Final-state interaction effects in charmless B_{u,d,s} to PP decays are studied. We investigate the B(bar)^0 to pi^+ pi^-, pi^0 pi^0 rates and the K pi direct CP violations, which lead to the so-called K pi puzzle in CP violation (Delta A). We found that sizable and complex color-suppressed tree amplitudes, which are crucial for the large pi^0 pi^0 rate and Delta A, are generated through exchange rescattering. The correlation of the ratio B(pi^0 pi^0)/B(pi^+ pi^-) and Delta A is studied. Predictions on B_s rates, direct and time-dependent CP asymmetries are made.
Various new measurements in charmless $B_{u,d,s}\to PP$ modes, where $P$ is a low lying pseudoscalar meson, are reported by Belle and LHCb. These include the rates of $B^0\toπ^0π^0$, $ηπ^0$, $B_s\toη'η'$, $B^0\to K^+K^-$ and $B^0_s\toπ^+π^-$ decays. Some of these modes are highly suppressed and are among the rarest $B$ decays. Direct CP asymmetries on various modes are constantly updated. It is well known that direct CP asymmetries and rates of suppressed modes are sensitive to final state interaction (FSI). As new measurements are reported and more data will be collected, it is interesting an…
The large localized CP asymmetries observed by LHCb in three-body charmless decays of $B$ mesons brings new challenge for experimentalists and their traditional models to fit data. With higher statistics, rescattering and three-body effects, previously ignored on data analysis, become more visible. The time is ripe to use better theoretical assumptions as an ingredient in order to improve the analysis. In this paper we address the issue of rescattering effects in the charmless three-body decays of $B$ mesons. In particular, we study the case of the $B^+ \to π^-π^+π^+$ decay and show that the p…
Final State Rescattering and Color-suppressed \bar B^0-> D^{(*)0} h^0 Decays
The color-suppressed \bar B^0-> D^{(*)0}π^0, D^{(*)0}η, D^0ωdecay modes have just been observed for the first time. The rates are all larger than expected, hinting at the presence of final state interactions. Considering \bar B^0-> D^{(*)0}π^0 mode alone, an elastic D^{(*)}π-> D^{(*)}πrescattering phase difference δ \equiv δ_{1/2} - δ_{3/2} \sim 30^ \circ would suffice, but the \bar B^0-> D^{(*)0}η, D^0ωmodes compel one to extend the elastic formalism to SU(3) symmetry. We find that a universal a_2/a_1=0.25 and two strong phase differences 20^ \circ \sim θ< δ< δ^ \prime \sim 50^ \circ can desc…
Charmed meson rescattering in the reaction pbar d to D Dbar N
我们研究的可能性提取信息的DN和DbarN的相互作用从pbar D D Dbar N反应。我们利用的概念，开放的魅力介子是第一次产生的反质子湮灭的一个核子在氘核，随后rescatter的其他（旁观者）核子。后一个过程，然后利用调查DN和DbarN的相互作用。我们研究了从D ^0 p和D^-p重散射项中分离出贡献的不同方法。
Recently Belle collaboration reported new measurements for the branching fractions with the first observing two processes of $\mathcal{B}(Ξ_c^0\toΛK^0_S)$, $\mathcal{B}(Ξ_c^0\toΣ^0 K^0_S)$ and updating data for $\mathcal{B}(Ξ_c^0\toΣ^+ K^-)$. Combined with other known data on charmless two body decays of anti-triplet charmed baryons, a lot of information can be derived with the assistance of $SU(3)$ flavour symmetry. Using $SU(3)$ relations between different decay modes, we can give some predictions based on the new measurements which can be tested with the high luminosity experiments in the f…
Charmless three-body decays of B mesons is studied using a simple model based on the framework of the factorization approach. Hadronic three-body decays receive both resonant and nonresonant contributions. Dominant nonresonant contributions to tree-dominated three-body decays arise from the $b\to u$ tree transition which can be evaluated using heavy meson chiral perturbation theory valid in the soft meson limit. For penguin-dominated decays, nonresonant signals come mainly from the penguin amplitude governed by the matrix elements of scalar densities $<M_1M_2|\bar q_1 q_2|0>$. We use the measu…
We study the charmless two-body decays of $b$-baryons $(Λ_b$, $Ξ_b^-$, $Ξ_b^0)$. We find that ${\cal B}(Ξ_b^-\to Λρ^-)=(2.08^{+0.69}_{-0.51})\times 10^{-6}$ and ${\cal B}(Ξ_b^0\to Σ^+ M^-)=(4.45^{+1.46}_{-1.09},11.49^{+3.8}_{-2.9},4.69^{+1.11}_{-0.79},2.98^{+0.76}_{-0.51})\times 10^{-6}$ for $M^-=(π^-,ρ^-,K^-,K^{*-})$, which are compatible to ${\cal B}(Λ_b\to p π^-,p K^-)$. We also obtain that ${\cal B}(Λ_b\to Λω)=(2.30\pm0.10)\times 10^{-6}$, ${\cal B}(Ξ_b^-\toΞ^- ϕ,Ξ^- ω)\simeq {\cal B}(Ξ_b^0\toΞ^0 ϕ,Ξ^0 ω)=(5.35\pm0.41,3.65\pm0.16)\times 10^{-6}$ and ${\cal B}(Ξ^-_b\toΞ^{-} η^{(\prime)})\si…
