arXiv subjects

Federico Alberto Ceccopieri

Publications and source records attributed to Federico Alberto Ceccopieri.

At least 19 recordsLinked to original sources

arXiv2026

Double parton scattering off nuclei and the double-EMC effect

The double-parton scattering process off light and heavy nuclei is proposed as an effective tool to open a novel window for accurately studying the effects of nuclear binding on the internal structure of the nucleon, in the spirit of the European Muon Collaboration (EMC) effect. The key ingredient is the actual calculation of nuclear double-parton distributions that contain information about double-parton distributions and generalized-parton distributions of the nucleon, folded with nuclear light-front distributions. It allows to introduce a new quantity, which we call double-EMC ratio that appears to be much more sensitive than the standard EMC effect to both the nucleon partonic structure and to the nuclear binding. Hence, it could help solving long-standing questions about how nucleons change when they are bound in atomic nuclei.

hep-ph↗

arXiv2025

Theoretical insights on nuclear double parton distributions

In this paper, we address double parton scattering (DPS) in pA collisions. Within the Light-Front approach, we formally derive the two contributions to the nuclear double parton distribution (DPD), namely: DPS1, involving two partons from the same nucleon, and DPS2, where the two partons belong to different parent nucleons. We then generalize the sum rule for hadron DPDs to the nuclear case and analytically show how all contributions combine to give the expected results. In addition partial sum rules for the DPDs related to DPS1 and DPS2 mechanisms are discussed for the first time. The deuteron system is considered for the first calculation of the nuclear DPD by using a realistic wave function obtained from the very refined nucleon-nucleon AV18 potential, embedded in a rigorous Poincaré covariant formalism. Results are used to test sum rules and properly verify that DPS1 contribution compares with the DPS2 one, although smaller. We also introduce EMC-like ratios involving nuclear and free DPDs to address the potential role of DPS in understanding in depth the EMC effect.

nucl-th↗

arXiv2022

Enlighting the transverse structure of the proton via double parton scattering in photon-induced interactions

In the present paper we address double parton scattering (DPS) in quasi-real photon-proton interactions. By using electromagnetic and hadronic models of the photon light cone wave functions, we compute the so-called effective cross-section, $σ_{eff}^{γp}$ which allows us to calculate the DPS contribution to these processes under dedicated assumptions. In particular, for the four-jet photoproduction in HERA kinematics we found a sizeable DPS contribution. We show that if the photon virtuality $Q^2$ could be measured and thus the dependence of $σ_{eff}^{γp}$ on such a parameter exposed, information on the transverse distance between partons active in proton could be extracted. To this aim, we set lower limits on the integrated luminosity needed to observe such an effect which would allow the extraction of novel information on the proton structure.

hep-ph↗

arXiv2019

Double parton scattering and the proton transverse structure at the LHC

We consider double parton distribution functions (dPDFs), essential quantities in double parton scattering (DPS) studies, which encode novel non perturbative insight on the partonic proton structure. We develop the formalism to extract this information from dPDFs and present results by using constituent quark model calculations within the Light-Front approach, focusing on radiatively generated gluon dPDFs. Moreover, we generalize the relation between the mean transverse partonic distance between two active partons in a DPS process and the so called effective cross section to include partonic correlations and the so called 2v1 mechanism contribution. Finally we investigate the impact of relativistic effects on digluon distributions and study the structure of the corresponding longitudinal and transverse correlations.

hep-ph↗

arXiv2018

Pion nucleus Drell-Yan process and parton transverse momentum in the pion

We present a thorough analysis of unpolarized Drell-Yan (DY) pair production in pion-nucleus scattering. On the nucleus side, we use nuclear parton distributions along with parametrisations of the nucleon partonic transverse distribution available in the literature. Partonic longitudinal and transverse distributions of the pion are those obtained in a recent calculation in a Nambu-Jona Lasinio (NJL) framework, with Pauli-Villars regularization. The scale of the NJL model is fixed by a comparison between NLO predictions based on NJL evolved pion distributions and rapidity differential DY cross sections data. The resulting distributions are then used to describe, up to next-to-leading logarithmic accuracy, the transverse momentum spectrum of dilepton pairs up to a transverse momentum of 2 GeV. With no additional parameters, fair agreement is found with available pion-nucleus data, confirming the virtues of the NJL description of pion parton structure. We find sizable evolution effects on the shape of the distributions and on the generated average transverse momentum of the dilepton pair. We discuss the possibility of extracting details on pion unpolarized transverse momentum dependent parton distribution from pion nucleus DY data. In this respect, the region of low invariant mass of the lepton pair appears to be favored to discriminate between different descriptions of the non-perturbative pion transverse structure.

hep-ph↗

arXiv2018

Hadronic structure from double parton scattering

In the present paper we consider the so-called effective cross section, a quantity which encodes the experimental knowledge on double parton scattering in hadronic collisions that has been accomulated so far. We show that the effective cross section, under some assumptions close to those adopted in its experimental extractions, can be used to obtain a range of mean transverse distance between an interacting parton pair in double parton scattering. Therefore we have proved that the effective cross section offers a way to access information on the hadronic structure.

