Events

All future and past seminars

AUTUMN semester 2020

 

Sep. 16 : Dr Anatael CABRERA, CNRS-IN2P3
Title : Novel LiquidO Opaque Neutrino Detection & Possible Physics

Abstract

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

Details

8:30 – 9:30
Prof. Andrii Neronov, Université de Paris-Diderot et Université de Genève
TitleUniverse 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
TitlePrecision 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

Abstract

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

Abstract

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

Abstract

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
of HL-LHC.

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

Abstract

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.

 

Nov 11 : Dr Werner LUSTERMANN, ETHZ,  Zurich
Title : SAFIR, a fast pre-clinical PET insert - slides, gif

Abstract

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

Abstract

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.

 

Jan 13 : Dr Jakob SALFELD-NEBGEN, CERN
Title : DM Searches with non-conventional triggers at CMS

 

Jan 20 : Prof Andrii  Tykhonov, Univ. of Geneva

Title : Catching TeV - PeV cosmic rays in space

 

Jan 27 : Dr Elena CUOCO, Scuola Normale Superiore, Pisa, Italy
Title : ML & gravitational waves

 

 

 

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

Abstract

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.

 

 

 

AUTOMN semester 2019

 

Sep. 25 : Prof. Susanne Mertens, TU, Munich
Title : First neutrino mass results from KATRIN - Access to the talk

Abstract

The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to directly probe the neutrino mass with a sensitivity of 0.2 eV (90% CL).

KATRIN persues a model-independent approach, solely based on the kinematics of tritium beta decay. A non-zero neutrino mass manifests itself as a small spectral distortion close to the endpoint of the decay. In spring 2019 KATRIN performed its first neutrino mass measurement campaign. With this first data set new limits on the neutrino mass could be established, reaching for the first time the sub-eV regime. In this talk the KATRIN working principle and the first neutrino mass results will be presented. A short perspective to the future scientific program of KATRIN will be given.

 

Oct 02 : Prof. Andrea Wulzer, University of Padova & CERN - Access to the talk
Title : Present and Future Colliders Physics

Abstract

High-energy colliders are indispensable tools for a broad, systematic and robust exploration of Fundamental Interactions Physics. One such collider, the LHC including its high-luminosity upgrade (HL-LHC), will deliver data during the next several decades. I will illustrate by concrete examples the HL-LHC potential to probe presently unexplored new physics. I will also outline some of the exciting challenges in theoretical and experimental physics, and in data analysis, that will have to be addressed in order to exploit this potential fully. Finally I will summarise some aspects of the physics potential of future collider projects like the FCC, CLIC and ILC, and of more speculative proposals such as the muon collider.

 

Oct 16 : Prof. Marcello Messina, NYU, Abu Dhabi
Title : The PTOLEMY project: from an idea to a real experiment to detect the Cosmological Relic Neutrinos - Access to the talk

Abstract

In the first part the seminar a novel idea on the detection of Cosmological Relic Neutrinos (CRN) and more in general, on the detection of neutrinos of vanishing energy will be presented. This idea is described in detail in the paper [1]. The method is based on the fact that neutrino interactions on beta-instable nuclei have the key feature of requiring no energy threshold for the neutrino interaction. Some phenomenological aspects will be presented.

The second part of the seminar will be dedicated to the PTOLEMY project, in a starting phase at the Laboratori Nazionali del Gran Sasso, Italy. In this project we aim at demonstrating the detection principle of the CRN and finalize the design of the future full scale experiment. The technologies on which the detector concept is based will be presented and the key features explained.

A new-concept of electrostatic filter discussed in a paper [2] recently published by the PTOLEMY collaboration will also be explained in details.

 

Oct 30 : Dr Marco Apollonio, Diamond Light Source, UK
Title : Synchrotron Radiation: a bright light for science

Abstract

Diamond Light Source is the UK’s national synchrotron science facility, located at the Harwell Science and Innovation Campus in Oxfordshire. The machine accelerates electrons to near light speeds so that they give off light 10 billion times brighter than the sun. These bright beams are then directed off into laboratories known as ‘beamlines’. Here, scientists use the light to study a vast range of subject matter, from new medicines and treatments for disease to innovative engineering and cutting-edge technology. Whether it’s fragments of ancient paintings or unknown virus structures, at the synchrotron, scientists can study their samples using a machine that is 10,000 times more powerful than a traditional microscope.

I will illustrate the main characteristics of the light produced at Diamond, the way it is generated by means of dedicated devices and the techniques used to improve the quality of such radiation by a substantial reduction of size and divergence of the electron beams. I will show a comparison of the different solutions adopted in present and (near) future machines and conclude with few science cases related to the use of synchrotron radiation at our facility.

 

Nov 06 : Dr Nathal Severijns, KU, Leuven University
Title : Probing physics beyond the Standard Model in neutron and nuclear beta decay- Access to the talk

Abstract

Precise measurements of observables in beta decay allow testing the symmetries of the Standard Model, or searching for new physics at the low-energy frontier. Such measurements provide information on physics beyond the Standard Model that is complementary to direct searches at the Large Hadron Collider.

