Publications (170)
The Path to NLO Parton Distributions
The NNPDF Collaboration, Richard D. Ball, Andrea Barontini +16
We extend the existing leading (LO), next-to-leading (NLO), and next-to-next-to-leading order (NNLO) NNPDF4.0 sets of parton distribution functions (PDFs) to approximate next-to-ne…
Parton distributions for the LHC Run II
The NNPDF Collaboration, Richard D. Ball, Valerio Bertone +9
We present NNPDF3.0, the first set of parton distribution functions (PDFs) determined with a methodology validated by a closure test. NNPDF3.0 uses a global dataset including HERA-…
Renormalization group approach to Sudakov resummation in prompt photon production
Paolo Bolzoni, Stefano Forte, Giovanni Ridolfi
We prove the all-order exponentiation of soft logarithmic corrections to prompt photon production in hadronic collisions, by generalizing an approach previously developed in the co…
Tests of the Standard Model at HERA
Stefano Forte
We review how experimental data collected at the HERA lepton-hadron collider have improved our theoretical and phenomenological understanding of the standard model, and specificall…
Interpreting Parton Distributions with Shapley Values
Raphaël Bonnet-Guerrini, Stefano Carrazza, Stefano Forte +3
We show that Shapley values can be used to trace how individual parton distributions (PDFs) shape the theory predictions for high-energy observables computed from them. This provid…
A first unbiased global determination of polarized PDFs and their uncertainties
Emanuele R. Nocera, Richard D. Ball, Stefano Forte +2
We present a first global determination of spin-dependent parton distribution functions (PDFs) and their uncertainties using the NNPDF methodology: NNPDFpol1.1. Longitudinally pola…
An Instanton-Induced Contribution to the Decay of the Eta_c into P-Pbar
Mauro Anselmino, Stefano Forte
We compute the decay rate for the process using an effective helicity-flipping proton-antiproton-gluon vertex which incorporates nonperturbative chiral symmetry b…
Unbiased determination of polarized parton distributions and their uncertainties
The NNPDF Collaboration, Richard D. Ball, Stefano Forte +4
We present a determination of a set of polarized parton distributions (PDFs) of the nucleon, at next-to-leading order, from a global set of longitudinally polarized deep-inelastic…
Future tests of parton distributions
Juan Cruz-Martinez, Stefano Forte, Emanuele R. Nocera
We discuss a test of the generalization power of the methodology used in the determination of parton distribution functions (PDFs). The "future test" checks whether the uncertainty…
Precision determination of electroweak parameters and the strange content of the proton from neutrino deep-inelastic scattering
The NNPDF Collaboration, Richard D. Ball, Luigi Del Debbio +6
We use recent neutrino dimuon production data combined with a global deep-inelastic parton fit to construct a new parton set, NNPDF1.2, which includes a determination of the strang…
Resummation prescriptions and ambiguities in SCET vs. direct QCD: Higgs production as a case study
Marco Bonvini, Stefano Forte, Giovanni Ridolfi +1
We perform a comparison of soft-gluon resummation in SCET vs. direct QCD (dQCD), using Higgs boson production in gluon fusion as a case study, with the goal of tracing the quantita…
Fitting Parton Distribution Data with Multiplicative Normalization Uncertainties
The NNPDF Collaboration, Richard D. Ball, Luigi Del Debbio +5
We consider the generic problem of performing a global fit to many independent data sets each with a different overall multiplicative normalization uncertainty. We show that the me…
Perturbatively Stable Resummed Small x Evolution Kernels
Guido Altarelli, Richard D. Ball, Stefano Forte
We present a small x resummation for the GLAP anomalous dimension and its corresponding dual BFKL kernel, which includes all the available perturbative information and nonperturbat…
Higgs production at RHIC and the positivity of the gluon helicity distribution
Daniel de Florian, Stefano Forte, Werner Vogelsang
We show that the negative polarized gluon distribution found in a recent global next-to-leading order QCD analysis of the nucleon helicity structure is incompatible with the…
Reweighting NNPDFs: the W lepton asymmetry
The NNPDF Collaboration, Richard D. Ball, Valerio Bertone +7
We present a method for incorporating the information contained in new datasets into an existing set of parton distribution functions without the need for refitting. The method inv…
Can we trust small x resummation?
