Measurement of the very rare K+→π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

Study of the K+→π0e+νγK^{+} \rightarrow \pi^{0} e^{+} \nu \gamma decay with NA62 experiment at CERN

I performed different measurements of $K^{+} \rightarrow \pi^{0} e^{+} \nu \gamma$ decay (Ke3$\gamma$) branching ratio normalized to $K^{+} \rightarrow \pi^{0} e^{+} \nu$ decay (Ke3) with the NA62 experiment at CERN. For $E^*_{\gamma}> 10 MeV$ and $\theta^*_{e,\gamma}> 10^\circ$, 12242 candidate events have been selected, with the estimated fraction of background at the level of $(3.5 \pm 1.4)\%$, and I obtained $\frac{BR(Ke3\gamma)}{BR(Ke3)} =(1.95 \pm 0.04)\%$. With the same selection the asymmetry $A_\xi = \frac{N_+ - N_-}{N_+ + N_-}$ of the T-odd observable $\xi = \frac{[\overrightarrow{p_{\gamma}} \cdot (\overrightarrow{p_e} \times \overrightarrow{p_\pi})]}{M_K^3}$ has been computed, and I measured $A_\xi = (0.016 \pm 0.017)$. The measurements are still dominated by statistical uncertainties, and they can be improved collecting and analysing more data

Measurement of Br(K+→π+ννˉ)Br(K^+ \to \pi^+ \nu \bar\nu) with the NA62 experiment at CERN

The ultra-rare decay $K^+ \to \pi^+ \nu \bar\nu$, with a very precisely predicted branching ratio of less than $10^{-10}$, is one of the best candidates to reveal indirect effects of new physics at the highest mass scales. The NA62 experiment at CERN SPS is designed to measure $Br(K^+ \to \pi^+ \nu \bar\nu)$ with a decay-in-flight technique, novel for this channel. NA62 took data in 2016, 2017 and 2018. Statistics collected in 2016 and 2017 allows NA62 to reach the Standard Model sensitivity for the $K^+ \to \pi^+ \nu \bar\nu$ search. The analysis of the 2018 data, topic of this PhD thesis, leads to the most precise preliminary measurement ever performed combining the full data set: $Br(K^+ \to \pi^+ \nu \bar\nu) = (1.10^{+0.40}_{-0.35 \; stat} \pm 0.03_{syst}) \cdot 10^{-10}$, with $3.5 \sigma$ significance for the process observation. The context of the measurement is presented, the details of the data analysis are described, with particular emphasis on the improvements achieved in the experimental sensitivity, and the prospects are illustrated

The RICH detector of the NA62 experiment at CERN

The RICH detector of the NA62 experiment is one of the key detectors to achieve the muon rejection needed in the search for the ${K^ + } \to {\pi ^ + }\nu \bar \nu$ decay, performed by NA62. Since $BR({K^ + } \to {\mu ^ + }\nu )$ is higher than $BR({K^ + } \to {\pi ^ + }\nu \bar \nu )$ by more than 9 orders of magnitude, it represents one of the most relevant background contributions. Its rejection is performed with kinematic reconstruction of the event and identification of the charged particles in the final state (pions against muons). The Ring Imaging Cherenkov detector (RICH) gives a muon rejection higher than a factor 100 in the momentum range 15-35 GeV/c, and measures the track crossing time with a resolution better than 100 ps. It is also exploited to provide trigger for charged particles. In this contribution the RICH detector will be described, together with its basic performance, the mirrors alignment procedure and its usage in ${K^ + } \to {\pi ^ + }\nu \bar \nu$ search

Measurement of Br(K+→π+ννˉ)Br(K^+ \rightarrow \pi^+ \nu \bar{\nu}) with the NA62 experiment at CERN SPS

The decay $K^{+} \rightarrow \pi^{+} \nu \bar{\nu}$, with a very precisely predicted branching ratio of less than $10^{-10}$, is one of the best candidates to reveal indirect effects of new physics at the highest mass scales. The NA62 experiment at CERN SPS is designed to measure &nbsp;&nbsp;$Br(K^{+} \rightarrow \pi^{+} \nu \bar{\nu})$ with a decay-in-flight technique, novel for this channel. NA62 took data in 2016, 2017 and 2018. Statistics collected in 2016 and 2017 allows NA62 to reach the Standard Model sensitivity for &nbsp;$K^{+} \rightarrow \pi^{+} \nu \bar{\nu}$; the analysis of the 2018 data leads to the most precise measurement ever performed. The preliminary result of $Br(K^{+} \rightarrow \pi^{+} \nu \bar{\nu})$ measurement from the analysis of the full data set 2016-2017-2018 is presented, and prospects for future reviewed. Passcode: 936602</p

Latest results from the NA62 experiment at CERN: precision measurements and searches in beam-dump mode

Proceedings for Lepton Photon 2023 Conferenc

The K+→π+ννˉK^+\to \pi^+ \nu \bar\nu decay: First results from the NA62 experiment

NA62 is a fixed target experiment installed in the CERN North Area that studies the physics of the $K^+$ meson. Its main purpose is to carry out a precision test of the Standard Model, measuring the branching ratio of the ultra-rare $K^+\to \pi^+ \nu \bar\nu$ decay with a 10% precision, then probing New Physics evidence. NA62 collected data in 2016 and 2017, and the 2018 run is going on. The full 2016 data sample has been analysed. It shows that the new in flight technique for the study of the $K^+\to \pi^+ \nu \bar\nu$ decay works, and 1 signal candidate event has been observed

The ECFA Early Career Researcher's Panel: composition, structure, and activities, 2021 -- 2022

The European Committee for Future Accelerators (ECFA) Early Career Researcher's (ECR) panel, which represents the interests of the ECR community to ECFA, officially began its activities in January 2021. In the first two years, the panel has defined its own internal structure, responded to ECFA requests for feedback, and launched its own initiatives to better understand and support the diverse interests of early career researchers. This report summarises the panel composition and structure, as well as the different activities the panel has been involved with during the first two years of its existence

The ECFA Early Career Researcher's Panel: composition, structure, and activities, 2021 -- 2022

The European Committee for Future Accelerators (ECFA) Early Career Researcher's (ECR) panel, which represents the interests of the ECR community to ECFA, officially began its activities in January 2021. In the first two years, the panel has defined its own internal structure, responded to ECFA requests for feedback, and launched its own initiatives to better understand and support the diverse interests of early career researchers. This report summarises the panel composition and structure, as well as the different activities the panel has been involved with during the first two years of its existence