- and post-course questionnaires, including the E-CLASS survey, completed by participating students. Some interesting observations about teamwork and equity emerged from these questionnaires, particularly about female students. These results will guide us in designing more effective and equitable lab courses.

In Italy, a five-year university course “Scienze della formazione primaria”, which can be translated as Primary Education Degree Course (henceforth PEDC), is dedicated to train the future teachers of kindergarten and primary school (age range 3–11). The Italian project PLS-Physics (“Piano Lauree Scientifiche”), financed by the government and coordinated by J. Immè, has among its objectives the improvement of school-university cooperation, through a pre- and in-service teacher education. In this context, a group composed of PLS members (named PLS group 6, coordinated by M. Michelini) organized a national survey to gather information about the physics courses for PEDC in all the Italian universities. A picture of a living community that has chosen to confront and improve together has emerged. The aim of this study is to monitor the status of the art concerning the initial training of kindergarten and primary school teachers in Italy, as a first step for the creation of shared formative actions, also in a dialogue with the national government. The relation between teaching practice and physics education research has also been investigated.

I-MCP is an R&D project aimed at the exploitation of secondary emission of electrons from the surface of micro-channel plates (MCP) for single ionizing particles and fast timing of showers in high rate environments. Results from tests with electrons with energies up to 50 GeV of MCP devices with different characteristics are presented. In particular detection efficiency and time resolution are measured for a range of MCP prototypes: different MCP channel diameter and layers configuration are studied. Devices operated in I-MCP configuration, where the particle detection proceed through direct ionization of the MCP layers, are studied in comparison with the more usual PMT-MCP configuration. The results show efficiencies up to 70% for single charge particle detection for I-MCP devices with a time resolution of about 40 ps. The efficiency raise to 100% in response to high energy electromagnetic showers.

Future high rate hadron colliders are expected to have hundreds of concurrent proton-proton interactions in the same bunch crossing, deteriorating the energy resolution and identification capabilities of calorimeters. The possibility to distinguish neutral particles coming from different interaction vertices is being pursued as a tool to reduce pile-up contamination in calorimeters, and restore optimal performance. A time of flight resolution of the order of 20 ps will be able to reduce neutral particles pile-up contamination at the calorimeter level by about one order of magnitude, restoring pile-up conditions similar to what is routinely sustained in the current run of the LHC . Micro-channel plates (MCP) can be used in PMT configuration as fast charged particles detector (resolution of better then 30 ps can be achieved with commercial devices). However they are not particularly radiation tolerant, mostly due to the ion feedback on the photocathode. The possibility of using micro-channel plates without a photocathode (i-MCP) has been studied in several test beams. Different MCP geometries are compared with the goal to identify the optimal configuration. Efficiency of more than 70% with a time resolution of better than 40 ps are achieved for single charged particles, leading to an efficiency close to 100% for EM shower after few radiation lengths. This opens the possibility to use i-MCPs as a timing layer in a sampling calorimeter or to use it in a pre-shower device independent from the calorimeter technology. Preliminary results on the radiation hardness of the i-MCP configuration will be also presented.

The barrel of the CMS electromagnetic calorimeter is currently under construction and will contain 61 200 PbWO4 crystals. Half of them are being fully characterized for dimensions, optical properties and light yield in the INFN-ENEA Regional Centre near Rome. This paper describes the measurements and results from a sample of about 6000 crystals. Results are presented on long term stability and precision of light yield and transmission measurements. A strong correlation between crystal light yield and longitudinal transmission in the range 350–370 nm is observed. As it will not be possible to precalibrate with particles the whole calorimeter, the light yield and transmission measurements performed at the Regional Centre will be crucial to provide an initial intercalibration for most crystals. Thanks to the observed correlation, transmission measurements can be combined with those of direct light yield to improve the crystal intercalibration precision. Expectations on the achievable precision are derived.

The REDACLE Project aims at the realization of a simple, flexible and fast database to assist the construction of the CMS electromagnetic calorimeter.The project started in January 2003 as a backup solution for the previously used product: CRISTAL.The REDACLE database was designed to be flexible enough to be used for the construction of virtually any kind of product.One of the key element of the project was the complete decoupling between the database structure and the workflow process software: rather than being a missing feature it allows to use the database for very different projects ranging from very simple to much more complex systems.

Even if laboratory practice is essential for all scientific branches of knowledge, it is often neglected at High School, due to lack of time and/or resources. To establish a closer contact between school and experimental sciences, Sapienza Universita di Roma and the Istituto Nazionale di Fisica Nucleare (INFN) launched the Lab2Go project, with the goal of spreading laboratory practice among students and teachers in high schools.

