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Physik-Institut

Experimental Particle and Astro-Particle Physics Seminar

Monday 14:00

UZH Irchel Y16 G05

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Connect to room and PIN 8057. Use these phone numbers with meeting extension 10501582 and PIN 8057. Use the gateway at 137.138.248.204, meeting extension 112757289656, PIN 8057.

Current Program - Autumn 2019

DATE SPEAKER TITLE INDICO / TALK LOCAL CONTACT
16 September Dr. Sebastiano Calchi Novati (Caltech / IPAC)

Exoplanets and Space-based Microlensing: the Spitzer
program and the WFIRST survey

 

Microlensing plays a key role in exoplanet astrophysics as it can access parts in key parameter spaces that no other method can explore: wide orbit and low mass planets, planets in both the Galactic bulge and disk, free
floating planets. I will discuss recent results in this framework with a focus on space-based microlensing programs. The ongoing Spitzer campaign has provided major breakthroughs thanks to the systematic measurements of
the microlensing parallax, with in particular the goal to probe the Galactic distribution of exoplanets. The planned NASA flagship mission, WFIRST, includes among its primary science objectives a microlensing exoplanet survey which is expected to detect thousands of exoplanets with the goal of completing the statistical census of planetary systems in the
Galaxy.

 

Prof. Philippe Jetzer

TUE 17 September
11:15am
Y11 J05
Dr. Tina Pollmann (TUM)

Special Seminar:
Dark matter search with DEAP-3600

 

The DEAP-3600 experiment is searching for WIMP dark matter with a 3.3 tonne single-phase liquid argon (LAr) target. Detector construction was completed at SNOLAB in 2016, and the experiment is currently taking physics data. Results from 1 year of open data (758 tonne-day exposure) were recently published, demonstrating stable detector operation and the power of pulse shape discrimination to reject electron-recoil backgrounds in LAr. This background-free search currently provides the most sensitive WIMP-nucleon scattering cross section limit on a LAr target for WIMP masses above 30 GeV. 

This talk will focus on the design and calibration of the DEAP-3600 detector, and on the physics results from the 1 year open dataset. It will also cover current plans for the future of liquid argon dark matter detectors and the complementarity with detectors using xenon targets.

  Prof. Dr. Laura Baudis
23 September        
30 September        
07 October

Dr. April Cridland

Testing Fundamental Symmetries with Anti-Hydrogen 

The ALPHA (Antihydrogen Laser PHysics Apparatus) Collaboration at CERN is engaged in measurements of the anti-hydrogen spectrum with a view to understanding the matter-antimatter asymmetry in the universe.  ALPHA uses the techniques of modern atomic physics to probe fundamental physics with the goal of conducting precise tests of CPT symmetry.  In 2018, ALPHA published the most precise measurement of a transition in antihydrogen with the characterization of the 1S-2S lineshape which was CPT invariant to a relative precision of 10-12.  During this talk, I will present how this monumental 1S-2S measurement was achieved and highlight some of the most recent milestones in ALPHA. 

In addition, ALPHA also intends to study anti-hydrogen’s gravitational interaction with the Earth using a brand-new experiment, ALPHA-g.  It is expected that ALPHA-g will be able to first determine the sign of the interaction and then go on to measure its magnitude to 1% precision.  I will present our progress in commissioning the new experiment and outline ALPHA’s ambitious plans for the future of anti-hydrogen studies.

  Dr. Abhijit Mathad
14 October

Loukas Gouskos (CERN)

Search for Higgs boson decaying to charm quarks with CMS

The discovery of a Higgs boson with properties compatible with the expectations from the Standard Model (SM) opened a whole new chapter of exploration. One of the highest priorities of the LHC physics program is the detailed measurement of the couplings of the Higgs boson to other SM particles. In this seminar, I will present the first direct search by the Compact Muon Solenoid experiment
(CMS) for Higgs bosons decaying to a pair of charm quarks. Due to the nature of the signal, dedicated object reconstruction tools and analysis techniques that significantly improve the sensitivity of the analysis were developed. The results presented use data recorded in 2016 by CMS and correspond to an integrated luminosity of ~35.9 fb-1

  Dr. Stefanos Leontsinis

21 October 14:00

Y16 G 05

Arne Reimers, Hamburg Anomaly-inspired searches for heavy particles coupled to top quarks   Prof. Dr. Ben Kilminster

21 October

16:15

Y16 G15

Prof. David Stevenson

Schrödinger Colloquium (Jupiter's Interior as Revealed by Juno)   Prof. Dr. Ravit Helled
28 October  

