Experimental Study of Nuclear Shadowing in Photoproduction

Michalowski, S. J.; Andrews, D.; Eickmeyer, J.; Gentile, Thomas R.; Mistry, N. B.; Talman, R.; Ueno, K.

doi:10.1103/physrevlett.39.737

Cited by 55 publications

(22 citation statements)

References 14 publications

(1 reference statement)

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“…Mücke et al 2000). Neglecting the nuclear shadowing effect in photoproduction (Michalowski et al 1977), the peak cross‐section is σ Δ ≃σ p γ A ≃ 4.1 × 10 −28 A cm 2 (Anchordoqui et al 2008; Murase et al 2008), where σ p γ is the peak cross‐section for protons. As ξ A (ε) ∼ξ p (ε)/ A , σ Δ ξ A is independent of A .…”

Section: Neutrino Background From Llgrbsmentioning

confidence: 99%

Nearby low-luminosity gamma-ray bursts as the sources of ultra-high-energy cosmic rays revisited

Liu

Wang

Dai

2011

Monthly Notices of the Royal Astronomical Society

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Low‐luminosity gamma‐ray bursts (GRBs) with the luminosity ≲ 1049 erg s−1 probably constitute a distinct population from the classic high‐luminosity GRBs. They are the most luminous objects detected so far within ∼100 Mpc, the horizon distance of ultra‐high‐energy cosmic rays (UHECRs), so they are considered to be the candidate sources of UHECRs. It was recently argued that the energy production rate in UHECRs is much larger than that in gamma‐ray photons of long GRBs measured by the Fermi satellite, which, if true, would challenge the view that GRBs can be the sources of UHECRs. We here suggest that many of the low‐luminosity GRBs, due to their low luminosity, cannot trigger the current GRB detectors and hence their contribution to the local gamma‐ray energy production rate is missing. We find that the real local energy production rate by low‐luminosity GRBs, taking into account the missing part, which constitutes a dominant fraction of the total amount, could be sufficient to account for the flux of UHECRs. Due to the low luminosity, only intermediate‐mass or heavy nuclei can be accelerated to ∼1020 eV. We discuss the acceleration and survival of these ultra‐high‐energy nuclei in low‐luminosity GRBs, especially in those missing low‐luminosity GRBs. At last, the accompanying diffuse neutrino flux from the whole low‐luminosity GRB population is calculated.

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Section: Neutrino Background From Llgrbsmentioning

confidence: 99%

Nearby low-luminosity gamma-ray bursts as the sources of ultra-high-energy cosmic rays revisited

Liu

Wang

Dai

2011

Monthly Notices of the Royal Astronomical Society

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“…Then the β have been derived from measurements of these reactions performed on a wide range of mass number [25], [26]. In the framework of a VMD description the relevant quantity is the coherence length of the hadronic fluctuations of the photon λ V = 2k/(Q 2 + m [18], open circles [3], squares [19], diamonds [20], and triangles [21]. Also shown is the proton absorption cross section [16] (solid line).…”

Section: Photoabsorption Strength In the Nuclear Mediummentioning

confidence: 99%

Photoabsorption on nuclei in the energy range 0.5–2.6 GeV

et al. 1999

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The energy and nuclear mass dependences of the total hadronic cross section in the energy range 0.5-2.6 GeV have been measured at Bonn using the SAPHIR tagged photon beam. The measurement, performed on C, Al, Cu, Sn and Pb, provides the first photoabsorption data in the region 1.2-1.7 GeV. The results show a significant reduction of the photoabsorption strength on the bound nucleon compared to the free nucleon case in the whole energy region. Above 1.2 GeV this reduction decreases with the nuclear density and can be interpreted as a signature of a low energy onset of the shadowing effect.PACS n. 25.20.Gf, 12.40.Vv

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“…This leads to K Ae σ Aγ | max ≈ (Z 2 /A) 10 −30 cm 2 , with a threshold photon energy of 1 MeV being required in the nucleus' rest frame. Though a photo-meson production channel may also be available for nuclei cooling [8], we ignore this process in our discussion.…”

Section: The Photo-disintegration Cooling Mechanismmentioning

confidence: 99%

Limitations on the photo-disintegration process as a source of VHE photons

Aharonian

Taylor

2010

Astroparticle Physics

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We consider whether photo-disintegration is ever able to provide an effective mechanism for the production of VHE γ-ray emission from astrophysical sources. We find that the efficiency of this process is always smaller by a factor A/Z 2 (∼ 4/A) than that of nuclei cooling through Bethe-Heitler pair-production. Furthermore, for sources optically thin to TeV emission, we find that the efficiency of this process can be no more than 3 × 10 −5 (Rsource/RLarmor), where Rsource is the source size and RLarmor is the CR nuclei Larmor radius. We conclude that this process is unable to provide an effective mechanism for VHE γ-ray emission from astrophysical sources.

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Experimental Study of Nuclear Shadowing in Photoproduction

Cited by 55 publications

References 14 publications

Nearby low-luminosity gamma-ray bursts as the sources of ultra-high-energy cosmic rays revisited

Nearby low-luminosity gamma-ray bursts as the sources of ultra-high-energy cosmic rays revisited

Photoabsorption on nuclei in the energy range 0.5–2.6 GeV

Limitations on the photo-disintegration process as a source of VHE photons

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