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Alan Martin's Outputs (54)

Exclusive J/ψ and ϒ production in high-energy pp and p-Pb collisions (2022)
Journal Article
Flett, C., Jones, S., Martin, A., Ryskin, M., & Teubner, T. (2022). Exclusive J/ψ and ϒ production in high-energy pp and p-Pb collisions. Physical Review D, 106(7), https://doi.org/10.1103/physrevd.106.074021

We present a formalism for determining the cross section for exclusive heavy vector meson production (J/ψ,Υ) as a function of rapidity, in both high-energy proton-proton and proton-heavy ion collisions, at next-to-leading order in QCD. We compare and... Read More about Exclusive J/ψ and ϒ production in high-energy pp and p-Pb collisions.

Predictions of exclusive ϒ photoproduction at the LHC and future colliders (2022)
Journal Article
Flett, C., Jones, S., Martin, A., Ryskin, M., & Teubner, T. (2022). Predictions of exclusive ϒ photoproduction at the LHC and future colliders. Physical Review D, 105(3), https://doi.org/10.1103/physrevd.105.034008

The cross section for exclusive ϒ ultraperipheral photoproduction at present and future colliders is determined using the low x gluon parton distribution function extracted from an analysis of exclusive J=ψ measurements performed at the Hadron-Electr... Read More about Predictions of exclusive ϒ photoproduction at the LHC and future colliders.

QED parton distribution functions in the MSHT20 fit (2022)
Journal Article
Cridge, T., Harland-Lang, L., Martin, A., & Thorne, R. (2022). QED parton distribution functions in the MSHT20 fit. The European Physical Journal C, 82(1), Article 90. https://doi.org/10.1140/epjc/s10052-022-10028-2

We present the MSHT20qed set of parton distribution functions (PDFs). These are obtained from the MSHT20 global analysis via a refit including QED corrections to the DGLAP evolution at O(α),O(ααS) and O(α2), and containing the photon PDF of the proto... Read More about QED parton distribution functions in the MSHT20 fit.

An investigation of the $$\alpha _S$$ and heavy quark mass dependence in the MSHT20 global PDF analysis (2021)
Journal Article
Cridge, T., Harland-Lang, L., Martin, A., & Thorne, R. (2021). An investigation of the $$\alpha _S$$ and heavy quark mass dependence in the MSHT20 global PDF analysis. The European Physical Journal C, 81(8), Article 744. https://doi.org/10.1140/epjc/s10052-021-09533-7

We investigate the MSHT20 global PDF sets, demonstrating the effects of varying the strong coupling αS(M2Z) and the masses of the charm and bottom quarks. We determine the preferred value, and accompanying uncertainties, when we allow αS(M2Z) to be a... Read More about An investigation of the $$\alpha _S$$ and heavy quark mass dependence in the MSHT20 global PDF analysis.

Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs (2021)
Journal Article
Bailey, S., Cridge, T., Harland-Lang, L., Martin, A., & Thorne, R. (2021). Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs. The European Physical Journal C, 81(4), Article 341. https://doi.org/10.1140/epjc/s10052-021-09057-0

We present the new MSHT20 set of parton distribution functions (PDFs) of the proton, determined from global analyses of the available hard scattering data. The PDFs are made available at NNLO, NLO, and LO, and supersede the MMHT14 sets. They are obta... Read More about Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs.

Dynamics of diffractive dissociation (2021)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2021). Dynamics of diffractive dissociation. The European Physical Journal C, 81(2), Article 175. https://doi.org/10.1140/epjc/s10052-021-08953-9

We describe a QCD based model which incorporates the main properties of the inclusive particle distributions expected for diffractive processes, including the diffractive dissociation at high energies. We study, in turn, the total cross section, σtot... Read More about Dynamics of diffractive dissociation.

Comments on Global Parton Analyses (2020)
Journal Article
Martin, A., & Ryskin, M. (2020). Comments on Global Parton Analyses. Acta Physica Polonica B, 51(5), 1079-1096. https://doi.org/10.5506/aphyspolb.51.1079

We discuss the causes which can limit the accuracy of the predictions based on the conventional PDFs when including in global parton analyses the data at moderate scales μ. The first is the existence of power corrections O(Q20/μ2) due to the double c... Read More about Comments on Global Parton Analyses.

