In this research the weak decay of $B^+_c$ decays to the $K^+K^-π^+$ final state, which is observed by LHCb collaboration for the first time, is calculated in the quasi-two-body decays which takes into account the $B^0_s$, $χ_{c0}$ and $D^0$ resonances and weak annihilation nonresonant contributions. In this process, the $B^+_c$ meson decays first into $B^0_sπ^+$, $χ_{c0}π^+$ and $D^0π^+$ intermediate states, and then the $B^0_s$, $χ_{c0}$ and $D^0$ resonances decay into $K^+K^-$ components, which undergo final state interaction. The mode of the $B^+_c\rightarrow D^0(\rightarrow K^-π^+)K^+$ is also associated to the calculation, in this mode the intermediate resonance $D^0$ decays to the $K^-π^+$ final mesons. The resonances $B^0_s$, $χ_{c0}$ and $D^0$ effects in the $B^+_c\rightarrow B^0_s(\rightarrow K^+K^-)π^+$, $B^+_c\rightarrow χ_{c0}(\rightarrow K^+K^-)π^+$ and $B^+_c\rightarrow D^0(\rightarrow K^+K^-)π^+, D^0(\rightarrow K^-π^+)K^+$ decays are described in terms of the quasi-two-body modes. There is a weak annihilation nonresonant contribution in which $B^+_c$ decays to the $K^+K^-π^+$ directly, so the point-like 3-body matrix element $\langle K^+K^-π^+|u\bar{d}|0\rangle$ is also considered. The decay mode of the $B^+_c\rightarrow \bar{K}^{*0}(892)K^+$ is contributed to the annihilation contribution. The branching ratios of quasi-two-body decays expand in the range from $1.98\times10^{-6}$ to $7.32\times10^{-6}$.
We show that the long known puzzling branching ratios of open-charm decays in electron-positron annihilation can be reasonably described with a simple form factor, which strongly suppresses open channels far above threshold. Application to the electron-positron annihilation into J/psi+pion+pion data on the X(4260) enhancement recently reported by the BABAR Collaboration [arxiv:0808.1543] allows a good fit with a simple nonresonant cusp structure around the D(*)(s)+Dbar(*)(s) threshold. Moreover, we argue that a closer look at the data reveals an oscillatory pattern, which we model as an interf…
We consider a new technique for neutrino energy and topology reconstruction at DUNE. In particular, we show that when the direction of the incoming neutrino is known, one can use the measured directions of the outgoing leptonic and hadronic particles to reconstruct poorly-measured quantities, such as the hadronic cascade energy. We show that this alternative technique yields an energy resolution which is comparable to current reconstruction methods which sum measured energies. As a proof of concept we apply this new reconstruction method to a search for dark matter annihilation in the Sun. We …
We present in this work a study of tree-dominated charmless three-body decays of $B$ mesons, $B^-\to K^+K^-π^-$ and $B^-\toπ^+π^-π^-$, within the factorization approach. The main results are: (i) There are two distinct sources of nonresonant contributions: one arises from the $b\to u$ tree transition and the other from the nonresonant matrix element of scalar densities $\langle M_1M_2|\bar q_1 q_2|0\rangle^{\rm NR}$. It turns out that even for tree-dominated three-body decays, dominant nonresonant contributions originate from the penguin diagram rather than from the $b\to u$ tree process, as i…
The CDF 3.7 sigma evidence of pure annihilation $B_s \to π^+ π^-$ decays, if confirmed, would imply a large annihilation scenario in the QCD factorization approach. This is somewhat unexpected as the large annihilation scenario was disfavored in previous studies. In this paper we reinvestigate the role of annihilation topology in QCD factorization. We find that it is not easy to reach the CDF central value of $B_s \to π^+ π^-$ decays when other decay channels are considered. Our analysis also reveals that, for well-measured charmless B decays into two final pseudoscalar mesons, the QCD factori…
We investigate the pure annihilation type radiative $B$ meson decays $B^0 \to ϕγ$ and $B_s \to ρ^0(ω)γ$ in the soft-collinear effective theory. We consider three types of contributions to the decay amplitudes, including the direct annihilation topology, the contribution from the electro-magnetic penguin operator and the contribution of the neutral vector meson mixings. The numerical analysis shows that the decay amplitudes are dominated by the $ω-ϕ$ mixing effect in the $B^0 \to ϕγ$ and $B_s \to ωγ$ modes. The corresponding decay branching ratios are enhanced about three orders of magnitudes r…