 

 

 

04 November Dr. Andrew Taylor (DESY)

Gamma-Ray Bursts, Neutron Star Merger Remnants and Extragalactic Cosmic Rays

Even on simple energetic grounds, very few candidate sources for extragalactic cosmic rays can be found. Further factoring in additional orthogonal information provided by the synchrotron emission from candidate sources, can provide additional discrimination between candidates. Until recently such an approach has only been applied to different AGN class sources. Taking advantage of recent observational results, however, new light is shed on the potential of GRB as UHECR sources. Focusing specifically on the short gamma-ray burst GRB 170817 and the related kilonovae emission, a case is put forward for their potential as extragalactic cosmic ray sources. The challenges faced by the source environment and its ability to safely accelerate nuclei up to the ultra high energy scale are discussed.

 

Dr. Alison Mitchell

11 November  

 

   
18 November Dr. Olena Karacheban (CERN)

Luminosity measurement at LHC. Summary of experience from Run-2 and prospects for Run-3 and HL-LHC. 

The luminosity is a key ingredient to many physics measurements obtained at accelerator-based particle physics experiments as it links the cross sections of physics processes with the rate of interactions observed in a collider. The luminosity systematics propagate directly to the ultimate precision of physics results, where it is expected to constitute the single largest error in some cases, owing to recent theoretical progress and the increased statistics expected from HL-LHC and other future accelerator facilities. 

The luminosity calibration for LHC experiments is derived from dedicated beam separation scans, known as van der Meer scans. This luminosity calibration obtained with specials beam optics at low pileup must be transferred to physics data-taking conditions, with more bunches and significantly higher instantaneous luminosity. Hence, additional measurements of the stability and linearity of the luminometers are required. A novel analysis technique has been developed during Run-2, so-called ``emittance'' scans. The analysis of the scans allows for powerful performance diagnostics of the luminometers in CMS throughout the year, and also per bunch crossing beam evolution studies. Nonlinear effects were important during Run 2 (2015 - 2018), where pileup during physics data taking reached up to 60, and will be especially important in Run-3 and HL-LHC, where pileup can reach up to 200. CMS experience from Run-2 luminosity measurements, systematic uncertainties, requirements on beam quality and our vision of the luminosity measurement in Run-3 and HL-LHC will be presented. 

 

  Prof. Ben Kilminster
25 November Prof. Giovanni De Lellis

 

  Dr. Christopher Beatencourt

02 December

16:15

Y16 G15

Prof. Michela Massimi 
(University of Edinburgh)
Schrödinger Colloquium   Prof. Laura Baudis and Prof. Florencia Canelli
09 December Prof. Steve Worm

Particle Detectors: MAPs to Discovery

The development of precision particle detectors has allowed physicists to investigate phenomena at unprecedented scales and with ever-increasing precision. Detectors have driven advancement in the sciences, for example in particle physics where searches for Dark Matter and the discovery of the Higgs particle depend critically on innovative instrumentation.  Detection technologies based on silicon imaging are one of the latest revolutions, with capabilities that are developing quickly as a result of the connection to industry and commercial electronics.  In the seminar I will explore this rapidly evolving silicon detector technology with an emphasis on Monolithic Active Pixels (MAPs), and discuss implications for the search for Dark Matter.  The colloquium will provide a survey of some of the latest detector innovations, and will look at possible paths for innovation in the future such as the revolution in quantum sensing.

  Prof. Ben Kilminster
16 December Prof. Mantovani (University of Ferrara)

State of the art of Geoneutrino and future prospects

Geoneutrinos, electron antineutrinos emitted along the decay chains of U and Th present in the Earth’s crust and mantle, are able to pass through most matter without interacting, therefore bringing to the surface instantaneous information about our planet’s composition. Experimental geoneutrino measurements give geoscientists the opportunity of building interdisciplinary bridges for addressing open questions about Earth’s heat production.

KamLAND (Japan) and Borexino (Italy) experiments are collecting geoneutrino events from 2002 and 2007 respectively and new data releases have been published in autumn 2019. The seminar will be dedicated to review recent experimental results and their implications for Earth science. Considering the incoming geoneutrino measurements from SNO+ (Canada) and JUNO (China), the new challenges for combining the multi-site measurements and for integrating data in coherent picture of the Earth will be discussed.

 

  Giovanni Volta

 

Directions Contact: Alison.Mitchell@physik.uzh.ch Room Connection Instructions (PDF, 3 MB)