Records |
Author |
Albandea, D.; Hernandez, P.; Ramos, A.; Romero-Lopez, F. |
Title |
Topological sampling through windings |
Type |
Journal Article |
Year |
2021 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
81 |
Issue |
10 |
Pages |
873 - 12pp |
Keywords |
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Abstract |
We propose a modification of the Hybrid Monte Carlo (HMC) algorithm that overcomes the topological freezing of a two-dimensional U(1) gauge theory with and without fermion content. This algorithm includes reversible jumps between topological sectors – winding steps – combined with standard HMC steps. The full algorithm is referred to as winding HMC (wHMC), and it shows an improved behaviour of the autocorrelation time towards the continuum limit. We find excellent agreement between the wHMC estimates of the plaquette and topological susceptibility and the analytical predictions in the U(1) pure gauge theory, which are known even at finite beta. We also study the expectation values in fixed topological sectors using both HMC and wHMC, with and without fermions. Even when topology is frozen in HMC – leading to significant deviations in topological as well as non-topological quantities – the two algorithms agree on the fixed-topology averages. Finally, we briefly compare the wHMC algorithm results to those obtained with master-field simulations of size L similar to 8 x 10(3). |
Address |
[Albandea, David; Hernandez, Pilar; Ramos, Alberto; Romero-Lopez, Fernando] UVEG, CSIC, IFIC, Edificio Inst Invest,Apt 22085, Valencia 46071, Spain, Email: David.Albandea@uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000703880600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
4979 |
Permanent link to this record |
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Author |
Albertus, C.; Aoki, Y.; Boyle, P.A.; Christ, N.H.; Dumitrescu, T.T.; Flynn, J.M.; Ishikawa, T.; Izubuchi, T.; Loktik, O.; Sachrajda, C.T.; Soni, A.; Van de Water, R.S.; Wennekers, J.; Witzel, O. |
Title |
Neutral B-meson mixing from unquenched lattice QCD with domain-wall light quarks and static b quarks |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
82 |
Issue |
1 |
Pages |
014505 - 29pp |
Keywords |
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Abstract |
We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the "2 + 1'' flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice spacing of a approximate to 0.11 fm (a(-1) = 1.729 GeV) and a lattice spatial volume of approximately (1.8 fm)(3). We simulate at three different light sea quark masses with pion masses down to approximately 430 MeV, and extrapolate to the physical quark masses using a phenomenologically-motivated fit function based on next-to-leading order heavy-light meson SU(2) chiral perturbation theory. For the b-quarks, we use an improved formulation of the Eichten-Hill action with static link-smearing to increase the signal-to-noise ratio. We also improve the heavy-light axial current used to compute the B-meson decay constant to O(alpha(s)pa) using one-loop lattice perturbation theory. We present initial results for the SU(3)-breaking ratios f(Bs)/f(Bd) and xi = f(Bs)root B-Bs/f(Bd)root B-Bd, thereby demonstrating the viability of the method. For the ratio of decay constants, we find f(Bs)/f(Bd) = 1.15(12) and for the ratio of mixing matrix elements, we find xi = 1.13(12), where in both cases the errors reflect the combined statistical and systematic uncertainties, including an estimate of the size of neglected O(1/m(b)) effects. |
Address |
[Albertus, C.; Flynn, J. M.; Sachrajda, C. T.] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000280124300003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
405 |
Permanent link to this record |
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Author |
Albertus, C.; Hernandez, E.; Hidalgo-Duque, C.; Nieves, J. |
Title |
(B)over-bar(s) -> K semileptonic decay from an Omnes improved constituent quark model |
Type |
Journal Article |
Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
738 |
Issue |
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Pages |
144-149 |
Keywords |
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Abstract |
