Wydział Fizyki UW > Badania > Seminaria i konwersatoria > Seminarium Fizyki Wielkich Energii

Seminarium Fizyki Wielkich Energii

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Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

Paweł Sznajder (NCBJ)

Phenomenology of Generalized Parton Distributions - from experimental data to 3D structure of the nucleon

The formalism of Generalized Parton Distributions (GPDs) provides a set of novel and powerful tools to investigate the nucleon structure. In particular, it allows to describe the nucleon as an extended object and it gives access to the QCD energy-momentum tensor. The latter allows to evaluate the contribution of orbital angular momentum to the nucleon spin through the so-called Ji’s sum rule and it helps to understand the distribution of "mechanical" forces acting on quarks in the nucleon.After a brief introduction to the formalism of GPDs the current status of experimental campaign to constrain those distributions will be summarised. Future projects with their physics cases for GPDs will be addressed as well. Finally, recent progress in the phenomenology of GPDs will be discussed.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr Magdalena Posiadała-Zezula (IFD UW)

Neutrino oscillations in the long-baseline experiments

Neutrino oscillations will be discussed based on the results coming from current world leading long-baseline experiments: T2K and NOVA.T2K is an accelerator-based project in which muon neutrino beam is produced in J-PARC in Tokai and send 295 km across Japan to Super-Kamiokande detector. NOVA uses 700kW NuMI neutrino beam at Fermilab directed towards northern Minnesota in the US.Two functionally identical scintillator-based detectors are placed at the off-axis locations, separated by 810 km.Both of these experiments study neutrino oscillations via the disappearance of muon neutrinos and the appearance of electron neutrinos and both are able torun with the neutrino and antineutrino beams.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr Andrzej Kupść (Uppsala University)

Novel aspects of baryon-antibaryon production in electron-positron annihilations

Spin degrees of freedom for baryon-antibaryon pairs produced in electron-positron collisions are sensitive probes of baryon properties and discrete symmetries. Precision studies of the spin structure of the processes are possible due to large data samples of baryon-antibaryon pairs from the J/psi and psi' decays. The spin orientations of the produced baryon and antibaryon are correlated and, since the process involves at least two amplitudes, a relative phase can lead to a transverse spin polarization. Spin of a hyperon can be easily analyzed using weak decays. Using 1.3x10^9 J/psi collected at BESIII experiment we observe the polarization signal for the e+e- -> J/psi -> Lambda antiLambda process (*). The polarization allows to determine values of the asymmetry parameters for hyperon decays. In particular the asymmetry value of the for the well-known Lambda hyperon polarimeter process, the Lambda weak decay into proton and negative pion, was found to be wrong by 17(3)%. This calls for a reinterpretation of all polarization results for Lambda. The J/psi -> hyperon antihyperon decays allow a direct comparison of the asymmetry parameters for the charge conjugated decay systems. This CP symmetry test, when applied to the foreseen future data sets, has potential to reach the precision level compatible with the expectations from the CKM mechanism.(*) BESIII Nature Phys. (2019) DOI: 10.1038/s41567-019-0494-8 e-Print:arXiv:1808.08917

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr hab. Marcin Konecki (IFD UW)

The Level-1 muon trigger of the CMS experiment - status report

The event selection in the CMS experiment is necessary to reduce the LHC event rate down to O(1kHz) suitable for event storage.This selection is done by the CMS trigger, which is divided into Level-1 and High-Level Trigger layers.The CMS level-1 muon trigger is custom-hardware device, processing signals from CMS muon detectors.In the presentation the evolution of the Level-1 muon trigger system is discussed.The performance of the trigger in LHC Run-1 and Run-2 is summarized.The perspectives for operation in Run-3 and upgrade for LHC Phase-II are given.The activities of Warsaw Group, responsible for the trigger operation in a barrel-endcap overlap of the CMS detector, are emphasized.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr hab. Krzysztof Cichy (Uniwersytet im. Adama Mickiewicza w Poznaniu)

Nucleon structure from Lattice Quantum Chromodynamics

In this talk, I will start by generally introducing Lattice QCD, the non-perturbative formulation of QCD on a Euclidean lattice. Then, I will show what Lattice QCD can tell us about the internal dynamics of the nucleon. In particular, I will present a state-of-the-art computation of unpolarized, helicity and transversity parton distribution functions (PDFs), calculated using the so-called quasi-PDF approach introduced by Xiangdong Ji in 2013 and intensively developed thereafter. I will show the steps needed to get from the lattice computation of bare matrix elements, i.e. renormalization, matching and target mass corrections, to arrive at the final light-cone PDFs. For the latter, we find a similar behavior between the lattice and phenomenologically extracted data. This presents a major success for the emerging field of direct calculations of quark distributions using Lattice QCD. At the same time, it is clear that a careful investigation of lattice systematic effects is needed to arrive at the final reliable result.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

prof. dr hab. Aleksander Filip Żarnecki (IFD UW)

