| 1. |
- Abraham, Roshan Mammen, et al.
(författare)
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Tau neutrinos in the next decade : from GeV to EeV
- 2022
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Ingår i: Journal of Physics G. - : Institute of Physics Publishing (IOPP). - 0954-3899 .- 1361-6471. ; 49:11
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Tidskriftsartikel (refereegranskat)abstract
- Tau neutrinos are the least studied particle in the standard model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
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| 2. |
- Ackermann, Markus, et al.
(författare)
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High-energy and ultra-high-energy neutrinos : A Snowmass white paper
- 2022
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Ingår i: Journal of High Energy Astrophysics. - : Elsevier. - 2214-4048 .- 2214-4056. ; 36, s. 55-110
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Tidskriftsartikel (refereegranskat)abstract
- Astrophysical neutrinos are excellent probes of astroparticle physics and high-energy physics. With energies far beyond solar, supernovae, atmospheric, and accelerator neutrinos, high-energy and ultrahigh-energy neutrinos probe fundamental physics from the TeV scale to the EeV scale and beyond. They are sensitive to physics both within and beyond the Standard Model through their production mechanisms and in their propagation over cosmological distances. They carry unique information about their extreme non-thermal sources by giving insight into regions that are opaque to electromagnetic radiation. This white paper describes the opportunities astrophysical neutrino observations offer for astrophysics and high-energy physics, today and in coming years.
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| 3. |
- Anchordoqui, Luis A., et al.
(författare)
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The Forward Physics Facility : Sites, experiments, and physics potential
- 2022
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 968, s. 1-50
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Tidskriftsartikel (refereegranskat)abstract
- The Forward Physics Facility (FPF) is a proposal to create a cavern with the space and infrastructure to support a suite of far-forward experiments at the Large Hadron Collider during the High Luminosity era. Located along the beam collision axis and shielded from the interaction point by at least 100 m of concrete and rock, the FPF will house experiments that will detect particles outside the acceptance of the existing large LHC experiments and will observe rare and exotic processes in an extremely low-background environment. In this work, we summarize the current status of plans for the FPF, including recent progress in civil engineering in identifying promising sites for the FPF and the experiments currently envisioned to realize the FPF's physics potential. We then review the many Standard Model and new physics topics that will be advanced by the FPF, including searches for long-lived particles, probes of dark matter and dark sectors, high-statistics studies of TeV neutrinos of all three flavors, aspects of perturbative and non-perturbative QCD, and high-energy astroparticle physics.
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| 4. |
- Bhattacharya, Atri, et al.
(författare)
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Charm decay in slow-jet supernovae as the origin of the IceCube ultra-high energy neutrino events
- 2015
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- We investigate whether the recent ultra-high energy (UHE) neutrino events detected at the IceCube neutrino observatory could come from the decay of charmed mesons produced within the mildly relativistic jets of supernova-like astrophysical sources. We demonstrate that the 5.7σ excess of neutrinos observed by IceCube in the energy range 30 TeV--2 PeV can be explained by a diffuse flux of neutrinos produced in such slow-jet supernovae, using the values of astrophysical and QCD parameters within the theoretical uncertainties associated with neutrino production from charmed meson decay in astrophysical sources. We discuss the theoretical uncertainties inherent in the evaluation of charm production in high energy hadronic collisions, as well as the astrophysical uncertainties associated with slow-jet supernova sources. The proton flux within the source, and therefore also the produced neutrino flux, is cut off at around a few PeV, when proton cooling processes become dominant over proton acceleration. This directly explains the sudden drop in event rates at energies above a few PeV. We incorporate the effect of energy dependence in the spectrum-weighted charm production cross-section and show that this has a very significant effect on the shape, magnitude and cut-off energies for the neutrino flux.
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| 5. |
- Bhattacharya, Atri, et al.
(författare)
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Energy-dependent flavour ratios in neutrino telescopes from charm
- 2024
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : Institute of Physics Publishing (IOPP). - 1475-7516. ; 2024:3
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Tidskriftsartikel (refereegranskat)abstract
- The origin of the observed diffuse neutrino flux is not yet known. Studies of the relative flavour content of the neutrino flux detected at Earth can give information on the production mechanisms at the sources and on flavour mixing, complementary to measurements of the spectral index and normalisation. Here we demonstrate the effects of neutrino fluxes with different spectral shapes and different initial flavour compositions dominating at different energies, and we study the sensitivity of future measurements with the IceCube Neutrino Observatory. Where one kind of flux gives way to another, this shows up as a non-trivial energy dependence in the flavour compositions. We explore this in the context of slow-jet supernovae and magnetar-driven supernovae – two examples of astrophysical sources where charm production may be effective. Using current best-fit neutrino mixing parameters and their projected 2040 uncertainties, we use event ratios of different event morphologies at IceCube to illustrate the possibilities of distinguishing the energy dependence of neutrino flavour ratios.
