1,601 research outputs found

    P-Wave Charmonium Production in B-Meson Decays

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    We calculate the decay rates of BB mesons into P-wave charmonium states using new factorization formulas that are valid to leading order in the relative velocity of the charmed quark and antiquark and to all orders in the running coupling constant of QCD. We express the production rates for all four P states in terms of two nonperturbative parameters, the derivative of the wavefunction at the origin and another parameter related to the probability for a charmed-quark-antiquark pair in a color-octet S-wave state to radiate a soft gluon and form a P-wave bound state. Using existing data on BB meson decays into χc1\chi_{c1} to estimate the color-octet parameter, we find that the color-octet mechanism may account for a significant fraction of the χc1\chi_{c1} production rate and that BB mesons should decay into χc2\chi_{c2} at a similar rate.Comment: 14 page

    Robust pricing and hedging of double no-touch options

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    Double no-touch options, contracts which pay out a fixed amount provided an underlying asset remains within a given interval, are commonly traded, particularly in FX markets. In this work, we establish model-free bounds on the price of these options based on the prices of more liquidly traded options (call and digital call options). Key steps are the construction of super- and sub-hedging strategies to establish the bounds, and the use of Skorokhod embedding techniques to show the bounds are the best possible. In addition to establishing rigorous bounds, we consider carefully what is meant by arbitrage in settings where there is no {\it a priori} known probability measure. We discuss two natural extensions of the notion of arbitrage, weak arbitrage and weak free lunch with vanishing risk, which are needed to establish equivalence between the lack of arbitrage and the existence of a market model.Comment: 32 pages, 5 figure

    Double marking revisited

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    In 2002, the Qualifications and Curriculum Authority (QCA) published the report of an independent panel of experts into maintaining standards at Advanced Level (A-Level). One of its recommendations was for: ‘limited experimental double marking of scripts in subjects such as English to determine whether the strategy would signi-ficantly reduce errors of measurement’ (p. 24). This recommendation provided the impetus for this paper which reviews the all but forgotten literature on double marking and considers its relevance now

    New perturbative solutions of the Kerr-Newman dilatonic black hole field equations

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    This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio (Q/M)2(Q/M)^2 of the Kerr--Newman black hole. We have uncovered a new, exact conjugation (mirror) symmetry for the theory, which maps the small coupling sector to the strong coupling sector (ϕ→−ϕ\phi \to -\phi). We also calculate the gyromagnetic ratio of the black hole.Comment: Revtex, 27 page

    Kondo effect in multielectron quantum dots at high magnetic fields

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    We present a general description of low temperature transport through a quantum dot with any number of electrons at filling factor 1<Μ<21<\nu <2. We provide a general description of a novel Kondo effect which is turned on by application of an appropriate magnetic field. The spin-flip scattering of carriers by the quantum dot only involves two states of the scatterer which may have a large spin. This process is described by spin-flip Hubbard operators, which change the angular momentum, leading to a Kondo Hamiltonian. We obtain antiferromagnetic exchange couplings depending on tunneling amplitudes and correlation effects. Since Kondo temperature has an exponential dependence on exchange couplings, quantitative variations of the parameters in different regimes have important experimental consequences. In particular, we discuss the {\it chess board} aspect of the experimental conductance when represented in a grey scale as a function of both the magnetic field and the gate potential affecting the quantum dot

    Temperature Integrators as tools to validate thermal processes in food manufacturing

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    AbstractCharacterisation of thermal processes remains is challenge as it involves rotating parts and reasonably high temperatures thus making use of measurement techniques such as thermocouples unusable. Time Temperature Integrators (TTIs) has been suggested as an alternative that would provide information that would allow process design and validation. In this work we aim to validate the use of TTIs as measurement tools to validate both the effect but also the uncertainty of thermal processes in conditions relevant to industrial processing. P values estimated using TTIs compared favourably with those obtained from thermocouple measurements for a range of temperature profiles relevant to food processing. Efficiency of large mixing vessels has been quantified in a pilot scale vessel. Factors such as fluid viscosity; fill level and heating options were examined. The results show that the free TTIs show higher P values than the thermocouple situated in the centre of the vessel (but similar to the thermocouple positioned on the wall of the vessel) while the TTIs fitted in balls correlate well with the centre thermocouple. The results indicate that the mixing performance is dependent on the fluid viscosity, the fill level and the heating options. As the free TTIs follow the fluid path they gave a more accurate representation of the real thermal impact on the food product. This work demonstrates that TTIs can be successfully used as a tool for validation of efficiency and uncertainty of industrial processes

    A novel generalization of Clifford's classical point-circle configuration. Geometric interpretation of the quaternionic discrete Schwarzian KP equation

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    The algebraic and geometric properties of a novel generalization of Clifford's classical C4 point-circle configuration are analysed. A connection with the integrable quaternionic discrete Schwarzian Kadomtsev-Petviashvili equation is revealed

    The complications of ‘hiring a hubby’: gender relations and the commoditisation of home maintenance in New Zealand

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    This paper examines the commoditization of traditionally male domestic tasks through interviews with handymen who own franchises in the company ‘Hire a Hubby’ in New Zealand and homeowners who have paid for home repair tasks to be done. Discussions of the commoditization of traditionally female tasks in the home have revealed the emotional conflicts of paying others to care as well as the exploitative and degrading conditions that often arise when work takes place behind closed doors. By examining the working conditions and relationships involved when traditionally male tasks are paid for, this paper raises important questions about the valuing of reproductive labour and the production of gendered identities. The paper argues that while working conditions and rates of pay for ‘hubbies’ are better than those for people undertaking commoditized forms of traditionally female domestic labour, the negotiation of this work is still complex and implicated in gendered relations and identities. Working on the home was described by interviewees as an expression of care for family and a performance of the ‘right’ way to be a ‘Kiwi bloke’ and a father. Paying others to do this labour can imply a failure in a duty of care and in the performance of masculinity

    Histological evaluation of microfilled and conventional composite resins on monkey dental pulps

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    The pulpal responses to two micro-filled composite resins and a conventional composite resin were investigated in adult rhesus monkey teeth. All materials were randomly placed in unetched and unlined class V buccal cavity preparations. A total of 90 teeth were used in the study. Each material was evaluated at 3 days, 5 weeks and 8 weeks. Following perfusion, the teeth were prepared using routine histological procedures. The results indicated that the pulpal response to the microfilled and conventional composite resins were similar for all time periods, characterized by an initial slight to moderate response at 3 days, followed at 5 and 8 weeks by a zero to slight response with evidence of reparative dentine formation. Brown and Brenn staining for bacteria indicated positive staining reactions along the cavity wails of all teeth for all materials at each time period.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73366/1/j.1365-2591.1985.tb00453.x.pd
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