Study of the s−s¯ asymmetry in the proton

Abstract

The study of s −s asymmetry is essential to better understand of the structure of nucleon and also the perturbative and nonperturbative mechanisms for sea quark generation. Actually, the nature and dynamical origins of this asymmetry have always been an interesting subject to research both experimentally and theoretically. One of the most powerful models can lead to s−s asymmetry is the meson-baryon model (MBM). In this work, using a simplified configuration of this model suggested by Pumplin, we calculate the s −s asymmetry for different values of cutoff parameter Λ, to study the dependence of model to this parameter and also to estimate the theoretical uncertainty imposed on the results due to its uncertainty. Then, we study the evolution of distributions obtained both at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) using different evolution schemes. It is shown that the evolution of the intrinsic quark distributions from a low initial scale, as suggested by Chang and Pang, is not a good choice at NNLO using variable flavor number scheme (VFNS).

From Ds± production asymmetry at the LHC to prompt ν at IceCube

“…Refs. [15][16][17][18][19]) and is not excluded by the recent data and by QCD global analysis. In reality, the strange sea in the proton is only poorly known, with its behavior being determined in a great extent by the neutrino -induced DIS data on charm production obtained by the CCFR/NuTeV and NOMAD experiments [20,21].…”

Probing cold nuclear matter effects with the productions of isolated- ${\gamma} $ and ${\gamma} $+jet in p+Pb collisions at ${\sqrt{{s}_{{NN}}}}= $ 8.16 TeV

“…Note the nuclear modification factor is sensitive to the nucleon PDF(nPDF) and p+p baseline [52], we may calculate the ratio of the photon production at forward and backward rapidity, which could get rid of the large uncertainty in free nucleon PDFs, which could be used to probe the CNM effects with less arbitrariness [12][13][14]. We define the forward-backward yield asymmetry as:…”

“…In high energy nuclear physics, productions of prompt photon and photon associated jet with high transverse momentum are valuable observations of the shortdistance dynamics of quarks and gluons [1]. Since prompt photon is precisely calculable by perturbative quantum chromodynamics (pQCD) at higher order corrections and carries no color charge like other gauge bosons, it has been widely regarded as an optimal probe of the initial state of the collisions [2][3][4][5][6], as well as an excellent tag of inversive parton (jet) to quantify the mechanisms of jet quenching in ultra-relativistic heavy ion collisions [7][8][9][10][11][12][13][14]. In the past few years, ATLAS [15][16][17] and CMS [18][19][20] collaborations have made lots of measurements on isolated prompt photon and γ+jet productions in proton-proton, proton-nucleus and nucleus-nucleus collisions.…”