| Thesis | |
| Report number | CERN-THESIS-2023-422 |
| Title | Beam intensity effects on the $K^+ \to \pi^+ \nu \bar\nu$ measurement at NA62 |
| Author(s) | Henshaw, Jack Christopher (University of Birmingham (GB)) |
| Publication | 168. |
| Thesis note | PhD : Birmingham U. : 2023-06-01 |
| Thesis supervisor(s) | Goudzovski, Evgueni ; Romano, Angela |
| Note | Presented 01 Dec 2023 |
| Subject category | Detectors and Experimental Techniques |
| Accelerator/Facility, Experiment | CERN SPS ; NA62 |
| Abstract | The ultra-rare $K^+ \to \pi^+ \nu \bar\nu$ decay, precisely predicted in the Standard Model, is a gateway into exploring new physics at mass scales unattainable at present collider experiments. The NA62 experiment at CERN aims at measuring the branching ratio of the $K^+ \to \pi^+ \nu \bar\nu$ decay to a precision of 15% with any deviation from the Standard Model prediction hinting at New Physics. A Cherenkov detector (CEDAR) is used in NA62 to identify a minority component of particles (kaons) in an unseparated hadron beam. The optical design for a new CEDAR detector optimised to work with hydrogen as radiator gas, Cedar-H, is presented. Cedar-H has been commissioned and installed into NA62 with more than satisfactory performances and a 20% increase in light yield. The single event sensitivity for the $K^+ \to \pi^+ \nu \bar\nu$ decay with data collected in 2021 is computed as $B_{SES} = (5.00 \pm 0.13_{stat}) \times 10^{−11}$. Studies of each component entering into this figure and their variation with the intensity of the NA62 hadron beam are performed. A new optimal beam intensity to maximise the number of $K^+ \to \pi^+ \nu \bar\nu$ events collected is discussed. |
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Record creato 2024-10-28, modificato l'ultima volta il 2024-10-30
