Two-current correlations in the pion in the Nambu and Jona-Lasinio model
- PDF / 817,674 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 43 Downloads / 158 Views
Regular Article - Theoretical Physics
Two-current correlations in the pion in the Nambu and Jona-Lasinio model Aurore Courtoy1,a , Santiago Noguera2,b , Sergio Scopetta3,c 1
Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 Ciudad de México, Mexico Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, 46100 Burjassot, Valencia, Spain 3 Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, and Istituto Nazionale di Fisica Nucleare Sezione di Perugia, Via A. Pascoli, 06123 Perugia, Italy
2
Received: 17 June 2020 / Accepted: 12 September 2020 © The Author(s) 2020
Abstract We present an analysis of two-current correlations for the pion in the Nambu–Jona-Lasinio model, with Pauli–Villars regularization. We provide explicit expressions in momentum space for two-current correlations corresponding to the zeroth component of the vector Dirac bilinear in the quark vertices, which has been evaluated on the lattice, thinking to applications in a high energy framework, as a step towards the calculation of pion double parton distributions. The numerical results show a remarkable qualitative agreement with recent lattice data. The factorization approximation into one-body currents is discussed based on previous evaluation of the relevant low energy matrix elements in the Nambu–Jona-Lasinio model, confirming the lattice result.
1 Introduction Due to the high partonic densities reached, processes with more than two partons from the two colliding protons participating in the actual scattering – the so called multiple parton interactions – are likely to happen at the LHC [1]. Double parton scattering (DPS), the simplest form of multiple parton interactions, involves two simultaneous hard collisions. It has been indeed observed at the LHC (see, e.g., Ref. [2]). The DPS cross section is expressed in terms of double parton distribution functions (dPDFs) [3,4]. The latter are related to the number density of two partons located at a given transverse separation in coordinate space with given longitudinal momentum fractions. The information encoded in these distributions therefore complements that accessed through electromagnetic probes in terms of generalized parton distribua e-mail:
[email protected] (corresponding author)
b e-mail:
[email protected]
c e-mail:
[email protected]
0123456789().: V,-vol
tions (GPDs) [5,6], one of the flagships of the future Electron Ion Collider (EIC) [7]. If measured, dPDFs would therefore represent a novel tool to study the three-dimensional hadron structure [8–12]. Indeed, they are sensitive to two-parton correlations not accessible via one body distributions, e.g. Parton Distribution Functions (PDFs) and GPDs –see Ref. [1,13] for a recent report. Since they are non perturbative objects, dPDFs have been evaluated within models of the hadron structure – estimates exist at low momentum scales for the proton dPDFs [14–20]. In order to match theoretical predictions with future experimental an
Data Loading...
