Events

All future and past seminars

Academic year 2022-2023

AUTUMN semester 2022

September 21 : Prof. Michele Doro (University of Padova, Department of Physics and Astronomy) -- in zoom

Title: Some topics of fundamental physics attainable with IACTs Slides

Abstract

Astrophysical gamma rays in the TeV regime are valid probes of new physics because of the high energies, large distances and/or times involved in the processes. The program of current ground-based imaging atmospheric Cherenkov telescopes (IACTs) on fundamental physics is wide: from the search of particle dark matter annihilation or decays (heavy and light) or other proposed exotic objects such as magnetic monopoles or quark nuggets, to that of signatures of new physics such that coming from Lorentz Invariance violation theories or involving tau neutrinos. This ample and complex program runs for more than a decade now within HESS, MAGIC and VERITAS, the current major IACTs, in strong competition with the astrophysical observation program. In this presentation, I will discuss some of these topics, arguing on the lessons learnt and the things to come for CTA and other future facilities. 

 

October 12 : Dr. Sofia Vallecorsa  (CERN)                
Title: CERN QTI: initial results and research perspective on Quantum Computing for HEP- Slides

Abstract

CERN launched a Quantum Technology Initiative in 2020 in order to investigate the use of quantum technologies in High Energy Physics (HEP). A three-years roadmap and research program has been defined with the HEP and quantum-technology research communities. In this context, a range of projects, set up at CERN in collaboration with HEP institutes worldwide, have explored the use of Quantum Computing, and Quantum Machine Learning algorithms, on different use cases which are representative of the next generation LHC experiments computing challenges. When reaching the end of the QTI second year, a set of preliminary results were gathered, outlining benefits, constraints and limitations of introducing quantum algorithms. These learnings will be used to feed into  the definition of a long-term research plan, closely aligned with the technological development of quantum infrastructure. This talk will summarize the experience accumulated through the past years, outline the research results and provide an initial perspective of future directions.

 

November 2 : Dr. Susanne Kuehn  (CERN)                 
Title: The Tracking detectors of the ATLAS and CMS experiments for the High-Luminosity LHC - Slides

Abstract

In the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk), aiming to provide tracking coverage up to |η|<4. Similarly, the CMS experiment will install a new tracking detector for operation at the HL-LHC. Beside the challenge of radiation hardness and high-rate capable silicon sensors and readout electronics many system aspects have to be considered for fully functional detectors. An overview of the concept and technology choices for the upgrade trackers will be presented. Mechanical and electrical results will be highlighted from various prototyping and pre-production efforts with an emphasis on the ITk of the ATLAS experiment. Moreover, performance estimates and a comparison of the detectors will be presented.

 

November 9 : Prof. Anna Soter  (ETH Zurich)                         
Title: Precision particle physics with exotic atoms and antimatter

Abstract

Despite the immense success of the Standard Model (SM), it is well known to be incomplete in describing Nature. Most obviously it is not incorporating gravity, and also falling short in explaining cosmological observations like the baryon asymmetry of the Universe, or the nature of dark matter and dark energy. In the recent years, tensions within the SM as well arose, especially concerning lepton universality with the latest result from LHCb [1], or from the muon g-2 experiment [2].

 

In this talk, precision particle physics efforts at the Paul Scherrer Institute (PSI) are introduced in the lepton sector, with the focus on two novel experiments, both exploring beyond-SM physics, but using rather different methods and physics processes.

 

PIONEER is a newly formed international collaboration, where we are searching for potential violations of lepton flavor universality by investigating branching ratios of the charged pion decay to electrons against to muons, a number precisely predicted by the Standard Model [3].

 

In the LEMING experiment we aspire to carry out next generation atomic physics and gravity experiments using muonium, which is an exotic atom consisting of a muon and an electron (M = μ⁺ + e⁻) [4]. We started this challenging task by developing a novel cold atomic M beam in vacuum using muon conversion in superfluid helium, based on a curious inert behavior of exotic atoms in the quantum liquid [5]. The new tantalizing results with the cold M beam production put us on a path for increased precision in 1S-2S laser spectroscopy of M, and may pave the way for a free fall experiment, that would be the first direct measurement of the gravitational interaction using (anti-)leptons.

