Using a data set of 2.93 fb−1 taken at a center-of-mass energy s=3.773 GeV with the BESIII detector at the BEPCII collider, we perform a search for an extra U(1) gauge boson, also denoted as a dark photon. We examine the initial state radiation reactions e+e−→e+e−γISR and e+e−→μ+μ−γISR for this search, where the dark photon would appear as an enhancement in the invariant mass distribution of the leptonic pairs. We observe no obvious enhancement in the mass range between 1.5 and 3.4 GeV/c2 and set a 90% confidence level upper limit on the mixing strength of the dark photon and the Standard Model photon. We obtain a competitive limit in the tested mass range.
|Original language||English (US)|
|Number of pages||6|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Nov 10 2017|
Bibliographical noteFunding Information:
The BESIII collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by National Key Basic Research Program of China under Contract No. 2015CB856700 ; National Natural Science Foundation of China (NSFC) under Contracts Nos. 11235011 , 11335008 , 11425524 , 11625523 , 11635010 ; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts Nos. U1332201 , U1532257 , U1532258 ; CAS under Contracts Nos. KJCX2-YW-N29 , KJCX2-YW-N45 , QYZDJ-SSW-SLH003 ; 100 Talents Program of CAS ; National 1000 Talents Program of China ; INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology ; German Research Foundation DFG under Contracts Nos. Collaborative Research Center CRC 1044 , FOR 2359 ; Istituto Nazionale di Fisica Nucleare , Italy; Joint Large-Scale Scientific Facility Funds of the NSFC and CAS ; Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) under Contract No. 530-4CDP03 ; Ministry of Development of Turkey under Contract No. DPT2006K-120470 ; National Natural Science Foundation of China (NSFC); National Science and Technology fund ; The Swedish Resarch Council ; U.S. Department of Energy under Contracts Nos. DE-FG02-05ER41374 , DE-SC-0010118 , DE-SC-0010504 , DE-SC-0012069 ; University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt; WCU Program of National Research Foundation of Korea under Contract No. R32-2008-000-10155-0 .
- Dark photon search
- Initial state radiation