Wydział Fizyki UW > Badania > Seminaria i konwersatoria > Seminarium Fizyki Wielkich Energii
2020-06-05 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
dr hab. Justyna Łagoda (NCBJ)

The Hyper-Kamiokande experiment. https://us02web.zoom.us/j/176261850?pwd=cWgzMkwvVjBTSm5ObTFMSnBPTndIQT09 Meeting ID: 176 261 850 Password: 8z2bfx

Hyper-Kamiokande (HK) is a proposed ~200 kiloton water Cherenkov detector, a continuation of the highly successful neutrino and proton decay program based in Japan. It was approved in February 2020 by Japanese parliament and is expected to start taking data in 2027. Having the fiducial mass of ~8 times larger than its predecessor, Super-Kamiokande, HK will offer a broad physics program, including precise measurements of atmospheric, beam, solar and supernova neutrinos and searches for nucleon decay. The talk will cover the main physics goals of the experiment as well as technical information on the detector and its expected performance.
2020-05-29 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
mgr Rafał Masełek (IFT UW)

Prospects of searches for long-lived SUSY and doubly charged particles with MoEDAL experiment. https://us02web.zoom.us/j/176261850?pwd=cWgzMkwvVjBTSm5ObTFMSnBPTndIQT09 Meeting ID: 176 261 850 Password: 8z2bfx

The Monopole & Exotics Detector at the LHC (MoEDAL) is a small experiment designed to search for highly ionising avatars of a New Physics. Its main goal is to study the possible existence of magnetic monopoles, but the physics program defines over 34 distinct scenarios, targeting extra dimensions, new symmetries, topological particles and Dark Matter.Currently, MoEDAL experiment is being upgraded to prepare for Run-3 data taking period. In my talk, I present the prospects of searches for New Physics after the upgrade. I discuss detection reach for various types of long-lived Supersymmetry and doubly charged particles, and I compare it to the results by ATLAS and CMS.
2020-05-22 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
dr hab. Jarosław Stasielak (IFJ)

Modern techniques of ultra-high energy cosmic rays detection. https://us02web.zoom.us/j/176261850?pwd=cWgzMkwvVjBTSm5ObTFMSnBPTndIQT09 Meeting ID: 176 261 850 Password: 8z2bfx

Studies on ultra-high energy cosmic rays, those exceeding energy $10^{18}$ eV, are conducted with giant ground-based detectors recording extensive air showers (cascades of secondary particles) induced by cosmic ray particles in the atmosphere. Over recent years, these studies have dramatically advanced our understanding of ultra-high energy cosmic rays. Nevertheless, the results obtained so far neither allow us to determine the sources of these most energetic particles we know in the Universe nor to explain the origin of the observed cosmic ray flux suppression above $4\times 10^{19}$ eV. The explanation of these puzzles is one of the most important goals of modern astrophysics. At the same time, the results obtained indicate that further advances in research on ultra-high energy cosmic rays require improving measuring capabilities of detectors. Therefore, there is a special need to search for new experimental solutions to improve the accuracy of measurements of extensive air showers, while reducing the costs of construction and operation of detectors. I will present modern techniques for the detection of ultra-high energy cosmic rays, both classic well-proven methods as well as the new radio detection method, intensively developed over the last decade, which is currently considered the most promising technique. As examples of works on alternative methods of extensive air shower detection, the microwave and radar detection techniques will be discussed. Also I will present the main goals and plans for the upgrade of the Pierre Auger Observatory -- the largest detector of ultra-high energy rays.
2020-05-15 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
dr hab. Krzysztof Piasecki (IFD UW)

Do Kaons change their mass inside hot and dense nuclear matter? Zoom meeting link: https://us02web.zoom.us/j/176261850?pwd=cWgzMkwvVjBTSm5ObTFMSnBPTndIQT09 Meeting ID: 176 261 850 Password: 8z2bfx

Do Kaons change their mass inside hot and dense nuclear matter? Zoom meeting link: https://us02web.zoom.us/j/176261850?pwd=cWgzMkwvVjBTSm5ObTFMSnBPTndIQT09 Meeting ID: 176 261 850 Password: 8z2bfx