  

References

 

       [1]     LHCb Collaboration, Nat. Phys. 18, 277–282 (2022)

       [2]     Muon g−2 Collaboration, Phys. Rev. Lett. 126, 141801 (2021)

       [3]     PIONEER: Studies of Rare Pion Decays, arXiv:2203:01981

       [4]     A. Soter and A. Knecht, SciPost Phys. Proc. 5, 31 (2021)

       [5]     A. Soter et. Al Nature 603, pages 411–415 (2022)

 

November 16 : Prof. Boisvert Veronique (Royal Holloway, University of London)   
Title: The Climate Emergency: can Particle Physics ever be sustainable? - Slides

Abstract

We live in a climate emergency and consequently all countries are putting in place measures to reduce their carbon emissions in order to reach a so-called “net zero emissions” by 2050. All aspects of economic life will be affected by such measures, including particle physics research. I will present some examples of sources of carbon emissions within the field of particle physics. This will include emissions associated with building and running accelerators, detector operations, high-performance computing and activities associated with our research life like travel. I will also present solutions being developed for addressing this in the near and long term as well as recommendations for the field. 

 

November 23 : Dr. Alex Winkler  (Detection Technology PLC, Finland)                      
Title: Detectors for more than science, but based on science - Slides

Abstract

Radiation detectors with cutting edge technology are designed and build by CERN research groups, in order to extend our knowledge on the mysteries of the universe and life itself. The CP asymmetry of the B mesons as a display of the matter-anti-matter imbalance in the universe, indicates that there is a lot to discover with potentially new physics. Some of the technologies developed for CERN experiments are used in applications that make our daily life easier, more safe and even safe our lives. This seminar will provide a short history of the detector technologies that were first employed at CERN, but are now used all around us, followed by an outlook of latest technologies that are finding their way in our daily world as well.

 

November 30 : Dr. Raffaele Tito D'Agnolo, IPhT, France
Title: Sliding Naturalness: A New Solution to the Strong-CP and Electroweak Hiearachy Problems

Abstract
 I will discuss the first joint solution to the strong-CP and electroweak hiearachy problems. At low energy it extends the Standard Model by two axion-like scalars and predicts correlated signatures in neutron EDM and fuzzy dark matter searches.

 

 

December 7 : Prof. Radoslav Marcewski (EPFL)                       
Topic: Kaon physics strikes back

 

December 14 : Prof. Francesco Salamida  (Università degli Studi dell'Aquila)         
Topic: Ultra High Energy Cosmic Rays with Pierre Auger observatory

Academic year 2021-2022

SPRING semester 2022

March 2 : Prof. François Grey, CUI, UniGe, CH
Topic: Citizen Science - Slides

Abstract

Kyiv, Covid, Climate Change and Crowdsourcing

The evolving role of citizen science in global crises

François Grey, Centre Universitaire d’Informatique

Citizen science is a term used over the last few decades to describe a range of methodologies that enable citizens to contribute data to science projects. Citizen science projects are often led by professional scientists in academic institutions. They may involve just a few participants or thousands of citizens at a time. They may run for just a few weeks or for decades. Increasingly, they depend on digital technologies, such as phone-based apps or web-based games, to gather, analyze and simulate new data.

Citizen Cyberlab is a partnership with CERN and UNITAR based at the Centre Universitaire d’Informatique. Since 2009, Citizen Cyberlab has initiated a series of citizen science projects as well as developed new digital tools and practical methodologies for collaboration between citizens and scientists. At Citizen Cyberlab, we take a broad view of citizen science, and include a range of digital crowdsourcing activities that may not have a direct scientific objective, but which can nevertheless generate data of scientific importance. A particular focus is on citizen-generated data of relevance to National Statistical Offices that are tracking progress towards the UN Sustainable Development Goals (SDGs).

