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G. Ingelman

Publications and source records attributed to G. Ingelman.

45 records · Page 3Linked to original sources

Signals for Intrinsic Charm in High Energy Interactions

The prospects to test the hypothesis of intrinsic charm quarks in the proton are investigated. We consider how this component can be directly or indirectly probed in deep inelastic scattering at HERA and in fixed target experiments and find that an overlooked signal might be present in existing NMC data. Applying the intrinsic charm model to hadron collisions we compare the resulting charm production cross-sections with those based on standard perturbative QCD and available data. Extrapolating to higher energies we obtain predictions for charm production at the Tevatron and LHC.

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High Energy Neutrino Production by Cosmic Ray Interactions in the Sun

The flux of neutrinos originating from cosmic ray interactions with matter in the Sun has been calculated based on Monte Carlo models for high energy particle interactions. The resulting flux at the Earth (within the Sun's solid angle) is higher than the corresponding one from cosmic ray interactions with the Earth atmosphere. The smallness of the absolute rate, however, precludes it as a practical `standard candle' for neutrino telescopes and limits neutrino oscillation searches. On the other hand, it facilitates dark matter searches based on neutrinos from neutralino annihilation in the Sun.

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Atmospheric muons and neutrinos from charm

We have updated our previous investigation of the production of muons and neutrinos in cosmic ray interactions with the atmosphere, taking account of recent results from the $ep$ collider HERA in our QCD-based model for hadronic interactions. Qualitatively, our previous results remain unmodified: our predictions for the conventional muon and neutrino fluxes agree with earlier calculations, whereas the charm particle treatment we use gives significantly lower prompt fluxes compared to earlier estimates. This implies better prospects for detecting very high energy neutrinos from cosmic sources.

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Charm Production and High Energy Atmospheric Muon and Neutrino Fluxes

Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with Monte Carlo models for hadronic interactions. The resulting conventional muon and neutrino fluxes (from $π$ and $K$ decays) agree well with earlier calculations, whereas our prompt fluxes from charm decays are significantly lower than earlier estimates. Charm production is mainly considered as a well defined perturbative QCD process, but we also investigate a hypothetical non-perturbative intrinsic charm component in the proton. The lower charm rate implies better prospects for detecting very high energy neutrinos from cosmic sources.

hep-ph↗

Soft Colour Interactions as the Origin of Rapidity Gaps in DIS

We introduce soft colour interactions as a novel mechanism to understand the observed events with large rapidity gaps in $ep$ collisions at HERA. Colour exchanges between produced partons and colour-charges in the proton remnant modifies the colour structure for hadronization, such that colour singlet systems may appear well separated in rapidity. Our explicit model show characteristics of diffractive scattering, although no explicit pomeron dynamics have been introduced, and for non-gap events an increased forward energy flow gives agreement with data.

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Rapidity Gaps in DIS through Soft Colour Interactions

We present a new mechanism for the creation of large rapidity gaps in DIS events at HERA. Soft colour interactions between perturbatively produced partons and colour-charges in the proton remnant, modifies the colour structure for hadronization giving colour singlet systems that are well separated in rapidity. An explicit model is presented that, although the detailed results depend on the initial state parton emission, can describe both the observed rapidity gaps and, in addition, the forward energy flow in an inclusive event sample.

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A Monte Carlo Calculation of Atmospheric Muon and Neutrino Fluxes

Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with a cascade simulation program based on Lund Monte Carlo programs. The resulting `conventional' muon and neutrino fluxes (from $π,K$ decays) agree well with earlier calculations, whereas the improved charm particle treatment used in this study gives significantly lower `prompt' fluxes compared to earlier estimates. This implies better prospects for detecting very high energy neutrinos from cosmic sources.

hep-ph↗

Renormalization scale uncertainty in tne DIS 2+1 jet cross-section

The deep inelastic scattering 2+1 jet cross- section is a useful observable for precision tests of QCD, e.g. measuring the strong coupling constant alpha(s). A consistent analysis requires a good understanding of the theoretical uncertainties and one of the most fundamental ones in QCD is due to the renormalization scheme and scale ambiguity. Different methods, which have been proposed to resolve the scale ambiguity, are applied to the 2+1 jet cross-section and the uncertainty is estimated. It is shown that the uncertainty can be made smaller by choosing the jet definition in a suitable way.

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