Seminarium Fizyki Wielkich Energii
2006/2007 | 2007/2008 | 2008/2009 | 2009/2010 | 2010/2011 | 2011/2012 | 2012/2013 | 2013/2014 | 2014/2015 | 2015/2016 | 2016/2017 | 2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025
2022-06-10 (Piątek)
Chris Parkes (CERN, University of Manchester)
LHCb reborn: the start of a new era
The Large Hadron Collider-beauty (LHCb) experiment completed its initial operating period (2010-2018) and has published over 600 scientific papers. Recent highlights of the physics output will be reviewed. The next era is now starting for LHCb, with the Upgrade I experiment having been installed. This is a major upgrade which will allow a significant increase of instantaneous luminosity and improve efficiencies and flexibility through the introduction of a fully software based trigger at 40MHz. Beyond this the collaboration is planning the Upgrade II for the 2030s, an ambitious flavour physics experiment at the HL- LHC, and a larger scale project than previously undertaken by LHCb. This will use a range of novel technological developments with many opportunities for the involvement of new collaborators in the research, design and construction activities.
2022-06-03 (Piątek)
prof. dr hab. Jacek Ciborowski (IFD UW)
New description of neutrino flavour evolution in solar matter -- oscillations or no oscillations?
Assuming that the interacting neutrino and the solar matter can be treated as an open quantum system we formulate a formalism of neutrino state evolution according to a quasilinear extension of the von Neumann equation. We broaden the classical linear Wolfenstein formalism (MSW effect) by means of reinterpreting the results in terms of the quantities appropriate for the quasilinear approach. We show that the dynamics of the neutrino evolution ("flavourconversion") is effectively governed by the distance of the evolving system to the structural instability point of the evolution equation. We obtain similar predictions for the averaged neutrino survival probability measured on Earth in both approaches, differing inside the Sun where the quasilinear evolution predicts a suppression of oscillations. A nonzero mean energy transfer between the neutrino and the Sun supports the initial assumption. We also discuss the speed of the state evolution in both approaches. Ways to test on Earth the quasilinear hypothesis will be mentioned.
2022-05-27 (Piątek)
dr hab. Grzegorz Grzelak (IFD UW)
Measurement of the cross-section ratio σ(ψ(2S))/σ(J/ψ(1S)) in exclusive photoproduction at HERA
During the seminar I will present new analysis performed with ZEUS data on exclusive vector meson photoproduction - measurement of the cross section ratio of two charmonia states: ψ(2S) and J/ψ(1S). The analysis was performed using muonic decay channels of the investigated vector mesons.The ratio of their production cross sections has been measured as a function of W (photon–proton centre-of-mass energy) and |t| (squared four-momentum transfer at the proton vertex) and compared to previous data in photoproduction and deep inelastic scattering and with predictions of QCD-inspired models of exclusive vector-meson production.
2022-05-20 (Piątek)
dr Sebastian Trojanowski (NCBJ)
Looking forward to new physics and neutrinos at the LHC and beyond
The search for new physics and studying the properties of the Standard Model (SM) neutrinos are among the main frontiers in contemporary particle physics. In particular, new physics searches at the Large Hadron Collider (LHC) have traditionally been performed in the high-pT region. If new particles are light and weakly-coupled, however, this focus may be misguided: light particles are typically highly concentrated within a few mrad of the beam line. This opens up a novel direction in the LHC searches focusing on sub-GeV beyond the SM species and neutrino measurements, which will be initiated by the FASER experiment during Run 3. In the talk, we will discuss the prospects of these and other related efforts that can extend towards the High-Luminosity phase of the LHC in the recently proposed Forward Physics Facility (FPF).
2022-05-13 (Piątek)
prof. dr hab. Barbara Badełek (IFD UW)
DIS landscape 2022 - a personal view
For the last 50+ years the Deep Inelastic Scattering is a source of our knowledge concerning properties of building blocks of nearby matter: nucleons and nuclei. DIS has supplied a wealth of astonishing discoveries and induced a development of the theory of strong interactions, the (perturbative) Quantum ChromoDynamics.A panorama of contemporary knowledge and problems concerning the free- and bound nucleon structure will be given and directions of future investigations and available tools will be presented.
