Low-lying baryon masses using 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>N</mml:mi><mml:mi>f</mml:mi></mml:msub><mml:mo>=</mml:mo><mml:mn>2</mml:mn></mml:math>
 twisted mass clover-improved fermions directly at the physical pion mass

Alexandrou, C.; Kallidonis, Christos

doi:10.1103/physrevd.96.034511

Cited by 83 publications

(102 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…slightly below the actual physical value). The lattice spacing is a = 0.0938(3)(2) fm [63] and the lattice has 48 3 × 96 sites, corresponding to the spatial extent L of around 4.5 fm and m π L = 2.98. ETMC calculated bare quasi-PDF matrix elements for the unpolarized, helicity and transversity cases, but we concentrate only on the unpolarized one.…”

Section: Lattice Datamentioning

confidence: 99%

Parton distributions from lattice data: the nonsinglet case

Cichy

Debbio

Giani

2019

J. High Energ. Phys.

View full text Add to dashboard Cite

We revise the relation between Parton Distribution Functions (PDFs) and matrix elements computable from lattice QCD, focusing on the quasi-Parton Distribution Functions (qPDFs) approach. We exploit the relation between PDFs and qPDFs in the case of the unpolarized isovector parton distribution to obtain a factorization formula relating the real and imaginary part of qPDFs matrix elements to specific nonsinglet distributions, and we propose a general framework to extract PDFs from the available lattice data, treating them on the same footing as experimental data. We implement the proposed approach within the NNPDF framework, and we study the potentiality of such lattice data in constraining PDFs, assuming some plausible scenarios to assess the unknown systematic uncertainties. We finally extract the two nonsinglet distributions involved in our analysis from a selection of the available lattice data.

show abstract

Section: Lattice Datamentioning

confidence: 99%

Parton distributions from lattice data: the nonsinglet case

Cichy

Debbio

Giani

2019

J. High Energ. Phys.

View full text Add to dashboard Cite

show abstract

“…Given that an extrapolation to the continuum, where the different definitions are expected to be consistent, is not carried out and the errors quoted are only statistical, this level of agreement is very satisfactory. For the renormalized strange and charm quark masses, we find m R s ¼ μ s =Z P ¼ 108.6ð2.2Þð5.7Þð2.6Þ MeV and m R c ¼ μ c =Z P ¼ 1.39ð2Þð7Þð3Þ GeV, where Z P is the pseudoscalar renormalization function determined nonperturbatively in the modified minimal subtraction scheme (MS) at 2 GeV [17].…”

mentioning

confidence: 99%

“…Computational approach.-We use one gauge ensemble employing two degenerate (N f ¼ 2) twisted mass cloverimproved fermions [14,15] with masses that approximately reproduce the physical pion mass [16] on a lattice of 48 3 × 96 and lattice spacing a ¼ 0.0938ð3Þ fm, determined from the nucleon mass [17]. The strange and charm valence quarks are taken as Osterwalder-Seiler fermions [18,19].…”

mentioning

confidence: 99%

“…The mass of the strange quark is tuned to reproduce the Ω − mass and the mass of the charm quark is tuned independently to reproduce the mass of Λ þ c , as described in detail in Ref. [17]. The strange and charm quark masses in lattice units determined through this matching are aμ s ¼ 0.0259ð3Þ and aμ c ¼ 0.3319ð15Þ, respectively, yielding μ c =μ s ¼ 12.8ð2Þ.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Nucleon Spin and Momentum Decomposition Using Lattice QCD Simulations