In this talk, I will focus on new trends in citizen science, where crowdsourcing technologies, often combined with artificial intelligence, enable citizens to contribute to tackling major crises. Examples I will describe include: open source intelligence used to document rapidly unfolding crises, such as the war in Ukraine; the roles of amateur scientists and crowdsourcing in tracking the origins and understanding the spread of Covid; how young people, inspired by the Fridays for Future movement, are using collaborative citizen science methodologies to gather data about climate change and its impacts, as well as to develop solutions for climate resilience and adaptation.

In the case of climate change, I will be illustrating examples from Crowd4SDG, an EU project that UNIGE leads, in collaboration with the Citizen Cyberlab partners CERN and UNITAR as well as partners in Barcelona, Milan and Paris.

 

 

March 16 : Dr. Kate Shaw, Univ. Sussex, UK
Title: Widening the talent pool in physics - Slides

Abstract

What if the next Curie or Einstein is a student in a country where scientific research and education is not a priority? Physics has historically been a field accessible only to a small minority of people, often in the richer countries around the world. To widen the talent pool available to science, the scientific community must be more reflective of the diversity of humankind. This means students from countries without strong scientific research centres or access to advanced training and opportunity must be given access through our wider scientific community. This talk will look at diversity and inclusion in physics, within nations and across the globe, and look at initiatives to ensure the brightest minds have access to opportunity and training.

 

March 30 : Dr. Jamie Boyd, CERN, CH
Title: The Forward Physics Facility at the HL-LHC - Slides

Abstract

High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe Standard Model (SM) processes and search for physics beyond the Standard Model (BSM). FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. The seminar will outline the FPF physics motivations, and the status of ongoing studies on the facility design and proposed experiments.

Further reading: https://arxiv.org/pdf/2203.05090.pdf

 

April 13 : Dr. Lorenzo Paolozzi, UniGe, CH
Title: Fast monolithic silicon pixel detectors in SiGe BiCMOS: the path to picosecond time resolution - Slides

Abstract

The monolithic integration of silicon pixel detectors in a CMOS process is a flexible and low-cost solution to manufacture tracking detectors for ionizing radiation with excellent space resolution and low material budget. The research team at the University of Geneva pioneered the integration of pixel sensors in commercial SiGe BiCMOS, making the first monolithic pixel detector with a time resolution below 100ps. This technology is now established, with the first applications being the new preshower detector of the FASER experiment at the LHC and a high-granularity scanner for Positron Emission Tomography. The new great challenge is the production of a detector that combines picosecond time resolution and state-of-the art tracking capability. The MONOLITH ERC Advanced project aims at producing the first silicon pixel detector with picosecond time resolution, using the concept of the Picosecond Avalanche Detector (PicoAD). Such a device would be groundbreaking for high-energy physics experiments, medical physics and commercial applications.

 

 

April 27 : Prof. Ivan De Mitri, GSSI, Italy
Title: Recent observations on High Energy Cosmic Rays - Slides

Abstract

The study of High Energy (HE) and Ultra-High Energy (UHE) cosmic rays is currently being driven by new and very interesting data from both space-borne and ground-based experiments. The talk will be devoted to a review of recent observations of electrons/positrons, protons/antiprotons, and nuclei, at energies above tens of GeV. New techniques and mission concepts will also be briefly discussed.

 

May 5: Dr. Christian Ohm - KTH, Stockholm, Sweden
Title: Long-lived particles at the LHC: Spectacular signatures and delayed discoveries? - Slides

Abstract
The Standard Model of particle physics has been frustratingly successful at predicting and describing experimental results at collider experiments for decades. Nonetheless, it suffers from several severe shortcomings that indicate that it is incomplete and needs to be extended. These beyond-SM extensions can give rise to a broad range of experimental signatures, and I will discuss the challenging phenomenology of long-lived beyond-SM particles and how we search for them at the LHC. I'll highlight several recent results and discuss ideas for future strategies in Run 3 of the LHC which is just starting.