2022-04-29 (Piątek)
dr Tomas Nosek (NCBJ)
NOvA is a two detector long-baseline neutrino oscillation experiment using Fermilab’s 700 kW NuMI neutrino beam. It studies the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos in the beam over a distance of 810 km between the detectors. The experiment has made over 4σ-significant observation of electron antineutrino appearance in muon antineutrino beam and constrained the oscillationparameters |Δm2 32|, sin2 θ23, and δCP. In this seminar, I will present the main features of the NOvA experimental setup and the neutrino oscillation analysis within the standard paradigm of three neutrinos mixing. I will point out the key differencesto the similar T2K experiment and its complementarity. I will review the 2020 resultsof NOvA and T2K and remind the potential of their combined analysis, which hasthe power to break the degeneracies of the individual measurements. By continuing tocollect data before the dawn of next-generation long-baseline experiments in the late 2020s, the statistical uncertainty will be reduced, and certain physics milestones might be within reach. To that end, it is vital to understand the major sources of systematic uncertainties and their correlations for both the interpretation and precision of theresults and for further improvements of the analyses.
The NOvA Experiment and Neutrino Oscillations
NOvA is a two detector long-baseline neutrino oscillation experiment using Fermilab’s 700 kW NuMI neutrino beam. It studies the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos in the beam over a distance of 810 km between the detectors. The experiment has made over 4σ-significant observation of electron antineutrino appearance in muon antineutrino beam and constrained the oscillationparameters |Δm2 32|, sin2 θ 23, and δ CP. In this seminar, I will present the main features of the NOvA experimental setup and the neutrino oscillation analysis within the standard paradigm of three neutrinos mixing. I will point out the key differencesto the similar T2K experiment and its complementarity. I will review the 2020 resultsof NOvA and T2K and remind the potential of their combined analysis, which has the power to break the degeneracies of the individual measurements. By continuing tocollect data before the dawn of next-generation long-baseline experiments in the late 2020s, the statistical uncertainty will be reduced, and certain physics milestones might be within reach. To that end, it is vital to understand the major sources of systematic uncertainties and their correlations for both the interpretation and precision of theresults and for further improvements of the analyses.
NOvA is a two detector long-baseline neutrino oscillation experiment using Fermilab’s 700 kW NuMI neutrino beam. It studies the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos in the beam over a distance of 810 km between the detectors. The experiment has made over 4σ-significant observation of electron antineutrino appearance in muon antineutrino beam and constrained the oscillationparameters |Δm2 32|, sin2 θ23, and δCP. In this seminar, I will present the main features of the NOvA experimental setup and the neutrino oscillation analysis within the standard paradigm of three neutrinos mixing. I will point out the key differencesto the similar T2K experiment and its complementarity. I will review the 2020 resultsof NOvA and T2K and remind the potential of their combined analysis, which hasthe power to break the degeneracies of the individual measurements. By continuing tocollect data before the dawn of next-generation long-baseline experiments in the late 2020s, the statistical uncertainty will be reduced, and certain physics milestones might be within reach. To that end, it is vital to understand the major sources of systematic uncertainties and their correlations for both the interpretation and precision of theresults and for further improvements of the analyses.
2022-04-22 (Piątek)
dr hab. Marcin Konecki, prof. UW (IFD UW)
The b-physics with the CMS experiment - an update
CMS is a general purpose experiment at the LHC, designed for a rich physics program that includes b-physics studies.Selected recent CMS results in b-physics will be presented: measurement of CP-violation phase Phi_s, results on B^0/B^0_sdecaying to mu^+ mu^- and observations of new states and decay modes in b-sector.
