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Tag Archives: Evento scientifico

New results on theoretically clean observables in rare B-meson decays from LHCb

Over the past decade, measurements involving the flavour changing neutral current transition $b\to s\ell^+\ell^-$ have shown tantalising tensions with Standard Model (SM) predictions. However, our current understanding of the hadronic uncertainties in these predictions hinders our ability to interpret these as physics beyond the SM. In order to resolve this impasse, measurements of observables that are theoretically pristine in processes that are accidentally suppressed in the SM are of paramount importance. Observables in $B^0_{s}\to\mu^+\mu^-$ decays as well a lepton flavour universality tests in $B^+\to K^+\ell^+\ell^-$ transitions are perfect examples of such measurements. In this mini-workshop, we will present the latest results in $B^0_{s}\to\mu^+\mu^-$ decays and the updated measurement of $R_K=BR(B^+\to K^+μ^+μ^−)/BR(B^+\to K^+e^+e^−)$ using the complete dataset collected by the LHCb experiment, and we will discuss the theoretical implications. Program Wednesday May 5 14:30 “Introduction” 14:40   Marco Santimaria  (LNF INFN) “Measurement of $B^0 \to μ^+μ^−$ decays with Run 1 + Run 2 data” 15:20   Flavio Archilli (University of Heidelberg, Germany) “Precision tests of the Standard Model with $b → sl^+l^-$ decay” 16:00 Gino Isidori (University of Zurich, Switzerland) “Theoretical implications of recent measurements of B-meson decays” 16:40 General Discussion 17:00 Conclusion

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Lepton flavour violation in muon decays: the MEG case

Lepton flavour violation is prohibited in the Standard Model of particle physics, thus its observation would clearly spots out the existence of physics beyond it. The muon sector is the most promising in this field. Muon properties, such as lifetime and mass, enable to construct very high intense and low energy -beams to be then transported on a target of a dedicated experimental apparatus and measure the emerging decay products. The lepton flavour violating decays under study are $\mu$ → e $\gamma$ and $\mu$ → eee; in addition the $\mu$ to e conversion is very promising channel as well. In the intensity frontier physics four experiments are in the commissioning phase aiming at searching for deviations from the Standard Model predictions a in the range 10−14÷10−17, depending on the process under study, thanks to innovative detector and beam line technologies. Currently two experiments for the measurement of the $\mu$ to e transitions are in preparation, Mu2e @FNAL and COMET @J-PARC; the MEG II experiment @Paul Scherrer Institut will measure the $\mu$→ e $\gamma$ decay and the Mu3e the $\mu$ → eee also @PSI. In the talk I will review possible Standard Model extensions from a phenomenological point of view and how future experiments results are complementary to define the nature of new physics, in case any evidence arises. In the second part of the talk I will concentrate in the MEG case, the results from the first phase of the experiment and the MEG II perspectives.   More ways to join: Join …

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POEMMA: the Probe of Extreme Multi-Messenger Astrophysics

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) has been designed to measure ultra-high energy cosmic rays (UHECRs) and observe cosmic neutrinos from space and with sensitivity over the full celestial sky for these extremely energetic cosmic messengers. POEMMA will observe the extensive air showers (EASs) from UHECRs and UHE neutrinos above 20 EeV via air fluorescence. Additionally, for cosmic neutrinos above 20 PeV POEMMA will observe the Cherenkov signal from upward-moving EASs induced by Earth-interacting tau neutrinos. The POEMMA spacecraft are designed to quickly re-orientate to view neutrino transient sources and follow these to obtain unparalleled neutrino flux sensitivity. POEMMA represents the final goal of the JEM-EUSO program. Developed as NASA Astrophysics Probe-class mission, POEMMA consists of two identical satellites flying in loose formation and 525 km altitude orbits. Each POEMMA instrument incorporates a wide field-of-view (45°) Schmidt telescope with over 6 m2 of collecting area. The hybrid focal surface of each telescope includes a fast (1 ms) near-ultraviolet camera for EAS fluorescence observations and an ultrafast (10 ns) optical camera for Cherenkov EAS observations. In a 5-year mission, POEMMA will provide measurements that open new multi-messenger windows onto the most energetic events in the universe, enabling the study of new astrophysics and particle physics at these otherwise inaccessible energies. During this seminar the mission science and design will be reported as well as the path towards its realization.   More ways to join: Join from the meeting link https://infn-lnf.webex.com/infn-lnf/j.php?MTID=ma031e54bc19051e8c5150052f6167d0e Join by meeting number Meeting number (access code): 163 849 …