Very low x gluon density determined by LHCb exclusive J/ψ data (2020)
Journal Article
Flett, C., Martin, A., Ryskin, M., & Teubner, T. (2020). Very low x gluon density determined by LHCb exclusive J/ψ data. Physical Review D, 102(11), Article 114021. https://doi.org/10.1103/physrevd.102.114021

The low x behavior of the gluon density x g ( x , μ 2 ) at scale μ 2 = 2.4     GeV 2 is determined using exclusive J / ψ production data from HERA and LHCb within the framework of collinear factorization at next-to-leading order (NLO). It is shown th... Read More about Very low x gluon density determined by LHCb exclusive J/ψ data.

How to include exclusive J/ψ production data in global PDF analyses (2020)
Journal Article
Flett, C., Jones, S., Martin, A., Ryskin, M., & Teubner, T. (2020). How to include exclusive J/ψ production data in global PDF analyses. Physical Review D, 101(9), Article 094011. https://doi.org/10.1103/physrevd.101.094011

We compare the cross section for exclusive J=ψ photoproduction calculated at next-to-leading order (NLO) in the collinear factorization approach with HERA and LHCb data. Using the optimum scale formalism together with the subtraction of the low kt co... Read More about How to include exclusive J/ψ production data in global PDF analyses.

Isolating the Odderon in central production in high energy pA and AA collisions (2020)
Journal Article
McNulty, R., Khoze, V., Martin, A., & Ryskin, M. (2020). Isolating the Odderon in central production in high energy pA and AA collisions. The European Physical Journal C, 80(3), Article 80. https://doi.org/10.1140/epjc/s10052-020-7846-5

We study the rapidity dependence of the central exclusive production cross sections of C-even mesons in pA and AA collisions, where A is a heavy ion. We observe qualitatively different behaviour of the contributions arising from γ-Odderon and Pomeron... Read More about Isolating the Odderon in central production in high energy pA and AA collisions.

Bethe phase including proton excitations (2020)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2020). Bethe phase including proton excitations. Physical Review D, 101(1), Article 016018. https://doi.org/10.1103/physrevd.101.016018

We evaluate the contribution of inelastic intermediate states (such as p → N excitations) to the phase between the one-photon-exchange and the “nuclear” high energy pp scattering amplitudes as t → 0, caused by multiphoton diagrams. It turns out to be... Read More about Bethe phase including proton excitations.

Ad Lucem: QED parton distribution functions in the MMHT framework (2019)
Journal Article
Harland-Lang, L., Martin, A., Nathvani, R., & Thorne, R. (2019). Ad Lucem: QED parton distribution functions in the MMHT framework. The European Physical Journal C, 79(10), Article 811. https://doi.org/10.1140/epjc/s10052-019-7296-0

We present the MMHT2015qed PDF set, resulting from the inclusion of QED corrections to the existing set of MMHT Parton Distribution Functions (PDFs), and which contain the photon PDF of the proton. Adopting an input distribution from the LUXqed formu... Read More about Ad Lucem: QED parton distribution functions in the MMHT framework.

Colliding Pomerons (2019)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2019). Colliding Pomerons. Journal of Physics G: Nuclear and Particle Physics, 46(11), Article 11LT01. https://doi.org/10.1088/1361-6471/ab3a88

We recall the main properties of inclusive particle distributions expected for Pomeron-proton and Pomeron–Pomeron interactions. Due to the small size of the Pomeron we expect larger transverse momenta of secondaries and a smaller probability of multi... Read More about Colliding Pomerons.

The fusion of hard and soft Pomerons: 3-jet diffractive production (2019)
Journal Article
Khoze, V., Martin, A., Ryskin, M., Shuvaev, A., & Surnin, I. (2019). The fusion of hard and soft Pomerons: 3-jet diffractive production. The European Physical Journal C, 79(7), Article 605. https://doi.org/10.1140/epjc/s10052-019-7120-x

We consider the central exclusive production of high E_T jets pp\rightarrow p+(X+\mathrm{dijet})+p. In particular we study the possible contamination of the purely exclusive signal by semi-exclusive production where no other secondaries are emitted i... Read More about The fusion of hard and soft Pomerons: 3-jet diffractive production.

