Search

We consider the branching ratio and the CP asymmetries in B → f 0 (980)K S decay to the end of determining the deviation of the time-dependent CP asymmetry from sin(2β), ΔS f0 K S ≡ η f0 K S S f0 K S -sin(2β), arising from standard model physics. We obtain ΔS f0 K S within the context of the QCD factorization framework for the B → f 0 (980)K S decay amplitudes assuming the f 0 (980) is a qq state and employing a random scan over the theoretical parameter space to assess the possible range in ΔS f0 K S . Imposing the value of the experimental branching ratio within 1σ and 3σ, respectively, of its central value as a constraint, we find the range of ΔS f0KS to be [0.018, 0.033] for a scan in which the parameters are allowed to vary within 1σ of their central values and the range [-0.019, 0.064] for a scan in which the parameters vary within 3σ of their central values.

A Faraday rotation experiment can set limits on the magnetic moment of a electrically-neutral, dark-matter particle, and the limits increase in stringency as the candidate-particle mass decreases. Consequently, if we assume the dark-matter particle to be a thermal relic, our most stringent constraints emerge at the keV mass scale. We discuss how such an experiment could be realized and determine the limits on the magnetic moment as a function of mass which follow given demonstrated experimental capacities., Comment: 24 pages, 5 figures

Negotiation skills play a critical role for today’s knowledge workers. Therefore, the need for university students to develop negotiation and problem-solving skills grows more important each year. Concurrently, the need for students to understand and work with computers continues to grow. This paper presents the exploratory results of using a prototype computer negotiation system developed around a set of real world data. The paper reviews previous research perspectives of negotiation, traditional (face to face) and information system perspectives (electronic). The social information processing theory posits that these characteristics differ between these two groups and that over time the characteristics exhibited by electronic group members should match those exhibited by the traditional group members. The results found differences in the characteristics of satisfaction, trust and tolerance, but did not find a convergence of perceptions between the two groups. The paper concludes by addressing critical success factors for future research in this area.

A fast hadron formed inside a nucleus collides with other nucleons on its passage out and may be absorbed. We present here an analytically solvable model: a positronium traversing N randomly oriented electric condensers, which may be related to the passage of a newly formed c c pair through the chromo-electric fields of the nucleons comprising the nucleus. The resulting absorption depends in a non-linear way on the initial size of the hadron.

If dark matter consists of cold, neutral particles with a nonzero magnetic moment, then, in the presence of an external magnetic field, a measurable gyromagnetic Faraday effect becomes possible. This enables direct constraints on the nature and distribution of such dark matter through detailed measurements of the polarization and temperature of the cosmic-microwave background radiation.

We consider the electric dipole form factor, F_3(q^2), as well as the Dirac and Pauli form factors, F_1(q^2) and F_2(q^2), of the nucleon in the light-front formalism. We derive an exact formula for F_3(q^2) to complement those known for F_1(q^2) and F_2(q^2). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F_2(q^2) and F_3(q^2), Fock state by Fock state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, kappa^n ~ - kappa^p., Comment: 25 pages, 1 figure. Published version. Ref. added

An assumption of isospin symmetry permits the determination of sin(2{alpha}) from the experimental study of B{yields}{pi}{pi} decays. Isospin, however, is merely an approximate symmetry; its breaking predicates a theoretical systematical error {sigma}{sub {alpha}}{sup IB} in the extraction of {alpha}. We focus on the impact of {pi}{sup 0}-{eta},{eta}{sup '} mixing, as well as the manner in which it is amenable to empirical constraint, and determine that {sigma}{sub {alpha}}{sup IB} can potentially be controlled to O(1 deg.)

A 21 acre sediment cap was designed for remediation of contaminated sediments at the McCormick & Baxter Creosoting Company Superfund Site in Portland, Oregon. The sediment cap was designed to provide physical and chemical isolation of the underlying contaminated sediment in addition to physical stability of the cap itself. Contaminants of concern at the site include arsenic, pentachlorophenol, carcinogenic polynuclear aromatic hydrocarbons (cPAH) and Dioxins/Furans. Hydraulic analyses conducted for the project included induced currents and propeller induced currents. The design incorporates several features to enhance both terrestrial and aquatic habitat at the site that is a migration route for endangered species of anadromous fish.

