Possible explanation of the electron positron anomaly at 17 MeV in 8Be transitions through a light pseudoscalar
Possible explanation of the electron positron anomaly at 17 MeV in 8Be transitions through a light pseudoscalar
 
  We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the $^8Be$ anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type quarks are about 0.3 times the coupling of the standard Higgs boson. Then constraints from K and B decays require that loop contributions to flavour changing vertices cancel at least at the 10% level. Constraints from beam dump experiments require the coupling of A to electrons to be larger than about 4 times the coupling of the standard Higgs boson, leading to a short enough A life time consistent with an explanation of the anomaly.
  hep-ph
  
  
  
    
      Ellwanger, Ulrich
      
        13d3bd7e-8699-4502-be9f-e6327b4aab22
      
     
  
    
      Moretti, Stefano
      
        b57cf0f0-4bc3-4e02-96e3-071255366614
      
     
  
  
   
  
  
    
    
  
    
    
  
  
    
      Ellwanger, Ulrich
      
        13d3bd7e-8699-4502-be9f-e6327b4aab22
      
     
  
    
      Moretti, Stefano
      
        b57cf0f0-4bc3-4e02-96e3-071255366614
      
     
  
       
    
 
  
    
      
  
  
  
  
  
  
    Ellwanger, Ulrich and Moretti, Stefano
  
  
  
  
   
    (2016)
  
  
    
    Possible explanation of the electron positron anomaly at 17 MeV in 8Be transitions through a light pseudoscalar.
  
  
  
  
    Journal of High Energy Physics, 11, [039].
  
   (doi:10.1007/JHEP11(2016)039). 
  
  
   
  
  
  
  
  
   
  
    
    
      
        
          Abstract
          We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the $^8Be$ anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type quarks are about 0.3 times the coupling of the standard Higgs boson. Then constraints from K and B decays require that loop contributions to flavour changing vertices cancel at least at the 10% level. Constraints from beam dump experiments require the coupling of A to electrons to be larger than about 4 times the coupling of the standard Higgs boson, leading to a short enough A life time consistent with an explanation of the anomaly.
         
      
      
        
          
            
  
    Text
 JHEP11(2016)039
     - Version of Record
   
  
  
    
  
 
          
            
          
            
           
            
           
        
        
       
    
   
  
  
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      Accepted/In Press date: 28 October 2016
 
    
      e-pub ahead of print date: 8 November 2016
 
    
  
  
    
  
    
     
        Additional Information:
        12 pages, discussion of nuclear shell model corrected,
      
    
  
    
  
    
  
    
  
    
     
        Keywords:
        hep-ph
      
    
  
    
     
        Organisations:
        Theory Group
      
    
  
    
  
  
  
    
  
  
        Identifiers
        Local EPrints ID: 411793
        URI: http://eprints.soton.ac.uk/id/eprint/411793
        
          
        
        
        
          ISSN: 1029-8479
        
        
          PURE UUID: 2fa976ea-c16f-4813-9783-185c80f82bea
        
  
    
        
          
        
    
        
          
            
              
            
          
        
    
  
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  Date deposited: 26 Jun 2017 16:30
  Last modified: 16 Mar 2024 03:34
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          Author:
          
            
            
              Ulrich Ellwanger
            
          
        
      
        
      
      
      
    
  
   
  
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