Next Seminars


Feb 27, 2023
CALICE - Implementation of large imaging calorimeters
Roman Poeschl (LAL Orsay)
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Description :

The next generation of collider detectors will make full use of Particle Flow algorithms, requiring full imaging calorimeters. The latter have been developed during the past 15 years by the CALICE collaboration and are now reaching maturity. The state-of-the-art and the remaining challenges will be presented for all investigated readout types. We will describe the commissioning, including beam test results, of large scale technological prototypes and the raw performances such as energy resolution, linearity and studies exploiting the distinct features of granular calorimeters regarding pattern recognition.

New results obtained in recent (2021/22) beam tests with technological prototypes will be available. Further, the design of experiments addressing the requirements and potential of imaging calorimetry will be discussed. In this context, the seminar will outline the R&D plans for the coming years that will put emphasis on timing and low-power readout. 

The CALICE prototypes provide an unprecedented wealth of highly granular data of hadronic showers for a variety of active sensor elements and different absorber materials. I will discuss detailed measurements of the spatial and the time structure of hadronic showers to characterise the different stages of hadronic cascades in the calorimeters, in comparison with GEANT4-based simulations using different hadronic physics models. These studies also extend to the two different absorber materials, steel and tungsten, used in the prototypes. The high granularity of the detectors is exploited in the reconstruction of hadronic energy, both in individual detectors and combined electromagnetic and hadronic systems, making use of software compensation and semi-digital energy reconstruction. The results include new simulation studies that predict the reliable operation of granular calorimeters.

Granular calorimeters are also an ideal testing ground for the application of machine learning techniques. We will outline how these techniques are applied to CALICE data and in the CALICE simulation framework. At the beginning a lightweight introduction for a non-specialist audience to the physics of sampling calorimeters and the definition and motivation of the particle flow technique will be given.

Start:
Monday, February 27, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, February 27, 2023 at 3:30:00 PM Central European Standard Time
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Mar 6, 2023
Particle accelerator on a chip (POSTPONED)
Peter Hommelhoff (Friedrich-Alexander Universität Erlangen-Nürnberg)
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Start:
Monday, March 6, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, March 6, 2023 at 3:30:00 PM Central European Standard Time
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Mar 20, 2023
CASPER experiment in Mainz for Axion and ALP searches
Hendrik Bekker (Mainz University)
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Start:
Monday, March 20, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, March 20, 2023 at 3:30:00 PM Central European Standard Time
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Mar 27, 2023
ALICE pixel sensor developments
Stefania Beolé (Torino University)
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Start:
Monday, March 27, 2023 at 2:00:00 PM Central European Summer Time
End:
Monday, March 27, 2023 at 3:30:00 PM Central European Summer Time
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May 15, 2023
Chasing Neutral Hydrogen: an Intensity Mapping view of the large scale structure
Marta Spinelli (INAF-OATs)
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Start:
Monday, May 15, 2023 at 2:00:00 PM Central European Summer Time
End:
Monday, May 15, 2023 at 3:30:00 PM Central European Summer Time
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5 last Seminars


Jan 30, 2023
CONCERTO at APEX: a new (sub-)millimeter spectrometer dedicated to line intensity mapping
Guilaine Lagache (LAM)
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Description :

CONCERTO is a new instrument that has been successfully installed in the Cassegrain Cabin of the APEX telescope in April 2021. It is a spectrometer with an instantaneous field of view exceeding 260 square arcminute and a spectral resolution up to 1.3 GHz. It is covering the frequency band 130-310 GHz. The main scientific aim of CONCERTO is to map in 3D the fluctuations of the [CII] line intensity in the reionisation and post-reionisation epoch (z>5). This technique, known as "intensity mapping", will allow us to address questions about the contribution of the dust-enshrouded star formation at z > 5, the history of metal enrichment, and the role of star-forming galaxies in shaping cosmic reionization. In addition to the main [CII] survey, we expect CONCERTO to bring a significant contribution in a number of areas, including the study of galaxy clusters (via the thermal and kinetic SZ effect), the observation of local galaxies, and the study of Galactic star-forming clouds. CONCERTO will also observe the CO intensity fluctuations arising from 0.3<z<2 galaxies, giving the spatial distribution and abundance of molecular gas at cosmic noon.

In this talk I will tell you the story of the CONCERTO adventure, from its conception to the first light. I will also review the major scientific goals of CONCERTO and show some first results.

