arXiv subjects

Jonathan L. Rosner

Publications and source records attributed to Jonathan L. Rosner.

At least 199 records · Page 11Linked to original sources

arXiv2001

Role of Present and Future Atomic Parity Violation Experiments in Precision Electroweak Tests

Recent reanalyses of the atomic physics effects on the weak charge in cesium have led to a value in much closer agreement with predictions of the Standard Model. We review precision electroweak tests, their implications for upper bounds on the mass of the Higgs boson, possible ways in which these bounds may be circumvented, and the requirements placed upon accuracy of future atomic parity violation experiments by these considerations.

hep-ph↗

arXiv2001

Final-State Phases in Doubly-Cabibbo-Suppressed Charmed Meson Nonleptonic Decays

Cabibbo-favored nonleptonic charmed particle decays exhibit large final-state phase differences in $\bar K π$ and $\bar K^* π$ but not $\bar K ρ$ channels. It is of interest to know the corresponding pattern of final-state phases in doubly-Cabibbo-suppressed decays, governed by the $c \to d u \bar s$ subprocess. An experimental program is outlined for determining such phases via measurements of rates for $D \to K^* π$ and $K (ρ, ω,ϕ)$ channels, and determination of interference between bands in Dalitz plots. Such a program is feasible at planned high-intensity sources of charmed particles.

hep-ph↗

arXiv2001

Production of the $η_b(nS)$ states

The rates for magnetic dipole (M1) transitions $Υ(nS) \to η_b(n'S) + γ$, $n' \le n$, are compared. The photon energies for allowed ($n' = n$) M1 transitions are very small, so hindered ($n' < n$) transitions could be more favorable for discovering the $η_b(1S,2S)$. The question then arises whether $Υ(2S)$ or $Υ(3S)$ is a better source of $η_b(1S)$. Whereas one nonrelativistic model favors $η_b(1S)$ production from $Υ(2S)$, this advantage is lost when relativistic corrections are taken into account, and is not common to all sets of wave functions even in the purely nonrelativistic limit. Thus, the prospects for discovering $η_b(1S)$ in $Υ(3S)$ radiative decays could be comparable to those in $Υ(2S)$ decays. We also discuss a suggestion for discovering the $η_b$ via $Υ(3S) \to h_b(^1P_1) ππ$, followed by $h_b \to η_b γ$.

hep-ph↗

arXiv2001

CP Symmetry Violation

An elementary description of CP violation for the non-specialist is presented. This article, for publication in {\it Macmillan Encylopedia of Physics, Supplement: Elementary Particle Physics}, is being submitted to the Archive for comments by colleagues.

hep-ph↗

arXiv2001

The Eightfold Way

An elementary description of the Eightfold Way for the non-specialist is presented. This article, for publication in {\it Macmillan Encylopedia of Physics, Supplement: Elementary Particle Physics}, is being submitted to the Archive for comments by colleagues.

hep-ph↗

arXiv2001

Implications of CP Asymmetry Limits for $B \to K π$ and $B \to ππ$

Recent experimental limits for the direct CP asymmetries in $B^0 \to K^+ π^-$, $B^+ \to K^+ π^0$, $B^+ \to K^0 π^+$, and $B^0 \to π^+ π^-$, and for the indirect CP asymmetry in $B^0 \to π^+ π^-$, are combined with information on CP-averaged branching ratios to shed light on weak and strong phases. At present such bounds favor $γ\ge 60^\circ$ at the $1 σ$ level. The prospects for further improvements are discussed.

hep-ph↗

arXiv2001

Extraction of a Weak Phase from $B \to D^{(*)} π$

To observe CP-violating asymmetries through the interference of a weaker amplitude with a stronger one in $\bo \to D^{(*)} π$ and $\ob \to D^{(*)} π$ decays, one must collect enough events that the intensity associated with the weaker amplitude would be statistically significant. We show that provided the weaker amplitude is measured separately in $B^\pm \to D^{(*)\pm} π^0$ decays, the time-integrated approach requires around $2.5 \cdot 10^8 \ B \bar B$ pairs for measurements of the weak phase $\sin(2β+ γ)$ with an uncertainty of $0.05$ or better. We also determine the optimal conditions for precise $2β+ γ$ measurements and discuss the possibilities for resolving a discrete ambiguity.

hep-ph↗

arXiv2001

Hierarchy and Anarchy in Quark Mass Matrices, or Can Hierarchy Tolerate Anarchy?

The consequences of adding random perturbations (anarchy) to a baseline hierarchical model of quark masses and mixings are explored. Even small perturbations of the order of 5% of the smallest non-zero element can already give deviations significantly affecting parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, so any process generating the anarchy should in general be limited to this order of magnitude. The regularities of quark masses and mixings thus appear to be far from a generic feature of randomness in the mass matrices, and more likely indicate an underlying order.

hep-ph↗

arXiv2001

Factorization in Color-Favored B Meson Decays to Charm

Improved $B$ meson decay data have permitted more incisive tests of factorization predictions. A concurrent benefit is the ability to constrain the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$. Using a simultaneous fit to differential distributions $d Γ(\ob \to D^{*+} l^- \bar ν_l)/ dq^2$ measured by the CLEO and LEP Collaborations, the rates for the color-favored decays $\ob \to D^{(*)+} (π^-,ρ^-,a_1^-)$, and the rate for $\ob \to D^+ l^- \bar ν_l$, we find $|V_{cb}| = 0.0415 \pm 0.0022$. The slope of the universal Isgur-Wise form factor is described by a parameter found to be $\rs = 1.52 \pm 0.11$. Taking the $D_s$ meson decay constant from the world average of direct measurements, we predict satisfactorily the branching ratios for $\ob \to D^{(*)+} D_s^{(*)-}$. Ratios of helicity amplitudes for color-favored processes are also found to be in accord with predictions.

