Data: 28.01.2022
Miejsce: Sala team 11:00
Temat: Pytania związane z niedawnymi pomiarami z MicroBooNE
Osoba: Jan Sobczyk
Opis: Omówię jak dobrze NuWro odtwarza, czy też nie odtwarza, niedawne pomiary przekrojów czynnych opublikowane przez eksperyment MicroBooNE i zastanowię się co z tego może wynikać. Seminarium będzie miało charakter roboczy, ale postaram się, by było zrozumiałe również dla nie specjalistów.

Data: 25.11.2020
Miejsce: Sala team 15:15
Temat: Oscylacje Neutrin
Osoba: Jan Sobczyk
Opis: Rozszerzona wersja referatu wygłoszonego na jubileuszowym zjeździe w 100-lecie Polskiego Towarzystwa Fizycznego.

Data: 06.11.2020
Miejsce: Sala team 10:30
Temat: Modeling two-nucleon knock-out in neutrino-nucleus scattering
Osoba: Kajetan Niewczas
Opis: Accelerator-based neutrino oscillation experiments rely on the description of neutrino interactions with bound nucleons inside atomic nuclei. Neutrino fluxes used in modern experiments (T2K, NOvA, MiniBooNE) are peaked in the 1–5 GeV energy region where one can identify contributions from multiple interaction channels and various nuclear effects. The neutrino-nucleus cross sections in this region are known with a precision not exceeding 20% and have to be investigated further in pursuing to reduce systematic errors in oscillation measurements. The Ghent group focuses on providing a consistent description of this process in the intermediate energy region. Various interaction channels are modeled, including the two-nucleon knock-out (2p2h) that is known to provide one of the least controlled sources of uncertainty. The 2p2h final states are obtained via two mechanisms: short-range correlations [Phys.Rev.C 94 (2016) 024611] and meson-exchange currents [Phys.Rev.C 95 (2017) 054611]. Refined treatment of nuclear effects is achieved by constructing both bound-state and continuum nucleon wave functions through a Hartree-Fock calculation with an effective Skyrme-type interaction. I will present the results of the aforementioned references, as well as the current status and prospects of the project.

Data: 30.10.2020
Miejsce: Sala team 10:30
Temat: Neutrinos in the Grimus-Neufeld model
Osoba: Vytautas Dūdėnas (Vilnus University)
Opis: The Grimus-Neufeld model is a two Higgs doublet model, extended with a single heavy seesaw neutrino. This setup allows for explaining both of the neutrino mass differences with the seesaw mechanism and radiative mass generation. Since this model is rather minimal, the neutrino Yukawa couplings have only few parameters. Connecting radiative mass generation with the seesaw mechanism, almost all of the neutrino Yukawa couplings can be expressed in terms of the neutrino mixing matrix and the neutrino masses. These Yukawa couplings contribute to physical observables, such as lepton flavor violation. I will introduce to the model by going through the two mass generation mechanisms and show how we can relate the neutrino Yukawa couplings to measured neutrino parameters at one loop.

Data: 15.06.2020
Miejsce: Sala team 12:15
Temat: Machine learning in quantum matter and high energy physics
Osoba: Krzysztof Graczyk
Opis: I will review two recent papers: arxiv:2005.08582 and arxiv:2003.11040 about applications of modern machine learning methods to quantum matter and high energy physics. The seminar is going to have informal character.

Data: 01.06.2020
Miejsce: Sala team 12:15 
Temat: Reweighting of Final State Interactions
Osoba: Jan Sobczyk
Opis: I will present simple mathematical models illustrating the idea of reweighting of Final State Interactions.

Data: 18.05.2020
Miejsce: Sala team 12:15
Temat: Polarization effects in neutrino-nucleon interactions (continued)
Osoba: Beata Kowal
Opis: Quasielastic neutrino-nucleon scattering and single pion production are important processes in neutrino oscillation experiments. I will show that polarization observables are well suited for studying the axial nucleon form factor, non-standard interaction and testing single pion production models. My presentation bases on the results published in Phys.Rev.D 101, 073002, Phys.Rev.D 97, 013001 and Phys.Rev.D 99, 053002.

Data: 11.05.2020
Miejsce: Sala mst 12:15
Temat: Polarization effects in neutrino-nucleon interactions
Osoba: Beata Kowal
Opis: Quasielastic neutrino-nucleon scattering and single pion production are important processes in neutrino oscillation experiments. I will show that polarization observables are well suited for studying the axial nucleon form factor, non-standard interaction and testing single pion production models. My presentation bases on the results published in Phys.Rev.D 101, 073002, Phys.Rev.D 97, 013001 and Phys.Rev.D 99, 053002.

