相关论文: Penguin pollution in the B^0 -> J/psi K_S decay

We study the penguin pollution in the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \alpha_s, m_b being the b quark mass and \alpha_s the strong coupling constant. The deviation \Delta S_{J/psi K_S} of…

We formulate the most-general time-dependent decay distributions of $B_s\to J/\psi (\to l^+l^-) \phi(\to K^+K^-)$ in which the direct CP violation is explicitly incorporated. We then investigate the $B \to J/\psi V$ decays in the…

The mixing-induced CP asymmetries in $B_d \to J/\psi K_S$ and $B_s \to J/\psi \phi$ are essential to detect or constrain new physics in the $B_d\! - \overline{\!B}{}_d$ and $B_s\! - \overline{\!B}{}_s$ mixing amplitudes, respectively. To…

Measurements of CP violation in $B^0_d\to J/\psi K_{\rm S}^0$ and $B^0_s\to J/\psi \phi$ decays play key roles in testing the quark-flavour sector of the Standard Model. The theoretical interpretation of the corresponding observables is…

We calculate the branching ratio of $B\to J/\Psi\pi^{0}$ with a mixed formalism that combines the QCD-improved factorization and the perturbative QCD approaches. The result is consistent with experimental data. The quite small penguin…

The B_s^0 -> J/psi K_S decay has recently been observed by the CDF collaboration and will be of interest for the LHCb experiment. This channel will offer a new tool to extract the angle gamma of the unitarity triangle and to control doubly…

We report on recent progress in studying two aspects of $B$ physics, in which penguin amplitudes play an important role: (1) Bounds on penguin pollution in $B^0(t) \to \pi^+\pi^-$ constraining CKM parameters, and a lower bound on $B^0 \to…

The most common decay used for measuring 2beta_s, the phase of Bs-Bsbar mixing, is Bs -> J/psi phi. This decay is dominated by the colour-suppressed tree diagram, but there are other contributions due to gluonic and electroweak penguin…

The theoretical precision of the measurement of the $B^0_{d,s}$-$\bar B^0_{d,s}$ mixing phases $\phi_{d,s}$ through the benchmark decays $B^0_d\to J/\psi K_S$, $B^0_s\to J/\psi \phi$ and $B^0_s\to J/\psi f_0(980)$ is limited by doubly…

The high precision to which the standard model has been confirmed implies that new physics effects have to be small in the observed processes. Together with the outstanding precision expected from present and future collider experiments…

Controlling the contributions from doubly Cabibbo-suppressed penguin topologies in the decays $B_d^0\to J/\psi K^0_S$ and $B_s^0\to J/\psi\phi$ is mandatory to reach the highest possible precision in the measurement of the $B^0_q$--$\bar…

We analyze the deviations of the mixing induced CP asymmetry in B-->phi Ks from sin(2beta), as well as the deviations of the asymmetries in Bs-->K*K*, Bs-->phi K* and Bs-->phi phi from sin(2beta_s), that arise in SM due to penguin…

Using isospin relations, we predict the Standard-Model correlation between S_{pi^0 K_S}=(sin 2beta)_{pi^0 K_S} and A_{pi^0 K_S}, the mixing-induced and direct CP asymmetries of B^0-> pi^0 K_S. The calculation uses flavour SU(3) only to fix…

The complex phases $\phi_d$ and $\phi_s$, associated with the mixing between neutral $B_q^0$ and $\bar B_q^0$ mesons ($q\in\{d,s\}$), are key observables to test the Standard Model and search for contributions from new physics. They are…

Performing a fit to the available experimental data, we quantify the effect of long-distance contributions from penguin contractions in B^0 to J/psi K^0 decays. We estimate the deviation of the measured S_CP term of the time-dependent CP…

From a time-dependent analysis of the decay $B^0_{d} \to \pi^+ \pi^-$ and using a model-dependent $A_P/A_T$ ratio of the penguin-to-tree amplitudes contributing to the decay, both the weak phase $\alpha$ and the strong phase shift…

We present an improved measurement of the standard model CP violation parameter sin2phi_1 (also known as sin2beta) based on a sample of 85 times 10^6 B Bbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB…

The decay $B^0 \to K^0 \pi^0$, dominated by a $b \to s$ penguin amplitude, holds the potential for exhibiting new physics in this amplitude. In the pure QCD penguin limit one expects $\ckp = 0$ and $\skp = \sin 2 \beta$ for the coefficients…

We present results for the \Delta S=2 matrix elements which are required to study neutral kaon mixing in the standard model (SM) and beyond (BSM). We also provide leading chiral order results for the matrix elements of the electroweak…

The precision of the CP phases $2\beta$ and $2\beta_s$ determined from the mixing-induced CP asymmetries in $B_d\to J/\psi K_S$ and $B_s\to J/\psi \phi$, respectively, is limited by the unknown long-distance contribution of a penguin…