 

May 10 : Prof. Jure Zupan, U. Cincinnati, US ** Unusual time: 16:15

Title: The quest for light new physics - Slides

Abstract

If light new physics states are produced in some of the laboratory experiments  this will give us a window to dynamics at very high scales, possibly all the way up to 10^12 GeV, depending on the process. I will illustrate this  on several well motivated examples of new physics models leading to light states. Special attention will be paid to the rare flavor experiments, which can probe complementary parameter space relative to the beam dump experiments and astrophysical systems.

 

May 18 : Dr. Pasquale Blasi, GSSI, Italy
Title: Transport of cosmic ray hadrons and leptons: status and perspectives - Slides

Recent measurements of the spectra of cosmic ray species (nuclei, electrons, antimatter) have revealed several new aspects of the problem of the origin of cosmic rays, that are expected to shed light on the microphysics responsible for the transport of cosmic rays in the Galaxy. After a pedagogical introduction to some basic aspects of the theory of transport of charged particles in magnetized plasmas I will establish possible connections with current observations and emphasise success and critical aspects of the current understanding of these phenomena. The non-linear aspects of cosmic ray transport, that have recently been subject of much investigation, will be granted special attention as observations suggest their important role in both particle acceleration (maximum energy, magnetic field amplification) and propagation (diffusion suppression around sources and TeV halos).

 

June 1 : Dr. Nick Rodd, CERN, CH
Title: Searching for the Heaviest Particle in the Universe - Slides

Abstract

If dark matter is a particle with a mass between the electroweak and Planck scale, we could detect it through its decays to high-energy cosmic rays. Testing this hypothesis requires a detailed understanding of the astrophysics of where these decays are occurring and the particle physics that dictates the spectra of produced cosmic rays. In this talk, I will describe recent progress on both fronts. On the astrophysics side, searches within our own Milky Way halo can significantly outperform extragalactic observations, and I will demonstrate how this insight allows for a definitive statement to be made about a longstanding decaying dark-matter anomaly, the 3.5 keV X-ray line. On the particle physics side, I will outline how to perform a field theory calculation at energies approaching the Planck scale, and show how working with the full unbroken Standard Model produces dark-matter spectra that differ by orders of magnitude from previous estimates.

AUTUMN semester 2021

 

Sep. 15 : Bruno Mesnet (IBM systems), Dr. Filip Leonarski (PSI), Dr. Lionel Clavien (InnoBoost)

Title : At last a new and proven technique to push the limits of our old conventional CPU-centric servers by adopting memory coherence! - Slides 1, Slides 2, Slides 3, Slides 4, Slides 5

 

Sep 22 : Dr. Massimo Passera - INFN, Padua
Title: Muon g-2 and Δα connection - slides

Abstract

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
Title :  Invisible Higgs decays & trigger challenges at the LHC - slides

Abstract

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
Title: Prototyping DUNE - The first beam run of ProtoDUNE-SP and plans for a second run - Slides

Abstract

The ProtoDUNE Single Phase (SP) detector is one of two ton-scale prototypes built at CERN as testbeds for the design validation of the upcoming DUNE far detector modules.

DUNE is a next-generation, multi-kton neutrino detector based on Liquid Argon Time Projection Chamber (LArTPC) technology; among its main physics goal are the precise measurement of the neutrino oscillation parameters, as well as the collection of neutrinos from astrophysical sources and the search for BSM physics.

Given DUNE dimensions, featuring four far detectors with a total mass of 17 kton each, it becomes fundamental to develop a strong and layered R&D program, that will bring the LArTPC technology to the next level, for safe employment during the long life-time of DUNE (10-20 years).

ProtoDUNE is the natural result of this R&D program. A kton detector allows testing all aspects of the technology to be deployed in DUNE, with full-scale components; it permits to characterize new solutions and materials to be employed; it works as the perfect training ground for detector installation, operation; it allows the development on real data of algorithms for acquisition, reconstruction, and analysis.

Building and operating ProtoDUNE SP in around 2 years was an incredible challenge carried out by the DUNE collaboration. Its success allowed the evolution of the design for the DUNE first far detector module, and interesting performance and physics results are being produced. This seminar will cover the construction and first beam run of ProtoDUNE SP; it will present the initial physics results obtained from the data collected, and finally it will give insight into the upcoming second beam run, which will see the deployment of new upgraded detector components.

