Título: | STRATEGIES FOR THE SEARCH OF CHARGE-PARITY VIOLATION IN THE D+ → PI−PI+PI+ DECAY IN THE LHCB EXPERIMENT | ||||||||||||
Autor: |
LUCAS CORDEIRO ROMAO |
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Colaborador(es): |
CARLA GOBEL BURLAMAQUI DE MELLO - Orientador |
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Catalogação: | 16/JAN/2023 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=61778&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=61778&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.61778 | ||||||||||||
Resumo: | |||||||||||||
Last century we discovered the existence of antiparticles, and since then
the search to understand the asymmetry between particles and antiparticles
has been a strong field of research in physics. Among the conditions that make
matter-antimatter asymmetry possible in the Universe is the Charge-Parity
Violation (CPV) phenomenon. Due to it we observe differences between the
decay processes of a particle and its antiparticle. Such a phenomenon has
important effects for mesons formed by b or s quarks, but the predictions of
this effect for the charm sector are very small, with CP asymmetries around
the order of 10−3 or smaller. In fact only recently has CPV been observed in
2-body decays of D0 mesons.
This dissertation presents the validation of strategies in the search for
CPV in the D+ → π−π+π+ channel using data from the LHCb experiment
during Run II. The CPV search method, the so-called Mirandizing method,
consists of statistically computing the populations of D+ and D− in intervals of
the two-dimensional phase space, obtaining the significance of the difference of
these populations. For large statistical samples, as is our case, the ultimate goal
is to apply an alternative method by obtaining the number of the populations
through mass fits for each interval.
This work aims to perform the validation of the method. Our strategy is
to perform the procedure by dividing the sample randomly into two subsamples,
but not separating into the D+ and D− samples. What is expected, then,
is that the results demonstrate statistical compatibility between the two samples.
In addition to this validation using data, we will also perform the same
procedure on 100 pseudo-experiments. Finally, we perform sensitivity studies
in order to verify the possible scenarios in which CPV could be observed in this
channel, given the total sample size. For this study, we will obtain the number
of the populations by directly counting the phase space events (Mirandizing)
within the mass region with the highest concentration of signal events.
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