scholarly journals Strange and light quark contributions to the nucleon mass from lattice QCD

2012 ◽  
Vol 85 (5) ◽  
Author(s):  
Gunnar S. Bali ◽  
Sara Collins ◽  
Meinulf Göckeler ◽  
Roger Horsley ◽  
Yoshifumi Nakamura ◽  
...  
Keyword(s):  
2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Luke Gayer ◽  
Nicolas Lang ◽  
Sinéad M. Ryan ◽  
David Tims ◽  
Christopher E. Thomas ◽  
...  

Abstract Isospin-1/2 Dπ scattering amplitudes are computed using lattice QCD, working in a single volume of approximately (3.6 fm)3 and with a light quark mass corresponding to mπ ≈ 239 MeV. The spectrum of the elastic Dπ energy region is computed yielding 20 energy levels. Using the Lüscher finite-volume quantisation condition, these energies are translated into constraints on the infinite-volume scattering amplitudes and hence enable us to map out the energy dependence of elastic Dπ scattering. By analytically continuing a range of scattering amplitudes, a $$ {D}_0^{\ast } $$ D 0 ∗ resonance pole is consistently found strongly coupled to the S-wave Dπ channel, with a mass m ≈ 2200 MeV and a width Γ ≈ 400 MeV. Combined with earlier work investigating the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , and $$ {D}_0^{\ast } $$ D 0 ∗ with heavier light quarks, similar couplings between each of these scalar states and their relevant meson-meson scattering channels are determined. The mass of the $$ {D}_0^{\ast } $$ D 0 ∗ is consistently found well below that of the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , in contrast to the currently reported experimental result.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Gavin K. C. Cheung ◽  
◽  
Christopher E. Thomas ◽  
David J. Wilson ◽  
Graham Moir ◽  
...  

Abstract Elastic scattering amplitudes for I = 0 DK and I = 0, 1 $$ D\overline{K} $$ D K ¯ are computed in S, P and D partial waves using lattice QCD with light-quark masses corresponding to mπ = 239 MeV and mπ = 391 MeV. The S-waves contain interesting features including a near-threshold JP = 0+ bound state in I = 0 DK, corresponding to the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ (2317), with an effect that is clearly visible above threshold, and suggestions of a 0+ virtual bound state in I = 0 $$ D\overline{K} $$ D K ¯ . The S-wave I = 1 $$ D\overline{K} $$ D K ¯ amplitude is found to be weakly repulsive. The computed finite-volume spectra also contain a deeply-bound D* vector resonance, but negligibly small P -wave DK interactions are observed in the energy region considered; the P and D-wave $$ D\overline{K} $$ D K ¯ amplitudes are also small. There is some evidence of 1+ and 2+ resonances in I = 0 DK at higher energies.


2001 ◽  
Vol 16 (supp01b) ◽  
pp. 591-599 ◽  
Author(s):  
Rajan Gupta ◽  
Kim Maltman

A summary of the extraction of light quark masses from both QCD sumrules and lattice QCD simulations is presented. The focus is on providing a careful statement of the potential weaknesses in each calculation, and on integrating the work of different collaborations to provide a coherent picture.


2004 ◽  
Vol 689 (3) ◽  
pp. 175-194 ◽  
Author(s):  
A. Ali Khan ◽  
T. Bakeyev ◽  
M. Göckeler ◽  
T.R. Hemmert ◽  
R. Horsley ◽  
...  

2018 ◽  
Vol 175 ◽  
pp. 13027 ◽  
Author(s):  
Bipasha Chakraborty ◽  
Christine Davies ◽  
Jonna Koponen ◽  
G Peter Lepage

he quark flavor sector of the Standard Model is a fertile ground to look for new physics effects through a unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. We present a lattice QCD calculation of the scalar and the vector form factors (over a large q2 region including q2 = 0) associated with the D→ Klv semi-leptonic decay. This calculation will then allow us to determine the central CKM matrix element, Vcs in the Standard Model, by comparing the lattice QCD results for the form factors and the experimental decay rate. This form factor calculation has been performed on the Nf = 2 + 1 + 1 MILC HISQ ensembles with the physical light quark masses.


2019 ◽  
Vol 34 (27) ◽  
pp. 1950220
Author(s):  
F. Chezani Sharahi ◽  
M. Monemzadeh ◽  
A. Abdoli Arani

In this study, the bound state energy of a four-quark system was analytically calculated as a two heavy–heavy anti-quarks [Formula: see text] and two light–light quarks [Formula: see text]. Tetraquark was assumed to be a bound state of two-body system consisting of two mesons, each containing a light quark and a heavy antiquark. Due to the presence of heavy mesons in the tetraquark, Born–Oppenheimer approximation was used to study its bound states. To assess the bounding energy, Schrödinger equation was solved using lattice QCD [Formula: see text] potential, having expanded the tetraquark potential [Formula: see text] up to 11th term. Binding energy state and wave function, however, were obtained in the scalar [Formula: see text] channel. Graphical results for wave functions obtained versus antiquark–antiquark distance [Formula: see text] confirmed the existence of the tetraquark [Formula: see text]. Analytical bound state energy obtained here was in good agreement with several numerical ones published in the literature, confirming the accuracy of the approach taken here.


2014 ◽  
Vol 731 ◽  
pp. 13-18 ◽  
Author(s):  
Jorge Segovia ◽  
Lei Chang ◽  
Ian C. Cloët ◽  
Craig D. Roberts ◽  
Sebastian M. Schmidt ◽  
...  
Keyword(s):  

2014 ◽  
Vol 26 ◽  
pp. 1460089 ◽  
Author(s):  
L. ALVAREZ-RUSO ◽  
T. LEDWIG ◽  
M. J. VICENTE VACAS ◽  
J. MARTIN-CAMALICH

Fits of the p4 covariant SU(2) baryon chiral perturbation theory to lattice QCD nucleon mass data from several collaborations for 2 and 2+1 flavors are presented. We consider contributions from explicit Δ(1232) degrees of freedom, finite volume and finite spacing corrections. We emphasize here on our Nf = 2 + 1 study. We obtain low-energy constants of natural size that are compatible with the rather linear pion-mass dependence of the nucleon mass observed in lattice QCD. We report a value of σπN = 41(5)(4) MeV in the 2 flavor case and σπN = 52(3)(8) MeV for 2+1 flavors.


2016 ◽  
Vol 2016 (12) ◽  
Author(s):  
Gavin K.C. Cheung ◽  
◽  
Cian O’Hara ◽  
Graham Moir ◽  
Michael Peardon ◽  
...  
Keyword(s):  
D Meson ◽  

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