Month: May 2017

Graduate Seminar, 30th May

Speaker: Oleg Shkola

Title : Search for charged massive particles with a disappearing track signature at CMS

Abstract: Among different scenarios of the supersymmetry breaking, Anomaly-Mediated SUSY Breaking (AMSB) predicts a small mass splitting between the lightest neutralino and chargino. Then chargino can decay into neutralino  and a low-momentum pion. If chargino decays in a tracker this leads to a disappearing track. In the presentation I will show how in the CMS detector we can reconstruct disappearing tracks. I will also present results as limits on the chargino mass and its mean lifetime for direct electroweak chargino-chargino and chargino-neutralino production.

Graduate Seminar, 23rd May

Speaker: Dobromił Załoga

Title: Research on emission of visible and X-ray radiation, and estimations of electron temperature in discharges of Plasma-Focus type

Abstract: This presentation reports on results of detailed experimental studies of the visible and x-ray emission, as well as estimations of plasma electron temperatures in discharges of the Plasma-Focus (PF) type, particularly in the PF‑1000U facility at IPPLM. In particular there are summarized measurements of the visible radiation from PF discharges, measurements performed by means of laser interferometry, time-integrated measurements of x-rays, as well as time-resolved measurements of soft x‑rays, which were performed by means of framed MCP (Micro-Channel Plate) and “pinhole” cameras equipped with scintillation detectors, as well as by means of a set of 4 semiconductor PIN-type diodes equipped with appropriate absorption filters. It was shown that the formation of different microstructures inside the dense and hot plasma column during PF‑type discharges depends strongly on experimental conditions, and particularly on gas conditions. At the same experimental conditions microstructures in form of plasma-current filaments are relatively well reproducible in the macroscopic scale, but microstructures in form of hot-spots are irreproducible. Due to a stochastic character of the formation of such microstructures, their parameters (i.e. positions, lifetime, density and electron temperature) can differ considerably, e.g. local values of electron temperature Te can change in a range from about 100 eV to about 880 eV.

Graduate seminar, 16th May

Speaker: Michał Palczewski

Title: „Detailed illustration of accuracy of presently used nuclear-mass models”

Abstract: The accuracy of used nuclear – mass models plays important role in nuclear research and is still being developed by different scientific groups. During the seminar I would like to focus more on that topic mentioned in my last talk. Different approaches to this problem give different accuracies but the precision of each model varies in different regions of nuclear chart. This can be represented by simple but very useful and detailed pictures showing the deviations between masses (experimental and theoretical one) for each nucleus. Later these data can be applied in research, e.g. in improvements of known models and in the prediction of values of masses of still unknown isotopes; with the predictive power seen mostly in macro-micro models. However, what should be mentioned, especially with other models, a model predicting well known masses doesn’t have to work well in the prediction of unknown ones, showing the problem of need of using appropriate models in a given area of the research.

Graduate Seminar, 9th May

Speaker: Katarzyna Frankiewicz

Title: The CosmicWatch project

Abstract: CosmichWatch is a simple, physics-motivated machine- and electronics-shop project for university students and schools. Our detector is a self-contained apparatus that employs a plastic scintillator as a detection medium and a silicon photomultiplier for light collection. The detector can be battery powered and used in conjunction with the provided software to make interesting physics measurements.

Venue: Room 22, 9:00 A.M.