Pith. Sign in

REVIEW

Total cross sections

High Energy Physics - Phenomenology · Submitted 2 Sep 1992 · 2 references

Pith's verdict: The paper that fixed the two-power Regge form everyone still quotes; the physics holds up, but the parameter set lives only in a figure and no chi-squared is tabulated anywhere.

T0 · AI review

How this review was made: An AI referee (selfhosted/deepseek-v4.1-flash) read the paper on November 11, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

  1. T0 AI review An AI read the paper and answered a fixed list of questions.
  2. T1 Audit Automatic checks that the references and files the paper relies on exist and match.
  3. T2 Compute The paper's code or calculations re-run with the same results.
  4. T3 Formal statement The claims written out in a formal math language a computer can read.
  5. T4 Proof Those claims proved, and the proof checked by computer.

How Pith checks papers →

· 4 major objections · 8 minor · Ask about this paper · The compiled record · Read the full review →
Challenge this review Comment (0) Read on arXiv ↗
Cite ▾
arXiv IDhep-ph/9209205 (version 1)
Pith ID7BFEKHHN, Pith's permanent record of this paper and its review
CitationA Donnachie, P V Landshoff. "Total cross sections." arXiv:hep-ph/9209205 (1992). https://pith.science/paper/7BFEKHHN
Cite this reviewBibTeX for Pith's review of this paper
Claim paper

Why Pith says this

Highlight any text to comment on it.

Referee report
The paper

The paper claims

A single two-term Regge formula is claimed to describe every measured total cross section, with one shared pair of exponents.

The reading

This paper argues that all measured hadronic total cross sections — $pp$, $pbar p$, $pi^pm p$, $K^pm p$, $pn$, and $gamma p$ — are described by one two-term Regge formula, $sigma_{rm tot} = X s^{epsilon} + Y s^{-eta}$, with the exponents $epsilon = 0.0808$ and $eta = 0.4525$ shared by every reaction. The first term is pomeron exchange and the second is exchange of the $rho,omega,f,a$ trajectory; because the pomeron carries vacuum quantum numbers, its coefficient $X$ must be the same for a reaction and its antiparticle, a constraint the polynomial fits quoted by the Particle Data Group do not respect. Nine cross sections are fitted with 16 free parameters against 45 for the polynomial form, at comparable $chi^2$ above roughly 5 to 10 GeV, so the case rests on economy plus theoretical grounding rather than on a better fit. If the claim holds, the observed rise of cross sections with energy is a property of something exchanged rather than of the hadrons themselves, which makes the rise universal and turns the pomeron into an object with measurable couplings and structure. The same fits are used to predict the Tevatron cross section, the photon-proton cross section soon to be measured at HERA, and a relation among strange-baryon cross sections.

What carries the argument

The load-bearing object is the two-power ansatz combined with a symmetry constraint: a pomeron term $X s^{epsilon}$ whose coefficient $X$ is forced to be equal for $sigma(ab)$ and $sigma(bar a b)$ because the pomeron has vacuum quantum numbers, plus a reggeon term $Y s^{-eta}$ that carries the $C=pm1$ assignments and so differs between particle and antiparticle. The exponents are explicitly effective powers rather than trajectory intercepts: $epsilon$ is slightly below $alpha(0)-1$ because the term absorbs the effect of exchanging more than one pomeron, and $eta$ is similarly shifted by combined reggeon-plus-pomeron exchange. That single shared pair of numbers is what makes the description economical, and it is also what makes it falsifiable, since every reaction must rise at the same rate. The constraint on $X$ is what separates this fit from the polynomial fits of the Review of Particle Properties, which the authors point out would have the $pp$ cross section overtaking $pbar p$ near $sqrt{s}=100$ GeV, in violation of the Pomeranchuk theorem.

Extended reading notes

Core claim

The paper's claim is that Regge theory, truncated to two effective powers, gives a complete and economical account of hadronic total cross sections. The fitted form is $sigma_{rm tot} = X s^{epsilon} + Y s^{-eta}$ with $epsilon = 0.0808$ and $eta = 0.4525$ fixed once from a simultaneous fit to $pp$ and $pbar p$ above $sqrt{s}=10$ GeV, and then reused unchanged for every other reaction, each new pair of reactions costing only three parameters: a common $X$ and a separate $Y$ for particle and antiparticle. The authors report that the ratio of $X$ for $pi p$ to $X$ for $pp$ comes out at 0.63, close to the $2/3$ of the additive-quark rule, that $X$ for $Kp$ is somewhat smaller, and that the coefficient $Y$ for $K^+p$ is poorly determined by the data. They note that the fits reproduce the Tevatron measurement, matching their own earlier prediction of about 73 mb at $sqrt{s}=1800$ GeV, and that the rising term is already present near $sqrt{s}=5$ GeV with no visible change of slope when charm and minijet production turn on. A further consequence they draw is that the additive-quark rule, applied to the combination $2sigma(Omega^- p) - sigma(Sigma^- p)$ where only pomeron exchange can contribute, predicts $16.26, s^{0.0808}$, giving 24.9 mb at $sqrt{s}=14$ GeV against a measured $25 pm 0.7$ mb.