 

Oct 20 : Dr Anja Butter, ITP, Heidelberg

Title: Machine Learning for LHC Theory - Slides

Abstract

Over the next years, measurements at the LHC and the HL-LHC will provide us with a wealth of data. The best hope of answering fundamental questions like the nature of dark matter, is to adopt big data techniques in simulations and analyses to extract all relevant information.
On the theory side, LHC physics crucially relies on our ability to simulate events efficiently from first principles. In the coming LHC runs, these simulations will face unprecedented precision requirements to match the experimental accuracy. Innovative ML techniques like generative models can help us overcome limitations from the high dimensionality of the parameter space. Such networks can be employed within established simulation tools or as part of a new framework.
At the analysis level, machine learning methods have already shown impressive performance boosts for instance in top tagging and jet calibration. While neural networks offer an attractive way to numerically encode functions, actual formulas remain the language of theoretical particle physics. Symbolic regression trained on matrix-element information provides optimal LHC observables in an easily interpretable form.

 

Oct 27 : Dr. Simon Spannagel - DESY

Title : Allpix Squared - Silicon Detector Monte Carlo Simulations for Particle Physics and Beyond - Slides

Seminar also in person, at the Grand Auditoire, École de Physique.

Abstract

Allpix Squared is a versatile, open-source simulation framework for
silicon pixel detectors. Its goal is to ease the implementation of
detailed simulations for both single sensors and more complex setups
with multiple detectors. While originally created for silicon detectors
in high-energy physics, it is capable of simulating a wide range of
detector types for various application scenarios, e.g. through its
interface to Geant4 to describe the interaction of particles with
matter, and the different algorithms for charge transport and
digitization. The simulation chain is arranged with the help of
intuitive configuration files and an extensible system of modules, which
implement the individual simulation steps. Detailed electric field maps
imported from TCAD simulations can be used to accurately model the drift
behavior of charge carriers, and an implementation of the Shockley-Ramo
theorem enables time-resolved signal formation studies, adding a new
level of detail to Monte Carlo simulations of particle detectors.

Recently, Allpix Squared has seen major improvements to its core
framework to take full advantage of multi- and many-core processor
architectures for simulating events fully parallel. Furthermore, new
sensor geometries such as hexagonal pixels have been introduced, further
extending the application range. This seminar provides an overview of
the framework and its components, highlighting the versatility and some
of the recent developments.

 

 Nov 3 : Dr. Vava Gligorov - LPNHE
Title: Real-time analysis at 30 MHz — the LHCb experience - Slides

Abstract

What does it mean to analyse terabytes of data per second in real time? What kind of computing architectures must we master to achieve such a goal? How do we write code which gives compatible results at the permille level across a range of computing architectures? How do we build teams of physicists and software specialists with highly heterogeneous skills and keep them working together for a decade in order to achieve these objectives? If those sound like interesting questions you will find some personal reflections on them, based on a decade of development within the LHCb collaboration, in this talk.

 

Nov 17 : Prof. Paolo Crivelli, ETHZ
Title: “The NA64 experiment searching for dark sectors at the CERN SPS " - Slides

Abstract

"NA64 is a fixed target experiment using the unique CERN SPS secondary beamlines to search for hidden sectors.  The experiment looks for new particles such as dark photons, axion-like particles, new light X or Z’ bosons by colliding 100-150 GeV energy electron beams onto an active target. I will present the NA64 experiment and report the latest results emphasizing the sensitivity of our experiment to search for possible new physics contributions in muon anomalous magnetic moment. I will conclude with the future prospects of the experiment which just resumed data taking this Summer after the 2 years CERN long shutdown.”