Direct CP violation can exist in untagged B-meson decays to self-conjugate, three-particle final states; it would be realized as a population asymmetry in the untagged decay rate across the mirror line of the Dalitz plot of the three-body decay. We explore the numerical size of this direct CP-violating effect in a variety of B-meson decays to three pseudoscalar mesons; we show that the resulting asymmetry is comparable to the partial rate asymmetry in the analogous tagged decays, making the search for direct CP violation in the untagged decay rate, for which greater statistics accrue, advantageous., Comment: 31 pages, REVTeX4, 1 eps figure, references added, typos corrected, version to appear in PRD

We consider radiative \beta--decay of the neutron in heavy baryon chiral perturbation theory, with an extension including explicit \Delta degrees of freedom. We compute the photon energy spectrum as well as the photon polarization; both observables are dominated by the electron bremsstrahlung contribution. Nucleon-structure effects not encoded in the weak coupling constants g_A and g_V are determined at next-to-leading order in the chiral expansion, and enter at the {\cal O}(0.5%)-level, making a sensitive test of the Dirac structure of the weak currents possible., Comment: 11 pages, 4 eps figures, misprints fixed, to appear in Phys Lett B

We discuss our knowledge of the scalar sector of QCD and how it impacts the determination of the CKM angle α from the isospin analysis of the B → ρπ decay.

We examine the role of ${B}^{0}({B}^{0})\ensuremath{\rightarrow}\ensuremath{\sigma}{\ensuremath{\pi}}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ decay in the Dalitz plot analysis of ${B}^{0}({B}^{0})\ensuremath{\rightarrow}\ensuremath{\rho}\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\pi}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ decays, employed to extract the CKM parameter $\ensuremath{\alpha}.$ The $\ensuremath{\sigma}\ensuremath{\pi}$ channel is significant because it can break the relationship between the penguin contributions in $\stackrel{\ensuremath{\rightarrow}}{B}{\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{0},$ $\stackrel{\ensuremath{\rightarrow}}{B}{\ensuremath{\rho}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}},$ and $\stackrel{\ensuremath{\rightarrow}}{B}{\ensuremath{\rho}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ decays consequent to an assumption of isospin symmetry. Its presence thus mimics the effect of isospin violation. The $\ensuremath{\sigma}{\ensuremath{\pi}}^{0}$ state is of definite $CP,$ however; we demonstrate that the $\stackrel{\ensuremath{\rightarrow}}{B}\ensuremath{\rho}\ensuremath{\pi}$ analysis can be generalized to include this channel without difficulty. The $\ensuremath{\sigma}$ or ${f}_{0}(400\ensuremath{-}1200)$ ``meson'' is a broad $I=J=0$ enhancement driven by strong $\ensuremath{\pi}\ensuremath{\pi}$ rescattering; a suitable scalar form factor is constrained by the chiral dynamics of low-energy hadron-hadron interactions---it is rather different from the relativistic Breit-Wigner form adopted in earlier $\stackrel{\ensuremath{\rightarrow}}{B}\ensuremath{\sigma}\ensuremath{\pi}$ and $\stackrel{\ensuremath{\rightarrow}}{D}\ensuremath{\sigma}\ensuremath{\pi}$ analyses. We show that the use of this scalar form factor leads to an improved theoretical understanding of the measured ratio $\mathrm{Br}({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})/\mathrm{Br}{(B}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}).$

