Tópicos Física de Partículas, Astrofísica e Cosmologia

11 Feb 2021, 14:00 → 29 Jul 2021, 20:00 Europe/Lisbon

Nuno Leonardo (LIP)

The workshop consists of student presentations, up to 25min, followed by a discussion period.

what: Final student presentation workshop

course: Tópicos Física de Partículas, Astrofísica e Cosmologia,

degree/university: MEFT/IST, 1st semestre 2020/2021

profs: N.Leonardo, M.Pimenta, G.Milhano, A.DeAngelis, A.Sousa

tfpac.pdf

Thursday 11 February

14:00 → 14:25 Overview of parton distribution functions

This paper provides a short overview of parton distribution functions (PDFs), starting with the historical motivation and main experimental results, as well as an introduction to the basics of PDF extraction from deep inelastic scattering (DIS) experiments, and a motivation for the inclusion of nuclear modified parton distributions (nPDFs). Recent literature is discussed, including recent measurements pertaining to evidence of nuclear modifications from electroweak processes, as well as a recent global fit to DIS and beam collision experiments to produce a nPDF set. The interplay of these publications is explored, highlighting the need for both careful parameterization and thourough experimental measurements.

arXiv:1503.05825, arXiv:1612.05741

Speaker: André Cordeiro (IST)

tfpac_AndreCordeiro.pdf

14:45 → 15:10 Search for heavy right-handed W gauge bosons and neutrinos

We review the two most recent papers from the CMS and ATLAS collaborations searching for heavy right-handed gauge bosons and neutrinos in final states containing two charged leptons and two jets. Both analyses use Run 2 proton-proton collision data at 13TeV. CMS uses 2016 and ATLAS 2015+2016 data corresponding to a total integrated luminosity of 35.9/fb and 36.1/fb, respectively. In the CMS analysis, the region in the mWR-mNR plane excluded at 95% confidence level extends to mWR = 4.4 TeV for Majorana neutrinos. In the ATLAS analysis, the excluded region extends to mWR = 4.7 TeV for both Majorana and Dirac NR neutrinos and the mNR > mWR scenario is explored for the first time.

arXiv:1803.11116, arXiv:1809.11105

Speaker: Maria Faria (IST)

tfpac_MariaFaria.pdf

15:30 → 15:55 A review of top quark physics

A review of top quark physics is presented. An overview of the top quark properties and their most recent measurements at the LHC, by the ATLAS and CMS collaborations, are given, and analyses of four top quark production by both collaborations are compared and summarised.

arXiv:2007.14858, arXiv:1908.06463

Speaker: Pedro Lagarelhos (IST)

tfpac_PedroLagarelhos.pdf

16:15 → 16:40 b-tagging methods in CMS and ATLAS

For a better identification and understanding of beyond the standard model physics, current known processes of tagging from jets originated from heavy flavour quarks need to be refined at the high energy colli- sion experiments. This report reviews all the way from the hardware used at ATLAS and CMS Collaborations to the respective simulation techniques and methods of b-tagging. Comparing the performances of the state of the art techniques in view of the Run 2 data at the Large Hadron Collider. Calibration methods to calculate b-jet tagging efficiency such as Tag and Probe and Likelihood Method are also addressed along with the systematic uncertainties for the whole b-tagging process.

arXiv:1805.01845, arXiv:1712.07158

Speaker: Vladlen Galetsky (IST)

tfpac_VladlenGaletsky.pdf

17:00 → 17:25 Exclusive production at the LHC

arXiv:2003.02811, arXiv:1604.04464

Speaker: Gonçalo Diogo (IST)

Friday 12 February

14:45 → 15:10 Axions as cold dark matter candidates

The axion is a hypothetical particle that first appeared as an explanation to the CP problem of Quantum Chromodynamics, however, its potential as a dark matter particle was soon discovered. Nonetheless, decades after it was first postulated, there is no experimental evidence of the axion despite several searches for this minuscule particle. The difficulty in this process was already foreseen, given that the axion couples very weakly to the Standard Model, in addition to being very stable. But all is not lost, the silver lining in the so far fruitless search for this "invisible" boson is that several constraints on the axion’s mass, as well as its coupling constants have been set, opening the door to new challenges. This paper starts with an introduction to the axion and its origin, describing its role as a dark matter particle. Secondly, it highlights some of the constraints imposed by experiments. Lastly, two papers are reviewed in more detail, which describe two very different, but equally important experiments.

arXiv:1705.02290, arXiv:2010.00169

Speaker: Clara Severino (IST)

tfpac_ClaraSeverino.pdf

15:30 → 15:55 A review of Kepler and PLATO 2.0 missions from the asteroseismic point of view

The paper presents a review on stellar astrophysics, specifically asteroseismology. First, an introduc- tion to the theory of oscillations in stars that explains the stellar interior properties. Second, a comparison of two extremely important missions Kepler and PLATO 2.0. One has already a tremendous amount of data that dictates the limit of we what know today, the other will be launched in 2026 with incredible precision and range that will answer the questions that remain.

arXiv:1310.0696, arXiv:1001.0139

Speaker: Beatriz Bordadágua (IST)

tfpac_BeatrizBordadagua.pdf

16:15 → 16:40 Particle acceleration mechanisms within blazars

This paper aims to summarily review the most noteworthy particle acceleration mechanisms which are thought to operate within blazars, with particular focus on the processes which occur in the jets associated with these phenomena. First, an initial description of blazars and their characteristics is provided, followed by a characterisation of the particle acceleration mechanisms proposed to operate within these phenomena. Second, the paper delves into a more detailed description of the particular case of the coincidence of the IceCube- 170922A neutrino and TXS 0506+056 blazar, including the methods and instruments involved throughout the study of this noteworthy phenomenon.

arXiv:1705.02021, arXiv:1604.00318

Speaker: Pedro Costa (IST)

tfpac_PedroCosta.pdf

Thursday 29 July

17:00 → 17:25 Multiple galactic sources

This paper is a review of the high energies studies and their contribution to astronomy. After intro- ducing the theme and theoretical motivation, the experimental aspects from HAWC in high energy experiments are explained and reviewed. Then, recent literature is discussed, such as recent observations of the Crab Nebula for comparison between experiments like LHAASO, which allows us to see the potential in these observatories. Also, recent observations of sources of the 2HWC catalogue are presented.

arXiv:2010.06205, arXiv:1909.08609

https://videoconf-colibri.zoom.us/j/83122186346?pwd=TkNwZjY2UUcwZ291MnlzTUM0UXFyUT09

Speaker: Beatriz Pereira (IST)

tfpac_BeatrizPereira.pdf