In this paper, the contributions of weak annihilation and hard spectator scattering in $B\to ρK^*$, $ K^* \bar{K}^*$, $ϕK^*$, $ρρ$ and $ϕϕ$ decays are investigated within the framework of QCD factorization. Using the experimental data available, we perform $χ^2$ analyses of end-point parameters in four cases based on the topology-dependent and polarization-dependent parameterization schemes. The fitted results indicate that: (i) In the topology-dependent scheme, the relation $(ρ_A^{i},ϕ_A^{i})\neq (ρ_A^{f},ϕ_A^{f})$ gotten through $B\to PP$ and $PV$ decays is favored by the penguin-dominated $…
We discusses the charge asymmetry in $ B\rightarrow D\bar DK$ decays with an invariant mass of the $D\bar D$ pair near the $Ψ(3770)$ resonance. Unlike $ Ψ(3770) $ decays in $ e^+e^- $ annihilation, in $B^+$ decays the probability of $D^0\bar D^0$ production is almost three times higher than $D^+ D^-$. In $B^0$ decays, the ratio of these probabilities will be opposite. The effect is explained by the fact that, in $B$ -meson decays, the $D\bar D$ pair is produced in a superposition of isoscalar and isovector states, and only in combination with $K$ -mesons the total state has $ 1/2 $ isospin. We…
We study the colored resonance production at the LHC in a most general approach. We classify the possible colored resonances based on group theory decomposition, and construct their effective interactions with light partons. The production cross section from annihilation of valence quarks or gluons may be on the order of 400 - 1000 pb at LHC energies for a mass of 1 TeV with nominal couplings, leading to the largest production rates for new physics at the TeV scale, and simplest event topology with dijet final states. We apply the new dijet data from the LHC experiments to put bounds on variou…
In this work, we calculate the {\it CP}-averaged branching ratios and the polarization fractions of the charmless hadronic $B_c \to A_2 A_3$ decays within the framework of perturbative QCD(pQCD) approach, where $A$ is either a light $^3P_1$ or $^1P_1$ axial-vector meson. These thirty two decay modes can occur through the annihilation topology only. Based on the perturbative calculations and phenomenological analysis, we find the following results: (a) the branching ratios of the considered thirty two $B_c\to A_2 A_3$ decays are in the range of $10^{-5}$ to $10^{-8}$; (b) $B_c\to a_1 b_1$, $\ov…
In this paper, we investigate the contributions of hard spectator scattering and annihilation in $B\to PV$ decays within the QCD factorization framework. With available experimental data on $B\to πK^{\ast}$, $ρK$, $πρ$ and $Kϕ$ decays, comprehensive $χ^2$ analyses of the parameters $X_{A,H}^{i,f}(ρ_{A,H}^{i,f},ϕ_{A,H}^{i,f})$ are performed, where $X_A^f$ ($X_A^i$) and $X_H$ are used to parameterize the endpoint divergences of the (non)factorizable annihilation and hard spectator scattering amplitudes, respectively. Based on $χ^2$ analyses, it is observed that (1) The topology-dependent paramet…
Two-body charmless hadronic $B_c$ decays involving a light $1^3\!P_2$-tensor($T$) meson are investigated for the first time within the framework of perturbative QCD(pQCD) at leading order, in which the other meson is the lightest pseudoscalar($P$) or vector($V$) state. The concerned processes can only occur through the pure weak annihilation topology in the standard model. We predict the CP-averaged branching ratios and polarization fractions of those considered decays in Cabibbo-Kobayashi-Maskawa(CKM) favored and suppressed modes. Phenomenologically, several modes$-$such as the $B_c \to K_2^*…
Following the experimental results from LHCb on the rare decay $B^+_c \to K^-K^+π^+$, we investigate the possibility where this process is dominated by a double charm rescattering. The $B_c$ decay to double charm channels have a weak topology that is favoured in comparison with the direct production of $K^-K^+π^+$ in the final state, suppressed by quark annihilation. The decay amplitude for $B^+_c \to K^-K^+π^+$ with $B_c$ decaying first to double charm channels is described by a charm penguin diagram, represented by charm hadronic triangle loops, which reach the final state of interest after …
