H2020Индивидуална стипендия2021–2023

ASymmetryNamedCP · CP symmetries in rare decays of beauty mesons

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

Период: 2021-09-01 → 2023-08-31
Финансиране от ЕС: 191 149 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Разпадите на beauty мезоните се анализират, за да се измери асиметрията между материята и антиматерията. Това помага да се разбере защо вселената днес се състои основно от материя, въпреки че в началото двете количества са били равни.

Този кратък обзор е генериран от изкуствен интелект

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

Резултати накратко

CP symmetries in rare decays of beauty mesons

Our understanding that everything in the universe is made from a few fundamental particles and governed by four fundamental forces led to the development of the Standard Model (SM) of particle physics in the 1960s and 1970s. The SM describes the relation between three out of four forces and all known fundamental particles. Through an ever increasing number of observations and theoretical developments, the SM has become a well-established model over the years. However, there are questions for which the SM does not provide answers. One of these important questions is why the universe is matter dominated today when it started with an equal amount of matter and antimatter. A mechanism that allows matter and antimatter to evolve differently with time, is called CP violation. It is one of the key conditions required in the early universe for it to evolve to the matter dominated state which we observe today. However the amount of CP violation predicted in the SM is very small and some new dynamics driving this asymmetry is needed. CP violation in the SM originates from a single phase in the CKM quark mixing matrix. Due to the unitarity of the matrix, it can be represented as a triangle in the complex plane, with angles α, β and γ. The measurements of CKM unitarity angles β(φ1) and γ(φ3) probe the internal consistency of the SM. The angle βs which is directly related to the CP violating weak phase φs in b → c ̄cs transitions, is very precisely predicted in the SM, therefore deviations from the SM can be interpreted as new physics. Current measurements of φs agree well with the theoretical predictions, however the uncertainty of the world average is still large and allows new physics effects to be at the order of 10%. The overall objective of the project is to measure CP violation in Bs decays as well as develop tools needed to perform the measurements now and in the future.

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

Цел на проекта

In the recent years, measurements of rare B decays involving b->sll transitions have shown discrepancies compared to predictions of the Standard Model of Particle Physics. These transitions are flavor-changing neutral currents (FCNC): they are forbidden at tree level in the SM and therefore sensitive to contributions of new particles in loops. Global fits to these data suggest new physics contributions that can be explained new physics models involving a tree-level exchange of a lepto-quark or a flavor changing $Z^\prime$ boson. In the decay of neutral Bs meson to a CP eigenstate, the interference between the decay and the B-meson mixing leads to additional observables that are not accessible to flavor specific final states. In the SM, all CP-violating effects are expected to be very small, therefore these observables can make powerful contributions to our understanding of the B-anomalies as they can differ significantly depending on the properties of new physics contributions. This project will measureme the CP violating observables arising in the interference of the decay and mixing of Bs mesons using a tagged analysis for the first time in phimumu decays using full LHCb data set which corresponds to 9 inverse-fb. Additionally a new method to calibrate decay time resolution at LHCb will be developed and tested on run 1-2 data collected at LHCb and will be ready to use for the run 3 which is expected to start at the end of 2021.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITAT ZURICH · ZurichКоординаторШвейцария