et al. 2017

Self Cite

View full text Add to dashboard Cite

We determine within lattice QCD the nucleon spin carried by valence and sea quarks and gluons. The calculation is performed using an ensemble of gauge configurations with two degenerate light quarks with mass fixed to approximately reproduce the physical pion mass. We find that the total angular momentum carried by the quarks in the nucleon is J uþdþs ¼ 0.408ð61Þ stat ð48Þ syst and the gluon contribution is J g ¼ 0.133ð11Þ stat ð14Þ syst , giving a total of J N ¼ 0.54ð6Þ stat ð5Þ syst that is consistent with the spin sum. For the quark intrinsic spin contribution, we obtain 1 2 ΔΣ uþdþs ¼ 0.201ð17Þ stat ð5Þ syst . All quantities are given in the modified minimal subtraction scheme at 2 GeV. The quark and gluon momentum fractions are also computed and add up to hxi uþdþs þ hxi g ¼ 0.804ð121Þ stat ð95Þ syst þ 0.267ð12Þ stat ð10Þ syst ¼ 1.07ð12Þ stat ð10Þ syst , thus satisfying the momentum sum. DOI: 10.1103/PhysRevLett.119.142002 Introduction.-The distribution of the proton spin among its constituent quarks and gluons has been a long-standing puzzle ever since the European Muon Collaboration showed in 1987 that only a fraction of the proton spin is carried by the quarks [1,2]. This was in sharp contrast to what one expected based on the quark model. This socalled proton spin crisis triggered rich experimental and theoretical activity. Recent experiments show that only 30% of the proton spin is carried by the quarks [3], while experiments at RHIC [4,5] on the determination of the gluon polarization in the proton point to a nonzero contribution [6]. A global fit to the most recent experimental data that includes the combined set of inclusive deep-inelastic scattering data from HERA and Drell-Yan data from Tevatron and LHC led to an improved determination of the valence quark distributions and the flavor separation of the up and down quarks [7]. The combined HERA data also provide improved constraints on the gluon distributions, but large uncertainties remain [7]. Obtaining the quark and gluon contributions to the nucleon spin and momentum fraction within lattice quantum chromodynamics (QCD) provides an independent input that is extremely crucial, but the computation is very challenging. This is because a complete determination must include, besides the valence, sea quark and gluon contributions that exhibit a large noise-to-signal ratio and are computationally very demanding. A first computation of the gluon spin was performed recently via the evaluation of the gluon helicity in a mixed action approach of overlap valence quarks on N f ¼ 2 þ 1 domain wall fermions that included an ensemble with pion mass 139 MeV [8]. In this Letter, we evaluate

show abstract

“…c (cud, 1/2 ± ) and Ξ +,0 c (csu or csd, 1/2 ± ) [38][39][40][41][42][43][44]. Assuming that the charm quark is a spectator, we can estimate the mass differences among the diquarks from those of the baryons.…”

mentioning

confidence: 99%

Chiral effective theory of diquarks and the UA(1) anomaly

et al. 2020

View full text Add to dashboard Cite

The diquark is a strongly-correlated quark pair that plays an important role in hadrons and hadronic matter. In order to treat the diquak as a building block of hadrons, we formulate an effective theory of diquark fields with SU (3)R × SU (3)L chiral symmetry. We concentrate on the scalar (0 + ) and pseudoscalar (0 − ) diquarks and construct a linear-sigma-model Lagrangian. It is found that the effective Lagrangian contains a new type of chirally symmetric meson-diquark-diquark coupling that breaks axial UA(1) symmetry. We discuss consequences of the UA(1) anomaly term to the diquark masses as well as to the singly heavy baryon spectrum, which is directly related to the diquark spectrum. We find an inverse mass ordering between strange and nonstrange diquarks. The parameters of the effective theory can be determined by the help of lattice QCD calculations of diquarks and also from the mass spectrum of the singly heavy baryons. We determine the strength of the UA(1) anomaly term, which is found to give a significant portion of the diquark masses.

show abstract

Low-lying baryon masses using Nf=2 twisted mass clover-improved fermions directly at the physical pion mass

Cited by 83 publications

References 69 publications

Parton distributions from lattice data: the nonsinglet case

Parton distributions from lattice data: the nonsinglet case

Nucleon Spin and Momentum Decomposition Using Lattice QCD Simulations

Chiral effective theory of diquarks and the UA(1) anomaly

Contact Info

Product

Resources

About