We show that the presence of intrinsic charm in the hadrons' light-cone wave functions, even at a few percent level, provides new, competitive decay mechanisms for B decays which are nominally CKM-suppressed. For example, the weak decays of the B-meson to two-body exclusive states consisting of strange plus light hadrons, such as B\to\pi K, are expected to be dominated by penguin contributions since the tree-level b\to s u\bar u decay is CKM suppressed. However, higher Fock states in the B wave function containing charm quark pairs can mediate the decay via a CKM-favored b\to s c\bar c tree-level transition. Such intrinsic charm contributions can be phenomenologically significant. Since they mimic the amplitude structure of ``charming'' penguin contributions, charming penguins need not be penguins at all., Comment: 28 pages, 6 figures, published version. References added, minor changes

We consider what constraints unitarity and CPT invariance yield on the strong and electromagnetic phases entering K -> pi pi decay. In particular, we show that the relative size of the electromagnetically-induced changes in the I=0 and I=2 phase shifts in the two--pion final state do not depend on the explicit coupling to the pi^+ pi^- gamma channel. This demonstrates that Watson's theorem can be extended to include the presence of electromagnetism. We point out the consequences for the general structure of the K -> pi pi decay amplitudes in the presence of isospin violation., Comment: 7 pages, LaTeX, axodraw.sty

(2000). Looking for Dr. Jekyll but Hiring Mr. Hyde: Preventing Negligent Hiring, Supervision, Retention, and Training. Hospital Topics: Vol. 78, No. 1, pp. 14-22.

We extract the {ital G}-parity-violating branching ratio B({omega}{r_arrow}{pi}{sup +}{pi}{sup {minus}}) from the effective {rho}{sup 0}-{omega} mixing matrix element {tilde {Pi}}{sub {rho}{omega}}(s), determined from e{sup +}e{sup {minus}}{r_arrow}{pi}{sup +}{pi}{sup {minus}} data. The {omega}{r_arrow}{pi}{sup +}{pi}{sup {minus}} partial width can be determined either from the timelike pion form factor or through the constraint that the mixed physical propagator D{sub {rho}{omega}}{sup {mu}{nu}}(s) possesses no poles. The two procedures are inequivalent in practice, and we show why the first is preferred, to find finally B({omega}{r_arrow}{pi}{sup +}{pi}{sup {minus}})=1.9{plus_minus}0.3{percent}. {copyright} {ital 1999} {ital The American Physical Society}

An isospin analysis of $\stackrel{\ensuremath{\rightarrow}}{B}\ensuremath{\pi}\ensuremath{\pi}$ decays yields $\mathrm{sin}2\ensuremath{\alpha},$ where $\ensuremath{\alpha}\ensuremath{\equiv}\mathrm{arg}[\ensuremath{-}{V}_{\mathrm{td}}{V}_{\mathrm{tb}}^{*}{/(V}_{\mathrm{ud}}{V}_{\mathrm{ub}}^{*})]$ and ${V}_{\mathrm{ij}}$ is a CKM matrix element, without hadronic uncertainty if isospin is a perfect symmetry. Isospin, however, is broken not only by electroweak effects but also by the u and d quark mass difference. The latter drives ${\ensuremath{\pi}}^{0}\ensuremath{-}\ensuremath{\eta},{\ensuremath{\eta}}^{\ensuremath{'}}$ mixing and converts the isospin-perfect triangle relation between the $\stackrel{\ensuremath{\rightarrow}}{B}\ensuremath{\pi}\ensuremath{\pi}$ amplitudes to a quadrilateral. The combined isospin-violating effects impact the extracted value of $\mathrm{sin}2\ensuremath{\alpha}$ in a significant manner, particularly if the latter is small.

We study direct CP violation in $B^\pm \to \rho^\pm\rho^0(\omega) \to \rho^\pm\pi^+\pi^-$ and focus specifically on the rate asymmetry in the $\rho^0$-$\omega$ interference region. Here the strong phase is dominated by isospin violation, so that it can be essentially determined by $e^+e^- \to \rho^0 (\omega) \to \pi^+\pi^-$ data. We find the CP-violating asymmetry to be of the order of 20% at the $\omega$ invariant mass. Moreover, it is robust with respect to the estimable strong-phase uncertainties, permitting the extraction of $\sin\alpha$ from this channel.

