189 research outputs found

    Experimental constraints for additional short-range forces from neutron experiments

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    We present preliminary results on sensitivity of experiments with slow neutrons to constrain additional forces in a wide distance range: from picometers to micrometers. In the sub-nanometer range, available data on lengths of neutron scattering at nuclei provide the most competitive constraint. We show that it can be improved significantly in a dedicated measurement of asymmetry of neutron scattering at noble gases. In the micrometer range, we present sensitivity of the future GRANIT experiment. Further analysis will be presented in following publications.Comment: presented in "les rencontres de Moriond" 2007 conferenc

    The comb-like representations of cellular ordinal balleans

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    Given two ordinal λ\lambda and γ\gamma, let f:[0,λ)[0,γ)f:[0,\lambda) \rightarrow [0,\gamma) be a function such that, for each α<γ\alpha<\gamma, sup{f(t):t[0,α]}<γ.\sup\{f(t): t\in[0, \alpha]\}<\gamma. We define a mapping df:[0,λ)×[0,λ)[0,γ)d_{f}: [0,\lambda)\times [0,\lambda) \longrightarrow [0,\gamma) by the rule: if x<yx<y then df(x,y)=df(y,x)=sup{f(t):t(x,y]}d_{f}(x,y)= d_{f}(y,x)= \sup\{f(t): t\in(x,y]\}, d(x,x)=0d(x,x)=0. The pair ([0,λ),df)([0,\lambda), d_{f}) is called a γ\gamma-comb defined by ff. We show that each cellular ordinal ballean can be represented as a γ\gamma-comb. In {\it General Asymptology}, cellular ordinal balleans play a part of ultrametric spaces.Comment: 5 pages, preprin

    Antideuteron production in proton-proton and proton-nucleus collisions

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    The experimental data of the antideuteron production in proton-proton and proton-nucleus collisions are analyzed within a simple model based on the diagrammatic approach to the coalescence model. This model is shown to be able to reproduce most of existing data without any additional parameter.Comment: To appear in Eur. Phys. J A (2002

    Antiproton annihilation on light nuclei at very low energies

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    The recent experimental data obtained by the OBELIX group on pˉ\bar{p}D and pˉ4\bar{p}^4He total annihilation cross sections are analyzed. The combined analysis of these data with existing antiprotonic atom data allows, for the first time, the imaginary parts of the S-wave scattering lengths for the two nuclei to be extracted. The obtained values are: Ima0sc=[0.62±0.02(stat)±0.04(sys)]fmIm a^{sc}_0 = [- 0.62 \pm 0.02 ({stat}) \pm 0.04 ({sys})] fm for pˉ\bar{p}D and Ima0sc=[0.36±0.03(stat)0.11+0.19(sys)]fmIm a^{sc}_0 = [- 0.36\pm 0.03({stat})^{+0.19}_{-0.11}({sys})] fm for pˉ4\bar{p}^4He. This analysis indicates an unexpected behaviour of the imaginary part of the pˉ\bar{p}-nucleus S-wave scattering length as a function of the atomic weight A: Ima0sc|Im a^{sc}_0| (pˉ\bar{p}p) > Ima0sc|Im a^{sc}_0| (pˉ\bar{p}D) > Ima0sc|Im a^{sc}_0| (pˉ4\bar{p}^4He).Comment: 13 pages, 5 figure

    Spontaneous emission of graviton by a quantum bouncer

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    Spontaneous emission of graviton rates for the quantum bouncer states are evaluated

    A New Constraint for the Coupling of Axion-like particles to Matter via Ultra-Cold Neutron Gravitational Experiments

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    We present a new constraint for the axion monopole-dipole coupling in the range of 1 micrometer to a few millimeters, previously unavailable for experimental study. The constraint was obtained using our recent results on the observation of neutron quantum states in the Earth's gravitational field. We exploit the ultimate sensitivity of ultra-cold neutrons (UCN) in the lowest gravitational states above a material surface to any additional interaction between the UCN and the matter, if the characteristic interaction range is within the mentioned domain. In particular, we find that the upper limit for the axion monopole-dipole coupling constant is (g_p g_s)/(\hbar c)<2 x 10^{-15} for the axion mass in the ``promising'' axion mass region of ~1 meV.Comment: 5 pages 3 figure

    Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement

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    Gravitational resonance spectroscopy consists in measuring the energy spectrum of bouncing ultracold neutrons above a mirror by inducing resonant transitions between different discrete quantum levels. We discuss how to induce the resonances with a flow through arrangement in the GRANIT spectrometer, excited by an oscillating magnetic field gradient. The spectroscopy could be realized in two distinct modes (so called DC and AC) using the same device to produce the magnetic excitation. We present calculations demonstrating the feasibility of the newly proposed AC mode

    Parameterization of the antiproton inclusive production cross section on nuclei

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    A new parameterization of the antiproton inclusive production cross section in proton-proton and proton-nucleus collisions is proposed. A sample of consistent pA->pbar X$ experimental data sets measured on 1<A<208 nuclei, from 12 GeV up to 400 GeV incident energy, have been used to constrain the parameters. A broader energy domain is covered for the pp->pbar X reaction with a simplified functional form used in the fits. The agreement obtained with the data is good. The results are discussed.Comment: 10 pages, 11 figures, 7 tables, submitted to Phys. Rev.

    Neutron scattering and extra short range interactions

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    The available data on neutron scattering were analyzed to constrain a hypothetical new short-range interaction. We show that these constraints are several orders of magnitude better than those usually cited in the range between 1 pm and 5 nm. This distance range occupies an intermediate space between collider searches for strongly coupled heavy bosons and searches for new weak macroscopic forces. We emphasise the reliability of the neutron constraints in so far as they provide several independent strategies. We have identified the most promising way to improve them

    Frequency shifts in gravitational resonance spectroscopy

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    Quantum states of ultracold neutrons in the gravitational field are to be characterized through gravitational resonance spectroscopy. This paper discusses systematic effects that appear in the spectroscopic measurements. The discussed frequency shifts, which we call Stern-Gerlach shift, interference shift, and spectator state shift, appear in conceivable measurement schemes and have general importance. These shifts have to be taken into account in precision experiments
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