 

Dec 1 : Dr Davide Pinci , INFN, Roma
Title: The CYGNO experiment: a gaseous optically readout TPC for rare events - Slides
studies

Abstract

The possibility of studying low energy events produced by weakly
interacting particles is becoming crucial in many aspects of
astroparticle physics, from the search of possible Dark Matter
candidates to solar neutrino spectroscopy.
The CYGNO collaboration is developing a gaseous TPC, operated at
atmospheric pressure and room temperature, where the light produced
during the multiplication process in the channels of a triple-GEM stack
is acquired by a system composed by CMOS optical sensors and
photo-multipliers.
This technology provides a set of information (energy released and its
space profile, 3D direction and 3D position) that allows to reconstruct
and identify ionisation produced in the gas by electronic or nuclear
recoils with energies down to few keV with the aim of the construction
of a 1 cubic meter demonstrator to be installed underground at the Gran
Sasso Laboratories.

In this presentation, the results obtained with different prototypes,
with a particular emphasis on the measurements performed with the 50
litres one, will be presented together with the studies about the
sensitivities in different physics research applications.

 

Dec 22 : Prof. Maurice Bourquin, Unige

Title: Comment détruire les déchets des centrales nucléaires - Slides

!!! special Xmas seminar !!!

Abstract

Transmutex SA est une entreprise privée, fondée en 2019 à Genève, qui vise à développer une nouvelle technologie d'énergie nucléaire permettant de « brûler » les déchets nucléaires existants tout en produisant une énergie décarbonée. Ce procédé a été démontré au CERN par le professeur Carlo Rubbia (prix Nobel 1984), puis confirmé par de nombreuses études.

Pour accélérer son développement, dans le but de lutter plus efficacement contre les changements climatiques, nous avons réuni les meilleurs centres de recherches et sociétés dans le domaine, incluant l’Institut Paul Scherrer en Suisse. De plus, Transmutex vise à acquérir de Russie la licence d'un réacteur nucléaire unique au monde, ayant propulsé les sous-marins soviétiques de classe Alfa, tenant du record de vitesse en immersion.

 

Jan 12 : Prof Raffaele Flaminio, CNRS/IN2P3

Title: Technical challenges in ground based laser interferometers for gravitational wave detection - Slides

Abstract

The first detection of gravitational wave events achieved by the LIGO-Virgo collaboration has open the field of gravitational wave astronomy. After the detection of the first merger of a binary black hole in 2015 and the observation of the first binary neutron star in 2017, during the O3 run gravitational wave transients have been recorded at a rate of one per week. Gravitational wave detectors are based on laser Michelson-type interferometers with arms several km in length. The detection of the events requires measuring variations in the arm length of the order of 10 -18 m. At this level of sensitivity tiny effects like thermal noise in the mirrors of the interferometer and quantum noise due to the Heisenberg principle play an important role. Moreover, the detector has to be perfectly shielded from environmental disturbances due to seismic and acoustic noise. To this purpose the interferometers are hosted inside some of the largest vacuum systems in the world and their mirrors are suspended to the most efficient seismic isolators available on Earth. In this talk I will give an overview of the technical challenges that LIGO and Virgo had to face to achieve the required sensitivity as well as the ones in front of us to realize more sensitive detectors like the Einstein Telescope.

 

Jan 19 : Dr Kathrin Valerius , KIT
Title: Probing the neutrino mass: latest results from KATRIN

Abstract

Precision measurements of the kinematics of weak decays offer a direct and mostly model independent approach to probe the absolute neutrino mass scale. The KArlsruhe TRItium Neutrino experiment (KATRIN) is searching for the minute imprint of the neutrino mass in the endpoint region of the tritium β-decay spectrum. KATRIN employs a high-intensity gaseous molecular tritium source and a high-resolution electrostatic filter with magnetic adiabatic collimation to target a neutrino-mass sensitivity of 0.2 eV based on five years of data.

With its initial two science runs already, KATRIN has substantially improved kinematic neutrino mass bounds – recently achieving the first direct constraint at sub-eV sensitivity. In addition, KATRIN has begun to address further science channels such as the direct search for light sterile neutrinos. As larger data sets are collected and further improvements in terms of signal-to-background ratio and systematics are being achieved, KATRIN is continuing its exploration of the sub-eV neutrino mass parameter space and its search for BSM physics in precision β-decay spectroscopy.