Several baryons containing a heavy b-quark have been discovered. The decays of these states provide new platform for testing the standard model (SM). We study $CP$ violation in SM for charmless two-body decays of the flavor $SU(3)$ anti-triplet beauty baryon (b-baryon) ${\cal B} = (Ξ^-_b,\;Ξ^0_b,\;Λ_b^0)$ in a model independent way. We found, in the flavor $SU(3)$ symmetry limit, a set of new predictive relations among the branching ratio $Br$ and $CP$ asymmetry $A_{CP}$ for $\cal B$ decays, such as $A_{CP}(Ξ_b^-\to K^0 Ξ^-)/A_{CP}(Ξ_b^-\to \bar K^0 Σ^-) = - Br(Ξ_b^- \to \bar K^0 Σ^-)/Br(Ξ_b^-…
On the basis of the generalized eikonal approximation we study the exclusive reactions $\bar p d \to J/ψ\, n$ and $\bar p d \to ψ^\prime\, n$ in vicinity of the thresholds for charmonium production on a free proton target. It is shown that the rescattering of the incoming antiproton and outgoing charmonium on the spectator neutron leads to a depletion of the charmonium production at low- and to an enhancement at high transverse momenta. This is in qualitative agreement with previous studies of hard proton knockout in proton-deuteron collisions. We analyze different physical sources of uncertai…
We express the amplitudes for charmless three-body B decays in terms of diagrams. In addition, we show how to use Dalitz-plot analyses to obtain decay amplitudes which are symmetric or antisymmetric under the exchange of two of the final-state particles. When annihilation-type diagrams are neglected, as in two-body decays, many of the exact, purely isospin-based results are modified, leading to new tests of the standard model (SM). Some of the tests can be performed now, and we find that present data agree with the predictions of the SM. Furthermore, contrary to what was thought previously, it…
The long awaited baryonic $B$ decay $\bar B{}^0\to p\bar p$ was recently observed by LHCb with a branching fraction of order $10^{-8}$. All the earlier model predictions are too large compared with experiment. In this work, we point out that for a given tree operator $O_i$, the contribution from its Fiertz transformed operator, an effect often missed in the literature, tends to cancel the internal $W$-emission amplitude induced from $O_i$. The wave function of low-lying baryons are symmetric in momenta and the quark flavor with the same chirality, but antisymmetric in color indices. Using thes…
Two-body charmless hadronic B decays involving a tensor meson in the final state are studied within the framework of QCD factorization (QCDF). Due to the G-parity of the tensor meson, both the chiral-even and chiral-odd two-parton light-cone distribution amplitudes of the tensor meson are antisymmetric under the interchange of momentum fractions of the quark and anti-quark in the SU(3) limit. Our main results are: (i) In the naive factorization approach, the decays such as $B^-\to \bar K_2^{*0}π^-$ and $\bar B^0\to K_2^{*-}π^+$ with a tensor meson emitted are prohibited owing to the fact that …
We first study the charmless two-body $Λ_b$ decays with the scalar mesons as the final states and predict that ${\cal B}(Λ_b\to Λf_0(980,1500))=(2.9\pm 0.7,12.4\pm 3.8)\times 10^{-6}$ and ${\cal B}(Λ_b\to p K^{*-}_0(800,1430))=(1.9\pm 0.5,14.1\pm 4.5)\times 10^{-6}$. With the resonant $f_0(980,1500)\to (π^+π^-,K^+K^-)$ and $K^{*-}_0\to \bar K^0 π^-$ decays, we then obtain ${\cal B}(Λ_b\to Λ(π^+π^-,K^+K^-))=(4.2\pm 1.0,3.5\pm0.7)\times 10^{-6}$ and ${\cal B}(Λ_b\to p\bar K^0 π^-)=(10.4\pm2.9)\times 10^{-6}$, in comparison with the data of $(4.6\pm 1.9,15.9\pm2.6)\times 10^{-6}$ and $(12.6\pm 4.…
Charm penguin diagrams are known to be the main contribution to charmless B decay process with strangeness variation equal to minus one, which is the case of $B^\pm \to K^\pm K^+ K^-$ decay. The large phase space available in this and other B three-body decays allows non trivial final state interactions with all sort of rescattering processes and also access high momentum transfers in the central region of the Dalitz plane. In this work we investigate the charm Penguin contribution to $B^\pm \to K^\pm K^+ K^-$, described by a hadronic triangle loop in nonperturbative regions of the phase space…
