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Sep 18, 2013
09/13
by
Tom Blum; Amarjit Soni; Matthew Wingate
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We compute the one-loop self-energy correction to the massive domain wall quark propagator. Combining this calculation with simulations at several gauge couplings, we estimate the strange quark mass in the continuum limit. The perturbative one-loop mass renormalization is comparable to that for Wilson quarks and considerably smaller than that for Kogut-Susskind quarks. Also, scaling violations appear mild in comparison to other errors at present. Given their good chiral behavior and these...
Source: http://arxiv.org/abs/hep-lat/9809065v1
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Jun 30, 2018
06/18
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Maurice Benayoun; Johan Bijnens; Tom Blum; Irinel Caprini; Gilberto Colangelo; Henryk Czyż; Achim Denig; Cesareo A. Dominguez; Simon Eidelman; Christian S. Fischer; Paolo Gauzzi; Yuping Guo; Andreas Hafner; Masashi Hayakawa; Gregorio Herdoiza; Martin Hoferichter; Guangshun Huang; Karl Jansen; Fred Jegerlehner; Benedikt Kloss; Bastian Kubis; Zhiqing Liu; William Marciano; Pere Masjuan; Harvey B. Meyer; Tsutomu Mibe; Andreas Nyffeler; Vladimir Pascalutsa; Vladyslav Pauk; Michael R. Pennington; Santiago Peris; Christoph F. Redmer; Pablo Sanchez-Puertas; Boris Shwartz; Evgeny Solodov; Dominik Stoeckinger; Thomas Teubner; Marc Unverzagt; Marc Vanderhaeghen; Magnus Wolke
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We present the mini-proceedings of the workshops Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of the accuracy of the theoretical prediction and $(g-2)_{\mu}$: Quo vadis?, both held in Mainz from April 1$^{\rm rst}$ to 5$^{\rm th}$ and from April 7$^{\rm th}$ to 10$^{\rm th}$, 2014, respectively.
Topics: High Energy Physics - Phenomenology, High Energy Physics - Lattice, Nuclear Experiment, Nuclear...
Source: http://arxiv.org/abs/1407.4021
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34
Sep 23, 2013
09/13
by
Takeshi Yamazaki; Yasumichi Aoki; Tom Blum; Huey-Wen Lin; Shigemi Ohta; Shoichi Sasaki; Robert Tweedie; James Zanotti
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We report our numerical lattice QCD calculations of the isovector nucleon form factors for the vector and axialvector currents: the vector, induced tensor, axialvector, and induced pseudoscalar form factors. The calculation is carried out with the gauge configurations generated with N_f=2+1 dynamical domain wall fermions and Iwasaki gauge actions at beta = 2.13, corresponding to a cutoff 1/a = 1.73 GeV, and a spatial volume of (2.7 fm)^3. The up and down quark masses are varied so the pion mass...
Source: http://arxiv.org/abs/0904.2039v1
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50
Sep 18, 2013
09/13
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Claude Bernard; Tom Blum; Carleton DeTar; Steven Gottlieb; Kari Rummukainen; Urs M. Heller; James Hetrick; Douglas Toussaint; Robert L. Sugar
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We present results of an ongoing study of the nature of the high temperature crossover in QCD with two light fermion flavors. These results are obtained with the conventional staggered fermion action at the smallest lattice spacing to date---approximately 0.1 fm. Of particular interest are a study of the temperature of the crossover a determination of the induced baryon charge and baryon susceptibility, the scalar susceptibility, and the chiral order parameter, used to test models of critical...
Source: http://arxiv.org/abs/hep-lat/9605028v1
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36
Sep 21, 2013
09/13
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Tom Blum; Carleton DeTar; Steven Gottlieb; Urs M. Heller; James E. Hetrick; Kari Rummukainen; R. L. Sugar; Doug Toussaint; Matthew Wingate
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We study the effect of modifying the coupling of Kogut-Susskind quarks to the gauge field by replacing the link matrix in the quark action by a "fat link", or sum of link plus three-link paths. Flavor symmetry breaking, determined by the mass difference between the Goldstone and non-Goldstone local pions, is reduced by approximately a factor of two by this modification.
Source: http://arxiv.org/abs/hep-lat/9609036v1
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Sep 18, 2013
09/13
by
Shoichi Sasaki; Tom Blum; Shigemi Ohta; Kostas Orginos
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In our previous DWF calculation with the Wilson gauge action at $\beta=6.0$ ($a^{-1}\simeq$ 1.9 GeV) on a $16^3 \times 32 \times 16$ lattice, we found that $\Ga$ had a fairly strong dependence on the quark mass. A simple linear extrapolation of $\Ga$ to the chiral limit yielded a value that was almost a factor of two smaller than the experimental one. Here we report our recent study of this issue. In particular, we investigate possible errors arising from finite lattice volume, especially in...