We determine the magnitude, phase, and $s$-dependence of $\rho$-$\omega$ ``mixing'' in the pion form factor in the time-like region through fits to $e^+e^- \ra \pi^+ \pi^-$ data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\rho$ resonance, are small. The systematic errors in the $\rho$ mass and width, however, are larger than previously estimated., Comment: 20 pages, REVTeX, epsfig, 2 ps figures, minor changes

We consider charge-symmetry violations in the nucleon-nucleon force which result from isospin-violating meson-baryon coupling constants. The vector mesons are assumed to couple to the nucleon's electromagnetic current, which we decompose into isoscalar and isovector quark components. We compute these currents in the context of a constituent quark model. The isospin violations in the meson-baryon couplings arise from the difference in the up and down constituent quark masses. We show that class IV charge-symmetry-breaking potentials arise in the resulting $\omega$ and $\rho$ exchange contributions to the $NN$ force. The magnitude of these contributions is consistent with that phenomenologically required by the measured difference of $n$ and $p$ analyzing powers in elastic $\vec{n}-\vec{p}$ scattering at 183 MeV., Comment: 8 pages, revtex

The asymmetry in the missing‐momentum distribution from the (e,e′p) reaction is calculated in a relativistic formalism. The lower components of the Dirac wave functions generate a large asymmetry in the momentum distribution at the plane‐wave level. This is in contract to a description in which relativistic nuclear‐structure effects are neglected.

A Reply to the Comment by Simon Capstick and B.D. Keister. {copyright} {ital 1997} {ital The American Physical Society}

The guerrilla war was fast brutalizing both adversaries. The worst scandals on the British side concerned colonial irregulars Australians, Canadians and South Africans whose official contingents, ironically, had won a reputation for gallantry in so many set-piece battles. The most notorious case involved a special anticommando unit, raised by Australians to fight in the wild northern Transvaal, and called the Bush Veldt Carbineers. Six of its officers (five Australians, one Englishman) were court-martialled for multiple murder. The facts were admitted: in August 1901, 12 Boers, earlier taken prisoner, had been shot by the Carbineers on the orders of their officers. The Australians' defence: as a reprisal, shooting prisoners was now accepted practice. Two of the Australian officers, Lieutenants 'Breaker' Morant and Handcock, were executed in February 1902, on the orders of Kitchener. The affair caused an outcry in Australia. There arose a misconception (still current) that foreign political pressures had induced Kitchener to make scapegoats of Morant and Handcock. In fact Kitchener's motives were cruder: evidence of his own army's indiscipline drove him wild with frustration. This journal article is available in Kunapipi: http://ro.uow.edu.au/kunapipi/vol3/iss1/6

’Moral panics’ of the ‘Black Peril’ ('Not a White Woman Safe!') variety are a staple of much more than the stock South African conversations Doris Lessing irritatedly noted in Going Home. Inter‐racial sexual encounters, coerced or consenting, and often culminating in social crisis, provide a plot for much colonial and post‐colonial fiction, hence fuelling literary criticism. They have, moreover, provoked debates within colonial social psychology and social history.1 My purpose here is to examine the contribution The Grass Is Singing makes towards understanding moral panics, and to assess how feminist this understanding is. (Referred to as GS, The Grass Is Singing was first published in 1950. All references are to the 1976 Penguin reprint.)

The shape of the electron energy spectrum in 3H beta-decay permits a direct assay of the absolute scale of the neutrino mass; a highly accurate theoretical description of the electron energy spectrum is necessary to the empirical task. We update Sirlin's calculation of the outer radiative correction to nuclear beta-decay to take into account the non-zero energy resolution of the electron detector. In previous 3H beta-decay studies the outer radiative corrections were neglected all together; only Coulomb corrections to the spectrum were included. This neglect artificially pushes m_nu^2 < 0 in a potentially significant way. We present a computation of the theoretical spectrum appropriate to the extraction of the neutrino mass in the sub-eV regime., 11 pages, 4 eps figures; discussion, figure added