Contribution to a conference proceedings/Internal Report

PUBDB-2015-05588

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Searching a Dark Photon with HADES

Holzmann, R. ; Gumberidze, M. ; HADES Collaboration (Collaboration Author)

2014
Deutsches Elektronen-Synchrotron, DESY Hamburg

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Please use a persistent id in citations: doi:10.3204/DESY-PROC-2014-04/9

Report No.: DESY-PROC-2014-04

Abstract: The existence of a photon-like massive particle, the $\gamma'$ or dark photon, is postulated inseveral extensions of the Standard Model. Such a particle could indeed help to explain the puzzlingbehavior of the observed cosmic-ray positron fraction as well as to solve the so far unexplained deviationbetween the measured and calculated values of the muon $g-2$ anomaly. The dark photon, unlike itsconventional counterpart, would have mass and would be detectable via its mixing with the latter.We present a search for the e$^+$e$^-$ decay of such a hypothetical dark photon, also named $U$~boson, in inclusive dielectron spectra measured with HADES in the p (3.5 GeV) + p, Nb reactions, as well asin the Ar (1.756 GeV/u) + KCl reaction. A new upper limit on the kinetic mixing parametersquared ($\epsilon^2$) at 90\% CL has been obtained in the mass range $M_U$ = 0.02 -- 0.55 GeVand is compared here with the present world data set. For masses 0.03 -- 0.1 GeV, the limit has beenlowered with respect to previous results, allowing to exclude a large part of the parameter spacefavored by the muon $g-2$ anomaly.

Keyword(s): positron: cosmic radiation ; particle: massive ; mixing: kinetic ; photon ; magnetic moment ; anomaly ; HADES ; muon

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Contributing Institute(s):

1. LHC/ATLAS Experiment (ATLAS)
2. LHC/CMS Experiment (CMS)
3. Uni Hamburg / Experimentalphysik (UNI/EXP)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)

Experiment(s):

1. No specific instrument

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Database coverage:

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Book/Proceedings/Internal Report Schmidt, A. (Editor)>Extern* ; Sander, C. (Editor)DESY*
Proceedings, 20th International Conference on Particles and Nuclei (PANIC 14)
2014Panic2014, Panic2014, HamburgHamburg, Germany, 25 Aug 2014 - 29 Aug 20142014-08-252014-08-29 Hamburg : Deutsches Elektronen-Synchrotron, DESY 1-754 (2014) [10.3204/DESY-PROC-2014-04]2014     Files  Fulltext BibTeX | EndNote: XML, Text | RIS

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