Browsing by Author "Constantinou, Martha G."
Now showing items 1-20 of 22
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Article
BK-parameter from Nf=2 twisted mass lattice QCD
Constantinou, Martha G.; Dimopoulos, Petros; Frezzotti, R.; Jansen, K.; Gimenez, V.; Lubicz, V.; Mescia, F.; Panagopoulos, Haralambos G.; Papinutto, M.; Rossi, G. C.; Simula, S.; Skouroupathis, A.; Stylianou, Fotos S.; Vladikas, A. (2011)We present an unquenched Nf=2 lattice computation of the B K parameter which controls K0-K̄0 oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence ...
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Conference Object
The chromomagnetic operator on the lattice
Constantinou, Martha G.; Costa, M. G.; Frezzotti, R.; Lubicz, V.; Martinelli, G.; Meloni, D.; Panagopoulos, Haralambos G.; Simula, S. (Proceedings of Science (PoS), 2013)We study matrix elements of the "chromomagnetic" operator on the lattice. This operator is contained in the strangeness-changing effective Hamiltonian which describes electroweak effects in the Standard Model and beyond. ...
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Article
Erratum: Two interacting charged particles in an Aharonov-Bohm ring: Bound state transitions, symmetry breaking, persistent currents, and Berry's phase (Physical Review B - Condensed Matter and Materials Physics (2004) 70, (235327))
Moulopoulos, Konstantinos; Constantinou, Martha G. (2007)
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Article
Exciton in an Aharonov-Bohm ring: An exactly soluble interacting mesoscopic system
Moulopoulos, Konstantinos; Constantinou, Martha G. (2006)A Green's function procedure leads to an exact determination of the energy spectrum and the associated eigenstates of a system of two oppositely charged particles interacting through a contact potential and moving in a ...
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Article
Gauge theories with overlap fermions in an arbitrary representation: Evaluation of the 3-loop β-function
Constantinou, Martha G.; Panagopoulos, Haralambos G. (2008)This work presents the calculation of the relation between the bare coupling constant g0 and the MS̄-renormalized coupling gMS̄, g0=Zg(g0,aμ)gMS̄, to 2 loops in perturbation theory, with fermions in an arbitrary representation ...
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Doctoral Thesis Open Access
Higher order Perturbative Calculations in Strong interaction physics with improved discretized actions for Quarks and Gluons
Constantinou, Martha G. (Πανεπιστήμιο Κύπρου, Σχολή Θετικών και Εφαρμοσμένων Επιστημών / University of Cyprus, Faculty of Pure and Applied Sciences, 2008-04)Στα πλαίσια της παρούσας Διατριβής πραγματοποιούνται διαταρακτικοί υπολογισμοί στην Κβαντική Χρωμοδυναμική Πλέγματος. Εφαρμόζουμε βελτιωμένες φερμιονικές και γκλουονικές δράσεις, οι οποίες χρησιμοποιούνται ευρέως στις ...
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Article
Improved perturbation theory for improved lattice actions
Constantinou, Martha G.; Panagopoulos, Haralambos G.; Skouroupathis, A. (2006)We study a systematic improvement of perturbation theory for gauge fields on the lattice
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Article
Magnetic-field-induced localization in networks with the T3 geometry
Moulopoulos, Konstantinos; Constantinou, Martha G. (2002)By following an exact analytical procedure we study the transmission properties of a network of quantum wires arranged in a so-called T3 configuration and in the presence of a perpendicular magnetic field. It is shown that ...
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Article
Non-perturbative renormalization of quark bilinear operators with N f = 2 (tmQCD) Wilson fermions and the tree-level improved gauge action
Constantinou, Martha G.; Dimopoulos, Petros; Frezzotti, R.; Herdoiza, G.; Jansen, K.; Lubicz, V.; Panagopoulos, Haralambos G.; Rossi, G. C.; Simula, S.; Stylianou, Fotos S.; Vladikas, A. (2010)We present results for the renormalization constants of bilinear quark operators obtained by using the tree-level Symanzik improved gauge action and the N f = 2 twisted mass fermion action at maximal twist, which guarantees ...
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Article
O(a 2) corrections to the one-loop propagator and bilinears of clover fermions with Symanzik improved gluons
Constantinou, Martha G.; Lubicz, V.; Panagopoulos, Haralambos G.; Stylianou, Fotos S. (2009)We calculate corrections to the fermion propagator and to the Green's functions of all fermion bilinear operators of the form , to one-loop in perturbation theory. We employ the Wilson/clover action for fermions and the ...