Exclusive vector meson production in heavy ion collisions (2019)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2019). Exclusive vector meson production in heavy ion collisions. Journal of Physics G: Nuclear and Particle Physics, 46(8), Article 085002. https://doi.org/10.1088/1361-6471/ab2009

We discuss the salient features of exclusive vector meson production in heavy ion collisions at LHC energies. Special attention is paid to the space-time picture of the process. We account for both coherent and incoherent contributions. The explicit... Read More about Exclusive vector meson production in heavy ion collisions.

Searching for the odderon in ultraperipheral proton-ion collisions at the LHC (2019)
Journal Article
Harland-Lang, L., Khoze, V., Martin, A., & Ryskin, M. (2019). Searching for the odderon in ultraperipheral proton-ion collisions at the LHC. Physical Review D, 99(3), Article 034011. https://doi.org/10.1103/physrevd.99.034011

We explore the possibility of observing odderon exchange in proton-ion collisions at the LHC, via the ultraperipheral photoproduction of C-even mesons. As well as the signal, we consider in detail the principle backgrounds, due to QCD-initiated produ... Read More about Searching for the odderon in ultraperipheral proton-ion collisions at the LHC.

Absorptive effects and power corrections in low x DGLAP evolution (2019)
Journal Article
Pelicer, M., de Oliveira, E., Martin, A., & Ryskin, M. (2019). Absorptive effects and power corrections in low x DGLAP evolution. The European Physical Journal C, 79(1), Article 9. https://doi.org/10.1140/epjc/s10052-018-6515-4

We address a long standing problem concerning the scale behaviour of parton densities in the low x, low Q2 domain. We emphasize the important role of absorptive corrections at low x and use knowledge of diffractive deep inelastic scattering to exclud... Read More about Absorptive effects and power corrections in low x DGLAP evolution.

MMHT Updates, LHC jets and α S (2018)
Presentation / Conference Contribution
Thorne, R., Harland-Lang, L., & Martin, A. (2018). MMHT Updates, LHC jets and α S. In XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2018) - WG1: Structure Functions and Parton Densities. https://doi.org/10.22323/1.316.0030

We summarise the effects of including jet data from the LHC in the MMHT PDF extraction. We also present the latest results on the preferred value of the strong coupling α S ( M 2 Z ) αS(MZ2) in a number of fit variations. The best current value with... Read More about MMHT Updates, LHC jets and α S.

Black disk radius constrained by unitarity (2018)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2018). Black disk radius constrained by unitarity. Physics Letters B, 787, 167-170. https://doi.org/10.1016/j.physletb.2018.10.054

We argue that if the elastic proton–proton cross section increases with energy, the Froissart-like high energy behaviour of the elastic amplitude (which corresponds to a ‘black disk’ of radius R(s) = c ln s −βln(ln s)) is the only possibility to sati... Read More about Black disk radius constrained by unitarity.

Elastic and diffractive scattering at the LHC (2018)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2018). Elastic and diffractive scattering at the LHC. Physics Letters B, 784, 192-198. https://doi.org/10.1016/j.physletb.2018.07.054

Inspired by the new TOTEM data on elastic pp scattering at 13 TeV, we study the possibility to describe all the diffractive collider data (, , ) in a wide interval of energy (0.0625 to 13 TeV) in the framework of a two-channel eikonal model. We show... Read More about Elastic and diffractive scattering at the LHC.

Open charm production and low x gluons (2018)
Journal Article
de Oliveira, E., Martin, A., & Ryskin, M. (2018). Open charm production and low x gluons. Physical Review D, 97(7), Article 074021. https://doi.org/10.1103/physrevd.97.074021

We compare the rapidity, y, and the beam energy, ffiffi s p , behaviors of the cross section of the data for D meson production in the forward direction that were measured by the LHCb Collaboration. We describe the observed cross sections using NLO p... Read More about Open charm production and low x gluons.

The impact of LHC jet data on the MMHT PDF fit at NNLO (2018)
Journal Article
Harland-Lang, L., Martin, A., & Thorne, R. (2018). The impact of LHC jet data on the MMHT PDF fit at NNLO. The European Physical Journal C, 78(3), Article 248. https://doi.org/10.1140/epjc/s10052-018-5710-7

We investigate the impact of the high precision ATLAS and CMS 7 TeV measurements of inclusive jet production on the MMHT global PDF analysis at next-to-next-to-leading order (NNLO). This is made possible by the recent completion of the long-term proj... Read More about The impact of LHC jet data on the MMHT PDF fit at NNLO.

