Constraining Weakly Interacting Slim Particles with a Massive Star and in the Laboratory

von Seggern, Jan Eike

Dissertation / PhD Thesis

DESY-2014-03173

Constraining Weakly Interacting Slim Particles with a Massive Star and in the Laboratory

von Seggern, J. E. (Corresponding Author)>Extern*

2014
Hamburg

Hamburg 151 pp. (2014) [10.3204/DESY-2014-03173] = Dissertation, University of Hamburg, 2014

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Please use a persistent id in citations: doi:10.3204/DESY-2014-03173

Report No.: DESY-THESIS-2014-001

Abstract: This doctoral thesis is devoted to constraining the allowed parameter space of weakly interacting slim particles (WISPs). WISPs are predicted by many extensions of the Standard Model of Particle Physics (SM): The Peccei-Quinn solution of the strong CP-problem of quantum chromo dynamics requires the existence of an axion; some embeddings of the SM into string theories predict a large number of axion-like particles (ALPs), the so called axi-verse, and hidden photons (HPs). Cosmological and astrophysical observables are sensitive to the existence of WISPs. Measurements of these observables allow to constrain the allowed WISP parameter space. In addition dedicated laboratory based experiments exist. Although the parameter space excluded by these experiments is generally smaller than the regions excluded by measurements of cosmological or astrophysical observables, the results from these experiment are valuable complements to these measurements because they are less model dependent. In this thesis, I present my work that helps to constrain the WISP parameter space in two ways: First, the existence of ALPs implies their production in stellar cores. The oscillation of ALPs with photons in the galactic magnetic field (GMF) suggest an X-ray flux from red supergiant (RSG) stars. RSGs are expected to emit no X-rays if ALPs do not exist. An upper limit for the X-ray count rate from the nearby RSG -Ori (Betelgeuse) is estimated from observations of -Ori with the Chandra X-ray Telescope. The interior of -Ori is modelled with the “Evolve ZAMS” code. Based on this, the corresponding ALP production rate is calculated. Using current estimates of the value of the regular component of the GMF, the resulting X-ray flux density at Earth from ALP-photon oscillations and the corresponding count rates with the Chandra instruments are calculated. Comparison of this estimate with the upper limit from the Chandra measurements allows to exclude values of the ALP-photon coupling above 2 : 1 10 11 GeV 1 for masses below 2 : 6 10 11 eV. Second, a CCD (PI 1024B) camera is characterized in preparation of the “Any Light Particle Search II” experiment (ALPS-II), which is a “light shining through a wall” experiment searching for WISPs that is currently under prepa- ration at DESY in Hamburg. This characterization includes the measurement of the fixed pattern noise (FPN), the read-out noise and dark count rate. It is found that clock-induced charges cause a spatial variation of the FPN and the read-out noise over the CCD chip area. The dark count rate is found to spatially vary, too, which is caused by a non-uniform thermal load on the CCD chip. In addition the quantum efficiency at 1064 nm, the wavelength used in ALPS-II, is measured to be 1 : 2 %. Based on these results, an analysis algorithm for the CCD data is developed and the sensitivity of ALPS-II if using the CCD is compared to the sensitivity if the experiment uses a transition edge sensor (TES) as detector as planned. I find that the sensitivity with CCD on the ALP-photon coupling is one order of magnitude worse than the sensitivity with TES. This deterioration of the sensitivity is caused in equal parts by the lower quantum efficiency and higher dark count rate of the CCD compared to the TES.

Keyword(s): Dissertation

Note: Dissertation, University of Hamburg, 2014

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