Abstract Most current educational presentations of quantum physics still propose the same difficulties that emerged in the early twentieth century, often as a mean to engage students. Those difficulties emerged among physicists mostly because the lack of a suitable meaning of what “reality” has to be considered. Instead of engaging students, those difficulties leave them confused because they lack the awareness of what a physical theory is and its relationship with the experiments. We will discuss this problem, both from the epistemological and the educational point of view and give indications to provide an increasingly solid foundation for the educational reconstructions of quantum physics starting from classical physics that must be reconsidered in view of the final objective rather than opposing it to modern physics.

When a free falling ping-pong ball collides on a horizontal surface, it loses kinetic energy. The ratio between the height reached by the ball after the collision and the initial height is called restitution coefficient. A method to measure it by using a home-made cathetometer was proposed during the Olimpiadi di Fisica 2018. In this paper we show how to measure it also by using the PhyPhox app and Arduino board.

A sampling calorimeter using cerium fluoride scintillating crystals as active material, interleaved with absorber plates made of tungsten, and read out by wavelength-shifting fibres has been tested with high-energy electron beams at the CERN SPS H4 beam line, as well as with lower-energy beams at the INFN Frascati Beam Test Facility in Italy. Energy resolution studies revealed a low stochastic term (<10%/E). This result, combined with high radiation hardness of the material used, marks this sampling calorimeter as a good candidate for the detectors׳ forward regions during the high luminosity phase of LHC.

In this paper, we describe a fully automatic device for the measurement of the light yield and the light collection efficiency of scintillating crystals. We also report the bench performance in terms of resolution and speed.

At a time when many companies are under pressure to reduce "times-to-market" the management of product information from the early stages of design through assembly to manufacture and production has become increasingly important. Similarly in the construction of high energy physics devices the collection of (often evolving) engineering data is central to the subsequent physics analysis. Traditionally in industry design engineers have employed Engineering Data Management Systems (also called Product Data Management Systems) to coordinate and control access to documented versions of product designs. However, these systems provide control only at the collaborative design level and are seldom used beyond design. Workflow management systems, on the other hand, are employed in industry to coordinate and support the more complex and repeatable work processes of the production environment. Commercial workflow products cannot support the highly dynamic activities found both in the design stages of product development and in rapidly evolving workflow definitions. The integration of Product Data Management with Workflow Management can provide support for product development from initial CAD/CAM collaborative design through to the support and optimisation of production workflow activities. This paper investigates this integration and proposes a philosophy for the support of product data throughout the full development and production lifecycle and demonstrates its usefulness in the construction of CMS detectors.

The CMS electromagnetic calorimeter (ECAL) comprises 75848 scintillating lead tungstate crystals. 61200 crystals are contained in the ECAL Barrel section and are read out by avalanche photodiode (APD) with internal gain of about 50. This gain is achieved with a high voltage (HV) of about 400 Volts. The gain stability requirement implies a supply voltage stable to within 0.01%. We describe our experience with the installed Barrel HV power supply system, which has been used for data taking since 2008.

The High-Luminosity phase of the Large Hadron Collider at CERN (HL-LHC) poses stringent requirements on calorimeter performance in terms of resolution, pileup resilience and radiation hardness. A tungsten-CeF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> sampling calorimeter is a possible option for the upgrade of current detectors. A prototype, read out with different types of wavelength-shifting fibers, has been built and exposed to high energy electrons, representative for the particle energy spectrum at HL-LHC, at the CERN SPS H4 beam line. This paper shows the performance of the prototype, mainly focussing on energy resolution and uniformity. A detailed simulation has been also developed in order to compare with data and to extrapolate to different configurations to be tested in future beam tests. Additional studies on the calorimeter and the R&D projects ongoing on the various components of the experimental setup will be also discussed.

A simple model is presented to explain Higgs boson physics to the grand public. The model consists of a children's ball pool representing a Universe filled with a certain amount of the Higgs field. The model is suitable for usage as a hands-on tool in scientific exhibits and provides a clear explanation of almost all the aspects of the physics of the Higgs field interaction with other particles.

The simplest regular expression is a plain alphanumeric string. Such a regexp matches with all strings containing its content as a substring. As an example, consider the following verse from Cenerentola, my favorite opera by G. Rossini: ``Zitto, zitto, piano, piano, senza strepito e rumore.'' The regexp /piano/ is said to match with the verse, because the latter contains the same characters, with the same sequence, of the regexp.