Stefano Forte, Guido Altarelli, Richard D. Ball
We review the current status of small x resummation of evolution of parton distributions and of deep-inelastic coefficient functions. We show that the resummed perturbative expansi…
Universality and Scaling in Perturbative QCD at Small x
Stefano Forte, Richard D. Ball
We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the deri…
BFKL at Next-to-Next-to-Leading Order
Simone Marzani, Richard D. Ball, Pietro Falgari +1
We determine an approximate expression for the O(alpha_s^3) contribution chi_2 to the kernel of the BFKL equation, which includes all collinear and anticollinear singular contribut…
Higgs production in bottom-quark fusion in a matched scheme
Stefano Forte, Davide Napoletano, Maria Ubiali
We compute the total cross-section for Higgs boson production in bottom-quark fusion using the so-called FONLL method for the matching of a scheme in which the -quark is treated…
Parton distributions from high-precision collider data
The NNPDF Collaboration, Richard D. Ball, Valerio Bertone +13
We present a new set of parton distributions, NNPDF3.1, which updates NNPDF3.0, the first global set of PDFs determined using a methodology validated by a closure test. The update…
Phenomenology of NNLO jet production at the LHC and its impact on parton distributions
Rabah Abdul Khalek, Stefano Forte, Thomas Gehrmann +8
We present a systematic investigation of jet production at hadron colliders from a phenomenological point of view, with the dual aim of providing a validation of theoretical calcul…
Correlation and Combination of Sets of Parton Distributions
Richard D. Ball, Stefano Forte, Roy Stegeman
We study the correlation between different sets of parton distributions (PDFs). Specifically, viewing different PDF sets as distinct determinations, generally correlated, of the sa…
Progress in perturbative QCD
Stefano Forte
We briefly summarize some recent theoretical developments in perturbative QCD, emphasizing new ideas which have led to widening the domain of applicability of perturbation theory.…
Neural network determination of parton distributions: the nonsinglet case
The NNPDF Collaboration, Luigi Del Debbio, Stefano Forte +3
We provide a determination of the isotriplet quark distribution from available deep--inelastic data using neural networks. We give a general introduction to the neural network appr…
Combined PDF and strong coupling uncertainties at the LHC with NNPDF2.0
Maria Ubiali, Richard D. Ball, Luigi Del Debbio +4
We present predictions for relevant LHC observables obtained with the NNPDF2.0 set. We compute the combined PDFs uncertainties on these observables, and show that combining errors…
Asymptotic Freedom at Small x
Richard D. Ball, Stefano Forte
We describe how perturbative QCD may be applied to inelastic e-p scattering at high center-of-mass energies, i.e. at small x and fixed Q^2.
Polarized Parton Distributions at an Electron-Ion Collider
The NNPDF Collaboration, Richard D. Ball, Stefano Forte +4
We study the potential impact of inclusive deep-inelastic scattering data from a future electron-ion collider (EIC) on longitudinally polarized parton distribution (PDFs). We perfo…
Factorization and Resummation of Small x Scaling Violations with Running Coupling
Guido Altarelli, Richard D. Ball, Stefano Forte
We discuss the inclusion of running coupling effects in perturbative small x evolution equations. We show that a running coupling BFKL-like x-evolution equation is fully compatible…
Top Quark Pair Production beyond NNLO
Claudio Muselli, Marco Bonvini, Stefano Forte +2
We construct an approximate expression for the total cross section for the production of a heavy quark-antiquark pair in hadronic collisions at next-to-next-to-next-to-leading orde…
Threshold resummation of Semi-Inclusive Deep-Inelastic Scattering
Stefano Forte, Giovanni Ridolfi, Francesco Ventola
We derive threshold resummation of semi-inclusive deep-inelastic scattering (SIDIS), by building upon previous results by some of us for the resummation of the Drell-Yan process at…
The PDF4LHC Working Group Interim Recommendations
Michiel Botje, Jon Butterworth, Amanda Cooper-Sarkar +8
This note provides an interim summary of the current recommendations of the PDF4LHC working group for the use of parton distribution functions (PDFs) and of PDF uncertainties at th…
Truncated moments of parton distributions
Stefano Forte, Lorenzo Magnea
We derive evolution equations satisfied by moments of parton distributions when the integration over the Bjorken variable is restricted to a subset (x_0 <= x <= 1) of the allowed k…
On the Impact of NMC Data on NLO and NNLO Parton Distributions and Higgs Production at the Tevatron and the LHC
