Related papers: Fourth generation effect on $\Lambda_b$ decays

B mesons are bound states of a b quark and a light anti-quark. While the binding is provided by the strong interaction B mesons can only decay by the weak interaction. Since the top quark mass is large, B mesons are the only mesons…

LHCb collaboration measured CPV at the level of one percent in the difference of assymetries in $D^0(\bar D^0)\to \pi^+ \pi^-, K^+ K^-$ decays. If confirmed on a larger statistics and final systematics this would mean New Physics…

We propose that the cascade decay $\Lambda_b \to D(\to K^+\pi^-) N(\to p\pi^-)$ may serve as the discovery channel for baryonic CP violation. This decay chain is contributed by, dominantly, the amplitudes with the intermediate $D$ state as…

The existence of the fourth quark-lepton generation is not excluded by the electroweak precision data. However, the recent results on the 126 GeV higgs boson production and decay do not allow an extra generation at least as far as the…

Low-scale baryogenesis could be discovered at $B$-factories and the LHC. In the $B$-Mesogenesis paradigm [G. Elor, M. Escudero, and A. E. Nelson, PRD 99, 035031 (2019), arXiv:1810.00880], the CP violating oscillations and subsequent decays…

Direct CP violations in $B_{l4}$ decays ($B^\pm \to \pi^+\pi^- l^\pm {\nu}_l$) are investigated within the Standard Model (SM) and also in its extensions. In the decay processes, we include various excited states as intermediate states…

We have just entered a new round in the testing of the flavour sector of the Standard Model through high-precision measurements of B-meson decays. A particularly exciting aspect is the exploration of the B_s-meson system at LHCb. We focus…

Searches for $B$ mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either $\Lambda_c$ or $\Lambda$ and the lepton is a muon or an electron. These decays violate both baryon and lepton number…

A perturbative new family of fermions is now severely constrained, though not excluded yet. We reconsider the current bounds (i.e., direct and from Higgs searches, R_b, oblique parameters) on the fourth generation parameter space assuming…

The decay $\Xi^-_b \to \pi^- \Lambda_b$ has recently been observed by the LHCb Collaboration at CERN. In contrast to most weak decays of $b$-flavored baryons, this process involves the decay of the strange quark in $\Xi_b$, and thus has…

We analyse the two purely isospin-violating decays $\Lambda_b\rightarrow \Sigma^0 \phi$ and $\Lambda_b\rightarrow \Sigma^0 J/\psi$, proceed merely via the exchange topologies, in the framework of perturbative QCD approach. Assuming…

We analyze in the four-generation model the first measurement of the branching ratio of rare kaon decay K^+\to\pi^+\nu\bar{\nu}, using the constraints from \Delta m_K, \epsilon_K, B_d-\bar{B_d} mixing, \Gamma (b\to s\gamma), B_s-\bar{B_s}…

We study the four-body semileptonic baryonic decay of $B^-\to \Lambda\bar p\nu\bar \nu$ in the standard model. We find that the decay branching ratio is $(7.9\pm 1.9)\times 10^{-7}$. Similar to the rare decays of $B^-\to K^{(*)-}\nu\bar…

In the heavy quark limit, the form factors for semileptonic and rare radiative B decays into light mesons are related by heavy quark spin symmetry. Here we compute the leading corrections of order \Lambda/m_Q to these symmetry relations,…

The exploration of B-meson decays has reached an unprecedented level of sophistication, with a phase of even much higher precision ahead of us thanks to run 2 of the LHC and the future era of Belle II and the LHCb upgrade. For many…

The branchings fractions of the rare $B_s$ decays are calculated in the framework of the QCD-motivated relativistic quark model. The form factors of the weak $B_s$ transitions to light mesons are expressed through the overlap integral of…

The $B$-Mesogenesis model explains the matter-antimatter asymmetry and leads to the right amount of dark matter in the Universe. In particular, this model predicts new decay channels of the $b$ quark. We investigate the modification of…

We study the $Z_{cs}(3985)$ and $Z_{cs}(4000)$ exotic states in the decays of $\Lambda_b$ baryons through a molecular scenario. In the final state interaction, the $\Lambda_b\to \Lambda_c^+ D_s^{(*)-}$ decays are followed by the…

In these lectures we give, first, the model-independent analysis of the exclusive rare decays B -> K l(bar) l and B_c -> D(D*) l(bar) l with special emphasis on the cascade decay B_c -> D(*)(-> D pi) l(bar) l. We derive a four-fold angular…

The special features of CP violation in the Standard Model are presented. The significance of measuring CP violation in B, K and D decays is explained. The predictions of the Standard Model for CP asymmetries in B decays are analyzed in…