The REDACLE Project aims at the realization of a simple, flexible and fast database to assist the construction of the CMS electromagnetic calorimeter. The project started in January 2003 as a backup solution for the previously used product: CRISTAL. The REDACLE database was designed to be flexible enough to be used for the construction of virtually any kind of product. One of the key element of the project was the complete decoupling between the database structure and the workflow process software: rather than being a missing feature it allows to use the database for very different projects ranging from very simple to much more complex systems.

The Avalanche Photodiodes (APD) were chosen as photon sensors for the barrel region of the CMS electromagnetic calorimeter. The LHC will be a hard environment for what concerns the radiation levels in the detectors. The most relevant damage on APDs is caused by neutrons that produce an increase in the dark current of these devices. In the CMS-ECAL collaboration a big effort was indeed done to understand this damage, but the evaluation of the absolute effect was limited by the knowledge of the neutron flux calibration of the various irradiation facilities. This investigation describes the calibration of the neutron flux of the Tapiro reactor in Rome and the calculation of the Non-Ionizing-Energy-Loss on Silicon for this reactor. The damage parameter for the APDs is evaluated to be about A/cm/neutron at 18 C and 2 days after the irradiation. Some cross-checks with other irradiation facilities are also presented.

Avalanche Photodiodes (APDs) will be used as photodetectors for the CMS crystal barrel calorimeter, made of lead tungstate (PWO) scintillating crystals. After two years of strong R&D effort a significant progress was achieved, in collaboration with manufacturers, in the relevant properties of the device for LHC applications. Quantum efficiency, noise contributions and radiation resistance measurements of APDs are presented.

To search for the production of a dark photon (A') in the process e+e- → A'γ, the PADME apparatus has been built at the INFN Laboratori Nazionali di Frascati. It is a small-scale detector consisting of an active target, a beam monitor system, a spectrometer to measure charged particle momenta in the range 50-400 MeV, a dipole magnet to deflect the primary positron beam out of the spectrometer and allow charged particle momentum analysis and an electromagnetic calorimetric system to detect signal and background photons produced in the annihilations with high accuracy. Each element has specific requirements that are stringent and sometimes at the limit of present technology.

Despite appearances, Newton’s dynamics is not simple at all, nor very intuitive. The three fundamental principles, for example, took centuries before they were recognised as true, as our collective experience tells us that bodies don’t move unless a force is applied to them. Galileo Galilei first realised that friction is responsible for this, a fact that is not straightforward in the absence of Newton’s first Law. Many conceptual difficulties in classical mechanics, such as those connected to Newton’s third Law or to the usage of non-inertial reference frames, can be at least partly ascribed to the confusion between the term force and the term interaction. Forces are the result of interactions, and interactions are only effective among at least two entities. In this respect, what we call fictitious or apparent forces can be considered, in fact, to be as real as gravity or the elastic force. On the other hand, we can measure them, thus they exist. The confusion comes from the fact that, in the past, forces and interactions were, in fact, used as if they were synonyms, as any interaction gave rise to a force, represented as a vector in Newtonian mechanics. Today, we know that this is not always the case. The weak interaction, for example, is responsible for radioactive decays. The interaction causes the change of state of a system composed of an atom of a given species into another in which the state is composed of an atom of a different species, together with one or more particles (a photon, an \(\alpha \)-particle or an electron and a neutrino). There is no place to which we can attach a vector in this case, hence there is no force, in the Newtonian sense. It would be better for us to say that interactions are responsible for the change of state of a system and the effects of interactions often can be, but are not always, represented by forces. In this chapter, we perform experiments in which we explore the physics in non-inertial frames, to dissipate doubts and to allow you to familiarise with them. This chapter introduces topics that are often only marginally covered in physics books. We perform experiments in a rotating reference frame and, interestingly enough, in a free-falling system. It is an interesting experiment, that today we can perform, thanks to the availability of tools like smartphones, but, in the past, it was considered an experiment that could only be conducted mentally: a gedankenexperiment. We learn the principles of operation of gyroscopes and study the Euler acceleration in a rotating bucket.

In this chapter, we take our first measurement, the result of which can be compared to another experiment. Comparing results with those of other experiments is of paramount importance in physics. As we believe that physics is universal, i.e., its laws are valid at any time and at any place, we expect that results obtained by different people in different experiments should be consistent with each other. That does not mean that they must be the same in the mathematical sense. We describe how to set up an experiment, making the necessary tools, such as photogates. We learn how to accurately measure times using Arduino and smartphones, how uncertainties propagate and how accelerometers work. We also learn how to make non-trivial graphical representations of data.

