Experimental study of pomeron Rostovtsev, A.
Surveys in high energy physics,
12/1/2001, Volume:
16, Issue:
3-4
Journal Article
Peer reviewed
Open access
A Pomeron phenomenon remains a mystery. A short review of the experimental situation in diffractive physics and an account of some spectacular manifestations of the Pomeron are given.
The review of the results obtained by the authors in the field of synthesis of Fe-Co, Fe-Ni, Co-Ni and Cu-Ni nano-size binary systems (NBS) by the liquid-phase reducing of metal chlorides by ...hydrazine (pH>10) and sodium tetrahydroborate (NaBH4) (pH 7-8) by the process conditions variation (temperature of reaction medium, concentration and input order of reagents) as well as NBS properties investigation is presented.
Exclusive photoproduction of ρ0(770) mesons is studied using the H1 detector at the ep collider HERA. A sample of about 900,000 events is used to measure single- and double-differential cross ...sections for the reaction γp→π+π-Y. Reactions where the proton stays intact (mY=mp) are statistically separated from those where the proton dissociates to a low-mass hadronic system (mp<mY<10GeV). The double-differential cross sections are measured as a function of the invariant mass mππ of the decay pions and the squared 4-momentum transfer t at the proton vertex. The measurements are presented in various bins of the photon–proton collision energy Wγp. The phase space restrictions are 0.5≤mππ≤2.2GeV, |t|≤1.5GeV2, and 20≤Wγp≤80GeV. Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the mππ dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the ρ0(770) meson mass and width at mρ=770.8-2.7+2.6(tot.)MeV and Γρ=151.3-3.6+2.7(tot.)MeV, respectively. The model is used to extract the ρ0(770) contribution to the π+π- cross sections and measure it as a function of t and Wγp. In a Regge asymptotic limit in which one Regge trajectory α(t) dominates, the intercept α(t=0)=1.0654-0.0067+0.0098(tot.) and the slope α′(t=0)=0.233-0.074+0.067(tot.)GeV-2 of the t dependence are extracted for the case mY=mp.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The interest in the detection of cosmic neutrinos with energies above 10
17
eV has increased considerably in recent years. Possible target materials for in-matter arrays of ∼100
km
3 size under ...discussion are water, ice and rock salt. Here we propose to investigate permafrost as an additional alternative, covering ∼20% of Earth land surface and reaching down to more than 1000
m depth at certain locations. If sufficiently large attenuation lengths for radio and acoustic signals can be demonstrated by in-situ measurements, the construction of a large hybrid array within this material may be possible in the Northern Hemisphere. Properties and problems of a possible location in Siberia are discussed below. Some acoustic data are compared with laboratory measurements using “artificial” permafrost.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The technology of flax harvesting depends on input impacts, including: flax harvester qualitative characteristics; working body parameters; indicators of working conditions; intervening variables ...reflecting the dynamic properties of the working bodies and the dynamics of the flax flow input. (
Research purpose
) To establish patterns and the degree of correlation between the qualitative operation indicators (pulling and deseeding quality, flax line stretching); design parameters; machine dynamic properties and harvesting conditions (height and density of flax stem, field surface, thickness and unevenness of flax straw, etc.). (
Materials and methods
) Based on system analysis, mathematical models of the technological process of flax harvesting were developed. Information models were introduced for examining the main flax harvesters. (
Results and discussion
) The paper shows that the most typical indicators of the flax harvester working conditions are the flax stem height
l
(
t
), centimeters; the seed pod area
a
(
t
), centimeters; and field surface roughness
z
(
t
), centimeters. It is found that the quality of operation is determined by the deseeding quality, percentages; the flax straw stretching, times; the location of its apical and root parts, centimeters. The estimated indicators are as follows: the pulling height
h
(
t
), centimeters, the vibrations of the combine in the longitudinal-vertical plane
Q
(
t
), degrees, the location of the apical part of the flax flaw in front of the stripper. (
Conclusions
) A hydraulic device was developed to adjust the pulling height from 10 to 40 centimeters, depending on the flax stem. An important reserve for increasing the deseeding quality is the change in the width of the deseeding zone of the
V
k
harvester, centimeters. For this purpose, a mechanism was created for moving the deseeder against the clamping conveyor, depending on the flax stem height
l
(
t
), centimeters.
A simple formula for the mean number of Pomerons, essential in the interaction, in terms of diffractive, elastic and total cross sections is presented. The formula can be used to compare the AGK ...cutting rule prediction with experimental data.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, UL, UM, UPCLJ, UPUK
BACKGROUND: In modern harvesting technologies, the main technological operation is mechanized crops pulling. The flax-pulling machine with transverse band-disc channels is the most promising. ...However, the basic design parameters of pulling sections are not justified sufficiently, the peculiarities of their layout are not considered, the processes of moving plants through sections and pulling short-stemmed flax are not sufficiently studied, which reduces the effectiveness of its use.
