All future and past seminars
Academic year 2021-2022
Sep. 15 : Bruno Mesnet (IBM systems), Dr. Filip Leonarski (PSI), Dr. Lionel Clavien (InnoBoost)
Sep 22 : Dr. Massimo Passera - INFN, Padua
Title: Muon g-2 and Δα connection - slides
The Muon g-2 experiment at Fermilab has recently confirmed Brookhaven's earlier measurement of the muon anomalous magnetic moment a_μ. This new result increases the discrepancy Δa_μ with the Standard Model (SM) prediction and strengthens its "new physics" interpretation. On the other hand, a recent lattice QCD result weakens this discrepancy. In this talk I will review the SM prediction of the muon g-2, focusing on some of the latest developments, and discuss the connection of the discrepancy Δa_μ to precision electroweak predictions via their common dependence on hadronic vacuum polarization effects. I will also briefly present the recently proposed MUonE experiment at CERN, where fixed-target muon-electron scattering will provide a new direct determination of the leading hadronic contribution to the muon g-2.
Sep. 28 : Prof. Tae Min Hong (U. Pittsburgh) * Seminar on Tuesday 16:15
Topic : Invisible Higgs decays & trigger challenges at the LHC - slides
With more data coming from LHC collisions, detailed measurements of Higgs boson properties allow us to probe whether it communicates with the unknown and/or undiscovered sector beyond the Standard Model. One motivation is weakly interacting dark matter, which are invisible to the detecting apparatus, through a Higgs portal. I will discuss the latest ATLAS results of the search for Higgs bosons decaying to invisible particles. I will also describe the technical challenges of triggering on such events using missing energy from the Higgs boson decay and/or hadronic jets from the Higgs boson production, including the potential use of machine learning methods on FPGA boards in real-time level-1 trigger systems.
Oct 13 : Dr Andrea Zani, INFN, Milan
Oct 20 : Dr Anja Butter, ITP, Heidelberg
Topic: Generative network applications in particle physics
Oct 27 : Dr. Simon Spannagel - CERN
Topic : AllpixSquared - MC simulations of pixel detectors
Nov 3 : Dr. Vava Gligorov - LPNHE
Topic : LHCb trigger - from CPU to GPU
Nov 17 : Prof. Paolo Crivelli, ETHZ
Dec 1 : Dr Davide Pinci , INFN, Roma
Topic: R&D HPTPC for CYGNO
Jan 19 : Dr Kathrin Valerius , KIT
Topic: Katrin - recent results
Feb 9 : Dr Valentina Cairo, CERN
Topic: HH at the LHC
Feb 22 : Dr Kazuhiro Terhao, SLAC * Seminar on Tuesday 16:15
Topic: ML in LAr
March 3 : Prof. Elisa Resconi - TUM, Germany
Title: New direction in high energy neutrino physics: IceCube and the Pacific Ocean Neutrino Experiment
Abstract: A higher statistics of high energy neutrinos is needed to open the universe's exploration at the highest energies. In this talk, I will address questions related to the nature of dark matter, the existence of long-lived exotic particles, and how cosmic laboratories can accelerate particles at least up to the PeV scale. The availability of
multi-cubic-kilometer neutrino telescopes currently limits the advance. In this talk, I will discuss the field's status and new opportunities to collect more and better measured high energy neutrinos. To this end, I will cover IceCube and the planned Upgrade and the future neutrino telescopes IceCube-Gen2 and the Pacific Ocean Neutrino Experiment.
March 16 : Dr Ben Nachman - LBNL, USA * Seminar on Tuesday 16:15
Title: Modeling final state radiation on a quantum computer - slides
Particles produced in high energy collisions that are charged under one of the fundamental forces will radiate proportionally to their charge, such as photon radiation from electrons in quantum electrodynamics. At sufficiently high energies, this radiation pattern is enhanced collinear to the initiating particle, resulting in a complex, many-body quantum system. Classical Markov Chain Monte Carlo simulation approaches work well to capture many of the salient features of the shower of radiation, but cannot capture all quantum effects. We show how quantum algorithms are well-suited for describing the quantum properties of final state radiation. In particular, we develop a polynomial time quantum final state shower that accurately models the effects of intermediate spin states similar to those present in high energy electroweak showers. The algorithm is explicitly demonstrated for a simplified quantum field theory on a quantum computer. At the end of the talk, I will discuss how techniques from high energy physics can also improve measurements on quantum computers using unfolding algorithms.