We study charmless two-body baryonic $B$ decays using the topological amplitude approach. We extend a previous work to include all ground state octet and decuplet final states with full topological amplitudes. Relations on rates and CP asymmetries are obtained. The number of independent topological amplitudes is significantly reduced in the large $m_B$ asymptotic limit. With the long awaited $\overline B{}^0\to p\bar p$ data, we can finally extract information on the topological amplitudes and predict rates of all other modes. The predicted rates are in general with uncertainties of a factor o…
Involving of elastic rescattering and annihilation of quark-antiquark pairs in a final state allows us to explain a dependence of ratio for cross sections of $η'$ and $η$ mesons versus transfer momentum in charge exchange reactions. We estimate the mixing angle of mesons with isoscalar states of $\bar u u+\bar d d$ and $\bar s s$ of hidden strangeness. The evaluation includes the consistent description of yield ratio for $η'$ and $η$ mesons in decays of $B^0$, $B^0_s$ and $J/ψ$ mesons.
Observation in astronomy suggests that our Universe contains an abundance of matter over antimatter, which can only be explained if the combined CP symmetry is violated. Studies of CP violation have driven the flavor physics with the aim of testing the Standard Model of particle physics and searching for physics beyond. CP violation is discovered in strange, beauty and charm meson systems, however no conclusive sign of CP violation in baryon decays has been observed yet. This review summarizes CP violation studies performed by the LHCb experiment in charmless decays and rare decays of beauty b…
Transversity observables, such as the T-odd single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons, and the distributions which are measured in deeply virtual Compton scattering provide important constraints on the fundamental quark and gluon structure of the proton. In this talk I discuss the challenge of computing these observables from first principles; i.e., quantum chromodynamics, itself. A key step is the determination of the frame-independent light-front wavefunctions (LFWFs) of hadrons -- the QCD eigensolutions which are analogs of the Schrodinger wavef…
We study time-reversal~(T) asymmetries in the charmless two-body decays of antitriplet bottom baryons. We find that in ${\bf B}_b \to {\bf B}_n P$ with ${\bf B}_b = (Ξ_b ^- , \,Ξ_b^0, \,Λ_b)$ and ${\bf B}_n(P)$ a octet baryon (pseudoscalar meson), the positive and negative helicity amplitudes are both sizable, resulting in the large T-violating effects. Particularly, the T-odd parameters, $β_w$, for the color-enhanced channels are expected to be around $40\%$ and $-25\%$ in $b\to s $ and $b\to d $ transitions for the standard model, which can be measured by the experiments at LHCb, respectivel…
Using an improved "analytic K-matrix model", we reconsider the extraction of the sigma/f_0(600) and f_0(980) gamma-gamma widths from gamma-gamma to pi-pi scatterings data of Crystal Ball and Belle. Our main results are summarized in Tables 3 and 4. The averaged sigma "direct width" to gamma-gamma is 0.16(3) keV which confirms a previous result of [1] and which does neither favour a large four-quark (diquark-antidiquark) nor a molecule nor a pure \bar qq component. The "direct width" of the f_0(980) of 0.28(2) keV is much larger than the four-quark expectation but can be compatible with a \bar …
We study the lepton pair production in the photodisintegration of the deuteron process. The complete seven-fold differential cross section is calculated via the Bethe-Heitler mechanism with final state interactions taken into account. The deuteron bound state is described by a relativistic covariant deuteron-nucleon vertex. With numerical results, we find that the differential cross section has strong dependence on the lepton azimuthal angle in the small polar angle region and sharp peaks appear in the dependence on the invariant mass of the produced lepton pair or the two nucleons in the fina…
We investigate probing the hot and dense nuclear matter with strange vector mesons ($K^*, \bar{K}^*$). Our analysis is based on PHSD which incorporates partonic and hadronic dof and describes the full dynamics of HICs. This allows to study the $K^*$ and $\bar{K}^*$ meson formation from the QGP and the in-medium effects related to the modification of their properties during the propagation in dense and hot matter. We employ relativistic Breit-Wigner spectral functions for the $K^*,\bar{K}^*$ mesons with self-energies obtained from a G-matrix approach to study the role of in-medium effects on th…