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| 6. |
- Bhattacharya, Atri, et al.
(författare)
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Perturbative charm production and the prompt atmospheric neutrino flux in light of RHIC and LHC
- 2015
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- We re-evaluate the prompt atmospheric neutrino flux, using the measured charm cross sections at RHIC and the Large Hadron Collider to constrain perturbative QCD parameters such as the factorization and renormalization scales, as well as modern parton distribution functions and recent estimates of the cosmic-ray spectra. We find that our result for the prompt neutrino flux is lower than previous perturbative QCD estimates and, consequently, alters the signal-to-background statistics of the recent IceCube measurements at high energies.
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| 7. |
- Bhattacharya, Atri, et al.
(författare)
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Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects
- 2016
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- We evaluate the prompt atmospheric neutrino flux at high energies using three different frameworks for calculating the heavy quark production cross section in QCD: NLO perturbative QCD, kT factorization including low-x resummation, and the dipole model including parton saturation. We use QCD parameters, the value for the charm quark mass and the range for the factorization and renormalization scales that provide the best description of the total charm cross section measured at fixed target experiments, at RHIC and at LHC. Using these parameters we calculate differential cross sections for charm and bottom production and compare with the latest data on forward charm meson production from LHCb at 7 TeV and at 13 TeV, finding good agreement with the data. In addition, we investigate the role of nuclear shadowing by including nuclear parton distribution functions (PDF) for the target air nucleus using two different nuclear PDF schemes. Depending on the scheme used, we find the reduction of the flux due to nuclear effects varies from 10% to 35% at the highest energies. Finally, we compare our results with the IceCube limit on the prompt neutrino flux, which is already providing valuable information about some of the QCD models.
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| 8. |
- Enberg, Rikard, et al.
(författare)
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High energy neutrinos from charm in astrophysical sources
- 2009
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Ingår i: Physical Review D. - : The American Physical Society. - 1550-7998 .- 1550-2368. ; 79:5, s. 053006-
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Tidskriftsartikel (refereegranskat)abstract
- Charm production gives rise to a flux of very high energy neutrinos from astrophysical sources with jets driven by central engines, such as gamma ray bursts or supernovae with jets. The neutrino flux from semileptonic decays of charmed mesons is subject to much less hadronic and radiative cooling than the conventional flux from pion and kaon decays and therefore has a dominant contribution at higher energies, which is of relevance to future ultrahigh energy neutrino experiments.
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| 9. |
- Enberg, Rikard, et al.
(författare)
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Perturbative Charm Production and the Prompt Atmospheric Neutrino Flux in light of RHIC and LHC
- 2020
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Prompt neutrinos due to the decay of charmed mesons produced in the atmosphere from cosmic-ray and atmospheric nuclei interactions may be a significant source of background to ultra-high energy neutrino searches above 10 TeV. We re-evaluate this flux using updated charm production cross-sections based on QCD parameters, the charm quark mass, and the range for the factorization and renormalization scales that provide the best description of this data at fixed target experiments, at RHIC, and at LHC. We find that the prompt neutrino flux is reduced from previous results in the literature by a factor between two and eight, depending on the energy. We discuss the implications of our results for current IceCube data.
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| 10. |
- Enberg, Rikard, et al.
(författare)
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Prompt neutrino fluxes from atmospheric charm
- 2008
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 78:4, s. 043005-
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Tidskriftsartikel (refereegranskat)abstract
- We calculate the prompt neutrino flux from atmospheric charm production by cosmic rays, using the dipole picture in a perturbative QCD framework, which incorporates the parton saturation effects present at high energies. We compare our results with the next-to-leading order perturbative QCD result and find that saturation effects are large for neutrino energies above 10^6 GeV, leading to a substantial suppression of the prompt neutrino flux. We comment on the range of prompt neutrino fluxes due to theoretical uncertainties.
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