BASE – The Baryon Antibaryon Symmetry Experiment

Abstract

Abstract. The Baryon Antibaryon Symmetry Experiment (BASE) aims at performing a stringent test of the combined charge parity and time reversal (CPT) symmetry by comparing the magnetic moments of the proton and the antiproton with high precision. Using single particles in a Penning trap, the proton/antiproton g-factors, i.e. the magnetic moment in units of the nuclear magneton, are determined by measuring the respective ratio of the spin-precession frequency to the cyclotron frequency. The spin precession frequency is measured by non-destructive detection of spin quantum transitions using the continuous Stern-Gerlach effect, and the cyclotron frequency is determined from the particle's motional eigenfrequencies in the Penning trap using the invariance theorem. By application of the double Penningtrap method we expect that in our measurements a fractional precision of δg/g 10

Improved limit on the directly measured antiproton lifetime

“…The BASE apparatus [11] is located at CERNʼs Antiproton Decelerator (AD) facility in Geneva, Switzerland, and consists of four stacked Penning traps. A Penning trap is formed by the superposition of a homogeneous magnetic field in axial direction and a quadrupolar electrostatic field by applying appropriate voltages to trap electrodes of carefully chosen geometry [12].…”

Towards Quantum Logic Inspired Cooling and Detection for Single (Anti-)Protons

“…We are currently setting up an experiment to demonstrate this approach using protons. Since the design is adapted from the BASE experiment at CERN [10], it will be possible to implement these ideas at the BASE CERN setup with antiprotons once successfully demonstrated with protons. Our immediate focus is on implementing control over 9 Be + in a cryogenic Penning trap.…”

“…Parts of the trap array are based on the BASE CERN apparatus [10]. The trap stack will consist of modules with dedicated functions:…”

Perspectives for low energy antiproton physics at FAIR

“…overviews on ALPHA [10], ATRAP [11], and ASACUSA [12]). In recent years several new experiments at CERN-AD have been approved (AEgIS [13], GBAR [14], BASE [15]) or are proposed showing a growing interest in low-energy antiproton beams.…”