Multiple interactions and rapidity gap survival (2018)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2018). Multiple interactions and rapidity gap survival. Journal of Physics G: Nuclear and Particle Physics, 45(5), Article 053002. https://doi.org/10.1088/1361-6471/aab1bf

Observations of rare processes containing large rapidity gaps at high energy colliders may be exceptionally informative. However the cross sections of these events are small in comparison with that for the inclusive processes since there is a large p... Read More about Multiple interactions and rapidity gap survival.

Black disk, maximal Odderon and unitarity (2018)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2018). Black disk, maximal Odderon and unitarity. Physics Letters B, 780, 352-356. https://doi.org/10.1016/j.physletb.2018.03.025

We argue that the so-called maximal Odderon contribution breaks the ‘black disk’ behaviorof the asymp-totic amplitude, since the cross section of the events with Large Rapidity Gaps grows faster than the total cross section. That is the ‘maximal Odde... Read More about Black disk, maximal Odderon and unitarity.

Elastic proton-proton scattering at 13 TeV (2018)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2018). Elastic proton-proton scattering at 13 TeV. Physical Review D, 97(3), Article 034019. https://doi.org/10.1103/physrevd.97.034019

The predictions of a model which was tuned in 2013 to describe the elastic and diffractive p p - and/or p ¯ p -data at collider energies up to 7 TeV are compared with the new 13 TeV TOTEM results. The possibility of the presence of an odd-signature O... Read More about Elastic proton-proton scattering at 13 TeV.

Total π + p cross section extracted from the leading neutron spectra at the LHC (2017)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2017). Total π + p cross section extracted from the leading neutron spectra at the LHC. Physical Review D, 96(3), Article 034018. https://doi.org/10.1103/physrevd.96.034018

We use the very forward neutron energy spectra measured by the LHC forward experiment at 7 TeV to extract the πþp total cross section at center-of-mass energies in the range 2.3–3.5 TeV. To do this, we have to first isolate the π-exchange pole in for... Read More about Total π + p cross section extracted from the leading neutron spectra at the LHC.

MMHT PDFs: Updates and Outlook (2017)
Journal Article
Harland-Lang, L., Nathvani, R., Thorne, R., & Martin, A. (2017). MMHT PDFs: Updates and Outlook. Acta Physica Polonica B, 48(6), 1011-1024. https://doi.org/10.5506/aphyspolb.48.1011

We present the latest results of studies within the MMHT PDF framework. We discuss the impact of the most recent ATLAS 7 TeV jet data, demonstrating that while a good fit can be achieved for individual jet rapidity bins, it is not possible to achieve... Read More about MMHT PDFs: Updates and Outlook.

Optimal choice of factorization scales for the description of jet production at the LHC (2017)
Journal Article
Martin, A., & Ryskin, M. (2017). Optimal choice of factorization scales for the description of jet production at the LHC. The European Physical Journal C, 77(4), Article 218. https://doi.org/10.1140/epjc/s10052-017-4783-z

To obtain more precise parton distribution functions (PDFs) it is important to include data on inclusive high transverse energy jet production in the global parton analyses. These data have high statistics and the NNLO terms in the perturbative QCD (... Read More about Optimal choice of factorization scales for the description of jet production at the LHC.

Scale dependence of open cc¯ and bb¯ production in the low x region (2017)
Journal Article
Oliveira, E. D., Martin, A., & Ryskin, M. (2017). Scale dependence of open cc¯ and bb¯ production in the low x region. The European Physical Journal C, 77(3), Article 182. https://doi.org/10.1140/epjc/s10052-017-4750-8

The ‘optimal’ factorization scale μ0μ0 is calculated for open heavy quark production. We find that the optimal value is μF=μ0≃0.85p2T+m2Q−−−−−−−√μF=μ0≃0.85pT2+mQ2 ; a choice which allows us to resum the double-logarithmic, (αslnμ2Fln(1/x))n(αsln⁡μF2l... Read More about Scale dependence of open cc¯ and bb¯ production in the low x region.