According to QCD, strong interactions of a hadron with virtual quark-antiquark pairs in the vacuum are the process responsible for the acquisition of most of hadron's mass from the sum of current quark masses. During the relativistic collision of heavy ions the reverse process should occur, called the partial restoration of chiral symmetry. A hadron in hot and dense nuclear matter should change its basic properties like mass and decay constant with respect to the well known values in vacuum.Kaons produced in heavy ion collisions around threshold for their production in NN collision appear to be a good probe of these effects.First comparisons of experimentally found phase space distributions of kaons to the transport model calculations suggested a clear sensitivity to this effect. Meanwhile the theoretical predictions suggested that the mass change should be not only density-dependent, but also momentum-dependent. In the seminar these comparison will be presented.However, data from collisions around strangeness threshold published recently by HADES and FOPI suggest a much broader and complex landscape. Any extraction of possible changes of K- mass has to account for the downfeed from Phi meson decay. Also, comparisons for K0s and Lambda emitted from Au+Au at 1.2A GeV show that the model description is still not fully consistent.
2020-05-08 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
mgr Mateusz Fila (IFD UW)

ELITPC: toward studying nuclear reactions at astrophysical energies. (link: https://zoom.us/j/176261850 Zoom meeting ID: 176 261 850)

In the joint effort of several members of the Institute of Experimental Physics at the Faculty of Physics, University of Warsaw an active target TPC with electronic readout - ELITPC - is being developed. The detector is suited for studying nuclear reactions of the astrophysical interest at the stellar relevant energies. I will present the general detector design, used techniques and done developments as well as describe ongoing works and plans for the near future.
2020-04-24 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
Paweł Krawczyk (NCBJ)

PolFEL - Polish Free Electron Laser and its research capabilities. link: https://zoom.us/j/176261850 ID: 176 261 850

PolFEL is a new research facility currently under construction at NCBJ at Otwock-Świerk in Poland. The facility will comprise a free electron laser powered by an entirely superconductive accelerator designed for continues wave (cw) and long pulses (lp) operation. Besides the photon beams provided to the experimental end stations, the gain of the accelerator physics and engineering capabilities are a desired benefit of this project.PolFEL will be furnished with three undulator chains settled in the two accelerator branches. The full energy branch will provide an electron beam with energy up to 155 MeV in cw mode and up to 187 MeV in lp mode that will allow to generate the coherent light with the wavelength down to 55 nm (in the 3rd harmonics). The striving to attain VUV ranged beam in spite of limited electrons energy brings forth the need of a challenging, short period undulator design and impels to minimize an electron beam emittance. The low energy branch will provide the electrons with energies up to 80 MeV in cw. The radiation wavelength will cover two spectral ranges: IR – from 5 µm up to 50 µm and THz – covering the so called “terahertz gap” of 0.3 THz – 5 THz. Photon beamlines capable of providing the photon diagnostic setups and guiding the beams to the experimental stations will be constructed adjoined to the undulator chains. Still another experimental station will employ femtosecond x-ray pulses in the keV range generated in Compton backscattering process employing the accelerated electron beam and photon beam from auxiliary optical laser.PolFEL is constructed by a Consortium of 8 institutions lead by NCBJ. The project received funding from the European Regional Development Fund in the framework of the Smart Growth Operational Programme, Measure 4.2: Development of modern research infrastructure of the science sector and, noticeably, a support from the Industry.
2020-04-17 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
Michał Olszewski (IFD UW)

Machine Learning event identification in H → ττ analysis of CMS.(Link: https://zoom.us/j/176261850 Zoom meeting ID: 176 261 850)

The H → τ+τ− channel (branching fraction about 6%) is currently one of two (next to H → bb̄ with branching fraction of about 57%) at the LHC best suited to perform measurements of 125 GeV Higgs boson couplings to fermions. The first observation of this process in a single experiment was achieved by the CMS Collaboration and published in 2017. The analysis summarized in the publication is driven by several characteristics specific for aforementioned Higgs boson decay mode. First, the tau lepton cannot by directly observed at the detector due to short lifetime. Second, it decays either leptonically or semi-leptonically due to invariant mass larger than mass of the lightest mesons. Furthermore, the large QCD background at LHC and presence of the neutrinos in the final state enforces usage of sophisticated algorithms for tau identification and ditau system mass reconstruction (respectively). In the first part of the talk I’ll shortly present how CMS analysis deals with above topics. In the second part I’ll show how machine learning techniques can by used to reinforce the analysis sensitivity to the signal.
2020-04-03 (Piątek)
Zapraszamy na spotkanie o godzinie 10:15  Calendar icon
Michał Bluj (NCBJ)