The main challenges in order to further improve the sensitivity to new physics are to reach per mil precision levels and possibly beyond, while keeping control over systematics and small Standard Model effects that then start playing a role. 

A non-exhaustive overview of this field and future prospects will be presented based on selected, recent and planned state-of-the-art measurements that use a variety of techniques.

 

Nov 20 : Prof. Kostas Nikolopoulos, University of Birmingham
Title : NEWS-G: Search for Light Dark Matter with a Spherical Proportional Counter - Access to the talk

Abstract

The NEWS-G collaboration is searching for light dark matter candidates using a spherical proportional counter. Access to the mass range from 0.1 to 10 GeV is enabled by the combination of low energy threshold, light gaseous targets (H, Ne), and highly radio-pure construction.  

 The current status of the experiment will be presented, along with the first NEWS-G results obtained with SEDINE, a 60 cm in diameter spherical proportional counter operating at LSM (France), excluding cross-sections above 4.4x10^{37} cm^2 for 0.5 GeV WIMP using a neon-based gas mixture.  

 The construction of the next generation, 140 cm in diameter, spherical proportional counter constructed using 4N copper at LSM will be discussed, along with the latest advances in SPC instrumentation. The detector, following initial commissioning at LSM is currently being transported to SNOLAB (Canada), with the first physics run scheduled for 2020. Finally, future prospects and applications of spherical proportional counters will be summarised.

 

 

Dec 04 : Dr Giovanni Rumolo, CERN
Title : LHC Injectors Upgrade Project: Towards New Territory Beam Parameters - Access to the talk

Abstract

The LHC Injectors Upgrade (LIU) project aims at increasing the intensity and brightness in the LHC injectors in order to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring high availability and reliable operation of the injectors complex well into the HL-LHC era. This requires extensive hardware modifications and new beam dynamics solutions in the entire LHC proton and ion injection chains: the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS), together with the ion PS injectors (the Linac3 and the Low Energy Ion Ring (LEIR)). All hardware modifications are being implemented during the 2019-2020 CERN accelerators shutdown.

A view on the future operation of the LHC injectors is also presented, highlighting the benefits in terms of beam parameters for both the LHC beams and those for fixed target physics.

 

Dec 11 : Dr Anna Soter, PSI
Title : Fundamental physics with muons: from the proton radius to antimatter gravity - Access to the talk

Abstract
At the Paul Scherrer Institute ongoing precision experiments involving muons and muonic atoms are targeting fundamental questions in flavor physics, probing the symmetries of the Standar Model, and measuring fundamental constants. In this talk these ongoing precision efforts will be introduced by concentrating on a newly proposed experiment to measure gravitational interaction of muonium (Mu). 
 
Carrying out a direct gravity experiment on Mu atoms would be of fundamental interest. Such a measurement would provide an exotic test of the weak equivalence principle, since the positive muon that dominates the Mu mass is an elementary antimatter particle, and also a lepton from  the second generation. 
 

To make this experiment possible, we are investigating methods to create a novel Mu source based on conversion in  superfluid helium (SFHe). The unique chemical properties of SFHe may allow the production of a high brightness atomic Mu beam in vacuum. A high quality atomic beam would then benefit next generation precision laser spectroscopy experiments, and would make intertial measurements in an atom interferometer feasible. The promising preliminary results on cold Mu production and the feasibility of a Mu interferometer.

 

Jan 15 : Paola Villa, University Wisconsin- Madison
Title : Romancing the CERN: Constructive Interferences between Physics and Literature - Access to the talk

Abstract

Physics and literature make odd bedfellows. More than 60 years after the famous C.P. Snow’s anathema sanctioning the incommunicability between the sciences and the humanities, the debate on the two cultures is still very much alive. Studies in the field of Literature and Science flourished in the past 20 years. The humanities, in general, have become increasingly aware of the important contribution of scientific ideas into shaping modern cultures and artistic productions. Yet, there still seems to be a fundamental asymmetry between literature’s understanding of physics and physics’ reception of literature. When confronted with the idea of what literature can do for science, the answer has been as much unanimous as reductive: “storytelling”. Is it really the case that all literature has to offer is a series of narrative tricks?

Drawing from examples of novels written by physicist and literary authors alike, I will explore some of the mechanisms that emerge at the crossroads of the two disciplines. What happens when the experimental apparatus of physics becomes the centerpiece of a fictional account? How does the material culture of detectors and particle accelerators influence the construction of a novel? And conversely, what tools does fiction offer to scientists in order to explore their ideas and their social environment? The goal of this presentation is not to discount the important lesson of “storytelling”, but rather to offer additional reasons why scientists, and physicists in particular, might want to pay more attention to literature.

 

 

Login
Département de Physique Nucléaire et Corpusculaire | 2017 | Impressum.