Nucleon strangeness form factors from<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:mo>+</mml:mo><mml:mn>1</mml:mn></mml:math>clover fermion lattice QCD

Doi, Takumi; Deka, Mridupawan; Dong, Shao-Jing; Draper, Terrence; Liu, Keh-Fei; Mankame, Devdatta; Mathur, Nilmani; Streuer, T.

doi:10.1103/physrevd.80.094503

Cited by 58 publications

(57 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, a large number of theoretical results predicted negative values, notably, meson cloud model [18,19], chiral quark model [20,21], and unquenched constituent quark model [22]. A remarkable issue is that the lattice-QCD approaches [23][24][25][26][27] have kept predicting negative strangeness magnetic moment for the proton. Note that in various works prior to the advent of the first data, the general trend was predicting negative sign for the strangeness magnetic moment of the proton µ s , as reviewed in Refs.…”

Section: Introductionmentioning

confidence: 99%

Strangeness magnetic form factor of the proton in the extended chiral quark model

Saghai

2013

Phys. Rev. C

View full text Add to dashboard Cite

Background: Unravelling the role played by nonvalence flavors in baryons is crucial in deepening our comprehension of QCD. The strange quark, a component of the higher Fock states in baryons, is an appropriate tool to study nonperturbative mechanisms due to the pure sea quark.Purpose: Study the magnitude and the sign of the strangeness magnetic moment µ s and the magnetic form factor (G s M ) of the proton. Methods:Within an extended chiral constituent quark model, we investigate contributions from all possible five-quark components to µ s and G s M (Q 2 ) in the four-vector momentum range Q 2 ≤ 1 (GeV/c) 2 . The probability of the strangeness component in the proton wave function is calculated employing the 3 P 0 model. Results:Predictions are obtained by using input parameters taken from the literature. The observables µ s and G s M (Q 2 ) are found to be small and negative, consistent with the lattice-QCD findings as well as with the latest data released by the PVA4 and HAPPEX Collaborations.Conclusions: Due to sizeable cancelations among different configurations contributing to the strangeness magnetic moment of the proton, it is indispensable to i) take into account all relevant five-quark components and include both diagonal and non-diagonal terms, ii) handle with care the oscillator harmonic parameter ω 5 and the ss component probability.

show abstract

Section: Introductionmentioning

confidence: 99%

Strangeness magnetic form factor of the proton in the extended chiral quark model

Saghai

2013

Phys. Rev. C

View full text Add to dashboard Cite

show abstract

“…(0) we present values in the second and third column employing µ s from Refs. [56] and [57], respectively. The uncertainties are combined in quadrature and symmetrized.…”

Section: Low-energy Coefficientsmentioning

confidence: 99%

“…A phenomenological analysis employing lattice data [56] and a direct lattice simulation with n f = 2 + 1 dynamical quarks [57] support a small value for the strange contribution to the proton magnetic moment [58],…”

Section: Vector Current Matrix Elementsmentioning

confidence: 99%

Standard Model anatomy of WIMP dark matter direct detection. II. QCD analysis and hadronic matrix elements

2015

View full text Add to dashboard Cite

Models of Weakly Interacting Massive Particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy SU (2) W × U (1) Y charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of n f = 3 flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order v 2 /c 2 in the nonrelativistic nucleon effective theory are derived.

show abstract

“…We correlate the nucleon propagators at different source locations with the already computed quark loops which results in significant reduction of errors [15,16].…”

Section: Lattice Calculations and Numerical Parametersmentioning

confidence: 99%

“…For DI, we sum over the current insertion time, t 1 , between the source and the sink time, i.e. from t 1 = t 0 + 1 to t 2 − 1 [13,14,15,16] in order to increase the statistics. Similarly for the glue.…”

Section: Lattice Calculations and Numerical Parametersmentioning

confidence: 99%

Quark and glue momenta and angular momentum in the nucleon

Liu

2012

Proceedings of XXIX International Symposium on Lattice Field Theory — PoS(Lattice 2011)

Self Cite

View full text Add to dashboard Cite

We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a 16 3 × 24 quenched lattice at β = 6.0 and for Wilson fermions with κ = 0.154, 0.155, and 0.1555 which correspond to pion masses at 650, 538, and 478 MeV. The quark loops are calculated with Z 4 noise and signal-to-noise is improved further with unbiased subtractions. The glue operator is comprised of gauge-field tensors constructed from the overlap operator. The u and d quark momentum/angular momentum fraction is 0.66(5)/0.72(5), the strange momentum/angular momentum fraction is 0.024(6)/0.023 (7), and that of the glue is 0.31(6)/0.25(8). The orbital angular momenta of the quarks are obtained from subtracting the quark spins from the corresponding angular momentum components. As a result, the quark orbital angular momentum constitutes 0.50(2) of the proton spin, with almost all of it coming from the disconnected insertion. The quark spin carries a fraction 0.25(12) and glue carries a fraction 0.25(8) of the total proton spin.

show abstract

Nucleon strangeness form factors fromNf=2+1clover fermion lattice QCD

Cited by 58 publications

References 33 publications

Strangeness magnetic form factor of the proton in the extended chiral quark model

Strangeness magnetic form factor of the proton in the extended chiral quark model

Standard Model anatomy of WIMP dark matter direct detection. II. QCD analysis and hadronic matrix elements

Quark and glue momenta and angular momentum in the nucleon

Contact Info

Product

Resources

About