Experimental Particle Physics Seminars
Starting in academic year 2013/2014, the department regularly hosted a series of seminars, dedicated to our wide audience that includes physicists, students and engineers. These seminars have displayed excellent overviews presented by distinguished speakers and provided high value educational material for students . They proved to be the optimal venue for fruitful discussions among experts and the group members.
This page lists all seminars hosted by the Experimental Particle Physics group in the past academic years.
June 16, 2015
Silicon detectors: from fundamental physics to high-end instrumentation
Dr. Romualdo Santoro - Università dell'Insubria, Italy
In the last decades silicon detectors have played a major role in fundamental physic experiments, and thanks to the ever-growing challenging requirements and continuous R&D they will keep being the key technology in the next generation of apparatus, as LHC upgrade and future colliders. In this regards I?ll focus on two examples: 1) the silicon tracking system of ALICE, the only experiment using three different silicon detector technologies (pixel, drift and strip) to study the QCD properties; 2) the Silicon Photon-Multipliers, a new class of photon-sensitive detectors that are competing with the more mature technology of standard PMT.
In the second part I'll show how important are these technologies for novel instrumentation beyond particle physics. I'll list a series of example spanning from medical diagnostic to homeland security showing also the growing interest of high technological companies and European Commission funding.
May 19, 2015
Dr. Diego Aristizabal - University of Liege
The up to now absence of supersymmetric signals at LHC,
calls for "alternative" SUSY frameworks where the signals for BSM
physics differ from the standard missing energy signatures. In this
talk, I will discuss a well-motivated scenario, namely bilinear
R-parity violating (BRpV) SUSY. After briefly discussing current
bounds on the standard R-parity conserving supersymmetric spectra,
current bounds on BRpV models will be slightly discussed. The
phenomenology of Sneutrino LSP (lightest supersymmetric particle)
within these context will be reviewed, pointing out its potential
connection with low-energy neutrino data. Finally, I will argue how in
BRpV models, Higgs "invisible" decays might involve long-lived neutral
particles decaying within the detector.
April 28, 2015
Energy frontiers: ILC project and some trends in detector technologies
Dr. Maxim Titov - CEA Saclay
The LHC at CERN is a prime example of worldwide collaboration to build a
large instrument and pursue frontier science. The discovery there of a
particle consistent with the long-sought Higgs boson points to future
directions both for the LHC and more broadly for particle physics. Now, the
international community is considering machines to complement the LHC and
further advance particle physics, including one of the most favored option:
an international linear collider (ILC). The chosen technologies - including
SRF cavities with high gradients and state-of-the-art detector concepts -
have reached a stage where, should governments decide in favor of the
project, ILC construction could start almost immediately. The power of the
ILC lies in its flexibility. It can be tuned to well defined initial
states, allowing model-independent measurements from the Higgs threshold to
up to TeV energy, as well as precision studies that could reveal new
physics at a higher energy scale. The physics case and the current status
of the ILC project will be summarized. Detector R&D challenges, some being
common for the HL-LHC and ILC, will be discussed. Recent developments of
the Micro-Pattern Gaseous Detectors, in the framework of the RD51
collaboration, will be reviewed.
March 24, 2015
Neutrinos - Quo vadis?
Prof. Alfons Weber - Oxford University & STFC/RAL
Experiments at accelerators and reactors made precision measurement of many parameters which govern the phenomenon of neutrino oscillations in recent years. After the last unknown mixing angle θ13 was determined, the interest has now moved to determine the neutrino mass hierarchy and to investigate the possibility of CP violation in the neutrinos sectors. These measurements will only be possible with the help of new and much more sensitive experiments. The presentation will summarize the status of the field of accelerator based- neutrino oscillation experiments and also illustrate which future experiments are currently in preparation.
January 20, 2015
CLIC: physics and detectors at a future TeV-scale e+e- linear collider
Prof. Lucie Linssen - CERN, Switzerland
CLIC is a high-energy e+e- linear collider under development. It is based on a novel two beam accelerating scheme and has the capability to operate at centre-of-mass energies ranging from a few hundred GeV to 3 TeV. The talk will include a short introduction to the CLIC accelerator technology and the status of its development. The CLIC physics potential will be outlined: it includes high-precision Higgs measurements, top physics and searches for new physics phenomena; it is largely complementary to LHC. The physics aims, together with the experimental conditions at CLIC, set challenging requirements for the detectors. The CLIC experiment concept under study and its detector technologies will be presented. The precision physics capabilities will be illustrated on the basis of detailed physics benchmark studies at different CLIC centre-of-mass energies.
