Author: Wojciech Orpel

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 4 kwietnia (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Developments towards light Dark Matter Detection and Medical Applications”

Referuje: Prof. Masayuki Wada (Astrocent/CAMK PAN)

Dark matter candidates with masses below 10 GeV/c² hold promise, and a new detector, DarkSide-LowMass, is proposed based on the DarkSide-50 detector and progress towards the DarkSide-20k. DarkSide-LowMass is optimized for low-threshold electron-counting measurements, and sensitivity to light dark matter is explored for various potential energy thresholds and background rates. I will present the developments towards low mass dark matter searches with a new detector as well as sensitivity with DarkSide-20k, which is under construction.

I also discuss the activity for the medical application, Positron Emission Tomography (PET) scanner, using the same technologies as dark matter searches.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 28 marca (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Enhanced optical amplification structures for Dark Matter searches”

Referuje: André Filipe Cortez (AstroCeNT)

The development of radiation detectors has seen significant advancements over the past decades, particularly in those relying on electroluminescence. Optical time projection chambers (OTPCs) have become the preferred choice in the field of direct dark matter searches (more specifically in WIMP searches), having also been considered for neutrino experiments. Dark matter experiments examples include XENON, LZ, DarkSide, and CYGNO where directional information is expected to be explored. Moreover, these detectors have found applications in nuclear physics, such as in the study of ββ0ν decay (NEXT) and 2p-decay and related processes (Warsaw-TPC).

Even though significant progress has been observed in the development of these detectors since the first works in the 1960s, the optimization of the light collection efficiency remains an important concern. Historically, these structures were mostly made up of meshes or conventional micro-pattern gas detectors (MPGDs) designed for avalanche mode and working mainly in quenched gases.

Given the expected scalability of most of the aforementioned detectors, light production and collection pose unique challenges. Dealing with alignment, and the use of meshes or wires spanning large areas presents practical limitations.

In most cases, relying on scintillation originated in charge avalanches will affect not only the energy resolution but also impact the attainable spatial resolution. In addition, the use of lenses, while enabling the reduction of the number of optical sensors required to read large areas and improvement of the optical gain, may limit the spatial resolution attainable, introducing undesirable optical effects (e.g. aberrations). Nevertheless, it is important to consider techniques that can mitigate potential adverse effects associated with the current amplification structures and readout.

In this talk, the challenges for improving the light collection as well as the minimization of the background in dual-phase TPCs resulting from spurious emission will be discussed. We will start with a brief overview of the evolution of electroluminescence studies, along with strategies to address some of the main challenges faced in the development of such detectors for Dark matter searches. Alternative structures, GEM-based, capable of providing higher optical gains without relying on avalanche multiplication, thus enhancing energy resolution and detector stability (while eliminating ion back-flow), will be presented.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 21 marca (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Spin Structure of the Nucleon: From CERN SPS to EIC”

(powtórka konwersatorium z NCBJ)

Referuje: dr hab. Marcin Stolarski (NCBJ)

I will present over 40 years of involvement by Warsaw groups in studying the (spin) structure of the nucleon through CERN SPS muon experiments—including EMC, NMC, SMC, and COMPASS. While these experiments have led to many intriguing physics insights, precise answers to key questions remain elusive due to the kinematic limitations of fixed-target setups. This is set to change with the upcoming Electron-Ion Collider (EIC), the world’s first polarized electron-proton collider, which promises unprecedented access to the nucleon’s spin structure.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 14 marca (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Silicon Photomultipliers in Gamma and Neutron Radiation Detection – Principles and Applications”

Referuje: dr hab. inż. Martyna Grodzicka-Kobyłka (NCBJ)

Gamma-ray spectrometry using scintillation detectors is one of the most important measurement techniques employed in various fields of nuclear physics and related research. This method finds applications in fundamental nuclear physics studies, environmental monitoring, nuclear medicine, and modern border security systems.

Scintillation detectors consist of a scintillating material, which absorbs gamma quanta and subsequently emits light, and a photodetector responsible for registering this signal. The most commonly used photodetectors include PIN diodes, avalanche photodiodes (APDs), vacuum photomultiplier tubes (PMTs), and modern silicon photomultipliers (SiPMs).

