Zobrazeno 1 - 10
of 1 416
pro vyhledávání: '"Steffens F"'
Autor:
Alexandrou, C., Bacchio, S., Bergner, G., Burri, S., Finkenrath, J., Gasbarro, A., Hadjiyiannakou, K., Jansen, K., Kanwar, G., Kostrzewa, B., Koutsou, G., Ottnad, K., Petschlies, M., Pittler, F., Steffens, F., Urbach, C., Wenger, U.
Publikováno v:
Phys.Rev.D 108 (2023) 9, 094514
The neutral pion generates the leading pole contribution to the hadronic light-by-light tensor, which is given in terms of the nonperturbative transition form factor $\mathcal{F}_{\pi^0\gamma\gamma}(q_1^2,q_2^2)$. Here we present an ab-initio lattice
Externí odkaz:
http://arxiv.org/abs/2308.12458
Publikováno v:
Phys. Rev. D 103, 016003 (2021)
We present the first Monte Carlo based global QCD analysis of spin-averaged and spin-dependent parton distribution functions (PDFs) that includes nucleon isovector matrix elements in coordinate space from lattice QCD. We investigate the degree of uni
Externí odkaz:
http://arxiv.org/abs/2010.00548
Publikováno v:
Phys. Rev. D 99, 096008 (2019)
We study the role of purely external kinematical approximations in inclusive deep-inelastic lepton--hadron scattering within QCD factorization, and consider factorization with an exact treatment of the target hadron mass. We discuss how an observed p
Externí odkaz:
http://arxiv.org/abs/1901.09016
Autor:
Oehm, M., Alexandrou, C., Constantinou, M., Jansen, K., Koutsou, G., Kostrzewa, B., Steffens, F., Urbach, C., Zafeiropoulos, S.
Publikováno v:
Phys. Rev. D 99, 014508 (2019)
Using Nf=2+1+1 lattice QCD, we determine the fermionic connected contributions to the second and third moment of the pion PDF. Based on gauge configurations from the European Twisted Mass Collaboration, chiral and continuum extrapolations are perform
Externí odkaz:
http://arxiv.org/abs/1810.09743
We study the consistency of parton distribution functions in the presence of target mass corrections (TMCs) at low Q^2. We review the standard operator product expansion derivation of TMCs in both x and moment space, and present the results in closed
Externí odkaz:
http://arxiv.org/abs/1210.4398
Publikováno v:
Phys. Rev. E 86, 016217 (2012)
We analyze the behavior of a relativistic particle moving under the influence of a uniform magnetic field and a stationary electrostatic wave. We work with a set of pulsed waves that allows us to obtain an exact map for the system. We also use a meth
Externí odkaz:
http://arxiv.org/abs/1110.1871
Autor:
Steffens, F. M.
We analyze different prescriptions for the inclusion of target mass effects in the extraction of parton distributions from the measured structure functions. As a main result, the problem of defining parton distributions in the presence of mass is an
Externí odkaz:
http://arxiv.org/abs/1103.5710
Publikováno v:
Phys.Rev.E82:026402,2010
We investigate the concept of a standard map for the interaction of relativistic particles and electrostatic waves of arbitrary amplitudes, under the action of external magnetic fields. The map is adequate for physical settings where waves and partic
Externí odkaz:
http://arxiv.org/abs/1007.5360
Autor:
Gardim, F. G., Steffens, F. M.
Publikováno v:
Nucl.Phys.A825:222-244,2009
We present in this work a generalization of the solution of Gorenstein and Yang to the inconsistency problem of thermodynamics for systems of quasi-particles whose masses depend on both the temperature and the chemical potential. We work out several
Externí odkaz:
http://arxiv.org/abs/0905.0667
Autor:
Gardim, F. G., Steffens, F. M.
Publikováno v:
Nucl.Phys.A797:50-66,2007
We present in this work a generalization of the solution of Gorenstein and Yang for a consistent thermodynamics for systems with a temperature dependent Hamiltonian. We show that there is a large class of solutions, work out three particular ones, an
Externí odkaz:
http://arxiv.org/abs/0709.3853