Seminars SS 19

 

Tue 02.04.2019, 16.30 h (28B110)

Stefano Gariazzo (IFIC Valencia)

Relic neutrinos and the PTOLEMY project

Abstract:
The Cosmic Neutrino Background (CNB) is a prediction of the standard cosmological model, but it has been never observed directly. Several methods of direct detection for the CNB have been proposed in the past and the most promising one is currently adopted to develop the PTOLEMY proposal. I will review some theoretical aspects of the CNB, including the calculation of the local density of relic neutrinos in the Milky Way, some proposed detection techniques and finally discuss the specific case of PTOLEMY, mostly from the point of view of perspectives in neutrino physics.

 

Tue 21.05.2019, 16.30 h (28B110)

Yoann Genolini (ULB, Brussels)

DM and compact objects

Abstract:
Due to their extreme density and low temperature, neutron stars (NS) are efficient probes to unveil interactions between standard model and dark matter (DM) particles. From elastic scatterings on NS material, DM can get gravitationally trapped by the star. The cooling of DM through further collisions may lead to the formation of a dense core which could collapse into a black hole, thus destroying the whole NS. I will show that from the observation of old NS, such a scenario leads to very stringent constraints on the parameter space of asymmetric DM, and I will detail the novelties we have introduced.

 

Tue 28.05.2019, 16.30 h (28B110)

Andreas Meyer (DESY)

Physics at the HL-LHC

Abstract:
The High-Luminosity LHC (HL-LHC) is going to start operation in 2026. Upgrades of the experiments comprise substantially improved detectors with larger acceptance, better triggers, and enhanced background suppression. Until the end of the 2030s, an integrated luminosity of 3000 fb-1 of pp data will be recorded. Based on the recent new and precise results of LHC Run-2, the expectations for the physics yield at the HL-LHC have been updated. The report of the "Workshop on the Physics at the HL-LHC and Perspectives for the HE-LHC”,  input to the European Particle Physics Strategy Update 2018-2020, covers all aspects of HL-LHC physics. In my talk, I am presenting a selection of highlights.

 

Tue 18.06.2019, 16.30 h (28B110)

Belina von Krosigk (TRIUMF, Vancouver)

Searches for Dark Sector Particles with SuperCDMS SNOLAB

Abstract:
The Super Cryogenic Dark Matter Search (SuperCDMS) is a direct Dark Matter search experiment designed to observe nuclear recoils induced by WIMPs. However, it is also sensitive to Dark Matter particle candidates beyond the standard WIMP paradigm, which could create electron recoil signals in the cryogenic silicon and germanium detectors. The pool of candidates is rich and includes Dark Photons, ALPs (axion-like particles) and LDM (light Dark Matter) particles. Lacking knowledge of the particles that constitute the dark sector of the Universe it is essential to make the search for them as broad as possible. This talk will give an overview of the versatile dark sector particle search strategies at the upcoming SuperCDMS SNOLAB experiment and will highlight first results with R&D devices as well as the expected science reach of selected searches.

 

Tue 25.06.2019, 16.30 h (28B110)

Dietrich Bödeker (Uni Bielefeld)

Hot QCD

Abstract:
I present a brief introduction to finite temperature quantum field theory, in particular for Quantum Chromodynamics (QCD). Applications in cosmology, like the effect on gravitational waves, the production of dark matter and of the matter-antimatter asymmetry are discussed.

 

Tue 09.07.2019, 16.30 h (28B110)

Felice Pantaleo (CERN)

Towards a heterogenous computing farm for the CMS High Level Trigger

Abstract:
To fully exploit the physics reach of the High-Luminosity Large Hadron Collider, the LHC experiments are planning substantial upgrades of their detector technologies and increases of their data acquisition rates. Studies are ongoing to develop the Future Circular Collider (FCC) trigger and data acquisition infrastructure, which will have even higher requirements. The higher proton-proton interaction rate, pileup and event processing rate present an unprecedented challenge to the real-time and offline event reconstruction, requiring a processing power which is orders of magnitude larger than today. This exceeds by far the expected increase in processing power for conventional CPUs (at a fixed cost), demanding an alternative approach.
In recent years, Industry and High-Performance Computing centres have been successfully using heterogeneous computing platforms to achieve higher throughput and better energy efficiency, combining traditional processors with dedicated accelerators and matching each task to the most appropriate architecture.
The speaker will present the implications of the higher luminosity, pileup and event complexity for the trigger and data acquisition system of the Compact Muon Solenoid (CMS) experiment, and discuss the possibility of addressing them by employing a heterogeneous computing architecture. The speaker will also describe the main differences in the hardware and programming models between traditional CPUs and a widespread type of accelerator, general purpose GPUs, and discuss how they can be used together to explot their potential.
Finally, the speaker will present the Patatrack project, an incubator for R&D activities within the CMS collaboration aiming to use a heterogenous computing farm during the upcoming Run 3 (2021-2023), with the goal to improve the physics reach of the experiment and gain the necessary expertise in view of a wider deployment during the High-Luminosity runs at the LHC.