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First results from the Muon g-2 Experiment at Fermilab

Aim of the meeting: Increasingly precise measurements of the muon anomaly, a$\mu$ = (g – 2)/2 have been pursued since the 1960s, when CERN played a leading role in the determination of  with a series of pioneering experiments. Until now, the most precise measurement of a$\mu$ was carried out by the E821 Experiment at Brookhaven (USA), which resulted in a 3.7$\sigma$ discrepancy with the Standard Model prediction. This longstanding discrepancy is one of the most intriguing hints of new physics in particle physics. In order to understand this discrepancy a new Muon g-2 experiment started taking data at Fermilab in 2018. This mini-workshop is an afternoon dedicated to the presentation and discussion of the first results from the new Muon g-2 experiment at Fermilab, their theoretical importance, and prospects for the measurement. Program Thursday April 15 14:30 Fabio Bossi (LNF INFN) “Introduction” 14:40  Graziano Venanzoni  (INFN Pisa) “First results from the Muon g-2 Experiment at Fermilab” 16:40  Antonio Masiero (INFN Padova) “Theoretical implications of the measurements of g-2 “ 17:10 General discussion 17:30 Conclusion More ways to join: Join from the meeting link https://infn-lnf.webex.com/infn-lnf/j.php?MTID=m6522497392845e487ed2c02693296a0c Join by meeting number Meeting number (access code): 181 601 9367 Meeting password: 15042021

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The Light Dark Matter Experiment

The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus on a narrower range of masses: the natural scenario where dark matter originates from thermal contact with familiar matter in the early Universe requires the DM mass to lie within about one MeV to 100 TeV. Considerable experimental attention has been given to exploring Weakly Interacting Massive Particles in the upper end of this range (few GeV – ~TeV), while the region ~MeV to ~GeV is largely unexplored. Most of the stable constituents of known matter have masses in this lower range, tantalizing hints for physics beyond the Standard Model have been found here, and a thermal origin for dark matter works in a simple and predictive manner in this mass range as well. It is, therefore, a priority to explore this lower mass range. If there is an interaction between light DM and ordinary matter, as there must be in the case of a thermal origin, then there necessarily is a production mechanism in accelerator-based experiments. The most sensitive way, (if the interaction is not electron-phobic) to search for this production is to use a primary electron beam to produce DM in fixed-target collisions. The Light Dark Matter eXperiment (LDMX) is a planned electron-beam fixed-target missing-momentum experiment that has unique sensitivity to light DM in the sub-GeV range. This talk will give an overview of the theoretical motivation, the main …

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CYGNO: an Optical TPC for the search of rare events

The search for a novel technology able to detect and reconstruct nuclear and electron recoil events in the keV energy range has become more and more important as long as vast regions of high mass WIMP-like Dark Matter candidate have been excluded. Gaseous Time Projection Chambers (TPC) with optical readout are very promising candidate combining the complete event information provided by TPC technique to the high sensitivity and granularity of last generation scientific light sensors. CYGNO experiment (a CYGNus module with Optical readout) is developing this approach obtaining good energy and space resolution and a high sensitivity in the keV energy range together with a very good particle identification useful to distinguish nuclear recoils from electronic recoils. This experiment is part the CYGNUS proto-collaboration which aims at constructing a network of underground observatories for directional Dark Matter search. A 1 cubic meter demonstrator is expected to be built in 2021/22 aiming to a larger scale apparatus (30m3-100 m3), in a later stage.   Join Zoom Meeting https://uniroma1.zoom.us/j/84281361690?pwd=VWdncTBHWHNLVHVuNTltcUVzcVMrZz09 Meeting ID: 842 8136 1690 Passcode: 333703 Organized by L. Cardani, C. Rovelli

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Development and novel applications of hybrid pixel detectors

