Month: Styczeń 2022

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 27 stycznia (piątek) o godzinie 10:15, w sali B2.38 odbędzie się

seminarium, na którym zostanie wygłoszony referat pt.:

„How to detect GeV neutrinos using a magnetised detector? Iron Calorimeter @ India-based Neutrino Observatory”

Referuje: Dr Lakshmi S.Mohan (NCBJ)

Abstract:

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.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak
prof. dr hab. Jan Królikowski
prof. dr hab. Aleksander Filip Żarnecki

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 21 stycznia (piątek) o godzinie 10:15, w sali B2.38 odbędzie się

seminarium, na którym zostanie wygłoszony referat pt.:

„T2K Near Detector Fit -Exclusive Behind the Scenes Materials.”

Referuje: Kamil Skwarczyński

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.

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak
prof. dr hab. Jan Królikowski
prof. dr hab. Aleksander Filip Żarnecki

High Energy Physics Seminar (21 January 2022) · Indico (cern.ch)

 

SEMINARIUM FIZYKI WIELKICH ENERGII

Dnia 14 stycznia (piątek) o godzinie 10:15, w sali B2.38 odbędzie się

seminarium, na którym zostanie wygłoszony referat pt.:

„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.”

Referuje: Dr Artur Ukleja

Abstract

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).

Serdecznie zapraszamy

dr hab. Katarzyna Grzelak
prof. dr hab. Jan Królikowski
prof. dr hab. Aleksander Filip Żarnecki

High Energy Physics Seminar (14 January 2022) · Indico (cern.ch)