April 14 : Dr. Prasenjit Saha - Univ. of Zurich, CH
Next-generation optical interferometry and the return of Hanbury Brown and Twiss - slides
April 28 : Prof. Enrique Kajamovitz - Technion, Israel * postponed
Title : Searching for Muonic Force Carriers with ATLAS
May 5 : Prof. Florian Piegsa - Univ. of Bern, CH
Title : Fundamental Particle Physics with Neutrons - slides
The neutron represents a versatile tool in the realm of fundamental particle physics. It is often used to perform precision physics measurements at low energies with the goal to search for beyond standard model signals. In this seminar, I will introduce a few activities currently pursued at the University of Bern. The projects comprise the hunt for a CP-violating neutron electric dipole moment using a pulsed beam, the search for axions as dark matter candidates and the development of a high-sensitivity interferometer which shall ultimately be used to measure the neutron's electric charge.
May 12 : Dr Andrea Celentano - INFN Genova, Italy
Title : POKER: POsitron resonant annihilation into darK mattER - slides
May 19 : Prof. Gino Isidori - Univ. of Zurich, CH
Title : B-physics anomalies and the flavor problem - slides
May 26 : Dr. Andreas Hoecker - CERN
Title: Ultimate precision Standard Model tests: the muon magnetic moment — taming hadronic contributions - slides
Elementary particles with spin behave like tiny magnets with magnetic moments that can be measured and predicted extremely precisely for the electron and the muon. These moments receive contributions from quantum fluctuations, which — in the case of the muon — may involve new, heavy particles not yet directly observed at particle accelerators. A recent precise measurement of the muon magnetic moment at Fermilab confirmed a longstanding discrepancy, now reaching 4.2 standard deviations, with the theoretical prediction. That prediction is dominated by difficult to compute contributions from hadronic quantum fluctuations. The seminar will review the status of the magnetic moment measurements, their theory predictions, and then focus on the challenges of the hadronic contributions.
June 15: Prof. Jonathan Feng - UCI, USA * Seminar on Tuesday 16:15
Title: FASER and the Forward Physics Facility at CERN - slides
For decades, the focus of searches for new particles at the LHC has been on heavy particles and high pT. Recently, however, new ideas have led to novel opportunities for discovery in the far-forward region with relatively fast, small, and cheap experiments. These include FASER, which has recently been installed at the LHC, and FASERnu, which has recently opened up a new window on neutrinos at TeV energies. In this talk, I will give an overview of the physics motivations, including both Standard Model and new physics; describe FASER and FASERnu and their current status; and present a new proposal for a Forward Physics Facility at CERN.
AUTUMN semester 2020
The neutrino discovery, by Reines & Cowan (1956), also proved vital to pave the ground behind much of today’s neutrino detection technology. Large instrumented volumes for neutrino detection have been achieved via a key (implicit) principle: detection medium transparency and/or ultra-purity. Much of that technology has yielded historical success, including several Nobel prizes, where the discovery of the neutrino oscillation phenomenon, solving the long standing “solar” and “atmospheric” anomalies, is the latest example. Despite the stunning success of the “transparent technology”, for instances, the pioneering liquid scintillator detectors are known to suffer from key limitations such as little (or no) intrinsic particle identification (PID) ability, typically enabling active background rejection. Solving this (e.g segmentation, etc) while keeping the detector scaling to very large volumes remain a non-trivial technological and cost-effectiveness challenge. As of now, many of those otherwise overwhelming backgrounds can only be defeated — if possible at all — via an expensive passive shielding strategy, including the need for deep underground laboratories. In this seminar, we shall discuss the novel LiquidO technology whose rationale exploits detection medium extreme opacity for the first time, thus breaking apart with the need for transparency, to yield single and multiple particle energy deposition imaging thus holding an unprecedented potential for native PID. This technology, under final stages of R&D validation, could articulate detectors requiring far less passive shielding. As a highlight, I shall illustrate a possible new project in Europe, under active exploration called for now "Super Chooz”, to illustrate the major benefits of LiquidO for fundamental experimental physics. LiquidO is also a proto-collaboration involving about 20 institutions over over 10 countries leading both the detection R&D and the first round of physics explorations so far.
