Recent anomalies in B physics

It is widely believed that Standard model (SM) is not a final theory and should be an effective one of new theory at higher scale, because SM has a large number of parameters that have to be input from experiment, it does not provide any candidate for dark matter, dark energy and the resource of the matter-antimatter asymmetry of the universe, and does not incorporate gravity. For this reason, the major task of the particle physics switched to the search for the new physics (NP) beyond SM by probing the signals directly and testing SM precisely, after the discovery of Higgs in 2012. However, it is very depressing for us that there is still no strong evidence of NP on the two experiments (ATLAS and CMS) at the CERN Large Hadron Collider (LHC) up to date. In contrast, the LHCb experiment could study the properties of particles containing heavy quarks with high precision, with the large cross section for B meson production in pp collisions. Prior to the startup of LHCb, two B factory experiments, BaBar and Belle, had dominated the landscape of the heavy flavour physics. The measurements of CP violation in B sector confirmed SM expectations and led to Nobel prizes for Kobayashi and Maskawa in 2008. Furthermore, many notable results from these experiments, which not only tested SM, such as the CKM triangle, but placed stringent constraints on NP, such as, measurements of B mesons decays to final states containing τ leptons, i.e., purely leptonic B⁺ →τ⁺ν_τ , the mass differences of neutral mesons and the semileptonic decay B →^{K (∗)}ℓ⁺ℓ^- . Recently, LHCb and Belle experiments reported a few anomalous results in B sector, which cannot be accommodated in SM and might be hints of NP. In this short review, we will introduce these anomalies in detail.