New exclusion limits for dark gauge forces from beam-dump data

Abstract

We re-analyze published proton beam dump data taken at the U70 accelerator at IHEP Serpukhov with the ν-calorimeter I experiment in 1989 to set mass-coupling limits for dark gauge forces. The corresponding data have been used for axion and light Higgs particle searches in Blümlein et al. (1991Blümlein et al. ( , 1992 [1,2] before. We determine new mass and coupling exclusion bounds for dark gauge bosons.

Search for a Dark Photon ine+e−Collisions atBaBar

“…The average correlation between neighboring points is around 90%. Bounds at the level of 10 −4 -10 −3 for 0.02 < m A 0 < 10.2 GeV are set, significantly improving previous constraints derived from beamdump experiments [11,12,18], the electron anomalous magnetic moment [13], KLOE [14,15], WASA-at-COSY [16], HADES [17], A1 at MAMI [19], and the test run from APEX [20]. These results also supersede and extend the constraints based on a search for a light CP-odd Higgs boson at BABAR [21,22] with a smaller data set.…”

“…No unambiguous signal for a dark photon has been reported so far, and constraints have been set on the mixing strength between the photon and dark photon as a function of the dark photon mass [11][12][13][14][15][16][17][18][19][20][21][22]. Searches for an additional low-mass, dark gauge boson [23] or dark Higgs boson [24] have also yielded negative results.…”

Resonant production of dark photons in positron beam dump experiments

“…[42] the last assumption is required in order to evade the tight constraints from π 0 → γA 0 obtained by the NA48=2 experiment [43], and to render thus viable an explanation of the Fig. 4 the limits from the NA48=2 experiment [43] nor those from the ν-Cal I experiment at the U70 accelerator at IHEP Serpukhov [44,45] which also do not apply for protophobic A 0 . In the figure, the vertical black line gives the location of the DP resonance at m A 0 ¼ 17 MeV.…”

Dark Forces at KLOE/KLOE-2

“…This boson should be able to couple with strength ε 2 e to ordinary particles by means of kinetic mixing with the SM hypercharge field [27][28][29][30][31][32][33][34]. A tipical value for the kinetic mixing parameter ε is expected to be of the order 10 −3 [27,28,33,[35][36][37][38] so that observable effects can be induced at e + e − colliders [35,[39][40][41] and fixed target [42][43][44] or beam dump experiments [45][46][47][48][49].…”