Probing CP structure of the Higgs boson couplings with the CMS experiment. [Zoom meeting link: https://zoom.us/j/176261850 Zoom meeting ID: 176 261 850]

Violation of the CP symmetry is one of the Sakharov conditions required to explain the baryon asymmetry observed in Universe. Although the CP violation is already built in the Standard Model via quark mixing, its strength is not sufficient to explain the magnitude of the observed baryon asymmetry. This motivates searches for new sources of CP violation in the Higgs sector. In this seminar recent results of studies on the CP structure of the Higgs boson coupligs with the CMS experiment will be discussed.
2020-03-06 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr Adam Zadrożny (University of Texas)

Current state of observations from LIGO-Virgo detectors and O3 science run

The aim of a talk is to give an overview current state gravitational wave observations. During three science runs (2015-2016, 2016-2017, 2019-2020) of Advanced LIGO-Virgo detectors multiple binary merger events were observed. Most of the events are binary black hole mergers, but nine detected events had neutron star component. Those observations, especially GW170817, brought additional way to study neutron stars.
2020-02-28 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
prof. Roman Walczak (University of Oxford)

Plasma wakefield accelerators. EuPRAXIA and ALEGRO projects

After brief introduction to plasma wakefield accelerators, I will present the conceptual design of a new European research infrastructure, EuPRAXIA. The concept has been establish over last 4 years in a collaboration of 30 institutes in Europe and 11 laboratories in Asia, Russia and the United States. EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma concepts and laser technology. I will also present ALEGRO project, which considers long-term prospect of applying novel accelerators at the high-energy frontier of particle physics.
2020-01-24 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr hab. Grzegorz Grzelak (IFD UW)

The LUXE - Laser und XFEL Experiment - era of strong fields QED

The seminar will introduce LUXE, "Laser Und XFEL Experiment", currently being developed at DESY in Hamburg, an experiment that aims to use the high-quality electron beam of the European XFEL and a high-power laser.The scientific goal of the experiment is to study quantum electrodynamics in the largely unexplored territory, in the regime of strong fields, close to and beyond the Schwinger limit, revealing the non-perturbative face of QED.In the seminar the scientific case of the experiment will be presented.In particular the details of the nonlinear Compton scattering and nonlinear Breit-Wheeler pair production.The second part will cover the experimental setup of beam extraction from the European XFEL Linac, the requirements for a powerful laser and precise detectors optimized to measure electrons, positrons and photons.
2020-01-17 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
mgr Grzegorz Żarnecki (NCBJ)

CP violation in the neutrino sector: Recent long-baseline experiments results

The violation of CP symmetry in the neutrino sector may be manifested in different oscillation probabilities for neutrinos and antineutrinos. Long-baseline neutrino experiments search for this effect by studying electron (anti)neutrino appearance in primordial muon (anti)neutrino beam. In this talk T2K and NOvA experiments will be presented and their recent results on CP violation will be shown. Future experiments - DUNE and Hyper-Kamiokande - will also be discussed.
2020-01-10 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
mgr Piotr Podlaski (IFD UW)

Upgrade of the NA61/SHINE experiment

NA61/SHINE is a fixed target experiment located in the North Area of the CERN SPS accelerator. The main goal of the NA61/SHINE after Long Shutdown 2 at CERN (LS2, 2019-2021) is to measure open charm production in Pb+Pb interactions at SPS energies. To accomplish this, NA61/SHINE detection system undergoes a major hardware upgrade. The main purpose of the upgrade is to increase the readout rate up to 1 kHz and increase acceptance in the high density tracks environment. In this seminar I will discuss physics prospects for NA61/SHINE beyond LS2, I will also present status and plans of the upgrade.
2019-12-13 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr hab. Tania Robens (Institut Ruđer Bošković, Zagreb, Croatia)