Sep. 18 : Colloquia for the succession Prof. M. Pohl - More information
8:30 – 9:30
Prof. Andrii Neronov, Université de Paris-Diderot et Université de Genève
Title: Universe at Highest Energy Frontiers
Abstract: The high-energy Universe is an amazing laboratory which provides a wealth of possibilities for exploration of the limits of our knowledge of the laws of Nature. Our knowledge of the Universe is based on “multimessenger” data: signals from astronomical sources coming in the form of photons, neutrinos, gravitational waves and cosmic rays. I will review the status of the multi-messenger astronomy and concentrate at the high-energy ends of different observational windows on the Universe. I will show how the energy frontiers of astronomy could be extended beyond 10-100 TeV in the gamma-ray messenger channel, beyond 10 PeV in the neutrino channel and into 1e20 eV in the ultra-high-energy cosmic ray messenger channel. This will require a combination of approaches involving space and ground-based detectors which use the Earth atmosphere as a giant imaging high-energy particle calorimeter. Extension of the energy frontiers of astronomy will allow to advance understanding of the origin of cosmic rays, of cosmic magnetic fields, of the mechanisms of activity of black holes and will possibly reveal the nature of the dark matter.
9:35 – 10:35
Dr. Mercedes Paniccia, DPNC Université de Genève
Title: Precision measurements of cosmic rays in space: challenges and opportunities
Abstract: The study of cosmic rays in space allows to address unresolved fundamental issues of physics such as the asymmetry between matter and antimatter in the Universe, the nature of dark matter and the existence of exotic forms of matter. More than a century after the discovery of cosmic rays, a complete theoretical model capable of explaining experimental observations is still missing. In the last decade, the Alpha Magnetic Spectrometer, installed on the International Space Station, has opened a new era of precision measurements of cosmic rays providing essential new information relevant to these questions. I will review the current AMS results and ongoing research activities, highlighting their enormous impact on the understanding of the properties of cosmic rays. I will conclude by giving a perspective on the potential discoveries with AMS in the coming years and in the future with newly proposed space missions.
10:40 – 11:40
Dr. Michael Unger, Karlsruhe Institute of Technology
Title: Cosmic Particles at Extreme Energies
Abstract: Cosmic rays are the highest energy messengers of astrophysical phenomena in the Universe. The sources of these particles are unknown and it is one of the great puzzles of modern astrophysics how they are accelerated to macroscopic energies of >10^20 eV.
In this talk I will highlight recent experimental results on ultrahigh-energy cosmic rays, discuss their implications on our understanding of the physics and astrophysics at extreme energies and introduce ideas and plans for the next generation of cosmic-ray observatories.
11:45 – 12:45
Prof. Xin Wu, DPNC Université de Genève
Title: Particle Physics in Space: from X-rays to PeV particles
Abstract: Space Astroparticle Physics has been making rapid progress in recent years. Advanced particle detection technologies developed for accelerator experiments have been successfully applied to instruments deployed in space. Unprecedented measurement precisions have been achieved, and the frontier of direct cosmic ray detection has been pushed to the 100 TeV, and soon to the PeV, region. In addition, cutting-edge particle detection technologies are being applied to advanced x-ray and gamma-ray space instruments. Space astroparticle physics has become an essential ingredient of the emerging field of multi-messenger astrophysics. In this talk I will give an overview of the current status of space astroparticle physics, and use several current and future projects (DAMPE, HERD, POLAR-2, PAN and eXTP) as examples to illustrate the science impact and technology advancement of this growing research field.
Sep 30 : Dr TJ KHOO, Humboldt University of Berlin, Germany
Title : No leptons? No problem! Physics with jets and MET in ATLAS - slides
Pre-seminar mini-lecture : Hadronic reconstruction with the ATLAS Detector - slides
At the Large Hadron Collider, the high rate and strong interactions of high-energy proton-proton collisions imply huge challenges for physics analyses in the hadronic final state. Nevertheless, innovative strategies for pile-up suppression as well as effective event reconstruction methods have made it possible to do high precision measurements and powerful searches using events with many jets and missing transverse momentum. This seminar will describe two such analyses: determination of differential cross-sections for top pair-production and a quest for new particles with high-multiplicity hadronic decays.