The NNPDF Collaboration, Richard D. Ball, Valerio Bertone +7
We discuss the impact of the treatment of NMC structure function data on parton distributions in the context of the NNPDF2.1 global PDF determination at NLO and NNLO. We show that…
Threshold resummation of transverse momentum distributions beyond next-to-leading log
Stefano Forte, Giovanni Ridolfi, Simone Rota
We derive a general expression for the threshold resummation of transverse momentum distributions for processes with a colorless final state, by suitably generalizing the renormali…
High energy resummation for rapidity distributions
Simone Marzani, Fabrizio Caola, Stefano Forte
We discuss the generalisation of high-energy resummation to rapidity distributions to leading logarithmic accuracy. We test our procedure applying it to Higgs production in gluon-g…
Small Angle Polarization in High Energy P--P Scattering Through Nonperturbative Chiral Symmetry Breaking
Mauro Anselmino, Stefano Forte
We show that a large anomalous contribution due to nonperturbative instanton-like gluonic field configurations to the axial charge of the proton implies high-energy spin effects in…
Polarized structure functions: a status report
Stefano Forte
We review the present status of polarized structure functions measured in deep-inelastic scattering. We discuss the x and Q^2 dependence of the structure function g_1, and how it c…
Polarized Structure Functions: a Theoretical Update
Stefano Forte
We review recent developments in the theory and phenomenology of polarized structure functions. We summarize recent experimental data on the proton and deuteron structure function…
Forecasting the Socio-Economic Impact of the Large Hadron Collider: a Cost-Benefit Analysis to 2025 and Beyond
Massimo Florio, Stefano Forte, Emanuela Sirtori
In this paper we develop a cost-benefit analysis of a major research infrastructure, the Large Hadron Collider (LHC), the highest-energy accelerator in the world, currently operati…
Updated Higgs cross section at approximate NLO
Marco Bonvini, Richard D. Ball, Stefano Forte +2
We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (NLO) in in view of the recent full computation…
Small-x Resummation and HERA Structure Function Data
Guido Altarelli, Richard D. Ball, Stefano Forte
We apply our systematic NLO small x resummation of singlet splitting functions to the scaling violations of structure functions and compare the results with data. We develop variou…
Asymptotic Freedom in Parton Language: the Birth of Perturbative QCD
Stefano Forte
I review the contributions of Giorgio Parisi to perturbative QCD. Concentrated in a decade, they mark the transition of the theory of strong interactions from a set of loosely conn…
Higgs production in bottom-quark fusion: matching beyond leading order
Stefano Forte, Davide Napoletano, Maria Ubiali
We compute the total cross-section for Higgs boson production in bottom-quark fusion using the so-called FONLL method for the matching of a scheme in which the -quark is treated…
The sigma term and the quark number operator in QCD
Mauro Anselmino, Stefano Forte
We discuss the relationship of the forward matrix element of the operator , related to the so-called sigma term, to the quark number. We show that in the naive quark mode…
Resummation of Singlet Parton Evolution at Small x
Guido Altarelli, Richard D. Ball, Stefano Forte
We propose an improvement of the splitting functions at small x which overcomes the apparent problems encountered by the BFKL approach. We obtain a stable expansion for the x-evolu…
Signal-background interference effects for beyond leading order
Marco Bonvini, Fabrizio Caola, Stefano Forte +2
We study the effect of QCD corrections to the signal-background interference at the LHC for a heavy Higgs boson. We construct a soft-collinear approximation to…
Violation of the Bjorken Sum Rule in QCD
Stefano Forte
We show that the Bjorken sum rule for the first moment of the polarized nucleon structure function is not necessarily satisfied in QCD if the axial anomaly is taken into acco…
Evolution of parton distributions with truncated Mellin moments
Lorenzo Magnea, Stefano Forte
Evolution equations for parton distributions can be approximately diagonalized and solved in moment space without assuming any knowledge of the parton distribution in the region of…
Recent developments in Deep-Inelastic Scattering
Stefano Forte
We review several recent developments in the theory and phenomenology of deep-inelastic scattering, with particular emphasis on precision tests of QCD and progress in the detailed…
The High-Energy Interpretation of Quantum Mechanics
