scholarly journals Empirical determination of the very high energy heavy quark cross section from nonaccelerator data

1994 ◽  
Vol 49 (5) ◽  
pp. 2310-2315 ◽  
Author(s):  
M. C. Gonzalez-Garcia ◽  
F. Halzen ◽  
R. A. Vázquez ◽  
E. Zas
Keyword(s):  
Heavy Quark ◽  
Cross Section ◽  
High Energy ◽  
Empirical Determination ◽  
Very High Energy ◽  
Very High

scholarly journals Cross section to multiplicity ratios at very high energy

2014 ◽  
Vol 734 ◽  
pp. 207-209 ◽  
Author(s):  
M.M. Block ◽  
L. Stodolsky
Keyword(s):  
Cross Section ◽  
High Energy ◽  
Very High Energy ◽  
Very High

scholarly journals Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1081-1085
Author(s):  
◽  
H. Abdalla ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
E. O. Angüner ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Ray ◽  
Photon Index ◽  
Very High Energy ◽  
Stereoscopic System ◽  
Very High ◽  
Intrinsic Energy

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera–electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

scholarly journals Total photoproduction cross section at very high energy

2009 ◽  
Vol 63 (1) ◽  
pp. 69-85 ◽  
Author(s):  
R. M. Godbole ◽  
A. Grau ◽  
G. Pancheri ◽  
Y. N. Srivastava
Keyword(s):  
Cross Section ◽  
High Energy ◽  
Photoproduction Cross Section ◽  
Very High Energy ◽  
Very High

GAMMA RAYS FROM THE DEUTERON BOMBARDMENT OF BORON 10

1955 ◽  
Vol 33 (12) ◽  
pp. 828-840 ◽  
Author(s):  
J. T. Sample ◽  
G. C. Neilson ◽  
G. B. Chadwick ◽  
J. B. Warren
Keyword(s):  
Energy Level ◽  
Cross Section ◽  
Gamma Rays ◽  
High Energy ◽  
Crystal Spectrometer ◽  
Upper Limit ◽  
Very High Energy ◽  
Deuteron Bombardment ◽  
Bombarding Energy ◽  
Very High

Bombardment of B10 with 1.4 Mev. deuterons has been found to produce gamma rays of energy 4.46 ±.04, 4.75 ±.03, 5.03 ±.09, 5.35 ±.05, 6.52 ±.04, 6.78 ±.07, 7.29 ±.04, 8.27 ±.09, and 8.87 ±.02 Mev., as measured with a three-crystal pair spectrometer. Tentative assignments to transitions in B11 and C11 agree well in most cases with the known energy level schemes. No gamma rays of very high energy were observed, even with a single-crystal spectrometer; consequently an upper limit of 10−31 cm.2 has been placed on the cross-section of B10(d, γ)C12 at 0.95 Mev. bombarding energy.

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