New ALPS results on hidden-sector lightweights

Klaus Ehret,Maik Frede,Samvel Ghazaryan,Matthias Hildebrandt,Ernst-Axel Knabbe,Dietmar Kracht,Axel Lindner,Jenny List,Tobias Meier,Niels Meyer,Dieter Notz,Javier Redondo,Andreas Ringwald,Günter Wiedemann,Benno Willke

doi:10.1016/j.physletb.2010.04.066

Abstract

The ALPS Collaboration runs a “Light Shining through a Wall” (LSW) experiment to search for photon oscillations into “Weakly Interacting Sub-eV Particles” (WISPs) often predicted by extensions of the Standard Model. The experiment is set up around a superconducting HERA dipole magnet at the site of DESY. Due to several upgrades of the experiment we are able to place limits on the probability of photon–WISP–photon conversions of a few×10−25. These limits result in today's most stringent laboratory constraints on the existence of low mass axion-like particles, hidden photons and minicharged particles.

Highlights

Despite of its tremendous phenomenological success, it is believed that the Standard Model of elementary particle physics is not the ultimate theory of space, time and matter
The LSW probability P (γ → Weakly Interacting Sub-eV Particles” (WISPs) → γ) factorizes into the product of the probabilities for photon → WISP conversion before the wall and for WISP → photon conversion behind it. The latter are given by the same expression if CPT is conserved in the transitions – an assumption that holds in the cases considered in the following – but depend upon the WISP under consideration
Γ →axion-like particles (ALPs) conversions may occur in our case only if the magnetic field is switched on

Summary

Introduction

Despite of its tremendous phenomenological success, it is believed that the Standard Model of elementary particle physics is not the ultimate theory of space, time and matter. There is a growing number of theoretical proposals for extensions of the Standard Model (SM), trying to arrive at an even more unified description of particles and their interactions. Very frequently, these extensions exhibit their truly unifying features only at very high energy scales, far above the electroweak (∼ TeV) scale currently probed by the LHC. The pressures of both chambers are monitored with two Baratron [26] manometers. By doing this, (87 ± 5)% of the light arriving to the detector is contained in the same 42 × 42μm binned pixel. We will refer as pixels to what are bins of pixels

Methods

Results

Conclusion