arXiv subjects
Publications and source records attributed to Jonathan L. Rosner.
A class of amplitude relations for decays of $B$ mesons is discussed. Processes involving $η$ and $η'$ in the final state are shown to provide useful information about weak phases in some cases even in the presence of octet-singlet mixing in these states. Some of the relations are unaffected by first-order SU(3) breaking.
A quadrangle relation is shown to be satisfied by the amplitudes for $B^+ \to π^0 K^+,~π^+ K^0,~ηK^+$, and $η' K^+$. By comparison with the corresponding relation satisfied by $B^-$ decay amplitudes, it is shown that the relative phases of all the amplitudes can be determined up to discrete ambiguities. Making use of an SU(3) relation between amplitudes contributing to the above decays and those contributing to $B^{\pm} \to π^{\pm} π^0$, it is then shown that one can determine the weak phase $γ\equiv {\rm Arg} (V_{ub}^* V_{cb}/V_{us}^* V_{cs})$, where $V$ is the Cabibbo-Kobayashi-Maskawa matrix describing the charge-changing weak interactions between the quarks $(u,c,t)$ and $(d,s,b)$.
A project to detect the radio-frequency pulse associated with extensive air showers of cosmic rays is described briefly. Prototype work is being 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 proposal.
The width of a recently discovered excited charmed-strange baryon, a candidate for a state $Ξ_c^*$ with spin 3/2, is calculated. In the absence of configuration mixing between the ground-state (spin-1/2) charmed-strange baryon $Ξ_c^{(a)}$ and the spin-1/2 state $Ξ_c^{(s)}$ lying about 95 MeV above it, one finds $\tilde Γ(Ξ^*_c \to Ξ_c^{(a)} π) = (3/4) \tilde Γ(Ξ^* \to Ξπ)$ and $\tilde Γ(Ξ^*_c \to Ξ_c^{(s)} π) = (1/4) \tilde Γ(Ξ^* \to Ξπ)$, where the tilde denotes the partial width with kinematic factors removed. Assuming a kinematic factor for P-wave decay of $p_{\rm cm}^3$, one predicts $Γ(Ξ^*_c \to Ξ_c^{(a)} π) = 2.3$ MeV, while the $Ξ^*_c \to Ξ_c^{(s)} π$ channel is closed. Some suggestions are given for detecting the $Σ_c^*$, the spin-3/2 charmed nonstrange baryon, and the $Ω_c^*$, the spin-3/2 charmed doubly-strange baryon.
The impact of atomic parity violation experiments on determination of the weak mixing parameter $\sin^2 θ$ and the Peskin-Takeuchi parameters $S$ and $T$ is reassessed in the light of recent electroweak measurements at LEP, SLAC, and Fermilab. Since the weak charge $Q_W$ provides unique information on $S$, its determination with a factor of four better accuracy than present levels can have a noticeable effect on global fits. However, the measurement of $ΔQ_W / Q_W$ for two different isotopes provides primarily information on $\sin^2 θ$. To specify this quantity to an accuracy of $\pm 0.0004$, comparable to that now provided by other electroweak experiments, one would have to determine $ΔQ_W/Q_W$ in cesium to about 0.1\% of its value, with comparable demands for other nuclei. The relative merits of absolute measurements of $Q_W$ and isotope ratios for discovering effects of new gauge bosons are noted briefly.
This series of five lectures describes aspects of CP violation, emphasizing its description within the standard electroweak model. After discussing the kaon system, the only place in which CP violation has been seen so far, we turn to the leading contender for the effect, complex phases in the Cabibbo-Kobayashi-Maskawa (CKM) matrix. A number of suggestions are made for improved tests of the standard picture. Hadrons containing $b$ quarks play a key role in this program, and are discussed separately. We also mention a number of non-standard and speculative aspects of CP violation, including alternatives to the CKM description, direct tests of time reversal invariance, and baryogenesis.
Some aspects of $B$ physics relevant for experiments in hadron colliders are discussed. These include the determination of parameters of the CKM Matrix and confirmation of its role in CP violation, studies of mixing of nonstrange and strange $B$ mesons, lifetimes of hadrons containing $b$ quarks, the use of ``same-side'' tagging of neutral $B$ mesons via correlations with charged pions through fragmentation or resonances, and the determination of CKM phases through the study of decays of $B$ mesons to pairs of light hadrons.
The spacings between bound-state levels of the Schrödinger equation with the same principal quantum number $N$ but orbital angular momenta $\ell$ differing by unity are found to be nearly equal for a wide range of power potentials $V = λr^ν$, with $E_{N \ell} \approx F(ν, N) - G(ν,N) \ell$. Semiclassical approximations are in accord with this behavior. The result is applied to estimates of masses for quarkonium levels which have not yet been observed, including the 2P $c \bar c$ states and the 1D $b \bar b$ states.
The decays of $B$ mesons to two-body hadronic final states are analyzed within the context of broken flavor SU(3) symmetry, extending a previous analysis involving pairs of light pseudoscalars to decays involving one or two charmed quarks in the final state. A systematic program is described for learning information {}from decay rates regarding (i) SU(3)-violating contributions, (ii) the magnitude of exchange and annihilation diagrams (effects involving the spectator quark), and (iii) strong final-state interactions. The implication of SU(3)-breaking effects for the extraction of weak phases is also examined. The present status of data on these questions is reviewed and suggestions for further experimental study are made.