Start:
Monday, January 30, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, January 30, 2023 at 4:00:00 PM Central European Standard Time
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Jan 23, 2023
New measurements of rare B meson decays by the CMS experiment
Dmytro Kovalskyi (MIT/CERN)
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Description :

A number of anomalies have been observed in rare B decays by the LHCb experiment indicating a potential new physics contribution. To understand the nature of these anomalies and to confirm their existence we need to have independent measurements performed by other experiments. In this seminar, I will present a new measurement of the Bs → μμ branching fraction and effective lifetime, as well as results of a search for the B0 → μμ decay. The analysis is based on proton-proton collision data collected by the CMS experiment at the 13 TeV center of mass energy during the LHC Run 2, corresponding to an integrated luminosity of 140/fb.

Start:
Monday, January 23, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, January 23, 2023 at 3:30:00 PM Central European Standard Time
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Jan 16, 2023
The Next Golden Age of Supernova Cosmology
Mathew Smith (IP2I/IN2P3/CNRS)
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Description :

Type Ia supernova (SNIa) cosmology is a central pillar underpinning all cosmology analyses. These standardised distances were the first to discover the accelerated expansion of the Universe, and today are at the centre of two of the central cosmological mysteries: the nature of dark energy and the Hubble Tension. However, with the astrophysics underlying these events unknown, systematic uncertainties now dominate our conclusions.
In this talk, I will highlight how SNeIa have got us to the state-of-the-art in cosmology today, and the challenges that lie between us and precisely measuring the equation-of-state of dark energy, w, before addressing how these problems are being addressed by the two principal surveys today. Mapping the properties of supernovae and Universe’s expansion history at high and low redshift, both the Dark Energy Survey (DES) and the Zwicky Transient Facility (ZTF) have solved many of the problems underlying SNIa cosmology and opened up entirely new avenues of using these measurements as cosmological probes. This reinvention of the cosmological standard candle paves the way for the next decade of discoveries where both the Vera Rubin Observatory and the Roman Space Telescope, with over 1 million SNeIa, will map the cosmos to unparalleled accuracy, and finally unveil the nature of Dark Energy.

Start:
Monday, January 16, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, January 16, 2023 at 4:00:00 PM Central European Standard Time
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Jan 9, 2023
Hadron spectroscopy in multibody B decays at LHCb
Chen Chen (Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France)
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Description :

Studies of hadron spectroscopy are at the frontier of modern particle physics to promote the understanding of the nonperturbative property of low energy QCD. Multibody BB decays provide a unique platform for the experimental studies of excited hadrons (resonances). The information of the BB decay topology enables the utilization of amplitude analysis, a powerful technique that can precisely determine the mass, width, as well as spin-parity, of excited hadrons. The LHCb experiment is dedicated for efficient and precise reconstruction of heavy-flavor hadrons, and thus is an ideal platform for the studies of intermediate resonances in BB decays. In this seminar, I will present some recent studies of hadron spectroscopy to multibody BB decays at LHCb. New resonances containing charm quark(s) were observed with their properties measured using amplitude analysis, providing important experimental inputs to theoretical studies of hadron spectroscopy.

Start:
Monday, January 9, 2023 at 2:00:00 PM Central European Standard Time
End:
Monday, January 9, 2023 at 3:30:00 PM Central European Standard Time
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Dec 5, 2022
Low mass WIMP search with DarkSide-50, a liquid argon dual phase TPC experiment
Pascal PRALAVORIO (CPPM, Aix-Marseille Université, CNRS/IN2P3)
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Description :

The existence of dark matter (DM), supported by a variety of  astrophysical measurements, is one of the main puzzles in fundamental physics. As of today, one of the most favoured candidates as a DM particle is a weakly interacting massive particle (WIMP) in the mass range above 1 GeV/c2. DarkSide-50 is a first-generation dual phase liquid argon Time Projection Chamber (TPC) experiment that took data in 2015-2018 at Gran Sasso National Laboratory for a total exposure of 12 ton.day. With a target of only 50 kg of argon it provides the best world limits for a WIMP mass between 1.2-3.6 GeV. Details of the analysis will be presented and interpretations including the Migdal effect or in the framework of leptophilic models will also be shown. Status and prospects for future liquid argon TPCs will finally be discussed.
 

Start:
Monday, December 5, 2022 at 2:00:00 PM Central European Standard Time
End:
Monday, December 5, 2022 at 3:00:00 PM Central European Standard Time
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