2022-04-08 (Piątek)
dr Lech Raczyński (NCBJ)
Digital Signal and Image Processing in Jagiellonian Positron Emission Tomography
This presentation is devoted to introduction of data processing algorithms inJagiellonian PET (J-PET) scanner. In contrast to state-of-the-art PET scanners, in theJ-PET detector multiple small inorganic crystal scintillators are replaced with a longplastic scintillator strips. The operational principles of the J-PET scanner are similarto conventional tomographs, except that the highly accurate time information is ofparamount importance. Therefore, the J-PET scanner demands a preparation of novelmethods on each step of the data processing. The goal of the work presented in thistalk is a development of the signal and image processing algorithms taking intoaccount uniqueness of the J-PET detector. The proposed methods include: signalrecovery based on samples of a waveform registered on photomultiplier output,reconstruction of position of interaction of annihilation photon in the scintillator strip,classification of PET events types and image reconstruction that operates exclusivelyin the image space.
2022-04-01 (Piątek)
Prof. Wacław Gudowski (UZ3, NCBJ)
Development of nuclear reactors - 4th generation reactors, SMRs and others. Nuclear options for the Polish energy transformation
Almost 21 years have passed since Gen IV - Generation IV International Forum (GIF) has been founded in 2001 as a co-operative international endeavour which was set up to carry out the research and development needed to establish the feasibility and performance capabilities of the next, advanced generation of nuclear energy systems. The program, organizational structure and main achievements and weaknesses of GIF will be presented in the first part of the seminar. Then other modern reactor types not officially belonging to the Gen IV will be presented and briefly assessed. The focus of the presentation will then shift to the description and assessment of the high temperature gas cooled reactor – HTGR/HTR and its nuclear fuel - TRISO.The various options for solving the problem of USED rather than SPENT nuclear fuel will be briefly described and assessed, including ADS technology, i.e. accelerator-driven subcritical systems.Finally, possible options for nuclear energy for heat and electricity generation in the Polish energy system transformation program will be presented. Is there any BEST OPTION?A Q & A session will follow the seminar.
2022-03-25 (Piątek)
Prof. Karol Lang (University of Texas at Austin)
Abstract:Research in fundamental experimental particle physics requires new experiments and novel detectors. Knowledge and experience gained in these endeavors can generate spinoffs that benefit fields outside of particle physics. In this talk, we will describe our work on building a time-of-flight positron-emission-tomography (PET) scanner for proton therapy at MD Anderson in Houston and some other related ideas towards improving and expanding the use of PET detectors. Karol Lang mini-bio: Karol Lang is an experimental particle physicist and Jane and Roland Blumberg Professor of Physics at the University of Texas at Austin. He graduated with MSc from Warsaw University. He received his Ph.D. from the University of Rochester participating in an experiment that searched for neutrino oscillations. As a postdoc, Lang worked at SLAC (Stanford) measuring the spin content of the nucleon and on an electron beam dump search for low-mass axions. He then worked at Stanford on a search for KL--> mu-e decays at BNL and a search for the H dibaryon. Lang joined the faculty at the University of Texas at Austin shortly before the Superconducting Super Collider (SSC) was cancelled in 1993. He is now involved in long baseline neutrino oscillations experiments and searches for neutrinoless double beta decay.
From anti-neutrinos to anti-electrons: PET research at the University of Texas at Austin
Abstract:Research in fundamental experimental particle physics requires new experiments and novel detectors. Knowledge and experience gained in these endeavors can generate spinoffs that benefit fields outside of particle physics. In this talk, we will describe our work on building a time-of-flight positron-emission-tomography (PET) scanner for proton therapy at MD Anderson in Houston and some other related ideas towards improving and expanding the use of PET detectors. Karol Lang mini-bio: Karol Lang is an experimental particle physicist and Jane and Roland Blumberg Professor of Physics at the University of Texas at Austin. He graduated with MSc from Warsaw University. He received his Ph.D. from the University of Rochester participating in an experiment that searched for neutrino oscillations. As a postdoc, Lang worked at SLAC (Stanford) measuring the spin content of the nucleon and on an electron beam dump search for low-mass axions. He then worked at Stanford on a search for KL--> mu-e decays at BNL and a search for the H dibaryon. Lang joined the faculty at the University of Texas at Austin shortly before the Superconducting Super Collider (SSC) was cancelled in 1993. He is now involved in long baseline neutrino oscillations experiments and searches for neutrinoless double beta decay.