Load-bearing premise

The two exponents are held fixed, although the paper states immediately after its main formula that both are effective powers that vary slowly with energy and that multiple pomeron exchange should make $epsilon$ decrease as energy rises, so every coefficient and every extrapolation rests on freezing a quantity the authors say is not constant.

Editorial extensions

If this is right

  • The rise of every total cross section with energy is attributed to a single exchanged object rather than to the individual hadrons growing, which rules out geometric 'bigger and blacker hadron' pictures as the explanation of the rise.
  • The ratio of pomeron couplings, about $2/3$ for $pi p$ versus $pp$ and lower still for $Kp$, becomes a quantitative handle on how the pomeron couples to light versus strange quarks and on hadron-radius corrections to the additive-quark rule.
  • Because only the pomeron couples to both the proton and the $gamma p to phi p$ vertex, that cross section should behave as $s^{2epsilon}/b$ with a constant slope $b$, giving a clean test of the same exponent in a different channel.
  • The fits extrapolate to about 160 $mu$b for $sigma(gamma p)$ at $sqrt{s}=200$ GeV, a prediction the authors expect HERA to test shortly.
  • The fitted rise, if extrapolated naively to $sqrt{s}=40$ TeV, gives about 120 mb, which the authors flag as likely an over-estimate of a few mb because the effective exponent should drift downward.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The frozen-exponent approximation is itself testable from the same data: fitting the low-energy and high-energy halves of each dataset separately would expose the drift in $epsilon$ that the authors say must exist, and the size of that drift sets the real uncertainty on every quoted coefficient $X$ and $Y$.
  • If the exponent is genuinely universal, then a precise measurement of any single total cross section at a new energy constrains all the others, so the strange-baryon combination $2sigma(Omega^- p) - sigma(Sigma^- p)$ becomes a cheap indirect probe of the pomeron coupling to strange quarks.
  • The claim that new production channels such as minijets do not change the rate of rise, while their onset is unmistakable in multiparticle data, is a strong statement about cancellations between production processes; a measured change in slope across the minijet threshold would be evidence against the single-power description.
  • The comparison of $rho$, the real-to-imaginary ratio, in $pi^pm p$ and $K^pm p$ turns the fit into an over-determined system, since the same coefficients $Y$ must reproduce both the cross sections and the real parts; a better measurement of $rho$ in $K^pm p$ would tighten the poorly determined $Y_{K^+p}$ more efficiently than more cross-section points.
Original abstract

Regge theory provides a very simple and economical description of all total cross sections

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 1,545 input tokens, $0.0001 reported.

What the abstract itself states, as probabilities: claims first 0.02 · states limitation 0.04 · human participants 0.02 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.03 · compares with prior results 0.08 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

Regge theory provides a very simple and economical description of all total cross sections

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 Regge theory provides a very simple and economical description of all total cross sections background 0.83 0.08 0.61 asserted 1.00

What kind of paper the classifier reports this is: theoretical result 0.55 · evidence from argument 0.92.

What was examined, and what was not

sources read
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

References
How later papers used it

100 later papers cite it

Evidence: substantial. 100 of the citing papers share no author with it, and 29 of those carry a confident label from Pith's citation classifier.

Pith read 24 of the 125 citing sentences, choosing only those whose citation markers point at this paper alone, and wrote the paraphrases from them. The summary, the counts, the evidence level, the links and the quotes come from code; the summary counts the papers listed below. A later paper is listed under a label when Pith's citation classifier gives one of its sentences that label at probability 0.8 or more (0.95 for support), Pith's reading finds that the citing paper itself did it, and a second check confirms the paraphrase against the sentence. This section lists uses only. It does not list criticism or disagreement, so their absence here says nothing about how the paper has been received. Papers that share an author with this one are listed apart, under "By the same authors". A quote is the citing authors' own sentence, shown when their paper's licence is CC BY, CC BY-SA or CC0. JSON

Uses its method or tool 3 of 10 papers with this label
Uses its data or values 2 of 11 papers with this label
How the literature uses it

86 arXiv papers cite this in 104 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 64 sentences without a confident label

Contests it 1 paper
Uses its method or tool 8 papers
Uses its data or values 9 papers
Compares with it 7 papers
Cites it as background 12 papers
  • Historically, hadronic exchanges have been remarkably well described by the simple-pole model of Donnachie and Landshoff [ref] , which assumes that, at high energy, the hadronic amplitude is dominated by a simple-pole pomeron: [equation] The first question is whether this simple model extends to other processes, and in particular to those measured at HERA.

    The soft and the hard pomerons: elastic scattering and unitarisation · The effective trajectory · 0.99

  • The simplest and most successful parametrization of the total cross-section for proton-proton and proton-antiproton scattering [ref] follows from the optical theorem and describes the initial fall through the exchange of Regge trajectories, i.e. $s^α_R(0)-1$ with $α_R(0)<1$ and the rise as due to Pomeron exchange, i.e. $s^α_P(0)-1$ with $α_P(0)>1$.

    QCD Contributions to the Froissart bound for the total cross-section · Introduction · 0.85

  • Donnachie and Landshoff first showed that experimental data of various hadron-hadron total cross sections can be well reproduced with this description [ref] .

    Elastic proton-neutron and antiproton-neutron scattering in holographic QCD · Introduction · 0.86

Discussion

Disagree with the review, or know something it missed? Leave a comment, highlight any passage above to comment on it, or challenge this review formally.