Hadron diffractive production at ultrahigh energies and shadow effects

2016 ◽  
Vol 31 (28n29) ◽  
pp. 1645019 ◽  
Author(s):  
V. V. Anisovich ◽  
M. A. Matveev ◽  
V. A. Nikonov
Keyword(s):  
Light Nuclei ◽  
Ultrahigh Energy ◽  
Initial State ◽  
Final State ◽  
Black Disk ◽  
Deuteron Scattering ◽  
High Energies ◽  
Hadron Level ◽  
Diffractive Production ◽  
Three Body

Shadow effects at collisions of hadrons with light nuclei at high energies were subject of scientific interest of V.N. Gribov, first, we mean his study of the hadron-deuteron scattering, see Sov. Phys. JETP 29, 483 (1969) [Zh. Eksp. Teor. Fiz. 56, 892 (1969)] and discovery of the reinforcement of shadowing due to inelastic diffractive rescatterings. It turns out that the similar effect exists on hadron level though at ultrahigh energies. Diffractive production is considered in the ultrahigh energy region where pomeron exchange amplitudes are transformed into black disk ones due to rescattering corrections. The corresponding corrections in hadron reactions [Formula: see text] with small momenta transferred ([Formula: see text], [Formula: see text]) are calculated in terms of the [Formula: see text]-matrix technique modified for ultrahigh energies. Small values of the momenta transferred are crucial for introducing equations for amplitudes. The three-body equation for hadron diffractive production reaction [Formula: see text] is written and solved precisely in the eikonal approach. In the black disk regime final state scattering processes do not change the shapes of amplitudes principally but dump amplitudes by a factor [Formula: see text]; initial state rescatterings result in additional factor [Formula: see text]. In the resonant disk regime initial and final state scatterings damp strongly the production amplitude that corresponds to [Formula: see text] at [Formula: see text] in this mode.

Diffractive hadron production at ultrahigh energies

2015 ◽  
Vol 30 (11) ◽  
pp. 1550054 ◽  
Author(s):  
V. V. Anisovich ◽  
M. A. Matveev ◽  
V. A. Nikonov
Keyword(s):  
Energy Region ◽  
Hadron Production ◽  
Ultrahigh Energy ◽  
Production Amplitude ◽  
Initial State ◽  
Final State ◽  
Black Disk ◽  
Diffractive Production ◽  
Three Body ◽  
K Matrix

Diffractive production is considered in the ultrahigh energy region where pomeron exchange amplitudes are transformed into black disk ones due to rescattering corrections. The corresponding corrections in hadron reactions h1 + h3 → h1 + h2 + h3 with small momenta transferred [Formula: see text] are calculated in terms of the K-matrix technique modified for ultrahigh energies. Small values of the momenta transferred are crucial for introducing equations for amplitudes. The three-body equation for hadron diffractive production reaction h1 + h3 → h1 + h2 + h3 is written and solved precisely in the eikonal approach. In the black disk regime final state scattering processes do not change the shapes of amplitudes principally but dump amplitudes by a factor ~ ¼; initial state rescatterings result in additional factor ~ ½. In the resonant disk regime initial and final state scatterings damp strongly the production amplitude that corresponds to σ inel /σ tot → 0 at [Formula: see text] in this mode.

Identical nuclei in coherent pion production at intermediate energies

2002 ◽  
Vol 80 (9) ◽  
pp. 941-950
Author(s):  
P A Deutchman
Keyword(s):  
Forward Direction ◽  
Intermediate Energy ◽  
Initial State ◽  
Energy Distributions ◽  
Final State ◽  
Intermediate Energies ◽  
Body State ◽  
Pion Energy ◽  
Three Body ◽  
First Time

The formalism for the calculation of constructive, coherent production of pions through the collision of intermediate-energy nuclei now includes for the first time the exchange symmetry due to identical nuclei both in the initial two-body state and in the final three-body state. Of the eight terms that contribute to the pion-energy distributions, four of the amplitudes are equal in pairs, effectively leaving four amplitudes with direct terms in the initial state and direct and exchange terms in the final state. Of these remaining amplitudes, the final-state exchange terms are negligible as far as the calculation is concerned. This holds for pion-energy distributions over the incident energies from 100 MeV/nucleon to 2 GeV/nucleon for pions fixed in the forward direction (θπ = 0°) and the projectile and target, respectively, fixed in the fore and aft directions. This work is also generalized to include schematic solutions for the cases of identical nuclei in the initial state only, identical nuclei in the final state only, and the case of no identical nuclei at all. PACS Nos.: 24.10Cn, 24.30Cz, 25.70-z, 25.80-e

scholarly journals Central production of lepton–antilepton pairs and heavy quark composite states in hadron diffractive collisions at ultrahigh energies

2014 ◽  
Vol 29 (30) ◽  
pp. 1450176 ◽  
Author(s):  
V. V. Anisovich ◽  
M. A. Matveev ◽  
V. A. Nikonov ◽  
J. Nyiri
Keyword(s):  
Heavy Quark ◽  
Ultrahigh Energy ◽  
Black Disk ◽  
Proton Collisions ◽  
Production Processes ◽  
Energy Behavior ◽  
Diffractive Production ◽  
Central Production ◽  
K Matrix ◽  
Disk Mode