Data: 27.04.2020
Miejsce: Sala mst 12:15
Temat: Electroweak single-pion production off the nucleon: effective implementation in Monte Carlo event generators (part 2)
Osoba: Kajetan Niewczas
Opis: Neutrino-induced single-pion production (SPP) provides an important contribution to neutrino-nucleus interaction, ranging from intermediate to high energies. There exist a good number of low-energy models in the literature to describe this process in the region around the Delta resonance. However, their implementation in the Monte Carlo event generators, that are used in accelerator-based neutrino oscillation experiments, is still very limited. I will present a framework exhaustively described in Ref. [J.E. Sobczyk et al., Phys.Rev. D98 (2018) 073001] and its potential to be used for generic and optimized implementations of SPP models. The discussion will be exemplified using the model developed by the Ghent group [R. González-Jiménez et al., Phys.Rev. D95 (2017) 113007] and its implementation in NuWro Monte Carlo generator.

Data: 20.04.2020
Miejsce: Sala mst 12:15
Temat: Neutrino Electron Scattering: New Channel Implementation to NuWro
Osoba: Dmitry Zhuridov
Opis: I will discuss my progress in adding the following interaction dynamics to the NuWro package: neutrino-electron scattering in the framework of the Standard Model. This new channel includes six subchannels that differ from each other by the type of initial neutrino or antineutrino. Ten possible final states are produced there in the processes nu + e -> nu’ + l and nubar + e -> nubar’ + l, where charged current, neutral current and their interference are present. Prior to the implementation I made a separate C++ code to generate events from this dynamics and make histograms. First NuWro results for this new channel, visualized by ROOT, will be presented.

Data: 06.04.2020
Miejsce: Sala 412 12:15
Temat: Solid-state quantum computing – a simple overview
Osoba: Jarosław Pawłowski, PWr, Wydział Podstawowych Problemow Techniki, Katedra Fizyki Teoretycznej
Opis: In the seminar I will deal with the idea of quantum computing (QC). I will start with a brief description of the idea of quantum information processing, quantum parallelization and its advantage over the „classical” approach and show where it will be potentially useful. What kind of computational problems are already implemented in quantum and how they outperform classical ones. Then I will move to hardware issues and summarize the great problem of QC implementation. I will focus primarily on the solid-state QC, as it is considered to be easily scalable and integrable with classical semiconductor electronics. I will discuss the best qubit implementation techniques (as used in Google and IBM devices) and actual problems with them, as well as other, e.g. „exotic” topological QC ideas where a multi-qubit quantum state is „protected” from decoherence by the electron bands topology. I will finish on describing my own calculations and simulations of qubit proposals in quantum structures with reduced dimensionality, i.e. semiconductor nanowires with strong spin-orbit coupling or quantum dots in graphene like structures: J. Pawłowski, New Journal of Physics 21, 123029 (2019). J. Pawłowski, D. Żebrowski, and S. Bednarek, Physical Review B 97, 155412 (2018). J. Pawłowski, P. Szumniak, S. Bednarek, Physical Review B 94, 155407 (2016)

Data: 03.02.2020
Miejsce: Sala 412 12:15
Temat: Solving ordinary and partial differantial equations using neural networks (continued)
Osoba: Cezary Juszczak
Opis: Some examples of solving ordinary and partial differental equations using neural networks and the method of Lagaris et al. will be discussed.

Data: 16.12.2019
Miejsce: Sala 412 12:15
Temat: Detecting and Studying High-Energy Collider Neutrinos with FASER at the LHC
Osoba: Sebastian Trojanowski (University of Sheffield, UK & NCBJ, Poland)
Opis: Neutrinos are copiously produced at particle colliders, but no collider neutrino has ever been detected. Colliders, and particularly hadron colliders, produce both neutrinos and anti-neutrinos of all flavors at very high energies, and they are therefore highly complementary to those from other sources. In this talk, I will discuss the recently approved Forward Search Experiment (FASER) at the Large Hadron Collider, which is ideally located to provide the first detection and study of collider neutrinos during the upcoming LHC Run 3 from 2021-23. With mean neutrino energies of 600 GeV to 1 TeV, FASER will measure neutrino cross sections at energies where they are currently unconstrained, will bound models of forward particle production, and could open a new window on physics beyond the standard model. I will also discuss some theoretical uncertainties and challenges in modeling neutrino production and interactions relevant for the FASER experiment.