Status of the CLIC project

An overview of the CLIC project will be presented, covering accelerator and detector design, as well as the physics prospects. Presentation will focus on results presented at the CLIC workshop in January 2019 and prepared as an input to the European Strategy Update process.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr Krzysztof Kilian (SLCJ)

Positron Emission Tomography in preclinical studies

The Positron Emission Tomography (PET) technique is a relatively new imaging technique of significant importance for clinical diagnostics. It is widely used in the imaging of cancer, but the areas of application are extended by cardiology, neurology and metabolic diseases. At the same time, PET is used in science, designing new drugs, studying the molecular mechanisms of diseases, and assessing the effectiveness of therapy. The complexity of the process requires the combination of knowledge from various fields and interdisciplinary cooperation at all stages. During the lecture will be presented the results of such joint activities, carried out in groups and on the infrastructure of the Ochota Campus.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

mgr Michał Drągowski (IFD UW)

Study of quantum correlations in relativistic Moller scattering with electron Mott polarimetry (status of the 2POL project)

Current status of the 2POL experiment will be summarized. The 2POL polarimeter, built in Warsaw to study quantum spin correlations of electrons originating from relativistic Moller scattering, has been recently tested on beam at Mainzer Mikrotron. Results and conclusions from the first measurements will be discussed. Our activities in the field of electron Mott polarimetry, related to experiment optimization techniques based on Monte Carlo simulation, will also be presented. Results obtained using Geant4 package with interaction models developed by our group for simulation of polarized electron beams will we shown.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr Katarzyna Frankiewicz (NCBJ)

CosmicWatch - a pocket-size particle detector you can build yourself

CosmicWatch is a simple, low-cost, physics-motivated project for everyone.The detector is a self-contained apparatus that employs plastic scintillator as a detection medium and a silicon photomultiplier (SiPM) for light collection. The signal from the SiPM is sent through a custom designed printed circuit board (PCB) which shapes the signal such that a micro-controller can measure the time and amplitude of the SiPM signal. We use an Arduino Nano to measure the pulse amplitude and record the count number, time of the event, pulse amplitude, and detector dead time.CosmicWatch detector can be powered through mini USB and, in conjunction with the available open-source software, can be used to make interesting physics measurements, e.g. detect cosmic ray muons. It is easy to assemble, so one may gain experience in electronics and hardware related skills like soldering, mounting electronic components, designing PCBs, using oscilloscopes, waveform generators, and multimeters. The data gathered from the detector may serve as an input for anyone who wants to learn about basic techniques in data analysis, statistics, programming, and data visualization. The detector can be used for scientific purposes and educational outreach.The project has already gained attention on websites such as Physics Today, Symmetry Magazine, Endgadget, MIT news, MSN, Reddit, and many more. We've produced over two hundred detectors and have distributed internationally, mainly to high-school and undergraduate students. These include students from the United States, Poland, Germany, Canada, Peru, Germany, United Kingdom, and India.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

(IFD UW)

The status of NICA project and the Polish participation in the MPD Collaboration

The NICA accelerator complex is the new Mega-Science project co-financed by the Joint Institute of Nuclear Research in Dubna and the Russian Federation. The complex will deliver collisions of two beams of ions, from p to Au, and center-of-mass energies of 4-11 AGeV. The collider is currently under construction at JINR, with participation from Polish contributors. The capabilities of the complex as well as the status of the construction of the machine will be shortly presented. The NICA-PL consortium of polish scientific institutions interested in the participation in NICA will also be introduced.The major scientific experiment at the NICA Complex is the Multi-Purpose Detector. Its physics program and status of the construction of the detector will be described. Recently an international collaboration of MPD has been formed, which is now in the process of formalizing its structure and governing bodies. The opportunities for polish institutions for participation in MPD will be advertised.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

Dr Davide Franco (APC, Paryż)

The quest for dark matter with liquid argon and beyond

The field of direct dark matter search is experiencing a significant expansion in this decade, with many new experiments coming on board and exploring new avenues to increase sensitivity to Weakly Interacting Massive Particles (WIMPs), the leading dark matter candidate. Liquid argon detectors play a major role in the search of WIMPs, especially if they take advantage of ultra-low background argon extracted from deep underground, depleted in cosmogenic contamination. Very recently, DarkSide-50 and DEAP-3600 have completed major milestones of their programs by publishing results from ~20 and ~10 tonne-days exposure campaigns, respectively. The outcomes of the dark matter searches are null results. The discrimination between events induced by natural radioactivity and nuclear recoils – the potential candidate dark matter events – is outstanding, confirming once more that a future generation of liquid argon detectors will also be able to operate completely free of background and in a real discovery mode.We will discuss the achieved results and the potential of dark matter search with next generation liquid argon detectors. In addition, we will discuss the possibility to exploit technology, specifically developed for liquid argon, for neutrino physics and medical applications.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

prof. dr hab. Barbara Badełek (IFD UW)