Abstract:Research in fundamental experimental particle physics requires new experiments and novel detectors. Knowledge and experience gained in these endeavors can generate spinoffs that benefit fields outside of particle physics. In this talk, we will describe our work on building a time-of-flight positron-emission-tomography (PET) scanner for proton therapy at MD Anderson in Houston and some other related ideas towards improving and expanding the use of PET detectors. Karol Lang mini-bio: Karol Lang is an experimental particle physicist and Jane and Roland Blumberg Professor of Physics at the University of Texas at Austin. He graduated with MSc from Warsaw University. He received his Ph.D. from the University of Rochester participating in an experiment that searched for neutrino oscillations. As a postdoc, Lang worked at SLAC (Stanford) measuring the spin content of the nucleon and on an electron beam dump search for low-mass axions. He then worked at Stanford on a search for KL--> mu-e decays at BNL and a search for the H dibaryon. Lang joined the faculty at the University of Texas at Austin shortly before the Superconducting Super Collider (SSC) was cancelled in 1993. He is now involved in long baseline neutrino oscillations experiments and searches for neutrinoless double beta decay.
2022-03-18 (Piątek)
mgr Grzegorz Żarnecki (NCBJ)
Cross section measurement of the charged current muon antineutrino single π- production at T2K
T2K experiment is a long baseline neutrino oscillation experiment in Japan. Cross section measurements of (anti)neutrino interactions in sub-GeV to few GeV energy range allow to constrain the systematic uncertainties in the oscillation analysis. Single charged pion production is a relevant interaction mode at this energy scale.In this seminar I will present the cross section measurement of single π- production in muon antineutrino CC interaction on hydrocarbon. The cross section is reported as double-differential in muon kinematical variables i.e. momentum and cosine of the muon emission polar angle.
2022-03-11 (Piątek)
dr hab. Katarzyna Grzelak (IFD UW)
Status of LSND/MiniBooNE, Reactor and Gallium Anomalies and Sterile Neutrino Searches
Three different anomalies at accelerator, reactor and radio-chemicalneutrino experiments have brought attention to the searches for sterileneutrinos in the last decade.Numerous experiments have been launched to check whether sterile neutrino oscillations can be responsible for the experimental findings.During the seminar the status of experimental searches for sterile neutrino oscillations and new results from MicroBooNE, PROSPECT and BEST will be presented.
2022-01-28 (Piątek)
Dr Lakshmi S.Mohan (NCBJ)
How to detect GeV neutrinos using a magnetised detector? Iron Calorimeter @ India-based Neutrino Observatory
India-based Neutrino Observatory (INO) is a proposed underground lab to house a 50 kilo ton magnetised Iron Calorimeter (ICAL) detector to detect atmospheric neutrinos. The detector, mainly optimised for the detection of GeV muons will be able to separate μ− and μ+ from the charged current interaction of atmospheric muon neutrinos and muon antineutrinos respectively. The main goal of the experiment is to make use of Earth matter effects and determine neutrino mass hierarchy. It will consist of resistive plate chambers (RPCs) as the active detector elements and iron as neutrino target. I will give a brief summary of the R&D activities for ICAL experiment and some of its projected sensitivities to 2–3 neutrino oscillation parameters.
2022-01-21 (Piątek)
Kamil Skwarczyński (NCBJ)
T2K Near Detector Fit -Exclusive Behind the Scenes Materials
T2K (Tokai to Kamioka) is a long-baseline neutrino oscillation experiment located in Japan. One of the most challenging tasks of T2K is to study whether CP is violated in the lepton sector, which is suggested by recent T2K results. By utilizing the near detector (ND280) data, T2K can constrain neutrino interaction and flux uncertainties by fitting a parameterized model to data. This allows for a significant reduction of the systematic uncertainties in neutrino oscillation analyses.One of two fitters responsible for ND fit uses Markov Chain Monte Carlo (MCMC) Method. Great benefit of MCMC is that it returns distribution for each parameter rather than one just one best fit value.ND280 fit analysis, planned to be released this year, introduced lots of improvement, including the new photon-proton selection and new systematic parameter giving lots of freedom in nuclear effect description like Short Range Correlations and Pauli Blocking.