Exclusive J=ψ production at the LHC in the kT factorisation approach (2017)
Journal Article
Jones, S., Martin, A., Ryskin, M., & Teubner, T. (2017). Exclusive J=ψ production at the LHC in the kT factorisation approach. Journal of Physics G: Nuclear and Particle Physics, 44(3), Article 03LT01. https://doi.org/10.1088/1361-6471/aa56ea

The recent LHCb data for exclusive J y peripheral production at 13 TeV motivate an improved ‘NLO’ analysis to estimate the gluon distribution at low x in which we re-calculate the rapidity gap survival factors and use a more precise expression for th... Read More about Exclusive J=ψ production at the LHC in the kT factorisation approach.

The exclusive J/ψ process at the LHC tamed to probe the low x gluon (2016)
Journal Article
Jones, S., Martin, A., Ryskin, M., & Teubner, T. (2016). The exclusive J/ψ process at the LHC tamed to probe the low x gluon. The European Physical Journal C, 76(11), Article 633. https://doi.org/10.1140/epjc/s10052-016-4493-y

The perturbative QCD expansion for J/ψ photoproduction appears to be unstable: the NLO correction is large (and of opposite sign) to the LO contribution. Moreover, the predictions are very sensitive to the choice of factorisation and renormalisation... Read More about The exclusive J/ψ process at the LHC tamed to probe the low x gluon.

Two scales in Bose–Einstein correlations (2016)
Journal Article
Khoze, V., Martin, A., Ryskin, M., & Schegelsky, V. (2016). Two scales in Bose–Einstein correlations. The European Physical Journal C, 76(4), Article 193. https://doi.org/10.1140/epjc/s10052-016-4055-3

We argue that the secondaries produced in high-energy hadron collisions are emitted by small-size sources distributed over a much larger area in impact parameter space occupied by the interaction amplitude. That is, Bose–Einstein correlation of two e... Read More about Two scales in Bose–Einstein correlations.

The impact of the final HERA combined data on PDFs obtained from a global fit (2016)
Journal Article
Harland-Lang, L., Martin, A., Motylinski, P., & Thorne, R. (2016). The impact of the final HERA combined data on PDFs obtained from a global fit. The European Physical Journal C, 76(4), Article 186. https://doi.org/10.1140/epjc/s10052-016-4020-1

We investigate the effect of including the HERA run I + II combined cross section data on the MMHT2014 PDFs. We present the fit quality within the context of the global fit and when only the HERA data are included. We examine the changes in both the... Read More about The impact of the final HERA combined data on PDFs obtained from a global fit.

Advantages of exclusiveγγproduction to probe high mass systems (2016)
Journal Article
Martin, A., & Ryskin, M. (2016). Advantages of exclusiveγγproduction to probe high mass systems. Journal of Physics G: Nuclear and Particle Physics, 43(4), Article 04LT02. https://doi.org/10.1088/0954-3899/43/4/04lt02

We recall that the exclusive production of high mass objects via γγ fusion at the LHC is not strongly suppressed in comparison with inclusive γγ fusion. Therefore it may be promising to study new objects, X, produced by the γγ subprocess in experimen... Read More about Advantages of exclusiveγγproduction to probe high mass systems.

Charm and beauty quark masses in the MMHT2014 global PDF analysis (2016)
Journal Article
Harland-Lang, L., Martin, A., Motylinski, P., & Thorne, R. (2016). Charm and beauty quark masses in the MMHT2014 global PDF analysis. The European Physical Journal C, 76(1), Article 10. https://doi.org/10.1140/epjc/s10052-015-3843-5

We investigate the variation in the MMHT2014 PDFs when we allow the heavy-quark masses mcmc and mbmb to vary away from their default values. We make PDF sets available in steps of Δmc=0.05 GeVΔmc=0.05 GeV and Δmb=0.25 GeVΔmb=0.25 GeV , and present th... Read More about Charm and beauty quark masses in the MMHT2014 global PDF analysis.

