arXiv subjects
Publications and source records attributed to Jonathan L. Rosner.
The current status of some methods to determine the weak phase $γ$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V^*_{ub}$ using B decays is discussed, and comments are made on accuracy achievable in the next few years.
Flavor SU(3) is used for studying the time-dependent CP asymmetry in $B^0 \to π^0 K_S$ by relating this process to $B^0\to π^0π^0$ and $B^0 \to K^+K^-$. We calculate correlated bounds on $S_{πK} - \sin 2β$ and $C_{πK}$, with maximal magnitudes of 0.2 and 0.3, where $S_{πK}$ and $C_{πK}$ are coefficients of $\sinΔmt$ and $\cosΔmt$ in the asymmetry. Stronger upper limits on $B^0 \to K^+K^-$ are expected to reduce these bounds and to imply nonzero lower limits on these observables. The asymmetry is studied as a function of a strong phase and the weak phase $γ$.
Isosinglet vector-like quarks are predicted by some unified theories of electroweak and strong interactions. We study hadron collider signatures for the production and decay of isosinglet vector-like quarks with charge -1/3. Previous analyses of Run I data from the Fermilab Tevatron are used to set lower limits of 100--200 GeV/c^2 on the mass of such quarks, depending on assumptions about mixing with Standard Model quarks and the mass of the Higgs boson. For future Tevatron data (E_{c.m.} = 1.96 TeV) the corresponding mass range is (100-270, 100-320) GeV/c^2 for (1, 10) fb^{-1}. At the CERN Large Hadron Collider (LHC) (E_{c.m.} = 14 TeV, 100 fb^{-1}), an analysis of flavor-changing neutral-current decay modes should probe an $h$ quark mass range of 100-1100 GeV/c^2.
The decays of $B$ mesons to a charmless vector ($V$) and pseudoscalar ($P$) meson are analyzed within a framework of flavor SU(3) in which symmetry breaking is taken into account through ratios of decay constants in tree ($T$) amplitudes. The magnitudes and relative phases of tree and penguin amplitudes are extracted from data; the symmetry assumption is tested; and predictions are made for rates and CP asymmetries in as-yet-unseen decay modes. A key assumption for which we perform some tests and suggest others is a relation between penguin amplitudes in which the spectator quark is incorporated into either a pseudoscalar meson or a vector meson. Values of $γ$ slightly restricting the range currently allowed by fits to other data are favored, but outside this range there remain acceptable solutions which cannot be excluded solely on the basis of present $B \to VP$ experiments.
We discuss a potential discrepancy in an approximate relation among $B \to K π$ rates which, with increased statistical significance, would imply new physics in $ΔI=1$ transitions. An approximate relation between CP-violating rate differences in $B^0/\bar{B}^0 \to K^{\pm}π^{\mp}$ and $B^{\pm} \to K^{\pm}π^0$ is used to combine these rate differences to reduce upper limits on the two CP asymmetries. These rates and asymmetries are used to update bounds on the CKM phase $γ$.
Some theoretical aspects of $B$ physics are reviewed. These include a brief recapitulation of information on weak quark transitions as described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix, a description of CP asymmetries in $B$ decays to CP eigenstates and self-tagging modes, a discussion of final-state phases in $B$ and charm decays, some topics on $B_s$ properties and decays, the prospects for unusual excited $B$ states opened by discovery of some narrow $c \bar s$ resonances, and the prospects for seeing the heavier $Q=1/3$ quarks predicted in some extended grand unified theories.
We discuss implications of recent experimental data for B decays into two pseudoscalar mesons, with emphasis on those with $η$ and $η'$ in the final states. Applying a U-spin argument, we show that tree and penguin amplitudes, both in $B^+ \to π^+ η$ and in $B^+ \to π^+ η'$, are of comparable magnitudes. Nontrivial relative weak and strong phases between the tree-level amplitudes and penguin-loop amplitudes in the $B^{\pm} \to π^{\pm} η$ modes are extracted. We predict possible values for the averaged branching ratio and CP asymmetry of the $B^{\pm} \to π^{\pm} η'$ modes. We test the assumption of a singlet-penguin amplitude with the same weak and strong phases as the QCD penguin in explaining the large branching ratios of $η' K$ modes, and show that it is consistent with current branching ratio and CP asymmetry data of the $B^+ \to (π^0, η, η') K^+$ modes. We also show that the strong phases of the singlet-penguin and tree-level amplitudes can be extracted with further input of electroweak penguin contributions and a sufficiently well-known branching ratio of the $ηK^+$ mode. Using SU(3) flavor symmetry, we also estimate required data samples to detect modes that have not yet been seen.
