A Review of Hadronic and Rare B Decays

We review recent experimental results on B meson decays. These include measurements of the inclusive production of charmed and non-charmed mesons and baryons, the reconstruction of a large number of exclusive hadronic final states with charmed mesons, the search for exclusive hadronic final states without charmed mesons, and the first observation of the decay B-> K* gamma which is described by an electromagnetic penguin diagram. The theoretical implications of these results will be considered. The figures can be obtained in postscript format EMAIL from [email protected]: 77 pages; CLNS 93/1261, UH-511-778-93, OHSTPY-HEP-E-93-018, HEPSY 93-1

Nonleptonic Decays and Lifetimes of b-quark and c-quark Hadrons

We review recent experimental results on lifetimes and hadronic decays of hadrons that contain $c$ and $b$ quarks. The theoretical implications of these results are also considered. An understanding of hadronic decays of heavy quarks is required to interpret the CP violating asymmetries in $B$ decays that will be observed in experiments planned for the near future.Comment: 74 pages, LATEX format with 12 figures. To appear in Annual Review of Nuclear and Particle Science, Vol. 46. Also available at http://www-physics.mps.ohio-state.edu/~phys111/b-physics/bphysics.html and by anonymous ftp from ftp://pacific.mps.ohio-state.edu/pub/hepex/kh A serious typographical error on p. 8 is corrected. Other errors and typos are also correcte

Implications for the ΔAFB\Delta A_{FB} anomaly in Bˉ0→D∗+ℓ−νˉ{\bar B}^0\to D^{*+}\ell^- {\bar\nu} using a new Monte Carlo Event Generator

Recent experimental results in $B$ physics from Belle, BaBar and LHCb suggest new physics (NP) in the weak $b\to c$ charged-current and the $b\to s$ neutral-current processes. Here we focus on the charged-current case and specifically on the decay modes $\bar{B}^0\to D^{*+}\ell^- \bar{\nu}$ with $\ell = e$ and $\mu$. The world averages of the ratios $R_D$ and $R_D^{*}$ currently differ from the Standard Model (SM) predictions by $3.4\sigma$ while recently a new anomaly has been observed in the forward-backward asymmetry measurement, $A_{FB}$, in $\bar{B}^0\to D^{*+}\mu^- \bar{\nu}$ decay. It is found that $\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e \nu)$ is around $4.1\sigma$ away from the SM prediction in an analysis of 2019 Belle data. In this work we explore possible solutions to the $\Delta A_{FB}$ anomaly and point out correlated NP signals in other angular observables. These correlations between angular observables must be present in the case of beyond the Standard Model physics. We stress the importance of $\Delta$ type observables that are obtained by taking the difference of the observable for the muon and the electron mode. These quantities cancel form factor uncertainties in the SM and allow for clean tests of NP. These intriguing results also suggest an urgent need for improved simulation and analysis techniques in $\bar{B}^0\to D^{*+}\ell^- \bar{\nu}$ decays. Here we also describe a new Monte Carlo Event-generator tool based on EVTGEN that we developed to allow simulation of the NP signatures in $\bar{B}^0\to D^{*+}\ell^- \nu$, which arise due to the interference between the SM and NP amplitudes. We then discuss prospects for improved observables sensitive to NP couplings with 1, 5, 50, and 250 ab$^{-1}$ of Belle II data, which seem to be ideally suited for this class of measurements.Comment: 22 pages, 9 figures, Improved version of arXiv:2203.07189, which was submitted to the US Community Summer Study on the Future of Particle Physics (Snowmass2021), withdrawn from final proceedings. Improvements include calculations of correlations between several observables and discussions of prospects for NP-sensitive observables with several benchmark values of Belle II integrated luminosit

Heavy-Quark Symmetry and the Electromagnetic Decays of Excited Charmed Strange Mesons

Heavy-hadron chiral perturbation theory (HH$\chi$PT) is applied to the decays of the even-parity charmed strange mesons, D_{s0}(2317) and D_{s1}(2460). Heavy-quark spin symmetry predicts the branching fractions for the three electromagnetic decays of these states to the ground states D_s and D_s^* in terms of a single parameter. The resulting predictions for two of the branching fractions are significantly higher than current upper limits from the CLEO experiment. Leading corrections to the branching ratios from chiral loop diagrams and spin-symmetry violating operators in the HH$\chi$PT Lagrangian can naturally account for this discrepancy. Finally the proposal that the D_{s0}(2317) (D_{s1}(2460)) is a hadronic bound state of a D (D^*) meson and a kaon is considered. Leading order predictions for electromagnetic branching ratios in this molecular scenario are in very poor agreement with existing data.Comment: 25 pages, 3 figure

Comment on the new Ds(∗)+π0D_s^{(*)+} \pi^0 resonances

We propose an explanation of the new resonances observed in $D_s^{(*)+} \pi^0$ decays. We suggest that the data can be explained by the mixing of conventional p-wave excited $D_s^+$ mesons with 4-quark states. The narrow states observed in $D_s^+ \pi^0$ and $D_s^{*+}\pi^0$ are primarily p-wave $D_{sJ}^{*}$ states, while the predominantly 4-quark states are shifted above $D^{(*)} K$ threshold and should be broad. Ranges for the mixing parameter and mass of the 4-quark state in this scenario are given. Other experimental consequences are discussed.Comment: 4 pages, 2 figures. Updated references. To appear in Phys. Lett.

Prospects for Pentaquark Production at Meson Factories

Following Rosner [hep-ph/0312269], we consider B-decay production channels for the exotic I=0 and $I=3/2$ pentaquarks that have been recently reported. We also discuss new search channels for isovector pentaquarks, such as the $\Theta^{*++} (\bar s duuu)$, that are generically present in chiral soliton models but were not observed in recent experiments. Futhermore, we argue that weak decays of charmed baryons, such as the $\Lambda_c^+$ and $\Xi_c^0$, provide another clean way of detecting exotic baryons made of light quarks only. We also discuss discovery channels for charmed pentaquarks, such as the isosinglet $\Theta_c^0 (\bar c udud)$, in weak decays of bottom mesons and baryons. Finally, we discuss prospects for inclusive production of pentaquarks in $e^+ e^-$ collisions, with associated production of particles carrying the opposite baryon number.Comment: 15 pages, LaTeX; v2,v3: minor corrections, references added; v4: minor modifications, the version published in Physics Letters