Oct 07 : Dr Marie-Hélène GENEST, LPSC Université de Grenoble Alpes, France
Title : Exotic searches at the LHC - slides
Pre-seminar mini-lecture : Exotic searches at the LHC: from detecting particles to searching for new ones - slides
Despite the success of the Standard Model, many open questions remain and multiple theories addressing them predict new particles which could be produced and detected at the LHC. There is a vibrant search program looking for these so-called exotic particles, covering a variety of final states, from dijet resonances to long-lived particles. A selection of recent results will be discussed, with the aim of giving an overview of the various types of searches that can be performed.
Oct 28 : Prof. Alain Blondel, LPNHE Paris-Sorbonne and Univ. of Geneva
Title : The many challenges of FCC-ee - slides
The European Strategy Update of 2020 offers the vision of a Higgs
Factory followed by a High energy (>100 TeV hadron collider). The most
effective realization of this vision is the Future Circular Collider
(FCC-ee and hh) integral project, to be hosted in a new 100km tunnel
around Geneva. The first step, FCC-ee, is a Higgs and Electroweak
circular e+e- factory, that should start operation shortly after the end
Built under the principles developed at the B-factories, FCC-ee offers
huge luminosities and special qualities of beam energy calibration at
the 100 keV level, and possibly monochromatization for the s-channel
Higgs production, which single it out among the Higgs factory projects
with a set of unique measurement possibilities.
The full exploitation of these opportunities poses considerable
challenges both for detector design and theory, to reduce systematic
errors at the level of the available statistics.
Alain Blondel is honorary professor at University of Geneva, where he
created the neutrino group (now Sanchez group) in 2002. He has played a
seminal role in the development of e+e- circular colliders Higgs
Factories, and is a member of the FCC coordination group, in charge of
the Physics Experiments and Detector studies.
Nov 4 : Dr Max SWIATLOWSKI, TRIUMF, Canada
Title : Searching With di-Higgs Final States at ATLAS: A Window to the Standard Model and Beyond - slides
The discovery of the Higgs boson has been a triumph for the Large Hadron Collider's physics program, but many open questions remain about this mysterious particle. Why is the Higgs mass so many orders of magnitude lower than the straightforward prediction? Can we observe the shape of the Higgs potential which gives rise to the particle, and can this potential be related to cosmological inflation or baryogenesis? Final states with two Higgs bosons, though extremely rare, can provide answers to these questions and more. I will present new ATLAS results for searches for direct di-Higgs production, including full run 2 results in the vector boson fusion production mode, as well as searches for electroweak supersymmetry involving decays to pairs of Higgs bosons. These searches employ several key innovations, such as the use of b-jet triggers and Boosted Decision Trees in background estimation, to achieve some of the strongest sensitivities yet to di-Higgs production and provide new insights into the nature of the Higgs.
The SAFIR (Small Animal Fast Insert for MRI) project is developing a pre-clinical Positron Emission Tomography (PET) insert for a commercial Bruker BioSpin 70/30 Magnetic Resonance imaging (MRI) system. SAFIR aims at unprecedented temporal resolution, i.e. images of good quality should be acquired within seconds instead of minutes. This enables truly simultaneous PET/MR imaging and opens the possibility to study the dynamics of the tracer distribution precisely on the timescale of seconds. The PET insert is planned to be used for pre-clinical research in the Small Animal Imaging Lab at ETH-Zurich. In 2019 we successfully completed the construction of a fully functional prototype with 34 mm axial coverage. We describe the details of the construction and show the first results including performance measures, first images and a dynamic study. Moreover, we give a short outlook on the development of the full detector (140 mm axial coverage), which is presently ongoing.