This chapter is devoted to illustrating the way in which physicists establish phenomenological physical laws, i.e., purely experimentally-based relations between physical quantities. In doing so, we will not make any attempt to understand the underlying physics, apart from a few very basic properties. We illustrate how to interpret the data collected during an experiment to obtain plausible, phenomenological physical laws: a first step towards the understanding of the underlying physics.

When the number of trials increases in the discrete distributions illustrated in the previous chapters, the probability mass distribution tends to become symmetric around a central value. For large enough numbers, the shape of these distributions is not far from what we observe in many experimental data distributions. They also become wider and the width of each single bin becomes negligible with respect to the width of the distribution, such that the latter can be considered to be a continuous distribution. In this chapter, we study the properties of the Gaussian distribution, a distribution of capital importance in statistics, mostly because it is the one to which all other distributions tend, as stated by the central limit theorem. We also learn other important results. In this chapter, we derive the form of the Gaussian distribution and introduce the central limit theorem. We illustrate important results of probability theory, such as the inequalities of Chebyschev and Markov. Using these tools, and the Law of large numbers, we review our rules on the evaluation of uncertainties.

Newtonian mechanics is often mistaken as being coincident with the dynamics of point-like particles. Real-life objects are certainly not point-like, however, in most cases, the physics of point-like particles is enough to describe the observations that can be made about them. This is not always true. Sometimes, the behaviour of non-point-like objects (physicists call them rigid bodies) exhibits effects that cannot be described by the physics of those that are point-like. Often, these effects are very surprising and largely counterintuitive. This chapter is devoted to the study of certain properties of rigid bodies, from which we derive a formal definition of a what a rigid body is and debunk beliefs arising from the naive application of Newton’s Laws. This chapter introduces to advanced digital communications, such as the protocols i2c, SPI and 1-wire. Here, we learn how to store data collected with Arduino on an SD card.

This chapter is devoted to the experimental study of the motion of a projectile along an inclined plane. Despite its simplicity, characterising such a motion is very instructive and sheds some light on the very meaning of the equations of motion that can be found in physics textbooks. Those equations are always the result of (often) crude approximations and the behaviour of a real system may differ from that expected. Besides learning how to make interesting measurements in the domain of kinematics, we will then learn how to model systems in a more realistic situation. Here we do experiments on movement. We learn to measure distances with Arduino and to evaluate the goodness of a fit. We introduce the method of least squares and the 2.

Experimental data often distribute as Gaussians. The purpose of measuring quantities is to increase our confidence about the knowledge of a particular phenomena. It is important to recognise that we do not always need a measurement to know the value of a quantity. For example, the period T of a pendulum can be easily estimated by eye, and we would never consider the possibility of using an hourglass to obtain it. If we want to increase our knowledge about its value, we must choose an instrument, like a stopwatch, able to provide us with a better resolution, i.e., with less uncertainty, increasing the probability that the measured value \(T_0\) is closer to its true value. Thanks to the Bayes Theorem, the probability attached to each estimation, though subjective, can be formally computed, and even if it remains subjective, its value tends to be agreed upon by everyone. Most importantly, asymptotic results will be independent of our prior subjective knowledge. This chapter deals with the review of the meaning of the measurement process, leading to a formal justification of formulas used in the previous chapters. In this chapter we introduce a principle, according to which the result of an experiment is the one that maximises the probability of obtaining the observed data, at the same time introducing new and advanced programming techniques. In addition, we demonstrate the equivalence between the method of least squares and the method of maximum probability.

The physics of waves is of capital importance. It was used in the past to demonstrate that light propagates as a wave, while, nowadays, it is exploited to catch gravitational waves, one of the most elusive phenomena ever. Waves play a central role in electromagnetism, as well as in modern quantum physics, in which radiation and matter both behave like waves under certain conditions. To understand quantum mechanics, it is thus mandatory to master the physics of waves. In this chapter, we propose a few experiments that can be done using sound waves. By learning how to generate sound waves and studying their propagation and detection, we are presented with another important statistical distribution: the Student’s t-distribution. We learn general techniques on how to find the distribution of a function of a random variable and apply dimensional analysis to obtain important physical results, otherwise difficult to obtain. The Pearson correlation coefficient is introduced.