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Article
Perturbative renormalization factors and O(a2) corrections for lattice four-fermion operators with improved fermion/gluon actions
Constantinou, Martha G.; Dimopoulos, Petros; Frezzotti, R.; Lubicz, V.; Panagopoulos, Haralambos G.; Skouroupathis, A.; Stylianou, Fotos S. (2011)In this work we calculate the corrections to the amputated Green's functions of four-fermion operators, in 1-loop lattice perturbation theory. One of the novel aspects of our calculations is that they are carried out to ...
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Article
Perturbative renormalization functions of local operators for staggered fermions with stout improvement
Constantinou, Martha G.; Costa, M. G.; Panagopoulos, Haralambos G. (2013)In this paper we present the perturbative computation of the renormalization functions for the quark field and for a complete set of ultralocal fermion bilinears. The computation of the relevant Green's functions are carried ...
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Article
Perturbatively improving regularization-invariant momentum scheme renormalization constants
Constantinou, Martha G.; Costa, M. G.; Göckeler, M.; Horsley, R.; Panagopoulos, Haralambos G.; Perlt, H.; Rakow, P. E. L.; Schierholz, G.; Schiller, A. (2013)The determination of renormalization factors is of crucial importance in lattice QCD. They relate the observables obtained on the lattice to their measured counterparts in the continuum in a suitable renormalization scheme. ...
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Article
Precision study of excited state effects in nucleon matrix elements
Dinter, S.; Alexandrou, Constantia; Constantinou, Martha G.; Drach, V.; Jansen, K.; Renner, D. B. (2011)We present a dedicated analysis of the influence of excited states on the calculation of nucleon matrix elements. This calculation is performed at a fixed value of the lattice spacing, volume and pion mass that are typical ...
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Article
QCD with overlap fermions: Running coupling and the 3-loop β-function
Constantinou, Martha G.; Panagopoulos, Haralambos G. (2007)We calculate the relation between the bare coupling constant g0 and the MS̄-renormalized coupling gMS̄, g0=Zg(g0,aμ̄)gMS̄, to 2 loops in perturbation theory. We employ the standard Wilson action for gluons and the overlap ...
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Article
Renormalization and mixing in lattice QCD: The case of the chromomagnetic operator
Constantinou, Martha G.; Costa, M. G.; Frezzotti, R.; Lubicz, V.; Martinelli, G.; Meloni, D.; Panagopoulos, Haralambos G.; Simula, S. (2014)We study matrix elements of the "chromomagnetic" operator on the lattice. This operator is contained in the strangeness-changing effective Hamiltonian which describes electroweak effects in the Standard Model and beyond. ...
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Article
Renormalization of local quark-bilinear operators for N f=3 flavors of stout link nonperturbative clover fermions
Constantinou, Martha G.; Horsley, R.; Panagopoulos, Haralambos G.; Perlt, H.; Rakow, P. E. L.; Schierholz, G.; Schiller, A.; Zanotti, J. M. (2015)The renormalization factors of local quark-bilinear operators are computed nonperturbatively for Nf=3 flavors of stout link nonperturbative clover (SLiNC) fermions, with emphasis on the various procedures for the chiral ...
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Article
Renormalization of the chromomagnetic operator on the lattice
Constantinou, Martha G.; Costa, M. G.; Frezzotti, R.; Lubicz, V.; Martinelli, G.; Meloni, D.; Panagopoulos, Haralambos G.; Simula, S. (2015)We present our study of the renormalization of the chromomagnetic operator, OCM, which appears in the effective Hamiltonian describing ΔS=1 transitions in and beyond the Standard Model. We have computed, perturbatively to ...
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Article
Singlet versus nonsinglet perturbative renormalization of fermion bilinears
Constantinou, Martha G.; Hadjiantonis, Marios; Panagopoulos, Haralambos G.; Spanoudes, Gregoris (2016)In this paper, we present the perturbative evaluation of the difference between the renormalization functions of flavor singlet and nonsinglet bilinear quark operators on the lattice. The computation is performed to two ...
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Article
Triplet excitation energy dynamics in metal-organic frameworks
Lin, J.; Hu, X.; Zhang, P.; Van Rynbach, A.; Beratan, David N.; Kent, C. A.; Mehl, B. P.; Papanikolas, J. M.; Meyer, T. J.; Lin, W.; Skourtis, Spiros S.; Constantinou, Martha G. (2013)Metal-organic frameworks (MOFs) are appealing candidates for use in energy harvesting and concentrating because of their high chromophore density and structural tunability. The ability to engineer electronic excitation ...