Source: http://arxiv.org/abs/hep-lat/0110053v1
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Sep 21, 2013
09/13
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Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; A. Hasenfratz; Leo Karkkainen; D. Toussaint; R. L. Sugar
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We have extended our study of the high temperature transition with two flavors of Wilson quarks on 12^3 x 6 lattices to kappa=0.19. We have also performed spectrum calculations on 12^3 x 24 lattices at kappa=0.19 to find the physical lattice spacing and quark mass. At this value of kappa the transition is remarkable in that the plaquette and psi-bar-psi show a large discontinuity while the Polyakov loop changes very little. This and several other features of the transition are more suggestive...
Source: http://arxiv.org/abs/hep-lat/9404006v1
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Sep 22, 2013
09/13
by
Tom Blum; Shigemi Ohta; Shoichi Sasaki
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We present a preliminary domain-wall fermion lattice-QCD calculation of isovector vector and axial charges, g_V and g_A, of the nucleon. Since the lattice renormalizations, Z_V and Z_A, of the currents are identical with DWF, the lattice ratio (g_A/g_V)^{lattice} directly yields the continuum value. Indeed Z_V determined from the matrix element of the vector current agrees closely with Z_A from a non-perturbative renormalization study of quark bilinears. We also obtain spin related quantities...
Source: http://arxiv.org/abs/hep-lat/0011011v1
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Jun 30, 2018
06/18
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Taku Izubuchi; Michael Abramczyk; Tom Blum; Hiroshi Ohki; Sergey Syritsyn
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We present initial results of computing nucleon electric dipole moment induced by quark chromo-EDM, CP-violating quark-gluon coupling. Using chirally-symmetric domain wall and M\"obius fermions with pion mass $m_\pi=172\text{ MeV}$, we calculate the connected part of the electric dipole form factor $F_3(Q^2)$. In addition, we perform an exploratory study of the method to calculate EDM using uniform background electric field on a lattice introduced without breaking the periodicity in the...
Topic: High Energy Physics - Lattice
Source: http://arxiv.org/abs/1702.00052
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Sep 18, 2013
09/13
by
Shoichi Sasaki; Kostas Orginos; Shigemi Ohta; Tom Blum; for the RBCK Collaboration
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We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the Ward-Takahashi identity requires the vector and axial-vector currents to have the same renormalization, up to lattice spacing errors of order O(a^2). The DBW2 gauge action provides enhancement of the good chiral symmetry properties of domain wall fermions at larger...
Source: http://arxiv.org/abs/hep-lat/0306007v3
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Jul 20, 2013
07/13
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Tom Blum; Amarjit Soni; Matthew Wingate
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We present a first calculation of the strange quark mass using domain wall fermions. This paper contains an overview of the domain wall discretization and a pedagogical presentation of the perturbative calculation necessary for computing the mass renormalization. We combine the latter with numerical simulations to estimate the strange quark mass. Our final result in the quenched approximation is 95(26) MeV in the ${\bar{MS}}$ scheme at a scale of 2 GeV. We find that domain wall fermions have a...
Source: http://arxiv.org/abs/hep-lat/9902016v2
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65
Sep 22, 2013
09/13
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MILC Collaboration; Claude Bernard; Tom Blum; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matthew Wingate
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We present the current status of our ongoing calculations of the light hadron spectrum with both Kogut-Susskind (KS) and Wilson quarks in the valence or quenched approximation. We discuss KS quarks first and find that the chiral extrapolation is potentially the biggest source of systematic error. For the Wilson case, we focus on finite volume and source size effects at 6/g^2=5.7. We find no evidence to support the claim that there is a finite volume effect between N_s=16 and 24 of approximately...
Source: http://arxiv.org/abs/hep-lat/9707014v1
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61
Jul 20, 2013
07/13
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MILC Collaboration; Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs M. Heller; James Hetrick; Craig McNeile; K. Rummukainen; Bob Sugar; Doug Toussaint
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We investigate light hadron spectroscopy with an improved quenched staggered quark action. We compare the results obtained with an improved gauge plus an improved quark action, an improved gauge plus standard quark action, and the standard gauge plus standard quark action. Most of the improvement in the spectroscopy results is due to the improved gauge sector. However, the improved quark action substantially reduces violations of Lorentz invariance, as evidenced by the meson dispersion...
Source: http://arxiv.org/abs/hep-lat/9712010v2
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36
Sep 20, 2013
09/13
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Claude Bernard; Tom Blum; Carleton DeTar; Steven Gottlieb; Urs M. Heller; James E. Hetrick; K. Rummukainen; R. Sugar; D. Toussaint; Matthew Wingate
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Sigma models for the high temperature phase transition in quantum chromodynamics (QCD) suggest that at high temperature the SU(N_f) x SU(N_f) chiral symmetry becomes exact, but the anomalous axial U(1) symmetry need not be restored. In numerical lattice simulations, traditional methods for detecting symmetry restoration have sought multiplets in the screening mass spectrum. However, these methods were imprecise and the results, so far, incomplete. With improved statistics and methodology, we...