December 2, 2014
Pinpointing hadronic acceleration mechanisms with gamma-ray data
Prof. Julia Tjus - Ruhr-University Bochum, Germany
Gamma-ray astronomy began in the 1960, when the first gamma-ray satellite Explorer XI detected 22 photons isotropically distributed over the sky. Today, more than 100 gamma-ray sources are known, thanks to previous and today's generation of gamma-ray telescopes, making use of both satellite techniques and Cherenkov techniques on Earth. Among the gamma-ray emitters, extragalactic objects like active galactic nuclei and starburst galaxies are found, and there is a large number of Galactic sources like supernova remnants, pulsars and pulsar wind nebulae. The observed gamma-ray emission reflects non-thermal emission regions, with both electron and hadron populations. It is of particular interest to separate gamma-ray signatures from hadrons and electrons in order to identify the sources of hadronic cosmic rays - a riddle that is still open since the discovery of cosmic rays in 1912. Here, Imaging Air Cherenkov Telescopes like H.E.S.S. and CTA are one of the main techniques, providing measurements up to 10-100TeV, thus corresponding to cosmic rays close to where Galactic sources are believed to lose power. Huge progress has been made in the recent centuries using gamma-ray astronomy to start pin-pointing cosmic ray sources. In this talk, the current status of the field of gamma-ray astronomy will be summarized, highlighting those detections giving us first insights into the origin and nature of cosmic rays.
November 18, 2014
Standard Model physics at CMS
Prof. Dott. Alexander Savin - University of Wisconsin, US and DESY, Germany
The CMS Standard Model Physics group convener Alexander Savin presents in his lecture a short overview of different aspects of the SM measurements at CMS. Most important current and future measurements are discussed. Comparisons with theoretical models are presented. Plans for SM measurements at high-luminosity LHC are reviewed.
June 23, 2014
Neutrino Physics: The past, the present and the future
Dott. Teppei Katori - Queen Mary University of London
Neutrino physics show a dramatic progress in the last 30 years.
Recent P5 report placed long baseline neutrino facility (LBNF) as the future large project of USA.
In this talk, I start from the brief history of neutrino oscillation physics,
especially the path to establish the neutrino Standard Model
(Standard Model with 3 active massive neutrinos).
Then I move to discuss important applications of neutrino physics
both within the Standard Model and Beyond the Standard Model.
May 13, 2014
Highlights of run I and the road to run II of the CMS experiment at the LHC
Prof. Albert De Roeck - CERN, Switzerland
The LHC has provided proton-proton collisions in 2010-2012 at centre of mass energies of 7 TeV and 8 TeV, and is now being prepared for collisions at 13 TeV, starting in 2015. We will discuss in this seminar a few selected physics highlights of the first run, to show the status of the results obtained so far. We then look forward to what we can expect from the LHC in the next few years, in particularly in the first year(s). The experiment is now preparing actively for the upcoming high energy running.
March 24, 2014
Hot Physics with a Cool Experiment
Nick van Eijndhoven, Vrije Universiteit Brussel - IIHE (ULB-VUB), Belgium
Astroparticle Physics revolves around phenomena that involve (astro)physics under the most extreme conditions. Cosmic explosions, involving black holes with masses a billion times greater than the mass of the Sun, accelerate particles to velocities close to the speed of light and display a variety of relativistic effects. Some of the produced high-energy particles are detected on Earth and as such can provide us insight in the physical processes underlying these
cataclysmic events. Having no electrical charge and interacting only weakly with matter, neutrinos are special astronomical messengers. Only they can carry information from violent cosmological events at the edge of the observable universe directly towards the Earth. The South Pole houses the world's largest neutrino telescope, the IceCube Neutrino Observatory, with which a world wide search for high-energy neutrinos originating from cosmic phenomena has been initiated.
In this talk I will present the underlying ideas of high-energy neutrino production in explosive cosmic phenomena and the IceCube detection principles. It will be shown how the combination of IceCube data with satellite observations opens up the possibility to identify high-energy neutrinos originating from transient cosmic events. Of these transient phenomena Gamma Ray Bursts are believed to be the most violent cosmic explosions and recent results will be presented. Also the observation, for the first time in history, of very energetic neutrinos with a most likely cosmic origin, will be addressed.
