The spin-dependent two-loop splitting functions

We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering (SIDIS). We consider cross sections for various combinations of polarizations of the initial lepton and nucleon or the produced hadron, for which we perform the resummation of large double-logarithmic perturbative corrections arising at small transverse momentum. We present phenomenological results for the processes lp → lπX with longitudinally polarized leptons and protons. We discuss the impact of the perturbative resummation and of estimated non-perturbative contributions on the corresponding cross sections and their spin asymmetry. Our results should be relevant for ongoing studies in the COMPASS experiment at CERN, and for future experiments at the proposed eRHIC collider at BNL.

show abstract

“…For this we need the ∝ ǫ terms in the spin-dependent splitting functions. For longitudinal polarization we have [47] …”

Section: Nll Resummed Cross Sectionmentioning

confidence: 99%

Resummation for polarized semi-inclusive deep-inelastic scattering at small transverse momentum

2006

View full text Add to dashboard Cite

show abstract

“…We note that contrary to previous definitions of these splitting functions [41,42] we have not included a factor of 2N F in ∆P…”

Section: Appendix A: Polarized Splitting Functionsmentioning

confidence: 97%

“…We use Tracer [38] to implement these rules, together with in-house routines written in Form [39] as a cross-check. The use of the HV scheme necessitates an additional transformation in order to obtain the standard MS factorization scheme for the PDFs, as is well known in the literature [40][41][42][43][44][45]. Switching to a matrix notation in parton flavors, the beam function computing using Eq.…”

Section: Renormalization and Matchingmentioning

confidence: 99%

Spin-dependent quark beam function at NNLO

et al. 2017

View full text Add to dashboard Cite

We calculate the beam function for longitudinally-polarized quarks through next-to-next-toleading order (NNLO) in QCD perturbation theory. This is the last missing ingredient needed to apply the factorization theorem for the N -jettiness event-shape variable in a variety of polarized collisions through the NNLO level. We present all technical details of our derivation. As a by-product of our calculation we provide the first independent check of the previously-obtained unpolarized quark beam function. We anticipate that our result will have phenomenological applications in describing data from polarized collisions.

show abstract

“…The expression of the kernels in the helicity basis given below are obtained combining the NLO computations of [2,11] (1) gq,++ (x) =…”

Section: Appendix C Kernels In the Helicity Basismentioning

confidence: 99%

Direct solution of renormalization group equations of QCD in x-space: NLO implementations at leading twist

Cafarella

Corianò

2004

Computer Physics Communications

View full text Add to dashboard Cite

We illustrate the implementation of a method based on the use of recursion relations in (Bjorken) x-space for the solution of the evolution equations of QCD for all the leading twist distributions. The algorithm has the advantage of being very fast. The implementation that we release is written in C and is performed to next-to-leading order in α s . Program summaryTitle of program: evolution.c Catalogue identifier: ADUB Program summary URL: Nature of physical problem: The program provided here solves the DGLAP evolution equations to next-to-leading order α s , for unpolarized, longitudinally polarized and transversely polarized parton distributions. Method of solution:We use a recursive method based on an expansion of the solution in powers of log(α s (Q)/α s (Q 0 )). Typical running time: About 1 minute and 30 seconds for the unpolarized and longitudinally polarized cases and 1 minute for the transversely polarized case.

show abstract

The spin-dependent two-loop splitting functions

Cited by 135 publications

References 47 publications

Resummation for polarized semi-inclusive deep-inelastic scattering at small transverse momentum

Resummation for polarized semi-inclusive deep-inelastic scattering at small transverse momentum

Spin-dependent quark beam function at NNLO

Direct solution of renormalization group equations of QCD in x-space: NLO implementations at leading twist

Contact Info

Product

Resources

About