Scattering χ particles are stable and therefore can’t be detected by their decay. They can be, however, detected by their scattering on the target. We’ll consider two scattering channels: – elastic χN scattering; – deep inelastic scattering (DIS) on gluons The diagrams corresponding to these channels are given on Fig. 6.7. χ χ χ χ φ, p φ, p G N G N N X Figure 6.7: Scattering of the χ particle inside the detector. Left: DIS on gluons. Right: elastic scattering on nucleons Elastic scattering on the nucleons, i.e. the process χ + N → χ + N , occurs due to SNN coupling (6.1.11). Because of the scalar mediator propagator the cross-section crucially depends on the minimal detectable transferred momentum pmin. Namely, for mχ ' 1 GeV one has approximate formula m2 m2 E χN→χN CM χN 2 p2max(p2 , m2 ) φNN φχχ σ ' N χ g2 α sin2(θ), (6.1.13) min S χN where ECM is χN CM frame energy and p is χ CM frame momentum. The cross-section increases with increasing the ratio mχ/mφ, being maximal for mχ pmin > mφ. Taking the energy of χ particle at nucleon’s lab frame to be Eχ = 12 GeV, one obtains σχN→χN ≈ 10—5
Scattering. Construction slash shall be scattered outside the clearing limits without damaging trees. All logs shall be limbed. Stumps shall be scattered out of view from the road or scattered the slope distance as SHOWN ON THE DRAWINGS measured from the edge of roadbed, whichever is less. Logs and stumps shall be placed away from trees, positioned so they will not roll, and not be placed on top of one another. Other construction slash shall be limbed and scattered to reduce slash concentrations. Under (b) Specific Method (8) Decking Unmerchantable Material delete the first sentence and substitute the following: Logs not meeting utilization standards in Subsection 201.03 that are more than 8 inches in diameter and 10 feet or more in length which are suitable for use as firewood shall be decked in areas SHOWN ON THE DRAWINGS. SAMPLE Under (b) Specific Method (9) Disposal in Cutting Units delete "at least 50 feet" from the second sentence. R5-11 2 of 2 9/89 SPECIAL PROJECT SPECIFICATION SECTION 202 - REMOVAL OF STRUCTURES AND OBSTRUCTIONS 202.03 REMOVAL OF BRIDGES, CULVERTS, AND OTHER STRUCTURES. Delete the fourth sentence in the first paragraph and substitute: All removed culvert sections that are not DESIGNATED for salvage or to be re-laid shall be disposed of off of National Forest land. Delete the fourth paragraph and substitute: SAMPLE Structures and obstructions that are not DESIGNATED for salvage shall be disposed of off of National Forest land. R5-11 1 of 1 9/95 SECTION 203 - EXCAVATION AND EMBANKMENT 203.10 FINISHING SLOPES. Delete the second paragraph. 203.15 EMBANKMENT PLACING METHODS. In the first sentence under Method 4, Controlled Compaction, delete "12 inches (loose measure) and compacted," and substitute: "a thickness that can be accommodated by the compaction equipment, or as SHOWN ON THE DRAWINGS, and compacted."
Scattering. When ultrasound waves encounter targets that are small reflection as described above does not occur. Instead the wave is scattered over a large range of angles. In fact, if the target is considerably smaller than the wavelength of the wave then scattering occurs uniformly over all angles. In addition the total ultrasound power scattered by small targets is much smaller than that reflected at large interfaces. This is the reason why organ parenchyma, which contain a large number of small targets from the cellular to the macroscopic, produce a weak echo levels compared to organ interfaces.
Scattering. Much of the signal strength is lost due to scattering of waves, meaning energy loss due to processes like reflection, refraction and diffraction (Xxxxxxx and Xxxxxxx, 2005). Reflection is what we need in order to locate the bottom reflector of Styggedalsbreen. Unwanted scatter is characterised as noise. Dielectric (relative permittivity) and geometrical contrasts in scattering bodies in the ice will enhance energy loss. Scattering losses are a function of the bodies present (numbers, sizes and types) and increases with increased antenna frequency (Xxxxxxx and Xxxxxxx, 2005).