We discuss the role of electroweak penguins in $B$ decays to two light pseudoscalar mesons. We confirm that the extraction of the weak phase $α$ through the isospin analysis involving $B\toππ$ decays is largely unaffected by such operators. However, the methods proposed to obtain weak and strong phases by relating $B\toππ$, $B\toπK$ and $B\to KK$ decays through flavor SU(3) will be invalidated if electroweak penguins are large. We show that, although the introduction of electroweak penguin contributions introduces no new amplitudes of flavor SU(3), there are a number of ways to experimentally measure the size of such effects. Finally, using SU(3) amplitude relations we present a new way of measuring the weak angle $γ$ which holds even in the presence of electroweak penguins.
The spectra of states containing charmed and beauty quarks, and their regularities, are reviewed.
A brief overview is presented of the standard model of electroweak interactions, including precision tests, the role of the Cabibbo-Kobayashi-Maskawa (CKM) matrix in describing CP violation, windows on intermediate-scale physics, and the nature of the Higgs phenomenon.
The correlations between a $B$ meson and a pion produced nearby in phase space should respect isospin reflection symmetry $I_3 \to -I_3$. Thus, one generally expects similar $π^+ B^0$ and $π^- B^+$ correlations (non-exotic channels), and similar $π^- B^0$ and $π^+ B^+$ correlations (exotic channels). Exceptions include (a) fragmentation processes involving exchange of quarks with the producing system, (b) misidentification of charged kaons as charged pions, and (c) effects of decay products of the associated $\overline{B}$. All of these can affect the apparent signal for correlations of charged $B$ mesons with charged hadrons. The identification of the flavor of neutral $B$ mesons through the decay $B^0 \to K^{*0} J/ψ$ requires good particle identification in order that the decay $K^{*0} \to K^+ π^-$ not be mistaken for $\overline{K}^{*0} \to K^- π^+$, in which case the correlations of neutral $B$ mesons with hadrons can be underestimated.
We present a model--independent analysis of the $Z b \bar b$ vertex, with the aim of constraining contributions of new physics to the left- and right--handed couplings of the $b$. We find that the left--handed coupling of the $b$ is quite narrowly constrained by present data, but that the right--handed coupling is still largely unconstrained.
Flavor SU(3) symmetry implies certain relations among $B$-decay amplitudes to $ππ$, $πK$ and $K {\bar K}$ final states, when annihilation-like diagrams are neglected. Using three triangle relations, we show how to measure the weak CKM phases $α$ and $γ$ using time-independent rate measurements only. In addition, one obtains all the strong final-state phases and the magnitudes of individual terms describing tree (spectator), color-suppressed and penguin diagrams. Many independent measurements of these quantities can be made with this method, which helps to eliminate possible discrete ambiguities and to estimate the size of SU(3)-breaking effects.
The decays $B \to PP$, where $P$ denotes a pseudoscalar meson, are analyzed, with emphasis on charmless final states. Numerous triangle relations for amplitudes hold within SU(3) symmetry, relating (for example) the decays $B^+ \to π^+ π^0,~ π^0 K^+$, and $π^+ K^0$. Such relations can improve the possibilities for early detection of $CP$-violating asymmetries. Within the context of a graphical analysis of decays, relations are analyzed among SU(3) amplitudes which hold if some graphs are neglected. One application is that measurements of the rates for the above three $B^+$ decays and their charge-conjugates can be used to determine a weak CKM phase. With measurements of the remaining rates for $B$ decays to $ππ,~πK$, and $K \bar K$, one can obtain two CKM phases and several differences of strong phase shifts.
The theory of $CP$ violation based on phases in weak couplings in the Cabibbo-Kobayashi-Maskawa (CKM) matrix requires the phase $γ\equiv {\rm Arg~} V^*_{ub}$ (in a standard convention) to be nonzero. A measurement of $γ$ is proposed based on charged $B$ meson decay rates to $π^+ K^0$, $π^0 K^+$, $π^+ π^0$, and the charge-conjugate states. The corresponding branching ratios are expected to be of the order of $10^{-5}$. (submitted to Physical Review Letters)
The lowest-order expression for the partial $W$ width to $e ν,~Γ(W \to e ν) = G_μM_W^3 /(6 π\sqrt{2})$, has no oblique radiative corrections from new physics if the measured $W$ mass is used. Here $G_μ= (1.16639 \pm 0.00002) \times 10^{-5}$ GeV/$c^2$ is the muon decay constant. For the present value of $M_W = (80.14 \pm 0.27)$ GeV/$c^2$, and with $m_t = 140$ GeV$/c^2$, one expects $Γ(W \to e ν) = (224.4 \pm 2.3)$ MeV. The total width $Γ_{\rm tot}(W)$ is also expected to lack oblique corrections from new physics, so that $Γ_{\rm tot} (W)/ Γ(W \to e ν) = 3 + 6 [1 + \{α_s (M_W)/π\}]$. Present data are consistent with this prediction.