2022-01-14 (Piątek)
dr Artur Ukleja (NCBJ)
The charm of charm, i.e. how the LHCb is looking for new physics in precise measurements of CP violation effects in charm particle decays
The phenomenon of CP violation is one of the least-known part of the Standard Model. Its existence means that the laws of physics change if a particle is replaced by its antiparticle and the directions of all coordinates are changed. The known value of CP violation is too small to explain the existing matter domination over antimatter in the universe. This asymmetry (observed in cosmology) requires much larger value of CP violation than in the Standard Model.In addition, CP violation phenomenon is related to basic problems of particle physics. Perhaps here is the answer why there are three generations of quarks and leptons. So far, it has been known only that this is the smallest number that allows the introduction of a non-zero weak phase describing CP violation in the Cabibbo–Kobayashi–Maskawa matrix.Therefore, the main goal of High Energy Physics is a search for new sources of CP violation beyond the Standard Model (called new physics). The measurements in particle decays containing a charm quark create perfect environment for the new physics searches since the background from the Standard Model is small (the expected values of CP violation are about a few per milles or less). On the other hand, very sophisticated research methods are needed to be sensitive for such small effects. The examples of such methods use in the LHCb experiment at CERN I will present during seminar. Their measurements I will show in searches for CP violation in charm particle decays (mesons and baryons). These will be examples of measurements obtained in both two- and three-body decays. Although the three-body processes are always more rare than the two-body processes, they can provide much more information about CP violation. Many observables are available to measure in multi-body processes. In contrast, in two-body processes, only one variable is measured (global result of CP violation).
2021-12-17 (Piątek)
Dr Budimir Kliček (Ruder Boskovic Institute, Zagreb)
The ESSnuSB project: measuring CP violation at the 2nd neutrino oscillation maximum
ESSnuSB is a design study for an experiment which will measure CP violation in lepton sector by observing neutrino oscillations at the second muon neutrino to electron neutrino oscillation maximum. The signal of CP violation at the second oscillation maximum is expected to be three times larger than at the first one, which significantly increases the ratio between the signal and the systematic uncertainty, and thereby the physical reach of the project. The very intense muon neutrino beam will be generated by uniquely powerful ESS linear proton accelerator, which is currently under construction near Lund, Sweden. The oscillation signature will be measured by observing neutrino interactions in the large 538 kt fiducial volume of the far water Cherenkov detectors. The experiment will also feature near detectors which will be used to measure neutrino interaction cross-sections and the non-oscillated flux. This seminar will start with a short introduction to CP violation in neutrino oscillations, focusing on the oscillation channels relevant for ESSnuSB. It will continue with the description of the current design of the ESSnuSB experimental setup, and conclude with the expected physics reach of the project.
2021-12-03 (Piątek)
mgr Piotr Podlaski (IFD UW)
Latest results from the NA61/SHINE experiment at CERN
NA61/SHINE is a multipurpose fixed-target facility at the CERN Super Proton Synchrotron. The main goals of the NA61/SHINE strong interactions program are to look for the critical point of strongly interacting matter and study properties of the onset of deconfinement. To reach these goals, hadron production measurements are performed in the form of a two-dimensional scan by varying collision energy and system size. Additionally, NA61/SHINE performs reference hadron production measurements for neutrino and cosmic ray experiments.In this seminar the most recent NA61/SHINE results will be summarized. In particular, results from p+p, Be+Be, Ar+Sc and Pb+Pb reactions on hadron production spectra and fluctuations will be presented. The NA61/SHINE data will be compared with results from other experiments and predictions of various theoretical models. The talk will be concluded with plans and motivation for the NA61/SHINE operation and measurements after Long Shutdown 2 and 3 at the CERN SPS, followed by a brief summary of the ongoing hardware upgrade.
