H2020Индивидуална стипендия2021–2023

TAULEPGAMMA · Search for the Lepton Flavour Violating Decay Tau to Lepton + Gamma at the Belle II Experiment

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-06-01 → 2023-05-31
Финансиране от ЕС: 183 473 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Разпадът на тау-лептона до мюон и фотон се търси чрез анализ на данни от експеримента Belle II. Доказването на такъв процес би потвърдило съществуването на физични явления, които не се обясняват от Стандартния модел.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Search for the Lepton Flavour Violating Decay Tau to Lepton + Gamma at the Belle II Experiment

The Standard Model (SM) of elementary particle interactions is one of the best-tested theories in physics. The discovery of the Higgs boson was one of the big breakthroughs in physics of the past decade and the last missing piece of the SM. However, despite its success in describing fundamental forces, there is abundant evidence of phenomena not covered by this model, such as the existence of Dark Matter. In the SM, lepton flavour (LF) is empirically conserved: electrons, muons and tau are produced or decay in association with their respective neutrinos, such that the total number in each family remains the same. The tau can thus decay into a tau neutrino, a muon, and a muon antineutrino; with the antiparticle counted as (-1). Meanwhile the decay τ → μγ , where a muon is produced alongside a photon, is forbidden. The observation of neutrino oscillations, through which the three neutrinos can transform into each other, was the first direct observation of physics outside the SM, proving lepton flavor violation (LFV) is possible. However so far no such phenomenon has been observed with charged particles. Direct observation of charged LFV decays would constitute an enormous breakthrough in the field and an unambiguous, exciting proof of the existence of new physics. This project aims to exploit the unique data set collected by the Belle II experiment at the SuperKEKB electron-positron collider in Tsukuba, Japan, to perform a high-precision measurement of LFV decays of tau. Belle II, which has started full operation in 2019, has so far observed over 900 million tau decays that can be exploited to search for LFV decays of tau leptons with world-leading precision. This action produced a first important measurement of LFV using this data, set the basis for the measurement of a second LFV decay, and developed techniques broadly applicable to all tau research taking place at Belle II.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

I propose a measurement of the lepton flavour violating (LFV) tau -> lepton + gamma decay, where the lepton is a muon or an electron. This will be carried out at the University of Pisa (Italy) under the supervision of Prof. Francesco Forti. Although highly successful, the Standard Model (SM) of particle physics does not completely describe all the phenomena we observe, such as the recent discovery of neutrino oscillations which violate lepton flavour conservation in the neutral sector. Many scenarios have been advanced to extend the SM into a bigger picture; several of these models predict LFV to occur in the charged sector as well at measurable rates.I will exploit the unprecedented data sample provided by the Belle II experiment at SuperKEKB to measure the tau -> lepton + gamma decay rate with a sensitivity of at least a factor of four greater than any previous measurement. In order to achieve this result I will develop an advanced physics analysis, making full use of the characteristics of the state-of-the-art Belle II detector and incorporating modern techniques such as machine learning. I will use my experience in physics analysis, preparatory studies and detector performance measurements to make this possible.The impact of a measurement of such sensitivity would be tremendous. A discovery of charged LFV would constitute an enormous breakthrough which would spark a new era of particle physics; a non-observation would instead place strong constraints on possible extensions of the SM and inform physics studies for the coming decade.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITA DI PISA · PisaКоординаторИталия