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Author |
Bombacigno, F.; Boudet, S.; Montani, G. |
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Title |
Generalized Ashtekar variables for Palatini f(R) models |
Type |
Journal Article |
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Year |
2021 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
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Volume |
963 |
Issue |
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Pages |
115281 - 21pp |
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Abstract  |
We consider special classes of Palatini f(R) theories, featured by additional Loop Quantum Gravity inspired terms, with the aim of identifying a set of modified Ashtekar canonical variables, which still preserve the SU(2) gauge structure of the standard theory. In particular, we allow for affine connection to be endowed with torsion, which turns out to depend on the additional scalar degree affecting Palatini f( R) gravity, and in this respect we successfully construct a novel Gauss constraint. We analyze the role of the additional scalar field, outlining as it acquires a dynamical character by virtue of a non vanishing Immirzi parameter, and we describe some possible effects on the area operator stemming from such a revised theoretical framework. Finally, we compare our results with earlier studies in literature, discussing differences between metric and Palatini approaches. It is worth noting how the Hamiltonian turns out to be different in the two cases. The results can be reconciled when the analysis is performed in the Einstein frame. |
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Address |
[Bombacigno, Flavio] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, Valencia 46100, Spain, Email: flavio.bombacigno@ext.uv.es; |
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Elsevier |
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English |
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0550-3213 |
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Notes |
WOS:000613579500003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4706 |
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Author |
Nascimento, J.R.; Olmo, G.J.; Petrov, A.Y.; Porfirio, P.J. |
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Title |
On metric-affine bumblebee model coupled to scalar matter |
Type |
Journal Article |
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Year |
2024 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
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Volume |
1004 |
Issue |
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Pages |
116577 - 10pp |
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Keywords |
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Abstract |
We consider the coupling of the metric-affine bumblebee gravity model to scalar matter and calculate the lower -order contributions to two -point functions of bumblebee and scalar fields in the weak gravity approximation. We also obtain the one -loop effective potentials for both scalar and vector fields. |
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Address |
[Nascimento, J. R.; Petrov, A. Yu.; Porfirio, P. J.] Univ Fed Paraiba, Dept Fis, Caixa Postal 5008, BR-58051970 Joao Pessoa, PB, Brazil, Email: jroberto@fisica.ufpb.br; |
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Elsevier |
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English |
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ISSN |
0550-3213 |
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Conference |
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Notes |
WOS:001248177100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
6157 |
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Author |
Cirigliano, V.; Jenkins, J.P.; Gonzalez-Alonso, M. |
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Title |
Semileptonic decays of light quarks beyond the Standard Model |
Type |
Journal Article |
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Year |
2010 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
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Volume |
830 |
Issue |
1-2 |
Pages |
95-115 |
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Keywords |
Semileptonic decays; CKM unitarity; Effective theory; Beyond the Standard Model |
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Abstract |
We describe non-standard contributions to semileptonic processes in a model independent way in terms of in SU(2)(L) x U(1)(Y) invariant effective lagrangian at the weak scale, front which we derive the low-energy effective lagrangian governing muon and beta decays. We find that the deviation from Cabibbo universality, Delta(CKM) equivalent to vertical bar V-ud vertical bar(2) + vertical bar V-us vertical bar(2) + vertical bar V-ub vertical bar(2) – 1, receives contributions from four effective operators. The phenomenological bound Delta(CKM) = (-1 +/- 6) x 10(-4) provides strong constraints on all four operators, corresponding to art effective scale Lambda > 11 TeV (90% CL). Depending on the operator, this constraint is at the same level or better then the Z pole observables. Conversely, precision electroweak constraints alone would allow universality violations as large as Delta(CKM) = -0.01 (90% CL). An observed Delta(CKM) not equal 0 at this level Could be explained in terms of a single four-fermion operator which is relatively poorly constrained by electroweak precision measurements. |
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Address |
[Cirigliano, Vincenzo; Jenkins, James P.; Gonzalez-Alonso, Martin] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA, Email: cirigliano@lanl.gov |
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Elsevier Science Bv |
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English |
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ISSN |
0550-3213 |
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Conference |
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Notes |
ISI:000275150000003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
497 |
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Author |
Fonseca, R.M.; Malinsky, M.; Porod, W.; Staub, F. |
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Title |
Running soft parameters in SUSY models with multiple U(1) gauge factors |
Type |
Journal Article |
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Year |
2012 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
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Volume |
854 |
Issue |
1 |
Pages |
28-53 |
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Keywords |
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Abstract |
We generalize the two-loop renormalization group equations for the parameters of the softly broken SUSY gauge theories given in the literature to the most general case when the gauge group contains more than a single Abelian gauge factor. The complete method is illustrated at two-loop within a specific example and compared to some of the previously proposed partial treatments. |
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Address |
[Porod, W; Staub, F] Univ Wurzburg Hubland, Inst Theoret Phys & Astron, D-97074 Wurzburg, Germany, Email: renato.fonseca@ist.utl.pt |
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Elsevier Science Bv |
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English |
Summary Language |
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Series Volume |
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Series Issue |
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ISSN |
0550-3213 |
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Medium |
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Expedition |
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Conference |
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Notes |
WOS:000296167500002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
788 |
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Author |
Carrasco, N.; Deuzeman, A.; Dimopoulos, P.; Frezzotti, R.; Gimenez, V.; Herdoiza, G.; Lami, P.; Lubicz, V.; Palao, D.; Picca, E.; Reker, S.; Riggio, L.; Rossi, G.C.; Sanfilippo, F.; Scorzato, L.; Simula, S.; Tarantino, C.; Urbach, C.; Wenger, U. |
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Title |
Up, down, strange and charm quark masses with N-f=2+1+1 twisted mass lattice QCD |
Type |
Journal Article |
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Year |
2014 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
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Volume |
887 |
Issue |
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Pages |
19-68 |
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Keywords |
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Abstract |
We present a lattice QCD calculation of the up, down, strange and charm quark masses performed using the gauge configurations produced by the European Twisted Mass Collaboration with N-f = 2 + 1 + 1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their physical values. The simulations are based on a unitary setup for the two light quarks and on a mixed action approach for the strange and charm quarks. The analysis uses data at three values of the lattice spacing and pion masses in the range 210-450 MeV, allowing for accurate continuum limit and controlled chiral extrapolation. The quark mass renormalization is carried out non-perturbatively using the RI'-MOM method. The results for the quark masses converted to the (MS) over bar scheme are: m(ud) (2 GeV) = 3.70(17) MeV, m(s)(2 GeV) = 99.6(4.3) MeV and m(c)(m(c)) = 1.348(46) GeV. We obtain also the quark mass ratios m(s)/m(ud) = 26.66(32) and m(c)/m(s) = 11.62(16). By studying the mass splitting between the neutral and charged kaons and using available lattice results for the electromagnetic contributions, we evaluate m(u)/m(d) = 0.470(56), leading to m(u) = 2.36(24) MeV and m(d) = 5.03(26) MeV. |
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Address |
[Carrasco, N.; Lami, P.; Lubicz, V.; Picca, E.; Riggio, L.; Simula, S.; Tarantino, C.] Ist Nazl Fis Nucl, Sez Roma Tre, I-00146 Rome, Italy |
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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 |
0550-3213 |
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:000343339700002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1976 |
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