Inclusive prompt $$\chi _{c,b}(1^{++})$$ χ c , b ( 1 + + ) production at the LHC (2015)
Journal Article
Shuvaev, A., Khoze, V., Martin, A., & Ryskin, M. (2015). Inclusive prompt $$\chi _{c,b}(1^{++})$$ χ c , b ( 1 + + ) production at the LHC. The European Physical Journal C, 75(12), Article 616. https://doi.org/10.1140/epjc/s10052-015-3840-8

We study the prompt production of the χc(1+) and χb(1+) mesons at high energies. Unlike χ(0+,2+) production, χ(1+) mesons cannot be created at LO via the fusion of two on-mass-shell gluons, that is, gg→χc,b(1+) are not allowed. However, the available... Read More about Inclusive prompt $$\chi _{c,b}(1^{++})$$ χ c , b ( 1 + + ) production at the LHC.

Uncertainties on αSαS in the MMHT2014 global PDF analysis and implications for SM predictions (2015)
Journal Article
Harland-Lang, L., Martin, A., Motylinski, P., & Thorne, R. (2015). Uncertainties on αSαS in the MMHT2014 global PDF analysis and implications for SM predictions. The European Physical Journal C, 75(9), Article 435. https://doi.org/10.1140/epjc/s10052-015-3630-3

We investigate the uncertainty in the strong coupling αS(M2Z)αS(MZ2) when allowing it to be a free parameter in the recent MMHT global analyses of deep-inelastic and related hard scattering data that was undertaken to determine the parton distributio... Read More about Uncertainties on αSαS in the MMHT2014 global PDF analysis and implications for SM predictions.

Parton distributions in the LHC era: MMHT 2014 PDFs (2015)
Journal Article
Harland-Lang, L., Martin, A., Motylinski, P., & Thorne, R. (2015). Parton distributions in the LHC era: MMHT 2014 PDFs. The European Physical Journal C, 75(5), Article 204. https://doi.org/10.1140/epjc/s10052-015-3397-6

We present LO, NLO and NNLO sets of parton distribution functions (PDFs) of the proton determined from global analyses of the available hard scattering data. These MMHT2014 PDFs supersede the ‘MSTW2008’ parton sets, but they are obtained within the s... Read More about Parton distributions in the LHC era: MMHT 2014 PDFs.

Elastic scattering and diffractive dissociation in the light of LHC data (2015)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2015). Elastic scattering and diffractive dissociation in the light of LHC data. International Journal of Modern Physics A, 30(08), Article 1542004. https://doi.org/10.1142/s0217751x1542004x

We study the behavior of elastic and diffractive proton dissociation cross sections at high energy. First, we describe what would be expected to be observed at the Large Hadron Collider (LHC) based on conventional Regge theory. We emphasize the tensi... Read More about Elastic scattering and diffractive dissociation in the light of LHC data.

Evolution in opening angle combining DGLAP and BFKL logarithms (2014)
Journal Article
de Oliveira, E., Martin, A., & Ryskin, M. (2014). Evolution in opening angle combining DGLAP and BFKL logarithms. The European Physical Journal C, 74(10), Article 3118. https://doi.org/10.1140/epjc/s10052-014-3118-6

We present an evolution equation which simultaneously sums the leading BFKL and DGLAP logarithms for the integrated gluon distribution in terms of a single variable, namely the emission angle of the gluon. This form of evolution is appropriate for Mo... Read More about Evolution in opening angle combining DGLAP and BFKL logarithms.

The photon PDF of the proton (2014)
Journal Article
Martin, A., & Ryskin, M. (2014). The photon PDF of the proton. The European Physical Journal C, 74(9), Article 3040. https://doi.org/10.1140/epjc/s10052-014-3040-y

We show how the photon input parton distribution function (PDF) may be calculated with good accuracy and used in an extended DGLAP global parton analysis in which the photon is treated as an additional point-like parton. The uncertainty of the input... Read More about The photon PDF of the proton.

BFKL equation for an integrated gluon density (2014)
Journal Article
de Oliveira, E., Martin, A., & Ryskin, M. (2014). BFKL equation for an integrated gluon density. The European Physical Journal C, 74(8), Article 3030. https://doi.org/10.1140/epjc/s10052-014-3030-0

We show how it is possible to rewrite the BFKL equation for the unintegrated gluon distribution, in terms of integrated gluons, similar to that used in DGLAP. We add to our equation the next-to-leading log terms which provide exact energy-momentum co... Read More about BFKL equation for an integrated gluon density.