Stefano Forte
We address the issue of the interpretation of quantum mechanics by asking why the issue never arises in the description of high-energy interactions. We argue that several tenets of…
Determination of the Bjorken Sum and Strong Coupling from Polarized Structure Functions
Guido Altarelli, Richard D. Ball, Stefano Forte +1
We present a NLO perturbative analysis of all available data on the polarized structure function g_1(x,Q^2) with the aim of making a quantitative test of the validity of the Bjorke…
Inclusive Measurement of the Strong Coupling at HERA
Richard D. Ball, Stefano Forte
We describe the measurement of the strong coupling alpha_s from data on inclusive DIS at high energies. We present new results using the 1994 data from H1, and confirm directly the…
A First Determination of Parton Distributions with Theoretical Uncertainties
The NNPDF Collaboration, Rabah Abdul Khalek, Richard D. Ball +11
The parton distribution functions (PDFs) which characterize the structure of the proton are currently one of the dominant sources of uncertainty in the predictions for most process…
The intrinsic charm quark valence distribution of the proton
Richard D. Ball, Alessandro Candido, Juan Cruz-Martinez +7
We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence…
Spin Physics
Stefano Forte, Yuji Goto
We review recent experimental and theoretical progress in spin physics, as presented in the spin parallel session of DIS2006. In particular, we discuss the status of the nucleon sp…
A new prescription for soft gluon resummation
Riccardo Abbate, Stefano Forte, Giovanni Ridolfi
We present a new prescription for the resummation of the divergent series of perturbative corrections, due to soft gluon emission, to hard processes near threshold in perturbative…
Small x resummation of rapidity distributions: the case of Higgs production
Fabrizio Caola, Stefano Forte, Simone Marzani
We provide a method for the all order computation of small x contributions at the leading logarithmic level to cross-sections which are differential in rapidity. The method is base…
Parton distributions with LHC data
Richard D. Ball, Valerio Bertone, Stefano Carrazza +8
We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besid…
The scale of soft resummation in SCET vs perturbative QCD
Marco Bonvini, Stefano Forte, Margherita Ghezzi +1
We summarize and extend previous results on the comparison of threshold resummation, performed, using soft-collinear effective theory (SCET), in the Becher-Neubert approach, to the…
Machine Intelligence-Driven Classification of Cancer Patients-Derived Extracellular Vesicles using Fluorescence Correlation Spectroscopy: Results from a Pilot Study
Abicumaran Uthamacumaran, Mohamed Abdouh, Kinshuk Sengupta +5
Patient-derived extracellular vesicles (EVs) that contains a complex biological cargo is a valuable source of liquid biopsy diagnostics to aid in early detection, cancer screening,…
boson production in bottom-quark fusion: a study of -mass effects beyond leading order
Stefano Forte, Davide Napoletano, Maria Ubiali
We compute the total cross-section for boson production in bottom-quark fusion, applying to this case the method we previously used for Higgs production in bottom fusion. Namel…
Response to "Parton distributions need representative sampling"
The NNPDF Collaboration, Richard D. Ball, Juan Cruz-Martinez +7
We respond to the criticism raised by Courtoy et al., in which the faithfulness of the NNPDF4.0 sampling is questioned and an under-estimate of the NNPDF4.0 PDF uncertainties is im…
Deviations from NLO QCD evolution in inclusive HERA data
Fabrizio Caola, Stefano Forte, Juan Rojo
We search for deviations from next-to-leading order QCD evolution in HERA structure function data. We compare to data predictions for structure functions in the small x region, obt…
Precision NNLO determination of alpha_s(M_Z) using an unbiased global parton set
Richard D. Ball, Valerio Bertone, Luigi Del Debbio +6
We determine the strong coupling alpha_s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inel…
A first unbiased global NLO determination of parton distributions and their uncertainties
Richard D. Ball, Luigi Del Debbio, Stefano Forte +4
We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology: NNPDF2.0. Experimental data include dee…
Polarized Structure Functions: Theory and Phenomenology
Stefano Forte
We review the theory of polarized structure functions measured in deep-inelastic lepton-nucleon scattering, focusing on the most recent developments. We concentrate on the structur…
All Order Running Coupling BFKL Evolution from GLAP (and vice-versa)
Richard D. Ball, Stefano Forte