hep-ph↗

arXiv2017

Parton correlations effects in double parton distribution functions

Double parton distribution functions (dPDFs), measurable in hadron-hadron collisions and encoding information on how partons inside a proton are correlated among each other, could represent a new tool to explore the three dimensional partonic structure of hadrons. In the present contribution, results of the calculations of dPFDs are presented. Phenomenological calculations of experimental observables, sensitive to dPDFs are also discussed showing how double parton correlations could be estimated in the next LHC run.

hep-ph↗

arXiv2017

Parton correlations in same-sign $W$ pair production via double parton scattering at the LHC

Same-sign $W$ boson pairs production is a promising channel to look for signatures of double parton interactions at the LHC. The corresponding cross section has been calculated by using double parton distribution functions, encoding two parton correlations, evaluated in a Light-Front quark model. The obtained result is in line with previous estimates which make use of an external parameter, the so called effective cross section, not necessary in our approach. The possibility to observe for the first time two-parton correlations, in the next LHC runs, has been established.

hep-ph↗

arXiv2016

Relativistic effects in model calculations of double parton distribution function

In this paper we consider double parton distribution functions (dPDFs) which are the main non perturbative ingredients appearing in the double parton scattering cross section formula in hadronic collisions. By using recent calculation of dPDFs by means of constituent quark models within the so called Light-Front approach, we investigate the role of relativistic effects on dPDFs. We find, in particular, that the so called Melosh operators, which allow to properly convert the LF spin into the canonical one and incorporate a proper treatment of boosts, produce sizeable effects on dPDFs. We discuss specific partonic correlations induced by these operators in transverse plane which are relevant to the proton structure and study under which conditions these results are stable against variations in the choice of the proton wave function.

hep-ph↗

arXiv2016

Single-diffractive Drell-Yan pair production at the LHC

We present predictions for single-diffractive low-mass Drell-Yan pair production in $pp$ collisions at the LHC at $\sqrt{s}=13$ TeV. Predictions are obtained adopting a factorised form for the relevant cross sections and are based on a new set of diffractive parton distributions resulting from the QCD analysis of combined HERA leading proton data. We discuss a number of observables useful to characterise the expected factorisation breaking effects.

hep-ph↗

arXiv2016

Lambda production in the DIS target fragmentation region

By using a recently obtained set of Lambda fracture functions, we present predictions for Lambda production in the target fragmentation region of Semi-Inclusive Deep Inelastic Scattering in CLAS@12 GeV kinematics, supplemented with a conservative error estimates. We discuss a number of observables sensitive to the assumptions of the underlying theory and many of the assumptions of the proposed phenomenological model.

hep-ph↗

arXiv2015

Studies of backward particle production with A Fixed-Target Experiment using the LHC beams

The foreseen capability to cover the far backward region at A Fixed-Target Experiment using the LHC beams allows to explore the dynamics of target fragmentation in hadronic collisions. In this report we briefly outline the required theoretical framework and discuss a number of studies of forward and backward particle production. By comparing this knowledge with the one accumulated in Deep Inelastic Scattering on target fragmentation, the basic concept of QCD factorisation could be investigated in detail.

hep-ph↗

arXiv2014

On the QCD Evolution of Transverse Momentum Dependent Distributions

We reconsider the evolution equations for transverse momentum dependent distributions recently proposed by us and recast them in a form which allows the comparison with results recently appeared in the literature. We show under which conditions the obtained results might be consistent with each other.

hep-ph↗

arXiv2014

QCD analysis of forward neutron production in DIS

We consider forward neutron production in DIS within fracture functions formalism. By performing a QCD analysis of available data we extract proton-to-neutron fracture functions exploiting a method which is in close relation with the factorisation theorem for this class of processes.

hep-ph↗

arXiv2014

A second update on double parton distributions

We present two equivalent consistency checks of the momentum sum rule for double parton distributions and show the importance of the inclusion of the so-called inhomogeneous term in order to preserve correct longitudinal momentum correlations. We further discuss in some detail the kinematics of the splitting at the basis of the inhomogeneous term and update the double parton distributions evolution equations at different virtualities.

hep-ph↗

arXiv2013

QCD analysis of Lambda hyperon production in DIS target-fragmentation region

We consider Lambda-hyperon production in the target-fragmentation region of semi-inclusive deep-inelastic scattering within the framework of fracture functions. We present a first attempt to determine the flavour and energy dependences of these non-perturbative distributions through a simultaneous QCD-based fit to available neutral- and charged-current semi-inclusive-DIS cross sections. Predictions based on the resulting nucleon-to-Lambda fracture functions are in good agreement with data and observables not included in the regression. The successful prediction of the $Q^2$ dependence of the Lambda multiplicity notably represents the first validation of the perturbative framework implied by fracture functions.

hep-ph↗

arXiv2012

Revisiting QCD Fits in Diffractive DIS

A new method of extracting diffractive parton distributions is presented which avoids the use of Regge theory ansatz and is in much closer relation with the factorisation theorem for diffractive hard processes.

hep-ph↗

arXiv2011

One particle and Drell-Yan pair associated production

We briefly discuss the collinear factorization formula for the associated production of one particle and a Drell-Yan pair in hadronic collisions. We outline possible applications of the results to three different research areas.

hep-ph↗