We study the f(+) form factor for the semileptonic (B) over bar (s) -> K+ l(-) (V) over bar (l) decay in a constituent quark model. The valence quark estimate is supplemented with the contribution from the (B) over bar* pole that dominates the high q(2) region. We use a multiply-subtracted Omnes dispersion relation to extend the quark model predictions from its region of applicability near q(max)(2) = (M-Bs – M-K)(2) similar to 23.75 GeV2 to all q(2) values accessible in the physical decay. To better constrain the dependence of f(+) on q(2), we fit the subtraction constants to a combined input from previous light cone sum rule by Duplancic and Melic (2008) [11] and the present quark model results. From this analysis, we obtain Gamma ( (B) over bar (s) -> K+ l(-) (V) over bar (l)) = (5.47(-0.46)(+0.54)) vertical bar Vub vertical bar(2) x 10(-9) MeV, which is about 10% and 20% higher than the predictions based on Lattice QCD and QCD light cone sum rules respectively. The former predictions, for both the form factor f(+) (q(2)) and the differential decay width, lie within the 1 sigma band of our estimated uncertainties for all q(2) values accessible in the physical decay, except for a quite small region very close to q(max)(2). Differences with the light cone sum results for the form factor f(+) are larger than 20% in the region above q(2) = 15 GeV2. |
Address |
[Albertus, C.] Univ Granada, Dept Fis Atom Nucl & Mol, E-18071 Granada, Spain |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000344624900022 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2020 |
Permanent link to this record |
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Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
Title |
Exclusive c -> s, d Semileptonic Decays of Spin-1/2 and Spin-3/2 cb Baryons |
Type |
Journal Article |
Year |
2014 |
Publication |
Few-Body Systems |
Abbreviated Journal |
Few-Body Syst. |
Volume |
55 |
Issue |
8-10 |
Pages |
767-771 |
Keywords |
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Abstract |
We present results for exclusive semileptonic decay widths of ground state spin-1/2 and spin-3/2 cb baryons corresponding to a c -> s, d transition at the quark level. The relevance of hyperfine mixing in spin-1/2 cb baryons is shown. Our form factors are compatible with heavy quark spin symmetry constraints obtained in the infinite heavy quark mass limit. |
Address |
[Albertus, C.] Univ Granada, Fac Ciencias, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain, Email: albertus@ugr.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer Wien |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0177-7963 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000339828900036 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1865 |
Permanent link to this record |
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Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
Title |
B -> rho semileptonic decays and vertical bar V-ub vertical bar |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
90 |
Issue |
1 |
Pages |
013017 - 11pp |
Keywords |
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Abstract |
We reevaluate the B -> rho l(+) nu(l) decay width as a full B. pi pi iota(+)nu iota four-particle decay, in which the two final pions are produced via an intermediate. meson. The decay width can be written as a convolution of the B -> rho l(+) nu(l) decay width, for an off-shell., with the.. pp line shape. This allows us to fully incorporate the effects of the finite. meson width and a better comparison with actual experiments. We use an Omn s representation to provide the dependence of the B.. semileptonic form factors on q2. The Omn s subtraction constants and the overall normalization parameter jVubj are fitted to light cone sum rules and lattice QCD theoretical form-factor calculations, in the low and high q2 regions, respectively, together to the CLEO, BABAR, and Belle experimental partial branching fraction distributions. The extracted value from this global fit is jVubj d3.40 +/- 0.15_ x 10-3, in agreement with jVubj extracted using all other inputs in Cabibbo-Kobayashi-Maskawa fits and the exclusive semileptonic B. p channel, but showing a clear disagreement with jVubj extracted from inclusive semileptonic b. u decays. As estimated by [U.-G. Mei beta ner andW. Wang, J. High Energy Phys. 01 (2014) 107], taking into account the. meson width effects and the actual acceptance of the experiments is essential to render the jVubj determinations from exclusive B. p and B.. decays totally compatible. |
Address |
[Albertus, C.] Univ Granada, Dept Fis Atom Nucl & Mol, E-18071 Granada, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000339482900002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1859 |
Permanent link to this record |