The Paul Scherrer Institut (PSI), Switzerland, pursues an extensive R&D program on hybrid pixel detectors for high energy physics, photon science, and, more recently, transmission electron microscopy. The presentation will show how a technology originally developed for tracking detectors for HEP has been adapted to cover a variety of other applications. We will use as reference the pixel detectors developed at PSI: the present Compact Muon Solenoid (CMS) tracking readout chip and the EIGER photon counting detector for synchrotrons. To conclude, an overview of prospective developments and applications will be given.   More ways to join:  Join from the meeting link https://infn-lnf.webex.com/infn-lnf/j.php?MTID=mcab84c371197078a267fd7239a4c2ab4  Join by meeting number  Meeting number (access code): 181 911 2517 Meeting password: 18032021

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Fundamental Physics at the strangeness frontier at DAΦNE

The DAΦNE electron-positron collider at the Laboratories of Frascati, INFN-LNF, is a unique facility in the world to perform strangeness physics experimental studies with low-energy charged (and neutral) kaon mesons. Experiments measuring kaonic atoms transitions have been realized at DAΦNE in the last 25 years, with DEAR and SIDDHARTA which performed unique measurements on light kaonic atom transitions, such as the most precise kaonic hydrogen measurement and the first kaonic-helium3 transitions measurement. Presently SIDDHARTA-2, installed on DAΦNE, is aiming to perform the first kaonic deuterium measurement. The broad international scientific community involved in low-energy strangeness studies is envisaging and proposing new fundamental measurements using the unique kaon beams at DAΦNE. New experimental breakthroughs, parallelized by theoretical progress, can bring us into a new era in the strangeness physics studies with an impact extending from fundamental physics to astrophysics and beyond. These two-days workshop is devoted to discuss a road-map for the experiments to be proposed at DAΦNE for the next 5 years time window to start after the end of SIDDHARTA-2 run.   Organizing Committee: C. Curceanu, Laboratori Nazionali di Frascati INFN, Italy C. Guaraldo, Laboratori Nazionali di Frascati INFN, Italy K. Piscicchia, Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Italy A. Scordo, Laboratori Nazionali di Frascati INFN, Italy D. Sirghi, Laboratori Nazionali di Frascati INFN, Italy J. Zmeskal, Stefan Meyer Institut der österreichischen Akademie der Wissenschaften (SMI), Austria

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Dispersive study of pion-kaon scattering: the kappa and other strange resonances and threshold parameters

We have recently completed the coupled dispersive analysis of  pi pi -> K anti-K We show that just fitting data fails to satisfy the dispersive representation and leads to inconsistencies with threshold sum-rules as well as unreliable resonance parameterizations. Our main result is a set of constrained fits to data that satisfy 16 dispersion relations of different kinds and allow for a reliable extraction of threshold and subtreshold parameters to be compared with Chiral Perturbation Theory and lattice QCD. In addition, we obtain a precise dispersive determination of the controversial light kappa-meson parameters, which has therefore become a “confirmed” state in the PDG, completing the light meson scalar nonet. The constrained fits to data are easy to implement and ready for further theoretical and experimental studies. La riunione sarà effettuata in modalità telematica, tramite collegamento Webex, seguendo le istruzioni riportate. Si consiglia di scaricare l’app Cisco Webex Meeting: https://help.webex.com/en-us/0tow9g/Download-the-Cisco-Webex-Meetings-Desktop-App Meeting number (access code): 175 227 8093 Meeting password: 21012021 https://infn-lnf.webex.com/infn-lnf/j.php?MTID=m16d0aed8ba5dde2d9187d0d3aec71e28 Tap to join from a mobile device (attendees only) +44-20-7660-8149,,1752278093## United Kingdom Toll Join by phone +44-20-7660-8149 United Kingdom Toll Global call-in numbers Join from a video system or application Dial 1752278093@infn-lnf.webex.com You can also dial 62.109.219.4 and enter your meeting number. Join using Microsoft Lync or Microsoft Skype for Business Dial 1752278093.infn-lnf@lync.webex.com If you are a host, click here to view host information.   Need help? Go to https://help.webex.com

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The Borexino heritage: pp and CNO fusion processes in the Sun

The Borexino collaboration has recently completed the study of solar neutrinos by detecting the CNO cycle. Such process, though sub-dominant in the Sun, plays a key role in the Universe and its detection represents a substantial experimental achievement. The seminar will review the main experimental challenges faced faced to achieve the measurement. It will also summarise the various and rich results obtained by Borexino in its 13 years of data taking.      

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