High-energy elastic and diffractive cross sections (2014)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2014). High-energy elastic and diffractive cross sections. The European Physical Journal C, 74(2), Article 2756. https://doi.org/10.1140/epjc/s10052-014-2756-z

We present a ‘global’ description of the wide variety of high-energy elastic and diffractive data that are presently available, particularly from the LHC experiments. The model is based on only one pomeron pole, but it includes multi-pomeron interact... Read More about High-energy elastic and diffractive cross sections.

High-energy strong interactions: from ‘hard’ to ‘soft’. (2011)
Journal Article
Ryskin, M., Martin, A., & Khoze, V. (2011). High-energy strong interactions: from ‘hard’ to ‘soft’. The European Physical Journal C, 71(4), Article 1617. https://doi.org/10.1140/epjc/s10052-011-1617-2

We discuss the qualitative features of the recent data on multiparticle production observed at the LHC. The tolerable agreement with Monte Carlos based on LO DGLAP evolution indicates that there is no qualitative difference between ‘hard’ and ‘soft’... Read More about High-energy strong interactions: from ‘hard’ to ‘soft’..

Physical gluons and high-ET jets (2004)
Journal Article
Martin, A., Roberts, R., Stirling, W., & Thorne, R. (2004). Physical gluons and high-ET jets. Physics Letters B, 604(1-2), 61-68. https://doi.org/10.1016/j.physletb.2004.10.040

We propose a more physical parameterization of the gluon distribution for global parton analyses of deep inelastic and related hard scattering data. In the new parameterization the gluon distribution at large x in the -scheme is driven by the valence... Read More about Physical gluons and high-ET jets.

Predictions for g-2 of the muon and alpha(QED)(M(Z**2)) (2004)
Journal Article
Hagiwara, K., Martin, A., Nomura, D., & Teubner, T. (2004). Predictions for g-2 of the muon and alpha(QED)(M(Z**2)). Physical Review D, Particles and fields, 69, https://doi.org/10.1103/physrevd.69.093003

We calculate g–2 of the muon and the QED coupling alpha(MZ2), by improving the determination of the hadronic vacuum polarization contributions and their uncertainties. We include the recently reanalyzed CMD-2 data on e+e–-->pi+pi–. We carefully combi... Read More about Predictions for g-2 of the muon and alpha(QED)(M(Z**2)).

The SM prediction of g-2 of the muon (2003)
Journal Article
Hagiwara, K., Martin, A., Nomura, D., & Teubner, T. (2003). The SM prediction of g-2 of the muon. Physics Letters B, 557(1-2), 69-75. https://doi.org/10.1016/s0370-2693%2803%2900138-2

We calculate (g-2)/2 of the muon, by improving the determination of the hadronic vacuum polarisation contribution, a_mu^{had,LO}, and its uncertainties. The different e+e- data sets for each exclusive (and the inclusive) channel are combined in order... Read More about The SM prediction of g-2 of the muon.

Unintegrated parton distributions (2001)
Journal Article
Kimber, M., Martin, A., & Ryskin, M. (2001). Unintegrated parton distributions. Physical Review D, Particles and fields, 63(11), https://doi.org/10.1103/physrevd.63.114027

We describe how to calculate the parton distributions fa(x,kt2,μ2), unintegrated over the parton transverse momentum kt, from auxiliary functions ha(x,kt2), which satisfy single-scale evolution equations. The formalism embodies both DGLAP and BFKL co... Read More about Unintegrated parton distributions.

Double-diffractive processes in high resolution missing-mass experiments at the Tevatron (2001)
Journal Article
Khoze, V., Martin, A., & Ryskin, M. (2001). Double-diffractive processes in high resolution missing-mass experiments at the Tevatron. The European Physical Journal C, 19(3), 477-483. https://doi.org/10.1007/s100520100637

We evaluate, in a model-independent way, the signal-to-background ratio for Higgs→ b¯b detection in exclusive double-diffractive events at the Tevatron and the LHC. For the missing-mass approach to be able to identify the Higgs boson, it will be nece... Read More about Double-diffractive processes in high resolution missing-mass experiments at the Tevatron.