Central production of lepton–antilepton pairs (e+e- and μ+μ-) and heavy quark composite states (charmonia and bottomonia) in diffractive proton collisions (proton momenta transferred |q⊥| ~ m/ ln s) are studied at ultrahigh energies ( ln s ≫ 1), where σ tot (pp±) ~ ln N s with 1 ≲ N ≲ 2. The pp±-rescattering corrections, which are not small, are calculated in terms of the K-matrix approach modified for ultrahigh energies. Two versions of hadron interactions are considered in detail: the growth (i) σ tot (pp±) ~ ln 2 s, σ inel (pp±) ~ ln 2 s within the black disk mode and (ii) σ tot (pp±) ~ ln 2 s, σ inel (pp±) ~ ln s within the resonant disk mode. The energy behavior of the diffractive production processes differs strongly for these modes, thus giving a possibility to distinguish between the versions of the ultrahigh energy interactions.

scholarly journals N-jettiness in electroweak high-energy processes

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Junegone Chay ◽  
Taewook Ha ◽  
Taehyun Kwon
Keyword(s):  
High Energy ◽  
Hard Scattering ◽  
Initial State ◽  
Final State ◽  
High Energies ◽  
State Radiation ◽  
The Standard Model ◽  
Energy Processes ◽  
Effective Theories ◽  
Logarithmic Accuracy

Abstract We study N-jettiness in electroweak processes at extreme high energies, in which the mass of the weak gauge bosons can be regarded as small. The description of the scattering process such as e−e+ → μ−μ+ + X is similar to QCD. The incoming leptons emit initial-state radiation and the resultant particles, highly off-shell, participate in the hard scattering, which are expressed by the beam functions. After the hard scattering, the final- state leptons or leptonic jets are observed, described by the fragmenting jet functions or the jet functions respectively. At present, electroweak processes are prevailed by the processes induced by the strong interaction, but they will be relevant at future e−e+ colliders at high energy. The main difference between QCD and electroweak processes is that the initial- and final-state particles should appear in the form of hadrons, that is, color singlets in QCD, while there can be weak nonsinglets as well in electroweak interactions. We analyze the factorization theorems for the N-jettiness in e−e+ → μ−μ+ + X, and compute the factorized parts to next-to-leading logarithmic accuracy. To simplify the comparison with QCD, we only consider the SU(2)W gauge interaction, and the extension to the Standard Model is straightforward. Put it in a different way, it corresponds to an imaginary world in which colored particles can be observed in QCD, and the richer structure of effective theories is probed. Various nonzero nonsinglet matrix elements are interwoven to produce the factorized results, in contrast to QCD in which there are only contributions from the singlets. Another distinct feature is that the rapidity divergence is prevalent in the contributions from weak nonsinglets due to the different group theory factors between the real and virtual corrections. We verify that the rapidity divergence cancels in all the contributions with a different number of nonsinglet channels. We also consider the renormalization group evolution of each factorized part to resum large logarithms, which are distinct from QCD.

scholarly journals Dual subtractions

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Renato Maria Prisco ◽  
Francesco Tramontano
Keyword(s):  
Field Theory ◽  
Quantum Field ◽  
Matrix Elements ◽  
Leading Order ◽  
Initial State ◽  
Final State ◽  
Dual Representation ◽  
Subtraction Scheme ◽  
Theoretical Predictions ◽  
Perturbative Quantum

Abstract We propose a novel local subtraction scheme for the computation of Next-to-Leading Order contributions to theoretical predictions for scattering processes in perturbative Quantum Field Theory. With respect to well known schemes proposed since many years that build upon the analysis of the real radiation matrix elements, our construction starts from the loop diagrams and exploits their dual representation. Our scheme implements exact phase space factorization, handles final state as well as initial state singularities and is suitable for both massless and massive particles.

CHARMFUL BARYONIC $B\, \to \,{\rm{B\bar B}}'M_{c}$ DECAYS

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3638-3644 ◽  
Author(s):  
YU-KUO HSIAO
Keyword(s):  
Branching Fraction ◽  
B Decays ◽  
Final State ◽  
Three Body

We study the charmful three-body baryonic B decays with D(*) or J/Ψ in the final state. We explain the measured rates of [Formula: see text], [Formula: see text], and [Formula: see text]. In particular, the branching fraction of [Formula: see text] predicted to be of order 2.3 × 10-6 is in accordance with the Belle measurement, [Formula: see text].

scholarly journals Development and testing of a community flood resilience measurement tool

2016 ◽  
Author(s):  
Adriana Keating ◽  
Karen Campbell ◽  
Michael Szoenyi ◽  
Colin McQuistan ◽  
David Nash ◽  
...  
Keyword(s):  
Sustainable Livelihoods ◽  
Development Work ◽  
Measurement Tool ◽  
Disaster Resilience ◽  
Initial State ◽  
Final State ◽  
Sustainable Livelihoods Framework ◽  
Flood Characteristics ◽  
Over Time ◽  
Livelihoods Framework

Abstract. Given the increased attention on resilience-strengthening in international humanitarian and development work, there is a growing need to invest in its measurement and the overall accountability of "resilience strengthening" initiatives. We present a framework and tool for measuring community level resilience to flooding, built around the five capitals (5Cs) of the Sustainable Livelihoods Framework. At the time of writing the tool is being tested in 75 communities across 10 countries. Currently 88 potential sources of resilience are measured at the baseline (initial state) and endline (final state) approximately two years later. If a flood occurs in the community during the study period, resilience outcome measures are recorded. By comparing pre-flood characteristics to post flood outcomes, we aim to empirically verify sources of resilience, something which has never been done in this field. There is an urgent need for the continued development of theoretically anchored, empirically verified and practically applicable disaster resilience measurement frameworks and tools so that the field may: a) deepen understanding of the key components of "disaster resilience" in order to better target resilience enhancing initiatives, and b) enhance our ability to benchmark and measure disaster resilience over time, and compare how resilience changes as a result of different capacities, actions and hazards.

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