AIMS: Theoretical and experimental justification of the parameters and operation modes of pulling sections of the device with transverse band-disc channels.
METHODS: Experimental studies to justify the parameters and operation modes of experimental pulling machines were carried out according to known and developed methods, and the assessment of flax products was carried out according to current GOST standards. The influence of the velocity of the unit and the width of the grip of pulling sections on the indicators of the agrotechnical and technological assessment of the operation of pulling device was determined.
RESULTS: Dependences for determining the design parameters of a pulling section and the minimum height of plant stand suitable for mechanized harvesting were obtained, the conditions for finishing and moving plants in the zone of fixed guides were established. The structures of the experimental pulling machines were used to assess the unit velocity, the effect of the width of a pulling section and the elimination of the separation of technological currents of plants during processing on improving agrotechnical performance and increasing the yield and number of long fiber. The frame elements of the TLN-1.9P unit, are placed above the pull pulleys, and the operating width of a section is 0.38 m. In the TLN-1.9M and the TLN-1.9K units, they are located behind the pull pulleys, with the operating width of a section of 0.35 and 0.31 m respectively. As a result, the flax straw had higher quality indicators: 1.5 numbers for the TLN-1.9M and the TLN-1.9K and 1.25 numbers for the TLN-1.9P; the average yield of long fiber of these units was 13.41, 13.1 and 12.59% respectively.
CONCLUSIONS: When assembling pulling machines with transverse band-disc channels, the elements of the frame structure should be positioned behind pulling drums, technical solutions should be used to ensure the kinematic operation mode equal to one, with the operating width of a section of 0.31 m for harvesting seed breeding and 0.35 m for harvesting commercial crops.
This paper in detail addresses and, for the first time in the field, presents linguistic evidence related to the expression of elevational semantics in the Kartvelian languages. The domains of its ...expression include a wide range of parts of speech, such as adverbs, adjectives, postpositions, and verbs. Provided with a broad synchronic illustrative base, as well as with respective diachronic commentaries, the material under discussion is meant to lay the groundwork for the establishment of a diachronic grammar of elevation in Kartvelian.
This paper investigates the utilization of an oscillatory-type working body for the stripping process within the primary fiber flax processing line. It also introduces the equation governing the ...movement of this working body, thereby enabling the determination of the fundamental geometric parameters of the mechanism. (Research purpose) To develop the technology for fiber flax stripping at a flax mill using the proposed comb-type device, and to examine the parameters and modes of its functionality. (Materials and methods) A testing model was designed for a stripping machine, enabling an exploration of the flax combing process within the factory. The limitations of the parameters under investigation were identified. Furthermore, a theoretical model was formulated to calculate the performance of the stripper. (Results and discussion) The operation kinematic mode, stripping cleanliness, and seed losses during the stripping process are determined through theoretical analysis. It is discovered that the quality of stripping is influenced by the thickness of the flax ribbon. Specifically, an increase in the flax straw's thickness results in the clogging of the stripping device, subsequently leading to the formation of tangles and entanglements on the working body. On the other hand, insufficient thickness of the flax ribbon leads to significant damage to the stems. The limits for the thickness of the flax ribbon are established considering both the potential minimum and maximum yields: the lower limit being 0.01 meters and the upper limit set at 0.05 meters. The application of the factory's stripping technology is expected to ensure a 10 percent reduction in seed losses and an additional 6 percent reduction in production costs. (Conclusions) Theoretical justification for the parameters and operational modes of the stripper in the flax processing line, along with its design, is provided. The feed speed of the flax ribbon is configured to range between 1.0 and 1.5 meters per second, while the rotation frequency of the working body varies from 2.2 to 3.0 revolutions per second.
Transverse momentum spectra of charged particle production in heavy-ion collisions are considered in terms of a recently introduced Two Component parameterization combining exponential ("soft") and ...power-law ("hard") functional forms. The charged hadron densities calculated separately for them are plotted versus number of participating nucleons, \(N_{part}\). The obtained dependences are discussed and the possible link between the two component parameterization introduced by the authors and the two component model historically used for the case of heavy-ion collisions is established. Next, the variations of the parameters of the introduced approach with the center of mass energy and centrality are studied using the available data from RHIC and LHC experiments. The spectra shapes are found to show universal dependences on \(N_{part}\) for all investigated collision energies.
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