A short introduction to some current topics in $B$ physics is presented in order to set the stage for some results to be announced at this Workshop. After briefly reviewing the Cabibbo-Kobayashi-Maskawa (CKM) matrix and information on its parameters, the decays of neutral $B$ mesons to several CP eigenstates, and some $B \to πK$ decays, are discussed. It is shown that progress is being made on determination of all the angles of the unitarity triangle.
Examples are given of some current questions in $b$ physics to which LHC experiments may provide answers. These include (i) the precise determination of parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix; (ii) measurements of CKM phases using B decays to CP eigenstates; (iii) the search for direct CP asymmetries in B decays; (iv) rare radiative B decays; (v) the study of $B_s$ properties and decays, (vi) excited states of $B$ and $B_s$ mesons, and (vii) the search for heavier quarks which could mix with the $b$ quark.
Restrictive upper bounds on the heavy bottom squark mass when the gluino and one bottom squark are both light are based on the predicted reduction of $R_b$ (the fraction of $Z$ hadronic decays to $b \bar b$ pairs) in such a scenario. These bounds are found to be relaxed by the process $Z \to b\bar{\tilde b}{\tilde g}/{\bar b}{\tilde b}{\tilde g}$, which may partially compensate for the reduction of $R_b$. The relaxation of bounds on the top squark and the scale-dependence of the strong coupling constant are also discussed.
We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth's magnetic field. We perform simulations by calculating the trajectory and radiation of a few thousand charged shower particles. The results are then transformed to predict the strength and polarization of the electromagnetic radiation emitted by the whole shower.
In a recently suggested method for measuring the weak phase $γ$ in $B^\pm \to K^\pm (KK^*)_D$ decays, the relative strong phase $δ_D$ in $D^0 \to K^{*+} K^-$ and $D^0 \to K^{*-} K^+$ decays (equivalently, in $D^0 \to K^{*+} K^-$ and $\od \to K^{*+} K^-$) plays a role. It is shown how a study of the Dalitz plot in $D^0 \to K^+ K^- π^0$ can yield information on this phase, and the size of the data sample which would give a useful measurement is estimated.
Using the measured spectrum shape for $B \to π\ell ν$, the rate for $B^+ \to π^+ π^0$, information on the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{ub}|$, and theoretical inputs from factorization and lattice gauge theory, we obtain an improved estimate of the ``tree'' contribution to $B^0 \to π^+ π^-$. We find the branching ratio $\b(B^0 \to π^+ π^-)|_{\rm tree} = (5.25^{+1.67}_{-0.50}) \times 10^{-6}$, to be compared with the experimental value $\b(B^0 \to π^+ π^-) = (4.55 \pm 0.44) \times 10^{-6}$. The fit implies $|V_{ub}| = (3.62 \pm 0.34) \times 10^{-3}$. Implications for tree-penguin interference in $B^0 \to π^+ π^-$ and for other charmless $B$ decays are discussed.
Isospin and U-spin symmetries are useful approximations for studying penguin dominance in $B$ meson decays to three kaons, $B\to KK\bar K$. We point out certain subtleties in treating these decays in these approximations. Resulting uncertainties are discussed in determining the CP content of the final state in $B \to K^+K^-K_S$, and in relating the CP asymmetry in this process to the value of $\sin 2β$.
The recent observation of the decay $\ob \to Λ_c^+ \bar p$ suggests that related decays may soon be visible at $e^+ e^-$ colliders. It is shown how these decays can shed light on strong final-state phases and amplitudes involving the spectator quark, both of which are normally expected to be small in B decays.
The development of a system to detect the radio-frequency (RF) pulse associated with extensive air showers of cosmic rays is described. This work was performed at the CASA/MIA array in Utah, with the intention of designing equipment that can be used in conjunction with the Auger Giant Array. A small subset of data (less than 40 out of a total of 600 hours of running time), taken under low-noise conditions, permitted upper limits to be placed on the rate for pulses accompanying showers of energies around $10^{17}$ eV.
A prototype system for detecting radio pulses associated with extensive cosmic ray air showers is described. Sensitivity is compared with that in previous experiments, and lessons are noted for future studies.
At least one state in the first family of D-wave $b \bar b$ quarkonium levels has been discovered near the predicted mass of 10.16 GeV/$c^2$. This state is probably the one with J=2. This state and the ones with J=1 and J=3 may contribute a detectable amount to the decay $Υ(1D) \to Υ(1S) ππ$, depending on the partial widths for these decays for which predictions vary considerably. The prospects for detection of the chain $Υ(3S) \to Υ(1D) + X \to Υππ+ X$ are discussed.