This chapter is devoted to the experimental study of the motion of a spring, resulting in the Hooke Law. In fact, there is nothing particularly interesting about the motion of the end of a spring, except that it has a certain regularity. On the other hand, flipping through a physics textbook, it seems that physicists are almost obsessed by them. The reason why physicists are so interested in springs is that the elastic force that governs their motion is, in the first approximation, similar to the forces that govern other much more interesting phenomena. Understanding how a spring works allows us to investigate a variety of physical phenomena, from subnuclear to cosmological scales. Here, smartphones and Arduino are used to study the properties of elastic forces, and the results are compared with those obtained in an experiment in which the system is more or less well represented by its mathematical model. We learn how to extract the parameters of a function from a fit and briefly introduce the optimization methods, used in the calculation to find the minimums and maximums of the functions. In this chapter we also discuss how simple models can be useful in many contexts and understand their importance.

During 1991 two cosmic rays runs took place for the calibration of the L3 electromagnetic calorimeter. In this paper we present the results of the first high statistics cosmic ray calibration of the calorimeter in situ, including the end caps. Results show that the accuracy on the measurement of the calibration constants that can be achieved in one month of data taking is of 1.3%.

In this paper results obtained by the CMS collaboration in the study of the properties of PbWO4 crystals chosen to construct the electro-magnetic calorimeter for the CMS experiment at LHC are reported. The main activities carried out by the collaboration during 1995/1996 were devoted to the definition of the properties of the crystals needed to fully characterise them for the final calorimeter assembly.

IMCP is an R&D project aimed at the exploitation of secondary emission of electrons from the surface of microchannel plates (MCP) for fast timing of showers in high rate environments. The usage of MCPs in “ionisation” mode has long been proposed and is used extensively in ion time-of-flight mass spectrometers. What has not been investigated in depth is their use to detect the ionizing component of showers. The fast time resolution of MCPs exceeds anything that has been previously used in calorimeters and, if exploited effectively, could aid in the event reconstruction at high luminosity colliders. Results from tests with electrons with energies up to 150 GeV of MCP devices with different characteristics will be presented, in particular detection efficiency and time resolution.

In this paper we show the consequences of a principle, according to which the dynamics of the Universe must not depend on the number of the particles of which it is composed. The validity of such a principle lead us to the conclusion that inertia and intrinsic angular momenta are deeply interrelated between them. In particular, assuming the principles outlined in the paper, matter must be composed by fermions, all stable bosons must be vectors and massless and no scalar particles can exist in the Universe. We also apply the results to the holographic principle and found established results more naturally with respect to previous approaches as well as new predictions about the Unruh effect.

The LCG (Worldwide LHC Computing Grid) is a grid-based hierarchical computing distributed facility, composed of more than 140 computing centers, organized in 4 tiers, by size and offer of services. Every site, although indipendent for many technical choices, has to provide services with a well-defined set of interfaces. For this reason, different LCG sites need frequently to manage very similar situations, like jobs behaviour on the batch system, dataset transfers between sites, operating system and experiment software installation and configuration, monitoring of services.

The CMS detector at LHC is equipped with a high precision lead tungstate crystal electromagnetic calorimeter (ECAL). The front-end boards and the photodetectors are monitored using a network of DCU (Detector Control Unit) chips located on the detector electronics. The DCU data are accessible through token rings controlled by an XDAQ-based software component. Relevant parameters are transferred to DCS (Detector Control System) and stored into the Condition DataBase. The operational experience from the ECAL commissioning at the CMS experimental cavern is discussed and summarized.

In this paper we give a description of the database services for the control and monitoring of the electromagnetic calorimeter of the CMS experiment at LHC. After a general description of the software infrastructure, we present the organization of the tables in the database, that has been designed in order to simplify the development of software interfaces. This feature is achieved including in the database the description of each relevant table. We also give some estimation about the final size and performance of the system.

1 Sapienza Università di Roma & INFN-Sez. di Roma (ITALY)2 INAF - National Institute for Astrophysics (ITALY)

The Higgs mechanism is introduced in a completely classical framework in which the concept of energy is reviewed. After a brief review of the classical energy of a particle in a gravitational or electromagnetic fields, we show that postulating the existence of a new field (the Higgs field) one can easily introduce a new term in the energy that is consistent with the relativistic energy at rest of a particle, making the mass of a particle the result of a dynamic effect of the interaction with a scalar field. Our model also gives rise to interaction terms between particles and the new field, as well as to the mass of such a field (i.e. to the Higgs boson). Our approach allows a formal introduction of the Higgs field dynamics, much similar to other topics of classical textbooks, that does not require any knowledge of quantum field theory.

