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DARK MATTER: PADME ON THE STARTING BLOCKS

PADMETestBeam The PADME experiment for the search for dark matter is about to begin the data acquisition phase at the Frascati National Laboratories of the Italian National Institute of Nuclear Physics (INFN). PADME is dedicated to the search for the dark photon, a hypothetical particle similar to the photon of electromagnetic waves, but provided with a small mass. The hypothesis on which the experiment is based is that dark matter is sensitive to a new type of force, which is not among the four fundamental forces we know (gravitational, electromagnetic, strong nuclear and weak nuclear), to which it would be associated a "messenger" called precisely a dark photon. This hypothesis is predicted by some theoretical models that describe the dark matter that physicists from all over the world have been hunting for years. "The study of dark matter is one of the most fascinating frontiers of research in fundamental physics. We do not know what it is made of but we know that it consists of something different from the particles that make up ordinary matter such as protons, neutrons or electrons "states Mauro Raggi, spokesperson of the experiment,researcher of INFN and La Sapienza University of Rome. "PADME will enter data in the coming weeks and will then start to hunt for the dark photon, a particle similar to the ordinary photon but characterized by having a small mass" underlines Paolo Valente, co-spokesperson of the experiment, researcher of INFN and Sapienza University of Rome.

How does it work PADME works thanks to a small but extremely precise measuring device, able to observe the production of dark photons in collisions of electrons and anti-electrons, called positrons. The experiment is installed in the experimental room of the test facility (BTF) of the LNF linear accelerator that accelerates positrons by "shooting" them on a diamond target. By interacting with atomic electrons, the positrons could produce "dark photons" together with a visible photon. To be in operation, the experiment needs a magnetic field developed by a magnet made at CERN Super-Proto-Synchrotron. The PADME calorimeter is composed of about 600 inorganic sparkling crystals and will provide a precise measurement of the characteristics of the visible photon from which it is possible to extract valuable information on the existence and mass of the dark photon. PADME is an international collaboration involving researchers from the MTA Atomki institute in Debrecen, Hungary, where experiments have already been carried out on the "dark photon" and the University of Sofia, Bulgaria, which will take care of the scintillating bar detectors. They are also members of the Cornell University collaboration, Iowa University and William and Mary College.

CLAS EXPERIMENT: NEW RESULTS ON THE ROLE OF PROTONS IN THE NEUTRON STARS

Jlab 2018

Protons are responsible for the most energetic component of the heart of neutron stars. The study, published on August 13 in the scientific journal Nature, was obtained in laboratory thanks to the observations of the CLAS experiment at the CEBAF accelerator of the Jefferson Lab, in the United States, with the contribution of the INFN researchers. The CLAS experiment uses high energy electrons (5 GeV, billions of electron volts) to target different nuclei, such as carbon, iron and lead nuclei, with increasing number of nucleons and neutron-proton asymmetry. In the experiment, it has been possible to select for the first time the events in which a neutron and a proton were simultaneously detected both of high impulse, and therefore coming from interacting proton-neutron pairs. These observations showed that the percentage of high-pulse protons increases with the density of neutrons and, consequently, the average kinetic energy of the neutrons decreases in neutron-rich nuclei in favour of the energy brought by the protons. The results are relevant for the understanding of those extreme astrophysical systems, such as neutron stars, in which the number of protons, even if it is a minority, proves to be responsible for the most energetic part of it.

ATLAS AND CMS OBSERVED “BEAUTY” PRODUCED BY THE HIGGS BOSON

atals cms 2018 It is a process, predicted by the Standard Model of particle physics and long sought: indeed it took six years to identify the decay of the Higgs boson in a pair of fundamental particles, called b-quarks (from beauty). The observation, presented on August 28th at CERN, by the scientific collaborations ATLAS and CMS at the LHC accelerator, confirms the hypothesis that the quantum field of the Higgs boson, which pervades the whole universe, also couples with the b-quark giving it a mass. Identifying this decay channel has been anything but easy: there are, in fact, many ways to produce quark b in proton collisions. This makes it difficult to isolate the decay signal of the Higgs boson from the "background noise" associated with these processes. In order to definitively isolate the signal, the ATLAS and CMS collaborations had to combine the data of the first and second run of LHC, including collisions at the energies of 7, 8 and 13 TeV. The result, both for ATLAS and CMS, lead to the observation of the decay of the Higgs boson in a pair of b-quarks with a statistical significance of more than 5 standard deviations (5 sigma). Both collaborations measured a decay rate consistent with the Standard Model prediction, within the current measure.

PHYSICS PHOTOWALK 2018: THE ITALIAN WINNERS

The first phase of the Global Physics Photowalk is now closed. The photo contest tallows hundreds of professional and amateur photographers all over the world to freely explore, for one day, a large physics laboratory and photograph the physics behind the scenes. The most important physics laboratories of the planet joined the 2018 edition and between May and June they opened their doors to photographers laboratories in China, United States, Canada, Great Britain, Italy, Switzerland, France and Australia. The first phase of the competition includes the selection of the best photos of each workshop, which then participate in the global competition and will be evaluated by a jury of international experts. Among these there are also 12 photographs taken in the four INFN National Laboratories, chosen by the jury of the Italian photowalk, made up of a scientist, Pia Astone of the INFN section of the "Sapienza" University of Rome, by a journalist, Gianluca Dotti, collaborator of Wired and by a photographer, Luca Locatelli, collaborator of National Geographic Magazine and of many international newspapers. "Shooting behind the scenes of technology and science is a difficult but exciting challenge - commented Luca Locatelli - For me it represents a way of looking at the future, of telling about those communities and places where humanity is producing sustainable innovations and preparing the tools, which will change the world, as has already happened in the past. " This is the gallery of the 12 winning photos of the Italian selection, which will then participate in the international selection whose winners will be announced in the fall. The first two classified photos will be published in the next issue of Asimmetrie

1 181
1° classificato, Micheletti Gianluca, Laboratori Nazionali del Gran Sasso dell'INFN
2 17
2° classificato, Motta Enzo, Laboratori Nazionali del Sud dell'INFN
3 103
3° classificato, Riccioni Luca, Laboratori Nazionali di Frascati dell'INFN
4 112
4° classificato, Marzili Marco, Laboratori Nazionali di Frascati dell'INFN
5 168
5° classificato, Gualtieri Domenico, Laboratori Nazionali del Gran Sasso dell'INFN
6 5
6° classificato, Coppola Federica, Laboratori Nazionali del Sud dell'INFN
7 60
7° classificato (parimerito), Salvadori Mirco, Laboratori Nazionali di Legnaro dell'INFN
7 170
7° classificato (parimerito), Mariani Fabio, Laboratori Nazionali del Gran Sasso dell'INFN
9 48
9° classificato, Lombardi Anna, Laboratori Nazionali di Legnaro dell'INFN
10 37
10° classificato, Zuccaro Rosaria, Laboratori Nazionali del Sud dell'INFN
11 147
11° classificato, Ruzzini Stefano, Laboratori Nazionali di Frascati dell'INFN
12 43
12° classificato, Fabretti Giancarlo, Laboratori Nazionali di Legnaro dell'INFN

 

 


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DESIGN E REALIZZAZIONE
Coordinamento Grafico Uff. Comunicazione F. Cuicchio
Powered by Multimedia Service
REDAZIONE CONTENUTI
Coordinamento Uff. Comunicazione E. Cossi
Realizzazione testi Ufficio Comunicazione

LNF-INFN Servizi di Calcolo
SERVIZIO SISTEMA INFORMATIVO TECNOLOGIE E PORTALE WEB