Constraining Extended Scalar Sectors at the LHC and beyond

After the discovery of the Higgs boson on 2012, particle physics has entered an exciting era. One important question is to test whether the resonance observed and measured by the LHC experiments indeed corresponds to the Higgs boson predicted by the SM, or whether it is part of a more extended scalar sector. In this talk, I will briefly discuss several models that comply with current bounds from theory and experimental observations, while predicting new states, and will discuss discovery prospects at current and future colliders. I will also make a link to dark matter observables for models containing dark matter candidates.
2019-11-29 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr Wojciech Krzemień (NCBJ)

Discovery of CP violation in the charm neutral meson system

The studies of the CP-violating observables provide precise tests of the Standard Model, and in the broader context, tackle the question of the dominance of matter over antimatter in our Universe.The CP violation has been measured both in the strange and beauty sectors, however it has never been observed in charm particles decays.In this talk, a selection of the recent LHCb experimental results in the charm sector will be given, including the first discovery of the CP violation and the measurement of the charm oscillations.
2019-11-22 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
Barbara Badełek (IFD UW)

Proton's interior: an overview

The talk is a pedagogical introduction to main aspects of the contemporary view of the proton structure. It is based on a talk given at the 2019 MIT Conference “Frontiers and Careers in Photonuclear Physics”.According to the objective of this annual event, participants, PhD students and young researchers, "...will be provided the opportunity to interact with a panel of experienced faculty members and physicists, all with the (...) purpose of preparing themselves for their future careers."
2019-11-15 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr hab. Artur Kalinowski (IFD UW)

Highlights on track reconstruction in modern experiments

I will present some novel ideas on charged particles tracks reconstruction in LHC experiments experiments. In particular I will present an algorithm using quantuum computers. I will also present an algorithm, developed by a local team, that will be used for a track reconstruction in a TPC chamber that is under construction on our Faculty.
2019-10-25 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
dr Leszek Grzanka (IFJ PAN)

Measurements of proton-proton scattering in the TOTEM experiment and central exclusive production studies using PPS apparatus at CERN LHC

The TOTEM experiment at CERN is dedicated to the physics process in the region close to the beam (forward physics). It has measured proton-proton inelastic and elastic cross-sections for several LHC energies. The experiment is capable of detailed study of differential cross-sectionof elastic scattering. Recent measurements probes the existence of a colourless three-gluon bound state (the Odderon exchange).The CT-PPS (CMS TOTEM Precision Proton Spectrometer, now PPS) project is dedicated to study central exclusive production in proton-proton collisions (pp -> pXp). Its forward detectors, based on silicon tracking system and set of timing counters operate at high luminosity runs and are fully integrated in the CMS data acquisition system. Recent observation of proton-tagged, central (semi)exclusive production of high-mass lepton pairs in pp collisions demonstrate that PPS performs according to design specification.
2019-10-11 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
prof. dr hab. Aleksander Filip Żarnecki (IFD UW)

On the physics potential of ILC and CLIC

The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are the two options for a future high-energy, high-luminosity linear electron-positron collider. Both are expected to be built in stages, optimised for their physics potential. The main goals are the precision measurements of Higgs-boson and top-quark properties as well as direct and indirect searches for new physics Beyond Standard Model. In my talk I will review some of the latest results from both ILC and CLIC demonstrating their physics potential, pointing to similarities and complementarity of both projects.This talk was given at the Workshop on Connecting Insights in Fundamental Physics: Standard Model and Beyond, Corfu, Sepember 2019.
2019-10-04 (Piątek)
Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15  Calendar icon
prof. dr hab. Jan Królikowski (IFD UW)

Update of European Strategy for Particle Physics (UESPP 2020) i warsztaty ESPP w Granadzie (maj 2019)

Jestem polskim reprezentantem Europejskiej grupy strategicznej (ESG), która ma uchwalić dokument UESPP 2020 w styczniu 2020 r. Przedstawię procedurę uchwalania UESPP i naświetlę najważniejsze wybory stojące przed Europejskim i światowym środowiskiem naukowym fizyki cząstek. Oprę się na podsumowaniu aktualnego stanu badań, który został przedstawiony na Warsztatach w Granadzie w maju 2019 r. i podsumowanym w Particle Briefing Book, opublikowanej w zeszłym tygodniu.