2021-11-26 (Piątek)
mgr Mateusz Fila (IFD UW)
ELITPC: the first experiments with the full scale-prototype of an active-target Time Projection Chamber
An active-target Time Projection Chamber (TPC) has been developed at the University of Warsaw for studying nuclear reactions of astrophysical interest. The flagship experiment of the detector is the measurement of the cross-section of 16O(gamma, alpha)12C photodisintegration reaction down to the energy of 1 MeV in the centre of mass using monochromatic gamma-ray beams at HIgS, USA and ELI-NP, Romania.In the summer of 2021, the first experiments with the full-scale prototype of the chamber took place at the IFJ PAN Cracow.The performance of the detector was tested in experiment at the Van de Graaf accelerator at the IFJ PAN. The CO2 filled TPC was exposed to the13 MeV gamma beam produced in the 15N(p, gamma)16O reaction. Events corresponding to the 16O(gamma, alpha)12C photodisintegration reaction were observed.In another experiment, the neutron beam of IGN-14 MeV neutron generator at the IFJ PAN was used to populate the Hoyle state in in the 12C(n,n’) reaction with CO2 gas inside the detector. The products of 3-alpha decay of the Hoyle state were observed.Preliminary results of the measurements at IFJ will be presented and an outlook on the experiment at HIgS and plans for ELI-NP will be given.This scientific work is supported by the Polish Ministry of Science and Higher Education from the funds for years 2019-2021 dedicated to implement the international co-funded project no. 4087/ELI-NP/2018/0, by University of Connecticut under the Collaborative Research Contract no. UConn-LNS_UW/7/2018 and by the National Science Centre, Poland, under Contract no. UMO-2019/33/B/ST2/02176.
2021-11-19 (Piątek)
Barbara Maria Latacz (RIKEN, on behalf of the BASE collaboration)
Searches for exotic physics by comparing the fundamental properties of antiprotons and protons using Penning Traps at BASE experiment
The Standard Model is the most successful theory in physics, however, it does leave several questions open. For example the striking matter-antimatter imbalance in the visible Universe has yet to be understood, and the microscopic properties of dark matter have yet to be discovered. Related questions can be studied by ultra-high precision comparisons of the fundamental properties of protons and antiprotons, like the charge-to-mass ratios or the magnetic moments, which are subject of the experiments of the BASE collaboration at CERN. The core tool of BASE is the spectroscopy of single trapped antiprotons and protons using superconducting detectors in advanced cryogenic Penning trap systems. One of the state-of-the-art results of the BASE collaboration is the measurement of the antiproton magnetic moment with a fractional precision of 1.5 parts in a billion [C. Smorra et al., Nature 550, 371 (2017)], which improved previous measurements by more than three orders of magnitude. Very recently, BASE extended its experimental program and has set stringent limits on axion to photon conversion in the neV mass range, using superconducting LC circuits are haloscope detectors (J. A. Devlin et al., Physical Review Letters 126.4 (2021): 041301).In my talk, I will summarise the recent achievements of BASE, I will report on the progress in improving the frequency resolution of the experiment, and will outline strategies to further improve our high-precision studies of matter-antimatter symmetry to anticipated precision at the parts per trillion level. I will also summarize progress towards the development of the new broad-band axion haloscope BASE CDM.