This presentation will cover the operating principles of silicon photomultipliers, their advantages and limitations, as well as their potential applications in detecting light emitted by scintillators in gamma-ray spectrometry and neutron detection. Special emphasis will be placed on their use in physics, medicine, and security systems.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 7 marca (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„The scalar sector – story so far – from the ATLAS perspective”

Referuje: dr hab. Paweł Bruckman de Renstrom (IFJ PAN)

The long-awaited discovery of the Higgs boson has fundamentally changed the paradigm of experimental particle physics. The BEH mechanism turned from an attractive hypothesis into a physical reality. The detailed study of the properties of the only known fundamental scalar, as well as the direct search for an extended scalar sector, became the main focus of the LHC physics program. Based on ATLAS results, the talk will briefly review the current experimental status of the 125 GeV Higgs boson and focus on the searches for BSM phenomena in the scalar sector.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 28 lutego (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Understanding Quark and Neutrino Mixing: Theory and Experiments”

Referuje: dr Oleksandr Tomalak

The behavior of fundamental particles, such as quarks and neutrinos, is key to understanding the Standard Model of particle physics. Their mixing patterns are described by two mathematical

objects: the Cabibbo-Kobayashi-Maskawa (CKM) matrix for quarks and the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix for neutrinos. In this talk, I will explain how recent advances in theory and experiments are helping to improve the precision of these matrices.

For quarks, I will discuss how precise measurements of the neutron lifetime allow us to determine the largest CKM matrix element, Vud. I will present a modern theoretical framework that accounts for subtle effects, like radiative corrections, in low-energy processes with nucleons. These corrections are essential for achieving high precision in extracting Vud.

For neutrinos, future experiments such as Hyper-Kamiokande in Japan and LBNF/DUNE in the USA aim to answer fundamental questions, such as whether neutrinos preserve charge-parity (CP) violation and the ordering of their masses. These experiments depend on accurate predictions of how neutrinos interact with matter. I will review recent theoretical progress on radiative corrections, the structure of hadrons, and neutrino-nucleus interactions, and discuss their role in determining the elements of the PMNS matrix.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 24 stycznia (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Highlights on BSM searches at CMS”

Referuje: dr Małgorzata Kazana (NCBJ)

The searches for the Beyond the Standard Model physics with the CMS experiment at LHC will be presented

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 17 stycznia (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Linear Collider Vision for the update of the European Particle Physics Strategy”

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

LCVision idea was born in spring 2024. The main goal was to make a strong case for Linear Colliders in general, based on physics arguments. With mature designs for the first stage and attractive upgrade options Linear Collider Facility (LCF) is being proposed as an alternative option for the future project at CERN. Last week Linear Collider Vision Community Event took place at CERN with about 250 registered participants. Selected results from the meeting will be presented.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 10 stycznia (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„High Energy Neutrinos: Recent results from IceCube”

Referuje: dr Joanna Kiryluk  (Stony Brook University)

IceCube neutrino observatory is 1km3 detector located at the South Pole in Antarctica. It’s been continuously taking data, since its completion in 2010. 

In 2012, IceCube detected first PeV neutrino events, the highest energy neutrinos ever observed, and measured an unexpectedly large astrophysical diffuse neutrino flux. 

Since then, we characterized this flux utilizing different detection selections with:  all-flavor neutrino events starting in the detector,  muon neutrino induced tracks, and  cascades events, dominated by electron and tau neutrino flavors. The diffuse flux was found to be well described by a single power law with a spectral index of 2.5, softer than expected.

Its origin remains largely unknown. In 2017, an IceCube neutrino alert from a direction of TXS 0506+056 triggered a multi-wavelength campaign of followup observations, and identified TXS 0506+056 as a cosmic rays accelerator and a common source of high energy neutrinos and gamma rays: a breakthrough in multi-messenger astronomy.

Since then, IceCube found evidence that astrophysical neutrinos are correlated with NG1068, PKS1424+240 and TXS0506+056 active galaxies.

In this talk we will review IceCube results on astrophysical neutrino diffuse flux and sources, as well as plans for the future.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 6 grudnia (piątek) o godzinie 11:30, w sali B2.38 odbędzie się seminarium, na którym zostanie wygłoszony referat pt.:

„Latest Results and Status of the LUX-ZEPLIN Dark Matter Experiment”

Referuje: Leah Wolf  (Royal Holloway University of London)

The LUX-ZEPLIN (LZ) experiment is a dark matter direct detection experiment located 4,850 feet underground at the Sanford Underground Research Facility (SURF) in South Dakota. The detector is a dual-phase Time Projection Chamber (TPC) that whose target consists of 7 tonnes liquid xenon target aimed at detecting dark matter interactions, primarily from the highly-motivated candidate – Weakly Interacting Massive Particles (WIMPs), as well as some other phenomena beyond the standard model. LZ continues to constrain parameter-space for WIMP-like dark matter as it acquires more data towards its goal of 1,000 days of live time. This talk will present LZ’s new results from the combined 2022-2024 exposure and the status of the detector.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak

prof. dr hab. Aleksander Filip Żarnecki