hep-ph↗

arXiv2001

Charmless Final States and S--D-wave mixing in the $ψ''$

The $\ppp = ψ(3770)$ resonance is expected to be mainly $c \bar c(1^3D_1)$, but tensor forces and coupling to charmed particle pairs can mix it with $\pp(2^3S_1)$ and other states. Implications of this mixing for decays of $\ppp$ to non-charmed final states are discussed. (i) The ratio $Γ(\ppp \to γ+ χ_{c2})/ Γ(\ppp \to γ+ χ_{c0})$ is expected to be highly suppressed if $\ppp$ is a pure D-wave state, and is enchanced by mixing. (ii) The expected decay $\pp \to ρπ$ and other ``missing'' modes can appear as corresponding $\ppp$ partial widths, enhanced by a factor depending on the mixing angle. General arguments then suggest a branching ratio of about 1%, give or take a factor of 2, for charmless hadronic decays of $\ppp$. (iii) Enhancements can appear in penguin amplitudes in B decays, $B \to K η'$ branching ratios, and direct CP-violating asymmetries in $B \to K π$ decays.

hep-ph↗

arXiv2001

Production of the D-wave $b \bar b$ states

The first and second families of D-wave $b \bar b$ quarkonium states are expected to have masses near 10.16 and 10.44 GeV/$c^2$. The accuracy of these predictions is discussed, and the prospects of two methods for producing these states in electron-positron collisions are updated. Direct scans in the $e^+ e^-$ center-of-mass can give rise to the $^3D_1$ states. The $1^3D_J$ states have also been searched for in the electromagnetic cascades from $\ups(3S) \to γχ'_b \to γγ^3D_J$. The sample of $\ups(3S)$ decays required to definitively observe the $1^3D_J$ states is found to be only somewhat greater than the present world's total.

hep-ph↗

arXiv2001

CP Violation in B Decays

The role of B decays in the study of CP violation is reviewed. We treat the interactions and spectroscopy of the $b$ quark and then introduce CP violation in $B$ meson decays, including time-dependences, decays to CP eigenstates and non-eigenstates, and flavor tagging. Additional topics include studies of strange $B$'s, decays to pairs of light pseudoscalar mesons, and the roles of gluonic and electroweak penguin diagrams, and final-state interactions.

hep-ph↗

arXiv2001

Measuring $D^0-\bar D^0$ Mixing and Relative Strong Phases at a Charm Factory

We propose a set of measurements at a charm factory to determine the $D^0-\bar D^0$ mixing parameters $ΔM$ and $ΔΓ$ and the strong phase difference $δ$ between doubly-Cabibbo-suppressed (DCS) and Cabibbo-favored (CF) neutral $D$ decays into $K^-π^+$. The method can also be used to measure strong phase differences between other corresponding DCS and CF amplitudes. These phase differences are important for studies of $D^0$--$\bar D^0$ mixing.

hep-ph↗

arXiv2001

U-Spin Symmetry in Doubly Cabibbo-Suppressed Charmed Meson Decays

We prove a U-spin amplitude triangle relation among doubly Cabibbo-suppressed (DCS) charmed meson decays, $D^0\to K^+π^-, D^0 \to K^0π^0$ and $D^+_s \to K^0 K^+$, congruent to an isospin relation among corresponding Cabibbo-favored (CF) decays. U-spin breaking in relative phases between CF and DCS amplitudes affects time-dependent studies of $D^0-\od$ mixing. Comparison of final state phase patterns in DCS and CF amplitude triangles, which can shed some light on these phases, is carried out in a phenomenological framework incorporating resonance contributions.

hep-ph↗

arXiv2001

CP Violation: Past, Present, and Future

We discuss the history of CP violation and its manifestations in kaon physics, its explanation in terms of phases of the Cabibbo-Kobayashi-Maskawa matrix describing charge-changing weak quark transitions, predictions for experiments involving $B$ mesons, and the light it can shed on physics beyond the Standard Model.

hep-ph↗

arXiv2000

Factorization vs. Flavor SU(3) in Charmless B Decays

Two types of predictions for charmless B decays are compared. One involves estimates based on factorization and models for form factors, while the other involves the use of flavor SU(3), sometimes with assumptions about the smallness of certain amplitudes. After a comparison of some factorization predictions with recent data, specific decays of $B$ mesons to two charmless mesons are discussed.

hep-ph↗

arXiv2000

Comments on CKM elements

The sensitivity of determination of elements of the Cabibbo-Kobayashi-Maskawa (CKM) matrix to experimental inputs (particularly $|V_{cb}|$) is discussed and caution in assigning probable errors is urged.

hep-ph↗

arXiv2000

Tests for Coherence in Neutral B Meson Decays

A density-matrix method for the study of tagged states of neutral B mesons with arbitrary coherence properties is applied to several examples, including $e^+ e^-$ production both at and above the $Υ(4S)$ resonance, and hadronic production. In the absence of coherence the only term modulating the exponential decay of a neutral B meson behaves as $\cos Δm t$, while a $\sin Δm t$ modulation is a signal of partial or full coherence. Decays to CP eigenstates are needed to fully specify the density matrix. We relate these results to more familiar expressions for the cases of the $Υ(4S)$ and incoherent production.

hep-ph↗