Source: http://arxiv.org/abs/hep-lat/9611031v1
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33
Sep 22, 2013
09/13
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MILC Collaboration; Claude Bernard; Tom Blum; Carleton DeTar; Steven Gottlieb; Urs M. Heller; James E. Hetrick; Craig McNeile; K. Rummukainen; R. Sugar; D. Toussaint
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We calculate the light quark spectrum of lattice QCD in the quenched approximation using Kogut-Susskind quarks. By combining results for different lattice spacings, several volumes and five quark masses, we are able to take the light quark mass, infinite volume, continuum limit. When we use non-linear chiral extrapolations, we find that the nucleon to rho mass ratio is 1.254 +- 0.018 +- 0.027, where the errors are statistical and systematic (within the quenched approximation), respectively....
Source: http://arxiv.org/abs/hep-lat/9805004v2
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37
Sep 18, 2013
09/13
by
Christopher Aubin; Tom Blum
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We present the most recent lattice results for the lowest-order hadronic contribution to the muon anomalous magnetic moment using 2+1 flavor improved staggered fermions. A precise fit to the low-q^2 region of the vacuum polarization is necessary to accurately extract the muon g-2. To obtain this fit, we use staggered chiral perturbation theory with the inclusion of the vector particles as resonances, to evaluate the vacuum polarization. We discuss the preliminary fit results and attendant...
Source: http://arxiv.org/abs/hep-lat/0509064v1
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Sep 22, 2013
09/13
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MILC Collaboration; Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; A. Soni; Bob Sugar; Doug Toussaint; Matthew Wingate
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We present the current status of our ongoing calculations of pseudoscalar meson decay constants for mesons that contain one light and one heavy quark (f_B, f_{B_s}, f_D, f_{D_s}). We are currently generating new gauge configurations that include dynamical quarks and calculating the decay constants. In addition, we have several new results for the static approximation. Those results, as well as several refinements to the analysis, are new since Lattice '96. Our current (still preliminary) value...
Source: http://arxiv.org/abs/hep-lat/9707013v1
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34
Sep 20, 2013
09/13
by
Huey-Wen Lin; Tom Blum; Shigemi Ohta; Shoichi Sasaki; Takeshi Yamazaki
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We present a numerical lattice quantum chromodynamics calculation of isovector form factors and the first few moments of the isovector structure functions of the nucleon. The calculation employs two degenerate dynamical flavors of domain-wall fermions, resulting in good control of chiral symmetry breaking. Non-perturbative renormalization of the relevant quark currents is performed where necessary. The inverse lattice spacing, $a^{-1}$, is about 1.7 GeV. We use degenerate up and down dynamical...
Source: http://arxiv.org/abs/0802.0863v1
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32
Sep 17, 2013
09/13
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Yasumichi Aoki; Tom Blum; Huey-Wen Lin; Shigemi Ohta; Shoichi Sasaki; Robert Tweedie; Takeshi Yamazaki; James Zanotti
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We report on numerical lattice QCD calculations of some of the low moments of the nucleon structure functions. The calculations are carried out with gauge configurations generated by the RBC and UKQCD collaborations with (2+1)-flavors of dynamical domain wall fermions and the Iwasaki gauge action ($\beta = 2.13$). The inverse lattice spacing is $a^{-1} = 1.73$ GeV, and two spatial volumes of ((2.7{\rm fm})^3) and ((1.8 {\rm fm})^3) are used. The up and down quark masses are varied so the pion...
Source: http://arxiv.org/abs/1003.3387v1
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29
Sep 23, 2013
09/13
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Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs. M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matt Wingate
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Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum numbers inaccessible to conventional quark-antiquark states. Confirmation of such states would give information on the role of "dynamical" color in low energy QCD. We present preliminary results for hybrid meson masses using light Wilson valence quarks.
Source: http://arxiv.org/abs/hep-lat/9607031v1
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Sep 23, 2013
09/13
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Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matt Wingate
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We report on our simulation of finite temperature lattice QCD with two flavors of ${\cal O}(a)$ Symanzik-improved fermions and ${\cal O}(a^2)$ Symanzik-improved glue. Our thermodynamic simulations were performed on an $8^3 \times 4$ lattice, and we have performed complementary zero temperature simulations on an $8^3 \times 16$ lattice. We compare our results to those from simulations with two flavors of Wilson fermions and discuss the improvement resulting from use of the improved action.
Source: http://arxiv.org/abs/hep-lat/9607085v1
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36
Sep 19, 2013
09/13
by
Shoichi Sasaki; Tom Blum; Shigemi Ohta
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We present results of our numerical calculation of the mass spectrum for isospin one-half and spin one-half non-strange baryons, i.e. the ground and excited states of the nucleon, in quenched lattice QCD. We use a new lattice discretization scheme for fermions, domain wall fermions, which possess almost exact chiral symmetry at non-zero lattice spacing. We make a systematic investigation of the negative-parity $N^*$ spectrum by using two distinct interpolating operators at $\beta=6/g^2=6.0$ on...
Source: http://arxiv.org/abs/hep-lat/0102010v2