2021-11-05 (Piątek)
mgr Kamil Dulski (UJ)
Test of discrete symmetries with spin observables at J-PET
The phenomenon of positron-electron annihilation is a subject-of-interest in many fields from medical imaging to fundamental studies. Two photon annihilation of positron-electron pair is already well established mode allowing for determination of annihilation position distribution, by means of Positron Emission Tomography (PET). However, a particularly interesting research object is the unique relationship that can bind a positron and an electron, that is called positronium. Positronium as the lightest purely leptonic bound state can serve as a sensitive probe of effects such as violation of discrete symmetries [1,2]. A particularly interesting case is testing the CPT invariance, a violation of which can be searched for as non-disappearing angular correlations between the photons from positronium annihilation and its spin. So far, attempts to experimentally investigate this effect have been limited mostly by the knowledge of the latter [2,3]. An improvement in the estimation of the spin direction was recently proposed by the Jagiellonian PET (J-PET) collaboration, introducing the J-PET detector as a new device which allows for the estimation of the positron spin axis along with the polarization of photons from positronium annihilation on an event-by-event basis [1,5,6]. So far, it is the only detector capable of such operation. The results of the most precise measurement of an angular correlation operator sensitive to violation of the combine symmetry under charge conjugation (C), parity (P) and time reversal (T) on the study of ortho-positronium (o-Ps) annihilations will be presented. The presented results do not indicate any violation at the level of the per mille [1], improving the previous measurements [2,3].The new method of image reconstruction based on trilateration will be additionally presented [7]. It allows to determine the position of the o-Ps annihilation, which resulted in emission of three photons. Knowing the o-Ps annihilation position translated directly into the precision of estimating the o-Ps spin direction. The first reconstructed image of positron annihilation based on 3-photon o-Ps decays will be shown as a result from trilateration reconstruction [1]. Finally the world’s first positronium image of heart tissue from a patient will be presented [8]. The positronium image is a completely new imaging technique which is based on the determination of the mean positronium lifetime in each voxel. Resulting image allowed to distinguish the type of the tissue based on the mean positronium lifetime, which is not possible to distinguish by a conventional PET.
2021-10-29 (Piątek)
prof. dr hab. Aleksander Filip Żarnecki (IFD UW)
Sensitivity of future linear colliders to processes of dark matter production with light mediator exchange
As any e+e- scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with an invisible final state. Thus high energy e+e- colliders offer a unique possibility for the most general search ofdark matter (DM) based on the mono-photon signature. Production of DM particles at the International Linear Collider (ILC) and Compact Linear Collider (CLIC) experiments was studied for scenarios with a light mediator exchange. Limits on the production cross section and mediator couplings were set in a simplified DM model as a function of the mediator mass and width based on the expected two-dimensional distributions of the reconstructed mono-photon events. Systematic uncertainties were studied in details as well as the impact of the beam polarisation.
2021-10-22 (Piątek)
dr Pragati Mitra (IFD UW)
Reconstructing Air Shower properties with Radio Arrays
Cosmic rays have been an intriguing field of research since their discovery more than 100 years ago. The origin of these highest energetic particles still remain a mystery. When high-energy cosmic rays impinge upon the atmosphere, they create extensive air showers, which are cascades of secondary particles that are observed with various methods. Measuring the radio emission of air showers is a relatively new but increasingly popular method to extract information about the mass composition of cosmic rays. In this talk I will introduce the principles of radio detection technique focusing on the results obtained with The Low-Frequency Array (LOFAR) radio telescope. I will describe the method of reconstructing the shower maximum Xmax- an important estimator of cosmic ray mass, and ways to enhance the accuray of Xmax estimation by including local atmospheric effects. We will also explore the prospects of other cosmic ray mass estimators in addition to Xmax. I will also explain the prospects of a semi-analytic air shower simulation code for radio emission that is few orders of magnitude faster than the conventional monte carlo counterparts. In the end, I will briefly mention our current research plans with GP300- a prototype for The Giant Radio Array for Neutrino Detection (GRAND).
2021-10-15 (Piątek)
prof. dr hab. Krzysztof Doroba (IFD UW)
How to determine precisely luminosity at pp machine (LHC)?
in the talk presented will be methods used by the CMS to measure with 1.2 % accuracy luminosity delivered by LHC. The aim of the talk will be to stress an effort required to obtain such precision. In addition mentioned will be results on cross sections obtained by the TOTEM experiment in "luminosity indpendent way", These results in particular concern discovery of the ODDERON, proposed in 1973 by L. Lukaszuk (and B.Nicolescu)
2021-10-08 (Piątek)
dr hab. Artur Kalinowski , prof. UW (IFD UW)
Highlights from the Run-2 LHC results
I will present a very subjective selection of analyses using (mostly) full Run-2 data: W boson mass measurement, a short review of the status of the Higgs boson measurements, four top quark production, vector boson scattering and a measurement on LFV from LHCb.