The effect of the fluorescence yield selection on the energy scales of Auger, HiRes and TA

Thumbnail Image
Full text at PDC
Publication Date
Advisors (or tutors)
Journal Title
Journal ISSN
Volume Title
EDP Sciences
Google Scholar
Research Projects
Organizational Units
Journal Issue
The fluorescence yield data used for shower reconstruction in the Auger, HiRes and TA experiments are different, not only in the overall absolute value but also in the wavelength spectrum and the various atmospheric dependencies. The effect on the energy reconstruction of using different fluorescence yield parameterizations is discussed. In addition, the impact of a change in the fluorescence spectrum depends on the optical efficiency of the telescopes. A simple analytical procedure allows us to evaluate the combined effect of fluorescence yield and optical efficiency showing a non-negligible deviation between the energy scales of TA and Auger. However no relevant effect is found in the comparison between HiRes and Auger. Finally we show that a similar procedure could also be applied with real data.
© Owned by the authors, published by EDP Sciences, 2013. ESSN: 2100-014X This work has been supported by the former Ministerio de Ciencia e Innovación (FPA2009-07772 and CONSOLIDER CPAN CSD2007-42). Data of the fluorescence yield and optical efficiency of TA have been kindly provided by Y. Tsunesada and D. Ikeda. Fruitful discussions with our colleagues of the Auger collaboration are acknowledged. International Symposium on Future Directions in Ultra High Energy Cosmic Ray Physics (2012. Ginebra, Suiza).
UCM subjects
[1] Y. Tsunesada on behalf of the WG of UHECR spectrum data in these Proceedings. [2] M. Monasor et al., Astropart. Phys. 34 (2011) 467 [3] M. Nagano et al., Astropart. Phys. 22 (2004) 235 [4] M. Ave et al., [AIRFLY Collaboration], Astropart. Phys. 28 (2007) 41 [5] M. Ave et al., [AIRFLY Collaboration], Nucl. Instr. Meth. A 597 (2008) 50. Updated results can be found in [6] J. Abraham et al., [Pierre Auger collaboration], Nucl. Instr. and Meth. A 620 (2010) 227 [7] F. Kakimoto et al., Nucl. Instr. and Meth. A 372 (1996) 527 [8] A.N. Bunner, “Cosmic Ray Detection by Atmospheric Fluorescence”, Ph.D. Thesis, Cornell University, Ithaca, N.Y. (1967) [9] T. Z. AbuZayyad, “The Energy Spectrum of Ultra High Energy Cosmic Rays”, Ph.D. Thesis, The University of Utah, Salt Lake City, Utah (2000) [10] R. Abbasi et al., [FLASH Collaboration], Astropart. Phys. 29 (2008) 77 [11] A. Bucholtz, Applied Optics 34 (1995) 2765 [12] M. Unger et al., Nucl. Instr. and Meth. A 588 (2008) 433