Interplay of total cross sections and ratios of real to imaginary parts of hadron amplitudes

Dremin, I.

doi:10.1134/s0021364013100032

Cited by 3 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another, even less model-dependent, relation between σ tot and ρ can be obtained from dispersion relations [7,49]. If only the crossing-even component of the amplitude is considered, it can be shown that ρ is proportional to the rate of growth of σ tot with energy.…”

Section: Discussion Of Physics Implicationsmentioning

confidence: 99%

First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

Antchev¹,

Aspell

Atanassov³

et al. 2019

Eur. Phys. J. C

117

View full text Add to dashboard Cite

The TOTEM experiment at the LHC has performed the first measurement at $$\sqrt{s} = 13\,\mathrm{TeV}$$s=13TeV of the $$\rho $$ρ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at $$t=0$$t=0, obtaining the following results: $$\rho = 0.09 \pm 0.01$$ρ=0.09±0.01 and $$\rho = 0.10 \pm 0.01$$ρ=0.10±0.01, depending on different physics assumptions and mathematical modelling. The unprecedented precision of the $$\rho $$ρ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than $$10\,\mathrm{TeV}$$10TeV (from 2.76 to $$13\,\mathrm{TeV}$$13TeV), has implied the exclusion of all the models classified and published by COMPETE. The $$\rho $$ρ results obtained by TOTEM are compatible with the predictions, from other theoretical models both in the Regge-like framework and in the QCD framework, of a crossing-odd colourless 3-gluon compound state exchange in the t-channel of the proton–proton elastic scattering. On the contrary, if shown that the crossing-odd 3-gluon compound state t-channel exchange is not of importance for the description of elastic scattering, the $$\rho $$ρ value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-|t| reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton–proton cross-section measurement $$\sigma _{\mathrm{tot}} = (110.3 \pm 3.5)\,\mathrm{mb}$$σtot=(110.3±3.5)mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields $$\sigma _{\mathrm{tot}} = (110.5 \pm 2.4)\,\mathrm{mb}$$σtot=(110.5±2.4)mb.

show abstract

Section: Discussion Of Physics Implicationsmentioning

confidence: 99%

First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

Antchev¹,

Aspell

Atanassov³

et al. 2019

Eur. Phys. J. C

117

View full text Add to dashboard Cite

show abstract

“…was traditionally quoted. An interesting aspect of ρ is its predictive power in extrapolating the total cross-section to higher centre-of-mass energies via dispersion relations [13].…”

Section: Introductionmentioning

confidence: 99%

Measurement of elastic pp scattering at $$\sqrt{\hbox {s}} = \hbox {8}$$ s = 8 TeV in the Coulomb–nuclear interference region: determination of the $$\mathbf {\rho }$$ ρ -parameter and the total cross-section

et al. 2016

View full text Add to dashboard Cite

The TOTEM experiment at the CERN LHC has measured elastic proton-proton scattering at the centre-ofmass energy √ s = 8 TeV and four-momentum transfers squared, |t|, from 6 × 10 −4 GeV 2 to 0.2 GeV 2 . Near the lower end of the t-interval the differential cross-section is sensitive to the interference between the hadronic and the electromagnetic scattering amplitudes. This article presents the elastic cross-section measurement and the constraints it arXiv:1610.00603v1 [nucl-ex] 3 Oct 2016 2 imposes on the functional forms of the modulus and phase of the hadronic elastic amplitude. The data exclude the traditional Simplified West and Yennie interference formula that requires a constant phase and a purely exponential modulus of the hadronic amplitude. For parametrisations of the hadronic modulus with second-or third-order polynomials in the exponent, the data are compatible with hadronic phase functions giving either central or peripheral behaviour in the impact parameter picture of elastic scattering. In both cases, the ρ-parameter is found to be 0.12 ± 0.03. The results for the total hadronic cross-section are σ tot = (102.9 ± 2.3) mb and (103.0 ± 2.3) mb for central and peripheral phase formulations, respectively. Both are consistent with previous TOTEM measurements.

show abstract

“…The recent measurements of proton-proton total cross sections at the LHC by the TOTEM collaboration [1][2][3][4], at total center-of-mass energy √ s = 7 TeV and √ s = 8 TeV, have helped in reviving the study of the high-energy behaviour of hadronic total cross sections [5][6][7][8]. The main theoretical problem in this context is providing a convincing explanation of the rise with energy of total cross sections observed in experiments, and a definite prediction of its functional form, in the framework of QCD.…”

Section: Introductionmentioning

confidence: 99%

Hadronic total cross sections at high energy and the QCD spectrum

Giordano

Meggiolaro

2014

J. High Energ. Phys.

View full text Add to dashboard Cite

Abstract:We show how to obtain the leading energy dependence of hadronic total cross sections, in the framework of the nonperturbative approach to soft high-energy scattering based on Wilson-loop correlation functions, if certain nontrivial analyticity assumptions are satisfied. The total cross sections turn out to be of "Froissart" type, σfor s → ∞. We also discuss under which conditions the coefficient B is universal, i.e., independent of the hadrons involved in the scattering process. In the most natural scenarios for universality, B can be related to the stable spectrum of QCD, and is predicted to be B th 0.22 mb, in fair agreement with experimental results. If we consider, instead, the stable spectrum of the quenched (i.e., pure-gauge) theory, we obtain a quite larger value B (Q) th ≥ 0.42 mb, suggesting (quite surprisingly) large unquenching effects due to the sea quarks.

show abstract

Interplay of total cross sections and ratios of real to imaginary parts of hadron amplitudes

Cited by 3 publications

References 18 publications

First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

Measurement of elastic pp scattering at $$\sqrt{\hbox {s}} = \hbox {8}$$ s = 8 TeV in the Coulomb–nuclear interference region: determination of the $$\mathbf {\rho }$$ ρ -parameter and the total cross-section

Hadronic total cross sections at high energy and the QCD spectrum

Contact Info

Product

Resources

About