Dark $Z$ Implication for Flavor Physics

Abstract

Dark $Z$/dark photon ($Z^{\prime }$) is one candidate of dark force carrier, which helps to interpret the properties of dark matter (DM). Other than traditional studies of DM including direct detection, indirect detection and collider simulation, in this work we take flavor physics as a complementary approach to investigate the features of dark matter. We give an exact calculation of the new type of penguin diagram induced by $Z^{\prime }$ which further modifies the well-known $X,Y,Z$ functions in penguin-box expansion. The measurement of rare decays $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ and $B_s\to {\mu }^{+}{\mu }^{-}$ at LHC, together with direct CP violation ${\epsilon }^{\prime }/\epsilon$ in $K\to \pi \pi$ as well as $K_L\to {\mu }^{+}{\mu }^{-}$, are used to determine the parameter space. The size of coupling constant, however, is found to be $\mathcal{O}(1)$ which is much weaker than the known constraints.

13 pages, 3 figures; For V2 typo corrected, references added, published in JHEP

References in corpus (5)

• Observation of an anomalous positron abundance in the cosmic radiation
• Search for a dark photon in e+e- collisions at BABAR
• Probing New Physics via the $B_s^0\to {\mu }^{+}{\mu }^{-}$ Effective Lifetime
• Patterns of Flavour Violation in the Presence of a Fourth Generation of Quarks and Leptons
• Dark Photon as Fractional Cosmic Neutrino Masquerader