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Author (down) Coppola, M.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Weak decays of magnetized charged pions in the symmetric gauge Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 3 Pages 034003 - 13pp
Keywords
Abstract We consider the decay pi(-) -> l (nu) over bar (l) (l = e(-) , mu(-)) in the presence of an arbitrary large uniform magnetic field, using the symmetric gauge. The consequences of the axial symmetry of the problem and the issue of angular momentum conservation arc discussed in detail. In particular, we analyze the projection of both the canonical and the mechanical total angular momenta along the direction of the magnetic field. It is found that while the former is conserved in the symmetric gauge, the latter is not conserved in both the symmetric and Landau gauges. We derive an expression for the integrated pi(-) -> l (nu) over bar (l) width that coincides exactly with the one we previously found using the Landau gauge, providing an explicit test of the gauge independence of that result. Such an expression implies that for nonzero magnetic fields the decay width does not vanish in the limit in which the outgoing charged leptons can be considered as massless, i.e., it does not exhibit the helicity suppression found in the case of no external field.
Address [Coppola, M.; Scoccola, N. N.] Consejo Nacl Invest Cient & Tecn, Rivadavia 1917, RA-1033 Buenos Aires, DF, Argentina
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000511198700005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4273
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Author (down) Coppola, M.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Magnetic field driven enhancement of the weak decay width of charged pions Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 058 - 19pp
Keywords QCD Phenomenology
Abstract We study the effect of a uniform magnetic field B on the decays pi- > l- nu_l bar, where l(-)=e(-), μ(-), carrying out a general analysis that includes four pi (-) decay constants. Taking the values of these constants from a chiral effective Nambu-Jona-Lasinio (NJL) model, it is seen that the total decay rate gets strongly increased with respect to the B = 0 case, with an enhancement factor ranging from similar to 10 for eB = 0.1 GeV2 up to similar to 10(3) for eB = 1 GeV2. The ratio between electronic and muonic decays gets also enhanced, reaching a value of about 1 : 2 for eB = 1 GeV2. In addition, we find that for large B the angular distribution of outgoing antineutrinos shows a significant suppression in the direction of the magnetic field.
Address [Coppola, Maximo; Scoccola, Norberto N.] Consejo Nacl Invest Cient & Tecn, Rivadavia 1917, RA-1033 Buenos Aires, DF, Argentina, Email: coppola@tandar.cnea.gov.ar;
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 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000570908100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4534
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Author (down) Coppola, M.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Masses of magnetized pseudoscalar and vector mesons in an extended NJL model: The role of axial vector mesons Type Journal Article
Year 2024 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 109 Issue 5 Pages 054014 - 30pp
Keywords
Abstract We study the mass spectrum of light pseudoscalar and vector mesons in the presence of an external uniform magnetic field B., considering the effects of the mixing with the axial-vector meson sector. The analysis is performed within a two-flavor NJL-like model which includes isoscalar and isovector couplings together with a flavor mixing 't Hooft-like term. The effect of the magnetic field on charged particles is taken into account by retaining the Schwinger phases carried by quark propagators, and expanding the corresponding meson fields in proper Ritus-like bases. The spin-isospin and spin-flavor decomposition of meson mass states is also analyzed. For neutral pion masses it is shown that the mixing with axial vector mesons improves previous theoretical results, leading to a monotonic decreasing behavior with B that is in good qualitative agreement with lattice QCD (LQCD) calculations, both for the case of constant or B-dependent couplings. Regarding charged pions, it is seen that the mixing softens the enhancement of their mass with B. As a consequence, the energy becomes lower than the one corresponding to a pointlike pion, improving the agreement with LQCD results. The agreement is also improved for the magnetic behavior of the lowest.thorn energy state, which does not vanish for the considered range of values of B-a fact that can be relevant in connection with the occurrence of meson condensation for strong magnetic fields.
Address [Coppola, M.; Scoccola, N. N.] Comis Nacl Energia Atom, Dept Fis, Ave Libertador 8250, RA-1429 Buenos Aires, Argentina
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:001196327000010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6119
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Author (down) Carlomagno, J.P.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Neutral pseudoscalar and vector meson masses under strong magnetic fields in an extended NJL model: Mixing effects Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 106 Issue 7 Pages 074002 - 20pp
Keywords
Abstract Mixing effects on the mass spectrum of light neutral pseudoscalar and vector mesons in the presence of an external uniform magnetic field (B) over right arrow are studied in the framework of a two-flavor Nambu-Jona-Lasinio (NJL)-like model. The model includes isoscalar and isovector couplings both in the scalar-pseudoscalar and vector sectors, and also incorporates flavor mixing through a ' t Hooft-like term. Numerical results for the B dependence of meson masses are compared with present lattice QCD results. In particular, it is shown that the mixing between pseudoscalar and vector meson states leads to a significant reduction of the mass of the lightest state. The role of chiral symmetry and the effect of the alignment of quark magnetic moments in the presence of the magnetic field are discussed.
Address [Carlomagno, J. P.; Gomez Dumm, D.] Univ Nacl La Plata, IFLP, CONICET, Dept Fis,Fac Ciencias Exactas, RA-1900 La Plata, Argentina
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000898622400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5443
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Author (down) Carlomagno, J.P.; Gomez Dumm, D.; Izzo Villafañe, M.F.; Noguera, S.; Scoccola, N.N.
Title Charged pseudoscalar and vector meson masses in strong magnetic fields in an extended NJL model Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 106 Issue 9 Pages 094035 - 17pp
Keywords
Abstract The mass spectrum of pi(+) and rho(+) mesons in the presence of a static uniform magnetic field (B) over right arrow is studied within a two-flavor Nambu-Jona-Lasinio-like model. We improve previous calculations, taking into account the effect of Schwinger phases carried by quark propagators and using an expansion of meson fields in terms of the solutions of the corresponding equations of motion for nonzero B. It is shown that the meson polarization functions are diagonal in this basis. Our numerical results for the rho(+) meson spectrum are found to disfavor the existence of a meson condensate induced by the magnetic field. In the case of the pi(+) meson, pi-rho mixing effects are analyzed for the meson lowest-energy state. The predictions of the model are compared with available lattice QCD results.
Address [Carlomagno, J. P.; Dumm, D. Gomez] Univ Nacl La Plata, IFLP, CONICET, Dept Fis,Fac Cs Exactas, CC 67, RA-1900 La Plata, Argentina
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000917769000013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5470
Permanent link to this record