相关论文: Bounds on new physics from B_s mixing
The light gluino (12 - 16 GeV) and light sbottom (2 - 6 GeV) scenario has been used to explain the apparent overproduction of b-quarks at the Tevatron. This scenario also predicts the decay Z -> b b-bar ~g ~g where the gluinos subsequently…
The measurements of rare decays are highly sensitive to physics beyond the standard model. In this article limits on the branching ratios of the decays B0s -> mu+mu-, D0 -> mu+mu- and D+ -> pi+mu+mu- are presented. Furthermore the first…
The main challenge in the Standard Model calculation of the mass and width difference in $D^0 - \bar D^0$ mixing is to estimate the size of SU(3) breaking. We prove that mixing occurs in the Standard Model only at second order in SU(3)…
We discuss the calculation of the width difference $\Delta\Gamma_{B_s}$ between the $B_s$ mass eigenstates to next-to-leading order in the heavy quark expansion. $1/m_b$-corrections are estimated to reduce the leading order result by…
This is an addendum to the previous publication, P. Ko and J.-h. Park, Phys. Rev. D80, 035019 (2009). The semileptonic charge asymmetry in B_s decays is discussed in the context of general MSSM with gluino-mediated flavor and CP violation…
The $B_s$-meson system is a key element in the $B$-physics programme of hadron colliders, offering various avenues to explore CP violation and to search for new physics. One of the most prominent decays is $B_s\to J/\psi\phi$, the…
$B_d$ and $B_s$ meson systems play a fundamental role to test and improve our understanding of Standard Model flavor dynamics. The mixing parameters $\Delta m_{d,s}$ represent important constraints in the unitarity triangle analysis. Their…
The phenomenon of $B^0_q$-$\bar{B}^0_q$ mixing ($q=d,s$) provides a sensitive probe for physics beyond the Standard Model. We have a careful look at the determination of the Unitarity Triangle apex, which is needed for the Standard Model…
An update profile of the CKM matrix is given, providing numerical and graphical constraints on the CKM parameters in the Standard Model. Constraints on additional parameters accounting for possible new physics contribution in a…
We present a measurement of the time-dependent CP-violating asymmetry in B_s -> J/psi phi decays, using data collected with the LHCb detector at the LHC. The decay time distribution of B_s -> J/psi phi is characterized by the decay widths…
Recent results from CDF and D{\O} collaborations favor a large CP asymmetry in B_s^0-\bar{B}_s^0 mixing, while the standard model prediction is very small. Such a large phase may imply sizable new physics effects in B_s^0-\bar{B}_s^0…
Evidence for the decays $B^{0}\rightarrow\bar{D}^{0}\phi$ and $B^{0} \rightarrow \bar{D}^{*0}\phi$ is reported with a significance of 3.6$\,\sigma$ and 4.3$\,\sigma$, respectively. The analysis employs $pp$ collision data at centre-of-mass…
The recent measurements of the B_s meson mixing amplitude by CDF and of the leptonic branching fraction BR(B to tau nu) by Belle call for an upgraded analysis of the Unitarity Triangle in the Standard Model. Besides improving the previous…
Several methods have been devised to measure the weak phase gamma using decays of the type B+- --> D K+-, where it is assumed that there is no mixing in the D0-D0bar system. However, when using these methods to uncover new physics, one must…
In the limit of infinitely heavy b-quarks we compute the SU(3)-breaking ratio xi of neutral B-meson mixing matrix elements. We also present results for the ratio of decay constants f_{B_s}/f_{B_d}. Our calculation employs…
The CP violating phase $\phi_s$ can be measured in the interference between mixing and decay of $B_s^0$ mesons decaying to CP eigenstates. The phase $\phi_s$ the decay width difference $\Delta\Gamma_s$ and the average decay width $\Gamma_s$…
Using the full Belle Upsilon(5S) data sample of 121 fb^-1we have measured exclusive branching fractions for the decays B_s^0 -> D_s^(*)+D_s^(*)-. Assuming these decay modes saturate decays to CP-even final states, the branching fraction…
We have just entered an era of precision measurements for $B_s$-decay observables. A characteristic feature of the $B_s$-meson system is $B^0_s$--$\bar B^0_s$ mixing, which exhibits a sizable decay width difference. The latter feature leads…
We present a calculation of 1/m^2_b corrections to the lifetime differences of B_s mesons \Delta \Gamma_s in the heavy-quark expansion. We find that they are small to significantly affect \Delta \Gamma_s and present the result for lifetime…
I review the existing theoretical uncertainties in relating the semileptonic decay width in b->u transitions to the underlying Kobayashi-Maskawa mixing element |V_ub|. The theoretical error bars are only a few percent in |V_ub|, with…