Data: 09.12.2019
Miejsce: Sala 412 12:15
Temat: Compositeness and Democratic Neutrinos (part II)
Osoba: Dmitry Zhuridov
Opis: New model of lepton and quark substructure is introduced, and its possible consequences in particle physics are discussed. In particular, the neutrino masses are predicted to be democratic, which supposes an alternative explanation of several experimental results on neutrinos

Data: 02.12.2019
Miejsce: Sala 412 12:15
Temat: Compositeness and Democratic Neutrinos
Osoba: Dmitry Zhuridov
Opis: New model of lepton and quark substructure is introduced, and its possible consequences in particle physics are discussed. In particular, the neutrino masses are predicted to be democratic, which supposes an alternative explanation of several experimental results on neutrinos

Data: 25.11.2019
Miejsce: Sala 412 12:15
Temat: Influence of correlations between yields on the chemical freeze-out temperature (part II)
Osoba: Dariusz Prorok
Opis: The statistical (thermal) model is applied for the description of hadron yields measured at central nucleus-nucleus collisions at the top RHIC energy $sqrt{s_{NN}} = 200$ GeV and the LHC energy $sqrt{s_{NN}} = 2.76$ TeV. In contrast to previous analyzes the more general form of the least squares test statistic is used, which takes into account also possible correlations between different species of yields. When light nuclei are included into fits, the chemical freeze-out temperature about 158 MeV is obtained for both energies (156 MeV when correlations are neglected). Without light nuclei the temperature about 160 MeV is determined for LHC and RHIC when correlations are non-zero, whereas for zero correlations the difference in the chemical freeze-out temperatures between RHIC and LHC is 6 MeV.

Data: 18.11.2019
Miejsce: Sala 412 12:15
Temat: Influence of correlations between yields on the chemical freeze-out temperature
Osoba: Dariusz Prorok
Opis: The statistical (thermal) model is applied for the description of hadron yields measured at central nucleus-nucleus collisions at the top RHIC energy $sqrt{s_{NN}} = 200$ GeV and the LHC energy $sqrt{s_{NN}} = 2.76$ TeV. In contrast to previous analyzes the more general form of the least squares test statistic is used, which takes into account also possible correlations between different species of yields. When light nuclei are included into fits, the chemical freeze-out temperature about 158 MeV is obtained for both energies (156 MeV when correlations are neglected). Without light nuclei the temperature about 160 MeV is determined for LHC and RHIC when correlations are non-zero, whereas for zero correlations the difference in the chemical freeze-out temperatures between RHIC and LHC is 6 MeV.

Data: 28.10.2019
Miejsce: Sala 412 12:15
Temat: Solving ordinary and partial differantial equations using neural networks
Osoba: Cezary Juszczak
Opis: I will present the method from the paper: 'Artificial Neural Networks for Solving Ordinary and Partial Differential Equations’ by Lagaris et al. and some result of its application.

Data: 21.10.2019
Miejsce: Sala 412 12:15
Temat: Electroweak single-pion production off the nucleon: effective implementation in Monte Carlo event generators
Osoba: Kajetan Niewczas
Opis: Neutrino-induced single-pion production (SPP) provides an important contribution to neutrino-nucleus interaction, ranging from intermediate to high energies. There exist a good number of low-energy models in the literature to describe this process in the region around the Delta resonance. However, their implementation in the Monte Carlo event generators, that are used in accelerator-based neutrino oscillation experiments, is still very limited. I will present a framework exhaustively described in Ref. [J.E. Sobczyk et al., Phys.Rev. D98 (2018) 073001] and its potential to be used for generic and optimized implementations of SPP models. The discussion will be exemplified using the model developed by the Ghent group [R. González-Jiménez et al., Phys.Rev. D95 (2017) 113007] and its implementation in NuWro Monte Carlo generator.

Data: 17.06.2019
Miejsce: Sala 422 12:15
Temat: Computing in physics
Osoba: Marzieh Bahmani
Opis: In this talk I will discuss the fundamental concepts of Physics computing by addressing two specific aspects of scientific computing: tools and techniques for scientific software and Data Analysis. Tools and techniques dedicated to modern techniques for software design, better understanding and improving the existing software and Data Analysis aspect will be an introduction to data analysis techniques and Monte Carlo method.

Data: 27.05.2019
Miejsce: Sala 412 12:15
Temat: Supervised deep learning in high energy phenomenology
Osoba: Cezary Juszczak
Opis: I will present results of the paper arXiv:1905.06047 [hep-ph]

Data: 20.05.2019
Miejsce: Sala 412 12:15
Temat: Statistical methods in approaching solution of the proton radius puzzle
Osoba: Krzysztof Graczyk
Opis: I will shortly review recent approach to extraction of the proton radius. Special attention will be focused on the statistical methods.