Physics Beyond Colliders

European particle physics community is frantically completing documents summarising its research perspectives for 1-2 decades and its results and detailed plans for the next 6 years. These materials will be submitted to the `European Particle Physics Strategy' group by end of 2018. After consultations and consensus building within the community, a Physics Briefing Book with high energy physics programme recommendations will be created by the EPPS and submitted to the CERN Council for approval expected in March 2020.I shall tell about an initiative `Physics Beyond Colliders', set up in 2016 by CERN Management in the context of EPPS. Working groups of PBC are supposed to contribute with a particular input to the upcoming European Particle Physics Strategy Update.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr hab. Artur Kalinowski (IFD UW)

Machine learning in high energy physics

Machine learning is a dynamically developing field of computer science, with many applications in the IT industry (such as the automatic PL->ENG translation of this summary), which then diffuse into the natural sciences. In the seminar I will discuss selected algorithms and their application in the field of high energy physics. I will also discuss current activity Warsaw group of the CMS experiment in the field of machine learning

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr hab. inz. Tomasz Szumlak (AGH)

LHCb Upgrade

LHCb (Large Hadron Collider beauty) is a high precision experiment dedicated to searching for New Physics beyond the Standard Model in heavy flavour sector. With the Run 2 (2015 – 2018) data taking period coming to its end it seems less and less likely that the New Physics will be observed directly (energy frontier). Since LHCb is optimised to perform indirect studies and is sensitive to mass scales up to 50 TeV (intensity frontier) it may play a key role in a potential discovery of New Physics phenomena. This expectation is supported by many intriguing anomalies, especially related to rare decays and lepton flavour universality, observed and reported by LHCb. Thus, it is essential for LHCb to enter the high luminosity phase and continue data taking beyond LHC Long Shutdown 2 (LS2). For this the LHCb experimental setup needs a major upgrade that is being planned for years 2019 and 2020.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

Andrzej K. Drukier (Stockholm University)

Detecting DM via paleo-detectors

The different experiments attempting direct detection of Dark Matter candidates (DM) provides divergent results. DAMA-LIBRA observed the annual modulation in count rate which suggest existence of DM with MDM = O(10 GeV/c2). However, other (mostly l. Xenon detectors) put impressive limits on DM in mass range of 15 GeV/c2 < MDM < 500 GeV/c2. There is still possibility that DM are WIMPs, they are either low mass, MDM < 15 GeV/c2 or very heavy. We propose new DM detectors based on coherent scattering of neutrinos or DM in ancient crystals. Such crystals are available from deepest holes drilled for diverse purposes (depth > 8 km or > 20 km water equivalent). Thus the background due to CR is negligible (with exception of neutrinos). In this new detectors, the target is multi-elemental (up to 10 elements) which provides the signature and improve S/B. We elucidate the principles of paleo-detectors and describe a few promising methods of the signal detection. We also provide the first estimates of sensitivities, which for low mass DM (LM-DM) extends below the current definition of the “neutrino floor”. For example, for MDM = 10 GeV our sensitivity is about thousand fold better than for Ge-based or l. Xenon detectors. The problems of backgrounds will be discussed, including the trade-offs when one try use ice from Antarctica as paleo-detector.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

prof. dr hab. Tomasz Matulewicz (IFD UW)

Facility for Antiproton and Ion Research FAIR (Darmstadt): coordinates in the landscape

Facility for Antiproton and Ion Research (FAIR) is realized as an extension of the existing nuclear research center GSI Darmstadt. FAIR is organized as a company (GmbH) with Poland (Jagiellonian University) as one of shareholders. The civil construction is now progressing. Full operation is planned for 2025. SIS-100 synchrotron (100 Tm) will be the workhorse of the facility. Research areas are: hot and dense nuclear matter, charmonium spectroscopy, neutron-rich radioactive nuclei and strong e-m fields. The beam intensity will be 3 to 4 orders of magnitude above actually available elsewhere, so study of rare processes might be feasible.

Zapraszamy do sali B2.38, ul. Pasteura 5 o godzinie 10:15

dr hab. Justyna Łagoda (NCBJ)

Recent news on neutrinos - a report from NEUTRINO 2018 conference

The XXVIII International Conference on Neutrino Physics and Astrophysics has been held in Heidelberg from 4th to Saturday 9th June 2018. The conference program covered a wide range of topics, including the neutrino mass measurements, oscillations and detection of ultrahigh energy neutrinos from space. The overview of the most interesting (in speaker's opinion) results will be presented.