2017 Impact factor 1.947
Special Topics

EPJ A Highlight - The P2-Experiment - A future high-precision measurement of the weak mixing angle at low momentum transfer

The experimental setup of the P2-experiment to measure the weak mixing angle at the new electron accelerator MESA in Mainz.

The P2-experiment at the new electron accelerator MESA in Mainz aims at a high-precision determination of the weak mixing angle at the permille level at low Q2. This accuracy is comparable to existing measurements at the Z-pole but allows for sensitive tests of the Standard Model up to a mass scale of 50 TeV. The weak mixing angle will be extracted from a measurement of the parity violating asymmetry in elastic electron-proton scattering. The asymmetry measured at P2 is smaller than any asymmetry measured so far in electron scattering, with an unprecedented accuracy. This review just published in EPJ A describes the underlying physics and the innovative experimental techniques, such as the Cherenkov detector, beam control, polarimetry, and the construction of a novel liquid hydrogen high-power target. The physics program of the MESA facility comprises indirect, high-precision search for physics beyond the Standard Model, measurement of the neutron distribution in nuclei, transverse single-spin asymmetries, and a possible future extension to the measurement of hadronic parity violation.

Dominik Becker et al. (2018), The P2 experiment, Eur. Phys. J. A (2018) 54: 208, DOI 10.1140/epja/i2018-12611-6

Managing Editors
Anne Ruimy (EDP Sciences) and Sabine Lehr (Springer-Verlag)
Thank you very much, Isabelle! Very timely. And the cover looks fantastic! We are grateful for the great collaboration! Best wishes.

Dirk Helbing, ETH Zurich, Switzerland
Editor EPJ Special Topics 214, 2012

ISSN: 1951-6355 (Print Edition)
ISSN: 1951-6401 (Electronic Edition)

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