Data: 13.05.2019
Miejsce: Sala 422 12:15
Temat: Weak pion production ANL and BNL data – neverending story
Osoba: Jan Sobczyk
Opis: I will present a few (relatively) recent studies on the 40 years old weak pion production data on deuteron target.

Data: 29.04.2019
Miejsce: Sala 422 12:15
Temat: Towards a phenomenological 2p2h model
Osoba: Tomasz Bonus
Opis: Presentation of results achieved by implementing MEC scaling factor which depends on kinematic variables of the event. Main point is to discuss improvement of chosen quality metrics and way of diminishing them even further avoiding unphysical results.

Data: 08.04.2019
Miejsce: Sala 422 12:15
Temat: Studying of polarization observables in neutrino-nucleon scattering
Osoba: Beata Kowal
Opis: Studying of polarization observables in neutrino-nucleon scattering

Data: 04.03.2019
Miejsce: Sala 422 12:15
Temat: Hyperon Production in the NuWro Monte Carlo Generator
Osoba: Christopher Thorpe (Lancaster University)
Opis: Upcoming neutrino detectors such as SBND will be exposed to very intense neutrino beams and are predicted to observe thousands of hyperon production events versus the existing dataset of fewer than 100. These processes are of interest as they may be used to identify wrong sign contamination in neutrino beams, test the quark flavour model and search for time reversal violating interactions. These processes have been modelled in the NuWro MC event generator with the ability to include flavour and time reversal symmetry breaking modifications. Interactions between the hyperons and nuclear material have also been implemented. Some samples of the outputs from the generator will be presented to examine the effect of the changes to the model on various observables and to look at the severity of the nuclear effects.

Data: 21.01.2019
Miejsce: Sala 422 12:15
Temat: Rozwiązywanie równań różniczkowych przy pomocy sieci neuronowych
Osoba: Krzysztof Graczyk
Opis: Sieci neuronowe używane są przede wszystkim w problemach klasyfikacyjnych oraz regresji. W ostatnim okresie sztuczne sieci neuronowe stały się popularnym narzędziem wykorzystywanym w wielu dziedzinach życia. Ich zastosowania w fizyce są bardzo szerokie: od fizyki ciała stałego do fizyki cząstek elementarnych, od fizyki doświadczalnej do fizyki matematycznej. Metody sztucznej inteligencji są choćby jednym z narzędzi wykorzystywanym w klasyfikacji mierzonych zdarzeń w detektorach cząstek elementarnych. Metod tzw. uczenia maszynowego używa się również do rekonstrukcji funkcji falowych układów wielu ciał. Ciekawym zastosowaniem wydaję się użycie metod uczenia maszynowego do rozwiązywania numerycznego zwykłych i cząstkowych równań różniczkowych. Podczas seminarium omówię kilka zastosowań tej metody w rozwiązywaniu problemów fizycznych.

Data: 12.03.2018
Miejsce: Sala 422 12:15
Temat: Polarization Transfer in Weak Pion Production off the Nucleon
Osoba: Beata Kowal
Opis: During my presentation I will present results of the investigation of the polarization transfer observables in the single pion production in neutrino-nucleon scattering and methods for obtaining them. My presentation bases on the papers PhysRevD.97.013001 and APhysPolB.48.2219.

Data: 05.03.2018
Miejsce: Sala 422 12:15
Temat: Kilka słów o wybranych problemach statystyki matematycznej.
Osoba: Rafał Topolnicki
Opis: W referacie omówione zostaną dwa problemy z dziedziny teoretycznej statystyki matematycznej: (1) semiparametyczna estymacja krzywej ROC, (2) estymacja ilorazu procesu geometrycznego. W obu tych problemach wykorzystanie znajdują estymatory najmniejszej odległości. Dla krzywej ROC, która używana jest do oceny jakości klasyfikatorów binarnych, rozpatrzone zostaną dodatkowo metody estymacji nieparametrycznej, ze szczególnym uwzględnieniem tych wykorzystywanych w problemie estymacji dystrybuanty. Omówię również metodę wielowymiarowej estymacji jądrowej oraz jej praktyczne zastosowanie na przykładzie analizy trajektorii symulacji dynamiki molekularnej. Wystąpienie zostanie poprzedzone krótki wstępem do statystki matematycznej oraz teorii estymacji.

Data: 08.01.2018
Miejsce: Sala 422 12:15
Temat: Polarization transfer in SPP in neutrino-nucleon scattering
Osoba: Beata Kowal
Opis: I will present results of the investigation of the polarization transfer observables in the single pion production in neutrino-nucleon scattering and methods for obtaining them. My presentation bases mainly on the paper „Polarization transfer in weak Pion production off the nucleon” and less on the proceedings „Single pion production in neutrino-nucleon scattering studied with FORM package”.