We present a systematic formalism for the derivation of the kernel of the BFKL equation from that of the GLAP equation and conversely to any given order, with full inclusion of the…
Towards small x resummed DIS phenomenology
Juan Rojo, Guido Altarelli, Richard D. Ball +1
We report on recent progress towards quantitative phenomenology of small x resummation of deep-inelastic structure functions. We compute small x resummed K-factors with realistic P…
Unbiased determination of the proton structure function F_2^p with faithful uncertainty estimation
The NNPDF Collaboration, Luigi Del Debbio, Stefano Forte +3
We construct a parametrization of the deep-inelastic structure function of the proton F_2 based on all available experimental information from charged lepton deep-inelastic scatter…
Determination of alpha_s from scaling violations of truncated moments of structure functions
Stefano Forte, Jose I. Latorre, Lorenzo Magnea +1
We determine the strong coupling alpha_s(M_Z) from scaling violations of truncated moments of the nonsinglet deep inelastic structure function F_2. Truncated moments are determined…
An Improved Splitting Function for Small x Evolution
Guido Altarelli, Richard D. Ball, Stefano Forte
We summarize our recent result for a splitting function for small x evolution which includes resummed small x logarithms deduced from the leading order BFKL equation with the inclu…
Singlet parton evolution at small x: a theoretical update
Guido Altarelli, Richard D. Ball, Stefano Forte
This is an extended and pedagogically oriented version of our recent work, in which we proposed an improvement of the splitting functions at small x which overcomes the apparent pr…
A Determination of the Charm Content of the Proton
The NNPDF Collaboration, Richard D. Ball, Valerio Bertone +7
We present an unbiased determination of the charm content of the proton, in which the charm parton distribution function (PDF) is parametrized on the same footing as the light quar…
Progress in the Determination of the Partonic Structure of the Proton
Stefano Forte, Graeme Watt
We review the current state of the art in the determination of the parton substructure of the nucleon, as expressed in terms of parton distribution functions (PDFs), and probed in…
Determination of the theory uncertainties from missing higher orders on NNLO parton distributions with percent accuracy
The NNPDF Collaboration, Richard D. Ball, Andrea Barontini +16
We include uncertainties due to missing higher order corrections to QCD computations (MHOU) used in the determination of parton distributions (PDFs) in the recent NNPDF4.0 set of P…
Parton Distributions and New Physics Searches: the Drell-Yan Forward-Backward Asymmetry as a Case Study
Richard D. Ball, Alessandro Candido, Stefano Forte +4
We discuss the sensitivity of theoretical predictions of observables used in searches for new physics to parton distributions (PDFs) at large momentum fraction . Specifically, w…
The threshold region for Higgs production in gluon fusion
Marco Bonvini, Stefano Forte, Giovanni Ridolfi
We provide a quantitative determination of the effective partonic kinematics for Higgs production in gluon fusion in terms of the collider energy at the LHC. We use the result to a…
Polarized Structure Functions with Neutrino Beams
Stefano Forte
We review the potential impact of neutrino data on the determination of the spin structure of the nucleon. We show that a flavour decomposition of the parton structure of the nucle…
Progress in the small x resummation of the singlet anomalous dimension
Guido Altarelli, Richard D. Ball, Stefano Forte
We summarize our recent results on the small x resummation of the singlet anomalous dimension. We recall the main features of our approach, and briefly describe some work in progre…
Why Cannot be Determined from Hadronic Processes without Simultaneously Determining the Parton Distributions
Stefano Forte, Zahari Kassabov
We show that any determination of the strong coupling from a process which depends on parton distributions, such as hadronic processes or deep-inelastic scattering, generall…
PDF4LHC recommendations for LHC Run II
Jon Butterworth, Stefano Carrazza, Amanda Cooper-Sarkar +13
We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+ uncertainties suitable for applications…
Exploring cost-benefit analysis of research, development and innovation infrastructures: an evaluation framework
Massimo Florio, Stefano Forte, Chiara Pancotti +2
This paper presents the results and the lessons learned on how to apply ex-ante CBQ for major RDI infrastructures by a team of economists and scientists at the University of Milan…
