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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 (down) 81 Issue 10 Pages 873 - 12pp
Keywords
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 Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000703880600001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4979
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Author Bribian, E.I.; Dasilva Golan, J.; Garcia Perez, M.; Ramos, A.
Title Memory efficient finite volume schemes with twisted boundary conditions Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume (down) 81 Issue 10 Pages 951 - 25pp
Keywords
Abstract In this paper we explore a finite volume renormalization scheme that combines three main ingredients: a coupling based on the gradient flow, the use of twisted boundary conditions and a particular asymmetric geometry, that for SU (N) gauge theories consists on a hypercubic box of size l(2) x (Nl)(2), a choice motivated by the study of volume independence in large N gauge theories. We argue that this scheme has several advantages that make it particularly suited for precision determinations of the strong coupling, among them translational invariance, an analytic expansion in the coupling and a reduced memory footprint with respect to standard simulations on symmetric lattices, allowing for a more efficient use of current GPU clusters. We test this scheme numerically with a determination of the A parameter in the SU (3) pure gauge theory. We show that the use of an asymmetric geometry has no significant impact in the size of scaling violations, obtaining a value Lambda((MS) over bar)root 8t(0) = 0.603(17) in good agreement with the existing literature. The role of topology freezing, that is relevant for the determination of the coupling in this particular scheme and for large N applications, is discussed in detail.
Address [Bribian, Eduardo, I; Dasilva Golan, Jorge; Garcia Perez, Margarita] UAM CSIC, Inst Fis Teor, Nicolas Cabrera 13-15,Campus Cantoblanco, Madrid 28049, Spain, Email: jorge.dasilva@uam.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000712577800001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5011
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Author Feijoo, A.; Magas, V.K.; Ramos, A.; Oset, E.
Title A hidden-charm S =-1 pentaquark from the decay Lambda(b) into J/psi eta Lambda states Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume (down) 76 Issue 8 Pages 446 - 12pp
Keywords
Abstract The hidden-charm pentaquark P-c(4450) observed recently by the LHCb collaboration may be of molecular nature, as advocated by some unitary approaches that also predict pentaquark partners in the strangeness S = -1 sector. In this work we argue that a hidden-charm strange pentaquark could be seen from the decay of the Lambda b, just as in the case of the non-strange P-c(4450), but looking into the J/psi eta Lambda decay mode and forming the invariant mass spectrum of J/psi Lambda pairs. In the model presented here, which assumes a standard weak decay topology and incorporates the hadronization process and final-state interaction effects, we find the J/psi eta Lambda final states to be populated with similar strength as the J/psi K- p states employed for the observation of the non-strange pentaquark. This makes the Lambda b -> J/psi eta Lambda decay to be an interesting process to observe a possible strange partner of the P-c(4450). We study the dependence of the J/psi Lambda mass spectra on various model ingredients and on the unknown properties of the strange pentaquark.
Address [Feijoo, A.; Magas, V. K.; Ramos, A.] Univ Barcelona, Dept Fis Quant & Astrofis, Inst Ciencies Cosmos ICCUB, Marti & Franques 1, E-08028 Barcelona, Spain, Email: feijoo@icc.ub.edu;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000399606600001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3058
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Author Martinez Torres, A.; Prelovsek, S.; Oset, E.; Ramos, A.
Title Effective Field Theories in a Finite Volume Type Journal Article
Year 2018 Publication Few-Body Systems Abbreviated Journal Few-Body Syst.
Volume (down) 59 Issue 6 Pages 139 - 5pp
Keywords
Abstract In this talk I present the formalism we have used to analyze Lattice data on two meson systems by means of effective field theories. In particular I present the results obtained from a reanalysis of the lattice data on the KD(*()) systems, where the states D-s0*(2317) and D-s1*(2460) are found as bound states of KD and KD *, respectively. We confirm the presence of such states in the lattice data and determine the contribution of the KD channel in the wave function of D-s0*(2317) and that of KD* in the wave function of D-s1*(2460). Our findings indicate a large meson-meson component in the two cases.
Address [Martinez Torres, A.] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP, Brazil, Email: amartine@if.usp.br
Corporate Author Thesis
Publisher Springer Wien Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0177-7963 ISBN Medium
Area Expedition Conference
Notes WOS:000448041400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3772
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Author Sakai, S.; Oset, E.; Ramos, A.
Title Triangle singularities in B- -> K- pi- D(s0)+ and B- -> K- pi- D(s1)+ Type Journal Article
Year 2018 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume (down) 54 Issue 1 Pages 10 - 14pp
Keywords
Abstract We study the appearance of structures in the decay of the B- into K-pi D--(s0)+ (2317) and K-pi D--(s1)+ (2460) final states by forming invariant mass distributions of pi D--(s0)+ and pi D--(s1)+ pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the B- -> K- K*(0) D-0 (B- -> K- K*(0) D*(0)) decay process is followed by the decay of the K*(0) into pi(-) K+ and the subsequent rescattering of the K+ D-0 (K+ D*(0)) pair forming the D-s0(+) (2317) (D-s1(+) (2460)) resonance. We find this type of non-resonant peaks at 2850MeV in the invariant mass of pi D--(s0) pairs from B- -> K- pi(-) D-s0(+) (2317) decays and around 3000MeV in the invariant mass of pi D--(s1)+ pairs from B- -> K- pi(-) D-s1(+)(2460) decays. By employing the measured branching ratios of the B- -> K- K*(0) D-0 and B- -> K- K*(0) D*(0) decays, we predict the branching ratios for the processes B- into K-pi D--(s0)+ (2317) K-pi D--(s1)+ (2460), in the vicinity of the triangle singularity peak, to be about 8 x 10(-6) and 1 x 10(-6), respectively. The observation of this reaction would also give extra support to the molecular picture of the D-s0(+)(2317) and D-s1(+)(2460).
Address [Sakai, S.; Oset, E.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor,Ctr Mixto, Aptdo 22085, Valencia 46071, Spain, Email: shuntaro.sakai@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000423446700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3462
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