Related papers: Z-mediated charge and CP asymmetries and FCNCs in …
Recently the D{\O} Collaboration reported an observation of like-sign charge asymmetry (CA), which is about $3.2 \sigma$ deviation from the standard model (SM) prediction. Inspired by the observation we investigate the scalar unparticle…
A non-universal axigluon in generalized chiral color models leads to flavor changing neutral currents (FCNCs) at tree level. We analyze phenomenologically the new contributions to $B_{q}$ (q=d, s) mixing and the related CP asymmetries…
Recently, the D0 Collaboration measured the CP-violating like-sign dimuon charge asymmetry in neutral B decays, finding a 3.2sigma difference from the standard-model (SM) prediction. A non-SM charge asymmetry a_sl^s suggests a new-physics…
The D0 collaboration has announced the observation of the like-sign dimuon charge asymmetry since 2010, which has more than 3\sigma deviation from the Standard Model prediction. One of the promising explanation is considering the existence…
Recently, the D0 collaboration reported a large CP violation in the same-sign dimuon charge asymmetry which has the $3.2 \sigma$ deviation from the value estimated in the Standard Model. In this paper, several new physics models are…
We measure the charge asymmetry $A$ of like-sign dimuon events in 6.1 fb$^{-1}$ of $p\bar{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. From $A$, we extract…
The CP violation of the neutral $B$ meson is the important phenomenon to search for the new physics. The like-sign dimuon charge asymmetry observed by the D$\O$ Collaboration indicates the CP-violating new physics in the $B_s-\bar B_s$…
A large CP-violating phase uncovered recently by CDF and D$\O$ collaborations in the time-dependent CP asymmetry (CPA) of the $B_s\to J/\Psi \phi$ decay clearly indicates that a non-Cabibbo-Kobayashi-Maskawa (CKM) phase has to be brought…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
We reconsider the recent observation by the D0 experiment of a sizable like-sign dimuon charge asymmetry, highlighting that it could be affected by CP-violating New Physics contributions not only in Bd- and Bs-meson mixings, but also in…
Tree-level Flavor-Changing Neutral Currents (FCNC) are characteristic of models with extra vector-like quarks. These new couplings can strongly modify the B^0 CP asymmetries without conflicting with low--energy constraints. In the light of…
We confirm that in order to account for the recent D\O\ result of large like-sign dimuon charge asymmetry, a considerable large new physics effect in $\Gamma_{12}^s$ is required in addition to a large CP violating phase in $B_s -\bar{B}_s$…
We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\alpha_{SM}$ and $\beta_{SM}$, whose main feature is that they can…
The like-sign dimuon charge asymmetry of the $B$ meson, which was reported in the D$\O$ Collaboration, is studied in the SU(5) SUSY GUT model with $S_4$ flavor symmetry. Additional CP violating effects from the squark sector are discussed…
Recently Babar and Belle collaborations have measured direct CP asymmetry $A_{CP}=-0.114\pm 0.020$ in $\bar B^0 \to K^- \pi^+$. The experimental value is substantially different from QCD factorization prediction. We show that SUSY flavor…
Supersymmetric contribution to the CP asymmetry of B_d \to \phi K_S is re-examined. It is emphasized that our analysis takes into account the recently found constraint from the mercury electric dipole moment, in addition to the well-known…
The recent observation of the same-sign dimuon charge asymmetry in the B system by the D0 collaboration has 3.9 sigma deviation from the standard model prediction. However, the recent LHCb data on B-s neutral-meson mixing do not accommodate…
We measure the charge asymmetry $A\equiv(N^{++} - N^{--})/(N^{++} + N^{--})$ of like-sign dimuon events in 6.1~fb$^{-1}$ of $p\bar{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s}=1.96$~TeV at the Fermilab…
The D0 Collaboration reported a 3.2sigma deviation from the standard model prediction in the like-sign dimuon asymmetry. Assuming that new physics contributes only to B_{d,s} mixing, we show that the data can be analyzed without using the…
Recent experimental searches for $A_{SL}$, the CP asymmetry in semileptonic B decay, have reached an accuracy of order one percent. Consequently, they give meaningful constraints on new physics. We find that cancellations between the…