 

Feb 9 : Dr Valentina Cairo, CERN
Titel: Probing the Higgs self-coupling with the ATLAS Detector at the LHC - Slides

Abstract

The post-Higgs discovery era has been characterized by an exciting physics program targeting the investigation of the Higgs boson properties and couplings. The Higgs self-coupling, which determines the shape of the Higgs potential, is one of the building blocks of the Standard Model of Particle Physics, directly connected to the electroweak symmetry breaking mechanism.

Probing the self-coupling is among the most important goals of the High-Luminosity phase of the Large Hadron Collider (LHC) experiments, but much can already be learned from the available Run 2 dataset and from the upcoming Run 3 data taking expected to start in 2022.

This talk will describe the state of the art of direct tests of the Higgs self-coupling with the ATLAS experiment via Higgs pair production, with emphasis on the

 

Feb 22 : Dr Kazuhiro Terhao, SLAC * Seminar on Tuesday 16:15
Topic: ML in LAr - Slides

 

 

 

SPRING semester 2021

March 3 : Prof. Elisa Resconi - TUM, Germany
Title: New direction in high energy neutrino physics: IceCube and the Pacific Ocean Neutrino Experiment

Abstract

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

Abstract

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
Title : 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

Abstract
Muonic Force Carriers are a possible manifestation of Physics Beyond the Standard Model. These new particles have flavor-specific couplings, they couple to the Standard Model only through muons, and could be part of Dark Matter or act as mediators between the Standard Model and a Dark Sector. Muonic Force Carriers potentially explain the persistent inconsistency in the muon anomalous magnetic moment. 
In this talk, we will discuss how the ATLAS experiment can be used as a muon-beam fixed target experiment to search for Muonic Force Carriers. 

 

May 5 : Prof. Florian Piegsa - Univ. of Bern, CH
Title : Fundamental Particle Physics with Neutrons - slides

Abstract

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

Abstract
Light dark matter is the new compelling hypothesis that identifies dark matter with new sub-GeV “Hidden Sector” states, neutral under Standard Model interactions and interfacing with our world through a new force. Accelerator-based searches at the intensity frontier are uniquely suited to explore it. However, current efforts are either limited by the low sensitivity or the high backgrounds. This calls for a major breakthrough in the field.
 
The goal of POKER is to establish and demonstrate a new approach to search for light dark matter, based on a missing energy measurement with a positron-beam, active thick-target setup.
The new technique, based on light dark matter production through positron annihilation on atomic electrons, is characterized by a larger signal yield compared to previously explored reactions, and by a unique signal signature resulting from the underlying reaction dynamics: a peak in the missing energy distribution. 
The final objective of the project, approved as a 1.5 M€ ERC Starting Grant for 2020-2025, is to perform a pilot run with the 100 GeV positron beam available at the H4 beamline at CERN, to demonstrate the technique by exploring a so-far unknown territory in the Hidden Sector parameters space.
 
In this seminar, after a brief introduction the Hidden Sector physics case, I’ll first discuss the potential of accelerator-based light dark matter efforts. I’ll then present the POKER experiment, focusing on the active thick target - the key element of the project. I’ll finally show the sensitivity of POKER to different Light Dark Matter scenarios.

 

May 19 : Prof. Gino Isidori - Univ. of Zurich, CH
Title : B-physics anomalies and the flavor problem - slides

Abstract
Recent data in semileptonic B-meson decays indicate a coherent pattern of 
deviations from the Standard Model. I critically review these data and discuss their interpretation, both in terms of a generic effective-theory approach and in terms of more complete extensions of the Standard Model. I will discuss in particular how present data points toward some new dynamics not far from the TeV scale, possibly by linked to the origin of the flavor hierarchies. Implications for future measurements both at low and high-energies are also briefly discussed.

 

May 26 : Dr. Andreas Hoecker - CERN
Title: Ultimate precision Standard Model tests: the muon magnetic moment — taming hadronic contributions - slides

Abstract

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

Abstract

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.

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Département de Physique Nucléaire et Corpusculaire | Impressum.