February 25, 2014
Searches for new physics with leptons at the LHC: Current status and prospects for the high energy run
Didar Dobur, Université libre de Bruxelles, Belgium
The past few years of LHC data did not only lead to the discovery of a new scalar particle, but also extensive tests of new physics scenarios, that can address the hierarchy problem arising from this scalar, through searches and precision measurements. A plethora of searches performed by CMS and ATLAS resulted in stringent limits on new physics beyond the Standard Model at the TeV scale, in particular Supersymmetry. I will focus on the most up to date results on searches for supersymmetry carried out at CMS using 2012 LHC data, in particular those searches involving leptons in the final state. In this context, I will discuss inclusive searches for a dark-matter candidate as well as more exclusive topologies targeting particular production modes, e.g Electroweak, of superpartners. The unprecedented collision energy that will be reached by the LHC in 2015 will open up an unexplored parameter space, hence, ample opportunities for discoveries. I will also discuss the preparations, challenges and reach prospects for SUSY searches with 13 TeV data.
February 11, 2014
FLUKA Monte Carlo and its applications
Dott. Roberto Versaci, ELI Beamlines, Czech Republic
The FLUKA Monte-Carlo is a general purpose tool for calculations of
particle transport and interaction with matter. It has a wide range of
applications like cosmic rays and neutrino physics, calorimetry,
activation, dosimetry, radiotherapy, detector design, shielding, and
accelerator physics. It has become a common tool in many and different
communities and it is the CERN standard to address machine protection
issues and investigate radioprotection problems.
For these purposes, the evaluation of key physical quantities such as
energy deposition in the irradiated components, dose released in the
sensitive elements, material and environmental activation, and fluence of
particles at different locations, represents an essential ingredient. The
quality of the code turns out to be critical for the achievement of the
established goals when performing Monte-Carlo calculations for any
application. This requires an accurate development and benchmarking of the
underlying independent physics models, and their balanced and effective
interplay, aiming at an increasingly reliable and precise picture of the
radiation-matter interaction, in order to address present and future
research challenges. In this seminar I will provide a general overview of
FLUKA and of some of its many applications and benchmarks.
November 19, 2013
The role of top physics in the Higgs era
Prof. Roberto Tenchini, INFN Pisa and University of Pisa, Italy
The present status of top-quark experimental physics is reviewed, in the context of the Higgs boson discovery. The role of the heaviest known fermion in understanding the electroweak symmetry breaking and in opening the road to new physics is discussed. Recent top mass measurements and other measurements of top-quark properties are presented, together with top-production studies at the LHC.
November 5, 2013
Exploring new physics in the Top quark sector using Beyond-Two-Generations Quarks
Dr. Freya Blekman , IIHE, Vrije Universiteit Brussel
In many models of physics beyond the standard model, the coupling of new physics to third generation quarks is enhanced or signatures are expected that mimic top production. A review of searches for new physics beyond the standard model performed by the CMS experiment at LHC will be presented, in final states containing top quarks or bottom quarks. Many of the techniques used have solid roots in precision measurements of the standard model, and applying these techniques to searches has opened a rich and varied searches program in the CMS experiment. Examples include searches for heavy gauge bosons, excited quarks, sequential and vector-like top quark partners. The analyses span a range of final states, from multi-leptonic to entirely hadronic, and use complex techniques to reconstruct the highly boosted final states that are created in these topologies.
September 2, 2013
SoLid : Search for short baseline Oscillations with a novel Lithium-6 composite scintillator
Dr.Antonin Vacheret, University of Oxford
The Solid experiment is a proposal to search for active-to-sterile neutrino oscillation at very short baseline of the SCKoCEN BR2 research reactor.
The revised calculation of antineutrino flux for the Double CHOOZ reactor experiment led to an unexpected increase in the expected antineutrino rate
of ~7% compared to previous calculations. The resulting effect is about 3 sigma and called the "reactor anomaly". This recent deficit adds to some
older anomaly in calibration of Gallium experiments also recently reexamined. One possible explanation for these intriguing deficits in
observed event is to consider one or more sterile neutrino with a Δm^2 of ~1 eV^2. A way to test this is to look for distortions of the
antineutrino energy caused by oscillation from active to sterile neutrino at close stand-off (~ 6-8m) of a small reactor core. Due to the low rate
of antineutrino interactions the main challenge in such measurement is to control the high level of gamma and neutron background. A novel approach
to antineutrino detection with a highly segmented detector based in Lithium-6 has been developed in Oxford to perform this measurement.
Unprecedented sensitivity can be achieved compared to other state-of-the-art technology with the combination of high granularity, high
neutron-gamma discrimination in 6LiF:ZnS and precise localisation of the Inverse Beta Decay products. This compact system requires minimum passive
shielding and no external muon veto allowing for very close stand off to the reactor. After introducing briefly the motivation of the experiment I will describe
the detector technology and expected performance. I will conclude with the potential sensitivity reach to short baseline oscillations using two
identical detectors and a status of the prototype system currently deployed at BR2.