Nov 25 : Dr Federico Leo REDI, EPFL, Lausanne
Title : Feebly interacting particle searches at LHCb and beyond - slides
Searches for physics Beyond the Standard Model have, so far, not shown any clear sign of new physics. Strongly-coupled extensions to the Standard Model are a traditional direction of studies at the energy frontier. Orthogonally, feebly interacting particle searches at the intensity frontier represent an alternative route to answers to many fundamental open questions in high energy physics. This talk will cover the main searches of feebly interacting particles which take place today at the LHCb experiment. It will expand the subject showing the prospects for some of these searches with Run 3 data. Finally, the talk will further move into the future, providing some examples of proposed future experiments, such as SND@CERN, and the technological work that is linked to their possible future success.
Dec. 16 : Prof. Anna Sfyrla - Univ. of Geneva
Title : Looking forward to new physics: The FASER experiment at the CERN LHC - slides
Jan 13 : Dr Jakob SALFELD-NEBGEN, CERN
Title : High-rate Data-taking and Dark Sector Explorations with the CMS Experiment - slides
The nature of Dark Matter is one of the unresolved mysteries of fundamental physics. In particular its particle nature remains to be understood. Dark Matter particles may be part of a hidden Dark Sector with Dark Forces only feebly coupled to the visible matter content of the Universe. Detectors at the LHC have the potential to detect signatures of Dark Sector particles produced in proton-proton collisions. I will highlight the status and plans of the high-rate Scouting data-taking technique with the CMS Experiment and associated searches for Dark Sector particles.
Jan 20 : Prof Andrii Tykhonov, Univ. of Geneva
Title : Catching TeV - PeV cosmic rays in space
The DArk Matter Particle Explorer (DAMPE) mission has recently marked a new epoch in astroparticle physics, extending the direct measurements of cosmic rays beyond TeV with unprecedented energy resolution. In this decade the calorimetric experiments like DAMPE and next-generation High Energy Radiation Detection facility (HERD) will shape the future of the direct cosmic ray measurements in space at high-energy frontier, reaching a remarkable PeV milestone. We will gain crucial insights to solve the century-long problem of cosmic-ray origin at such high energies and its effects on the Universe composition. Yet having excellent instruments is only one part of a success story. The measurements are hampered by significant systematic uncertainties related to particle identification and hadronic interaction modelling. Beating the uncertainties is key to future discoveries. In this talk we will discuss the challenges of the direct TeV—PeV cosmic ray detection in space and ways to tackle them using state of the art artificial intelligence techniques.
Feb 3 : Dr Elena CUOCO, European Gravitational Observatory and Scuola Normale Superiore, Pisa, Italy
Title : Gravitational Wave science and Machine learning applications - slides
In recent years, Machine and Deep learning techniques approaches have been introduced and tested for solving problems in astrophysics. In Gravitational Wave (GW) science many teams in the LIGO-Virgo collaboration have experimented, on simulated data or on real data of LIGO and Virgo interferometers, the power and capabilities of machine learning algorithms both for the detector noise and gravitational wave astrophysical signal characterisation. The cost action CA17137 (g2net) aims to create an interdisciplinary network of Machine Learning and Gravitational Waves experts and to create collaborating teams to solve some of the problems of gravitational wave science using Machine Learning. In this seminar, I will show examples of the application of Machine Learning for the detection and classification of transient signals due to noise disturbances or to GW signals from Core Collapse Supernovae.
Feb 10 : Prof. Laura Baudis, Univ. of Zurich
Title : Recent results from XENON1T and status of XENONnT - slides
SPRING semester 2020
SEMINARS AS OF MARCH CANCELLED DUE TO COVID19
Feb 26 : Dr Michele Punturo, INFN Perugia
Title : Perspectives of Gravitational Wave observations from current Advanced detectors to Einstein Telescope - Access to the talk
The detection of the gravitational waves by Advanced LIGO and Advanced Virgo opened a new era in the observation of the Universe: a new messenger is allowing to discover unexpected dark events and to contribute to multimessenger observations of astronomical catastrophes. A new gravitational wave observatory, Einstein Telescope (ET), is proposed to fully exploit the potential of the gravitational wave astrophysics.
ET will observe the coalescence of black holes and neutron stars in almost the whole Universe having a decisive impact in cosmology, astrophysics, nuclear and fundamental physics. The achievements of the advanced detectors and the perspectives of Einstein Telescope project will be presented.