Search for $K^+\to\pi^+\nu\bar{\nu}$ at NA62

TL;DR

The NA62 experiment aims to precisely measure the rare decay $K^+ o o uar{ u}$, which tests the Standard Model's flavor sector with minimal theoretical uncertainty, using data from pilot runs at high beam intensity.

Contribution

This paper reports on the status and prospects of the NA62 experiment's measurement of the $K^+ o o uar{ u}$ decay, highlighting its experimental setup and initial data collection.

Findings

Reached design beam intensity in pilot runs

Collected initial data for rare decay measurement

Assessing experimental prospects for 10% BR measurement

Abstract

The decay $K^+\to\pi^+\nu\bar{\nu}$ is highly suppressed in the Standard Model (SM), while its rate can be predicted with minimal theoretical uncertainty. The branching ratio (BR) for this decay is thus a sensitive probe of the flavor sector of the SM; its measurement, however, is a significant experimental challenge. The primary goal of the NA62 experiment is to measure ${\rm BR}(K^+\to\pi^+\nu\bar{\nu})$ with 10% precision. NA62 took data in pilot runs in 2014 and 2015, reaching the design beam intensity. The status of the experiment and the prospects for the measurement of ${\rm BR}(K^+\to\pi^+\nu\bar{\nu})$ are presented.