On positivity of parton distributions
Guido Altarelli, Stefano Forte, Giovanni Ridolfi
We discuss the bounds on polarized parton distributions which follow from their definition in terms of cross section asymmetries. We spell out how the bounds obtained in the naive…
Structure Functions and Parton Distributions
Stefano Forte
I review recent progress in the determination of the parton structure of the nucleon, in particular from deep-inelastic structure functions. I explain how the needs of current and…
A simple introduction to soft resummation
Stefano Forte, Giovanni Ridolfi
We provide an elementary pedagogical introduction to some basic concepts and techniques of soft (or Sudakov) resummation, specifically in QCD, paying particular attention to simple…
An anomalous dimension for small x evolution
Guido Altarelli, Richard D. Ball, Stefano Forte
We construct an anomalous dimension for small x evolution which goes beyond standard fixed order perturbative evolution by including resummed small x logarithms deduced from the le…
The Small x Behaviour of Altarelli-Parisi Splitting Functions
Richard D. Ball, Stefano Forte
We extract the small x asymptotic behaviour of the Altarelli-Parisi splitting functions from their expansion in leading logarithms of 1/x. We show in particular that the nominally…
On the Sudakov form factor, and a factor of two
Stefano Forte
I answer a question that Roman Jackiw asked me, and I draw some lessons from the answer. The question is: why is the Sudakov form factor larger by a factor of two, if computed for…
Highlights of Short Baseline Physics at a Neutrino Factory
Stefano Forte
We review the physics potential for experiments with intense neutrino beams at the front-end of a muon storage ring, stressing the way the spin and flavour structure of neutrino in…
The single-jet inclusive cross-section and its definition
Matteo Cacciari, Stefano Forte, Davide Napoletano +2
We investigate some well-known problematic aspects of the single-jet inclusive cross-section, specifically its non-unitarity and the possibly related issue of apparent perturbative…
The Light-flavor structure of the nucleon
Stefano Forte
Recent data on the Gottfried sum and less recent ones on the pion-nucleon sigma term seem to disagree with naive parton-based expectations on the light (i.e., up, down and strange)…
The PDF4LHC Working Group Interim Report
Sergey Alekhin, Simone Alioli, Richard D. Ball +31
This document is intended as a study of benchmark cross sections at the LHC (at 7 TeV) at NLO using modern parton distribution functions currently available from the 6 PDF fitting…
A Determination of at Accuracy from a Global PDF Analysis
The NNPDF Collaboration, Richard D. Ball, Andrea Barontini +6
We present a determination of the strong coupling from a global dataset including both fixed-target and collider data from deep-inelastic scattering and a variety of ha…
Are Parton Distributions Positive?
Stefano Forte, Guido Altarelli, Giovanni Ridolfi
We show that the naive positivity conditions on polarized parton distributions which follow from their probabilistic interpretation in the naive parton model are reproduced in pert…
Geometric Scaling from GLAP evolution
Fabrizio Caola, Stefano Forte
We show that the geometric scaling of the total virtual photon-proton cross section data can be explained using standard linear GLAP perturbative evolution with generic boundary co…
Extractions of the strong coupling from collider data without PDF refitting are biased
Stefano Forte, Juan Rojo, Roy Stegeman
We present an explicit demonstration that a determination of the strong coupling constant from deep-inelastic scattering and hadron collider data without a simultaneous…
Small x Resummation with Quarks: Deep-Inelastic Scattering
Guido Altarelli, Richard D. Ball, Stefano Forte
We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and glu…
A Dynamical Resolution of the Sigma Term Puzzle
Richard D. Ball, Stefano Forte, Jason Tigg
We propose a resolution of the puzzle posed by the discrepancy between the pion-nucleon sigma term inferred from pion-nucleon scattering, and that deduced from baryon mass splittin…
Parton Distributions and Event Generators
Stefano Carrazza, Stefano Forte, Juan Rojo
We present the implementation within the Pythia8 event generator of a set of parton distributions based on NNPDF methodology. We construct a set of leading-order parton distributio…
Do we need NLO Parton Distributions?
Stefano Forte, Andrea Isgro', Gherardo Vita
We discuss the uncertainty on processes computed using next-to-next-to leading (NNLO) parton distributions (PDFs) due to the neglect of higher order perturbative corrections in the…