Quantum Mechanics is being included in numerous school programmes as part of the curriculum.Most modern textbooks introduce it emphasising its strange or, at least uncommon, somewhat paradoxical, character.We argue that such an approach is wrong because rather than attracting the interest of students toward the topic, it makes quantum mechanics almost unbelievable and artificial.The resulting perception is that quantum mechanics is in fact not understood at all and that we need a new theory that eventually will supersede it.In contrast, we propose a new approach on classical physics that, stressing the role of the measurements in physics, introduces the concept of state very early in the curriculum.Such a concept is reviewed on each classical physics topic and the concept of force as a vector is almost abandoned for the concept of interaction defined as something that change the state.In this way it is possible to introduce quantum mechanics without violating any conviction the students acquired learning classical physics.In other words quantum mechanics appears to be as natural as classical physics, at least from the point of view of the results of the experiments.

The characterisation of the Higgs boson discovered in 2012 around 125 GeV, and confirmed with the data collected in Run II, requires the precise determination of its mass, width and couplings. The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid Experiment (CMS) is crucial for measurements in the highest resolution channels, $\mathrm{H}\to\gamma\gamma$ and $\mathrm{H}\to 4$ leptons. In particular the energy resolution, the scale uncertainty and the position resolution for electrons and photons are required to be as good as possible. During Run II the LHC is continuously operating with 25 ns bunch spacing and increasing instantaneous luminosity. The calorimeter reconstruction algorithm has been adapted to cope with increasing levels of pile-up and the calibration and monitoring strategy have been optimized to maintain the excellent performance of the CMS ECAL throughout Run II. We show first performance results from the Run II data taking periods, achieved through energy calibrations using physics events, with a special emphasis on the impact on the measurement of the properties of the Higgs boson and on searches for new physics.

The PADME experiment at the DA$\Phi$NE Beam-Test Facility (BTF) of the INFN Laboratory of Frascati is designed to search for invisible decays of dark sector particles produced in electron-positron annihilation events with a positron beam and a thin fixed target, by measuring the missing mass of single-photon final states. The presence of backgrounds originating from beam halo particles can significantly reduce the sensitivity of the experiment. To thoroughly understand the origin of the beam background contribution, a detailed Geant4-based Monte Carlo simulation has been developed, containing a full description of the detector together with the beam line and its optical elements. This simulation allows the full interactions of each particle to be described, both during beam line transport and during detection, a possibility which represents an innovative way to obtain reliable background predictions

Abstract We address aspects of innovation in the practice of experimental physics that are made possible thanks to the availability of ubiquitous and/or cheap digital technologies having the potential to improve the experience and learning outcomes throughout the physics curriculum. The ongoing pandemic poses specific challenges on the traditional approach to laboratory teaching in large labs. The innovation described here, developed independently by us over many years, aims to help maintain or even improve the development of experimental skills also in this new context. We present an analysis of the current situation and describe our proposal with a call for action, centering on the development of an open and bottom-up “Smart Physics Lab” community for the sharing of resources and good practice.

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The Positron Annihilation to Dark Matter Experiment (PADME) uses the positron beam of the DA$\Phi$NE Beam-Test Facility, at the Laboratori Nazionali di Frascati (LNF) to search for a Dark Photon $A'$. The search technique studies the missing mass spectrum of single-photon final states in $e^+e^-\rightarrow A'\gamma$ annihilation in a positron-on-thin-target experiment. This approach facilitates searches for new particles such as long lived Axion-Like-Particles, protophobic X bosons and Dark Higgs. This talk illustrated the scientific program of the experiment and its first physics results. In particular, the measurement of the cross-section of the SM process $e^+e^-\rightarrow \gamma\gamma$ at $\sqrt{s}$=21 MeV was shown.

The inclusive cross-section of annihilation in flight $e^+e^-\rightarrow\gamma\gamma$ of 430 MeV positrons with atomic electrons of a thin diamond target has been measured with the PADME detector at the Laboratori Nazionali di Frascati. The two photons produced in the process were detected by an electromagnetic calorimeter made of BGO crystals. This measurement is the first one based on the direct detection of the photon pair and one of the most precise for positron energies below 1 GeV. This measurement represents a necessary step to search for dark sector particles and mediators weakly coupled to photons and/or electrons with masses ranging from 1 MeV to 20 MeV with PADME. The measurement agrees with the Next to Leading Order QED prediction within the overall 6% uncertainty.