Search for a dark photon in electroproduced $e^{+}e^{-}$ pairs with the Heavy Photon Search experiment at JLab

P.H. Adrian , N.A. Baltzell , M. Battaglieri , M. Bondí , S. Boyarinov , S. Bueltmann , V.D. Burkert , D. Calvo , M. Carpinelli , A. Celentano , G. Charles (1) , L. Colaneri , W. Cooper , C. Cuevas , A. d'Angelo , N. Dashyan , M. de Napoli , R. de Vita , A. Deur , R. Dupre (1) , H. Egiyan , L. Elouadrhiri , R. Essig , V. Fadeyev , C. Field , A. Filippi , A. Freyberger , M. Garçon (2) , N. Gevorgyan , F.X. Girod , N. Graf , M. Graham , K.A. Griffioen , A. Grillo , M. Guidal (1) , R. Herbst , M. Holtrop , J. Jaros , G. Kalicy , M. Khandaker , V. Kubarovsky , E. Leonora , K. Livingston , T. Maruyama , K. Mccarty , J. Mccormick , B. Mckinnon , K. Moffeit , O. Moreno , C. Munoz Camacho (1) , T. Nelson , S. Niccolai (1) , A. Odian , M. Oriunno , M. Osipenko , R. Paremuzyan , S. Paul , N. Randazzo , B. Raydo , B. Reese , A. Rizzo , P. Schuster , Y.G. Sharabian , G. Simi , A. Simonyan (1) , V. Sipala , D. Sokhan , M. Solt , S. Stepanyan , H. Szumila-Vance , N. Toro , S. Uemura , M. Ungaro , H. Voskanyan , L.B. Weinstein , B. Wojtsekhowski , B. Yale

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers

The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for a prompt, electroproduced dark photon with a mass between 19 and 81  MeV/c2. A search for a resonance in the e+e- invariant mass distribution, using 1.7 days (1170  nb-1) of data, showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square of the coupling of the dark photon to the standard model photon are set at the level of 6×10-6. Future runs with higher luminosity will explore new territory.

Mots clés: photon: electroproduction; photon: heavy; photon: mass; photon: hidden sector; photon: decay; quantum electrodynamics: background; luminosity: high; mass spectrum: (electron positron); coupling constant: upper limit; Jefferson Lab; Newport News CEBAF Linac; engineering; accelerator; experimental results; S029HPH

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique des Hautes Energies - Phénoménologie [hep-ph]

P.H. Adrian, N.A. Baltzell, M. Battaglieri, M. Bondí, S. Boyarinov, et al.. Search for a dark photon in electroproduced $e^{+}e^{-}$ pairs with the Heavy Photon Search experiment at JLab. Physical Review D, 2018, 98 (9), pp.091101. ⟨10.1103/PhysRevD.98.091101⟩. ⟨hal-01861976⟩