scholarly journals Cosmic Ray Antiprotons 5–12 GeV

1981 ◽  
Vol 94 ◽  
pp. 257-258 ◽  
Author(s):  
T. K. Gaisser ◽  
A. J. Owens ◽  
Gary Steigman

Secondary antiprotons are a potentially interesting probe of cosmic ray propagation because their production cross section is strongly energy-dependent, increasing by more than two orders of magnitude between 10 and 1000 GeV/c. This is quite unlike the case for fragmentation cross sections of complex nuclei, which are virtually constant with energy. Moreover, the flux depends primarily on the environment seen by protons which need not be identical to that probed by other nuclei.

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.


2020 ◽  
Vol 8 ◽  
Author(s):  
John W. Norbury ◽  
Giuseppe Battistoni ◽  
Judith Besuglow ◽  
Luca Bocchini ◽  
Daria Boscolo ◽  
...  

The helium (4He) component of the primary particles in the galactic cosmic ray spectrum makes significant contributions to the total astronaut radiation exposure. 4He ions are also desirable for direct applications in ion therapy. They contribute smaller projectile fragmentation than carbon (12C) ions and smaller lateral beam spreading than protons. Space radiation protection and ion therapy applications need reliable nuclear reaction models and transport codes for energetic particles in matter. Neutrons and light ions (1H, 2H, 3H, 3He, and 4He) are the most important secondary particles produced in space radiation and ion therapy nuclear reactions; these particles penetrate deeply and make large contributions to dose equivalent. Since neutrons and light ions may scatter at large angles, double differential cross sections are required by transport codes that propagate radiation fields through radiation shielding and human tissue. This work will review the importance of 4He projectiles to space radiation and ion therapy, and outline the present status of neutron and light ion production cross section measurements and modeling, with recommendations for future needs.


2015 ◽  
Vol 30 (36) ◽  
pp. 1550217
Author(s):  
A. I. Ahmadov ◽  
C. Aydin ◽  
R. Myrzakulov ◽  
O. Uzun

We calculate the contribution of the higher-twist Feynman diagrams to the large-[Formula: see text] inclusive gluon production cross-section in [Formula: see text] collisions in case of the running coupling and frozen coupling approaches within perturbative and holographic QCD. The structure of infrared renormalon singularities of the higher-twist subprocess cross-section is obtained and the resummed higher-twist cross-sections (Borel sum) with the ones obtained in the framework of the frozen coupling approach and leading-twist cross-section are compared and analyzed.


2009 ◽  
Vol 18 (02) ◽  
pp. 302-308
Author(s):  
PENGNIAN SHEN ◽  
HANTAO JING ◽  
HUANQING CHIANG

The Λ-hypernucleus (LHN) production in the proton-induced reaction is studied in the distorted wave impulse approximation(DWIA). The cross sections for the LHN production in the reactions where the proton bombards the 6Li, 12C and 16O targets, respectively, are calculated. It is shown that the reaction cross sections are of the order of μb, and the distortion effects tend to reduce the cross sections by a factor of 3~10. For the sΛ–LHN production, the differential cross section is decreased with the increasing mass of the target nucleus. The pΛ–LHN production cross section is normally higher than that for the sΛ–LHN production. The double differential cross sections (DDXS) with respect to the momenta of the outgoing proton and kaon are also demonstrated. The missing mass spectra of the inclusive reaction p+A → p+K++X for the 6Li, 12C and 16O targets, an alternative way to study hypernuclear physics, are proposed. From these spectra, the masses of LHN can accurately be extracted. Moreover, the exotic LHN production in the same type of reaction is also studied . The same physical quantities are calculated. It is shown that the magnitude of the cross section is also in the order of μb. The halo effect of the core nucleus that locates at a place far away from the stable line would make the wave function broader, and consequently reduces the production cross section.


2020 ◽  
Vol 239 ◽  
pp. 06004
Author(s):  
Hiroki Matsuda ◽  
Shin-ichiro Meigo ◽  
Hiroki Iwamoto ◽  
Fujio Maekawa

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in a lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, an experiment in J-PARC using natPb and 209Bi samples were carried out. The samples were thin foils with about 0.1 mm thick and 25 mm × 25 mm square and were irradiated with protons at kinematic energy points of 0.4GeV, 2.2GeV, and 3.0 GeV. After the irradiation, the nuclide production cross section was determined by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. In this paper, 14 nuclide production cross sections for lead and bismuth were obtained. They were compared with the calculated cross sections with various models and the evaluated one.


2001 ◽  
Vol 16 (supp01a) ◽  
pp. 342-344
Author(s):  
GIUSEPPE DELLA RICCA

Data collected with the DELPHI detector at [Formula: see text] up to LEP2 highest energies (i.e. exceeding 205 GeV) have been used to extract preliminary values of the cross-sections for quark-antiquark pair-production in e + e - annihilations. The values found were used to test the Standard Model predictions and to seek for physics beyond it.


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