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The effective interaction between a quark and an anti-quark as obtained previously with by the method of iterated resolvents is replaced by the so called up-down-model and applied to flavor off-diagonal mesons including the pion. The only…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hans-Christian Pauli

We discuss the flavor of leading jet partons as a valuable probe of nuclear matter. We point out that the coupling of jets to nuclear matter naturally leads to an alteration of jet chemistry even at high transverse momentum $p_T$. In…

Nuclear Theory · Physics 2008-11-26 W. Liu , R. J. Fries

The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-inelastic scattering. The quantity…

High Energy Physics - Experiment · Physics 2009-04-15 K. Ackerstaff

We investigate the impact of parton distribution functions (PDFs) uncertainties on W/Z production at the LHC, concentrating on the strange quark PDF. Additionally we examine the extent to which precise measurements at the LHC can provide…

High Energy Physics - Phenomenology · Physics 2013-03-04 A. Kusina , T. Stavreva , S. Berge , F. I. Olness , I. Schienbein , K. Kovarik , T. Jezo , J. Y. Yu , K. Park

We present, for the first time, an \textit{ab initio} calculation of the individual up, down and strange quark helicity parton distribution functions for the proton. The calculation is performed within the twisted mass clover-improved…

High Energy Physics - Lattice · Physics 2021-03-17 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , K. Jansen , F. Manigrasso

A measurement of the mass difference between top and anti-top quarks is presented. In a 4.7 fb-1 data sample of proton--proton collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC, events consistent with ttbar…

High Energy Physics - Experiment · Physics 2013-12-10 ATLAS Collaboration

The forward-backward asymmetry A_{FB}^t in top quark production at the Tevatron has been seen to be anomalously large both by CDF and D0. Parton-level asymmetries as large as 50%, with a large error bar, have been extracted from the data.…

High Energy Physics - Phenomenology · Physics 2011-02-04 Matthew J. Strassler

Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. In this article, we review the status of the flavor asymmetry of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jen-Chieh Peng , Gerald T. Garvey

We present a new set of parton distributions, NNPDF3.1, which updates NNPDF3.0, the first global set of PDFs determined using a methodology validated by a closure test. The update is motivated by recent progress in methodology and available…

An interesting mass relation between down type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)_c \times SU(2)_L \times U(1)_Y model based on the A4 flavor symmetry. Here we propose a simple extension…

High Energy Physics - Phenomenology · Physics 2013-08-02 S. Morisi , M. Nebot , Ketan M. Patel , E. Peinado , J. W. F. Valle

It has been more than 15 years since the discovery of the top quark. Great strides have been made in the measurement of the top quark mass and the properties of it. Most results show consistency with the standard model. However, using 5…

High Energy Physics - Experiment · Physics 2019-08-14 Yen-Chu Chen

The quark and charged lepton masses and the angles and phase of the CKM mixing matrix are nicely reproduced in a model which assumes SU(3)xSU(3) flavour symmetry broken by the v.e.v.'s of fields in its bi-fundamental representation. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 I. Masina , C. A. Savoy

We review recent progress in the determination of the parton distribution functions (PDFs) of the proton, with emphasis on the applications for precision phenomenology at the Large Hadron Collider (LHC). First of all, we introduce the…

High Energy Physics - Phenomenology · Physics 2018-05-23 Jun Gao , Lucian Harland-Lang , Juan Rojo

I review recent developments in the study of the low-x partonic content of protons and nuclei, with a focus on the latter, as one expects possible deviations from linear QCD evolution to be most pronounced in that case. I give examples of…

High Energy Physics - Phenomenology · Physics 2020-07-15 Thomas Peitzmann

Recent measurements of the neutron's electric to magnetic form factors ratio, R_n= \mu_n G_E^n/G_M^n, up to 3.4 (GeV/c)^2 combined with existing R_p= \mu_p G_E^p/G_M^p measurements in the same Q^2 range allowed, for the first time, a…

Nuclear Experiment · Physics 2015-06-16 I. A. Qattan , J. Arrington

We consider, at order $\alpha_s^2$ in the QCD coupling, top-quark pair production in the continuum at various center-of-mass energies and $b$-quark pair production at the $Z$ resonance by (un)polarized electron and positron beams. For top…

High Energy Physics - Phenomenology · Physics 2023-05-22 Werner Bernreuther , Long Chen , Peng-Cheng Lu , Zong-Guo Si

We present an unbiased determination of the charm content of the proton, in which the charm parton distribution function (PDF) is parametrized on the same footing as the light quarks and the gluon in a global PDF analysis. This…

The D0 collaboration at FermiLab has recently measured the top-quark pair forward-backward asymmetry in $\bar p p \to t \bar{t} X$ reactions as a function of the $t\bar{t} $ invariant mass $M_{t\bar{t}}$. The D0 result for $A_{\rm…

High Energy Physics - Phenomenology · Physics 2016-01-08 Sheng-Quan Wang , Xing-Gang Wu , Zong-Guo Si , Stanley J. Brodsky

Heavy flavor productions are important tests of QCD. In proton-proton collisions collected at LHCb, a long list of measurements for charm and bottom productions have been made. This talk focuses on the studies of fragmentation functions and…

High Energy Physics - Experiment · Physics 2018-04-16 Yanxi Zhang