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Author Araujo Filho, A.A.; Nascimento, J.R.; Petrov, A.Y.; Porfírio, P.J.
Title (down) Vacuum solution within a metric-affine bumblebee gravity Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 108 Issue 8 Pages 085010 - 13pp
Keywords
Abstract We consider a metric-affine extension to the gravitational sector of the Standard Model extension for the Lorentz-violating coefficients u and s(mu nu). The general results, which are applied to a specific model called metric-affine bumblebee gravity, are obtained. A Schwarzschild-like solution, incorporating effects of the Lorentz symmetry breaking through the coefficient X = xi b(2), is found. Furthermore, a complete study of the geodesic trajectories of particles is accomplished in this background, emphasizing the departure from general relativity. We also compute the advance of Mercury's perihelion and the deflection of light within the context of the weak-field approximation, and we verify that there exist two new contributions ascribed to the Lorentz symmetry breaking. As a phenomenological application, we compare our theoretical results with observational data in order to estimate the coefficient X.
Address [Araujo Filho, A. A.; Nascimento, J. R.; Petrov, A. Yu.; Porfirio, P. J.] Univ Fed Paraiba, Dept Fis, Caixa Postal 5008, BR-58051970 Joao Pessoa, Paraiba, Brazil, Email: dilto@fisica.ufc.br;
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:001151350300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5932
Permanent link to this record
 
 
Author Maluf, R.V.; Olmo, G.J.
Title (down) Vacuum polarization and induced Maxwell and Kalb-Ramond effective action in very special relativity Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 108 Issue 9 Pages 095022 - 13pp
Keywords
Abstract This work investigates the implications of very special relativity (VSR) on the calculation of vacuum polarization for fermions in the presence of Maxwell and Kalb-Ramond gauge fields in four-dimensional spacetime. We derive the SIM(2)-covariant gauge theory associated with an Abelian antisymmetric twotensor and its corresponding field strength. We demonstrate that the free VSR-Kalb-Ramond electrodynamics is equivalent to a massive scalar field with a single polarization. Furthermore, we determine an explicit expression for the effective action involving Maxwell and Kalb-Ramond fields due to fermionic vacuum polarization at one-loop order. The quantum corrections generate divergences free of nonlocal terms only in the VSR-Maxwell sector. At the same time, we observe UV/IR mixing divergences due to the entanglement of VSR-nonlocal effects with quantum higher-derivative terms for the Kalb-Ramond field. However, in the lower energy limit, the effective action can be renormalized like in the Lorentz invariant case.
Address [Maluf, Roberto, V; Olmo, Gonzalo J.] Univ Fed Ceara UFC, Dept Fis, Campus Pici,CP 6030, BR-60455760 Fortaleza, CE, Brazil, Email: r.v.maluf@fisica.ufc.br;
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:001111823400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5863
Permanent link to this record
 
 
Author Nebot, M.; Botella, F.J.; Branco, G.C.
Title (down) Vacuum induced CP violation generating a complex CKM matrix with controlled scalar FCNC Type Journal Article
Year 2019 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 79 Issue 8 Pages 711 - 23pp
Keywords
Abstract We propose. a viable minimal model with spontaneous CP violation in the framework of a two Higgs doublet model. The model is based on a generalised Branco-Grimus-Lavoura model with a flavoured Z(2) symmetry, under which two of the quark families are even and the third one is odd. The lagrangian respects CP invariance, but the vacuum has a CP violating phase, which is able to generate a complex CKM matrix, with the rephasing invariant strength of CP violation compatible with experiment. The question of scalar mediated flavour changing neutral couplings is carefully studied. In particular we point out a deep connection between the generation of a complex CKM matrix from a vacuum phase and the appearance of scalar FCNC. The scalar sector is presented in detail, showing that the new scalars are necessarily lighter than 1 TeV. A complete analysis of the model including the most relevant constraints is performed, showing that it is viable and that it has definite implications for the observation of New Physics signals in, for example, flavour changing Higgs decays or the discovery of the new scalars at the LHC. We give special emphasis to processes like t -> hc, hu, as well as h -> bs, bd, which are relevant for the LHC and the ILC.
Address [Nebot, Miguel; Branco, Gustavo C.] UL, Dept Fis, Inst Super Tecn, Av Rovisco Pais 1, P-1049001 Lisbon, Portugal, Email: miguel.r.nebot.gomez@tecnico.ulisboa.pt;
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:000483225300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4130
Permanent link to this record
 
 
Author Khosa, C.K.; Sanz, V.; Soughton, M.
Title (down) Using machine learning to disentangle LHC signatures of Dark Matter candidates Type Journal Article
Year 2021 Publication Scipost Physics Abbreviated Journal SciPost Phys.
Volume 10 Issue 6 Pages 151 - 26pp
Keywords
Abstract We study the prospects of characterising Dark Matter at colliders using Machine Learning (ML) techniques. We focus on the monojet and missing transverse energy (MET) channel and propose a set of benchmark models for the study: a typical WIMP Dark Matter candidate in the form of a SUSY neutralino, a pseudo-Goldstone impostor in the shape of an Axion-Like Particle, and a light Dark Matter impostor whose interactions are mediated by a heavy particle. All these benchmarks are tensioned against each other, and against the main SM background (Z+jets). Our analysis uses both the leading-order kinematic features as well as the information of an additional hard jet. We explore different representations of the data, from a simple event data sample with values of kinematic variables fed into a Logistic Regression algorithm or a Fully Connected Neural Network, to a transformation of the data into images related to probability distributions, fed to Deep and Convolutional Neural Networks. We also study the robustness of our method against including detector effects, dropping kinematic variables, or changing the number of events per image. In the case of signals with more combinatorial possibilities (events with more than one hard jet), the most crucial data features are selected by performing a Principal Component Analysis. We compare the performance of all these methods, and find that using the 2D images of the combined information of multiple events significantly improves the discrimination performance.
Address [Khosa, Charanjit Kaur; Sanz, Veronica; Soughton, Michael] Univ Sussex, Dept Phys & Astron, Brighton BN1 9QH, E Sussex, England, Email: Charanjit.Kaur@sussex.ac.uk;
Corporate Author Thesis
Publisher Scipost Foundation Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2542-4653 ISBN Medium
Area Expedition Conference
Notes WOS:000680038800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4927
Permanent link to this record
 
 
Author Liang, W.H.; Ikeno, N.; Oset, E.
Title (down) Upsilon(nl) decay into B(*) (B)over-bar(*) Type Journal Article
Year 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 803 Issue Pages 135340 - 6pp
Keywords
Abstract We have evaluated the decay modes of the Upsilon(4s), Upsilon(3d), Upsilon(5s), Upsilon(6s) states into B (B) over bar, B (B) over bar* + c.c., B* (B) over bar*, B-s(B) over bar (s), B-s(B) over bar (s)* + c.c., B-s* (B) over bar (s)* using the P-3(0) model to hadronize the bb vector seed, fitting some parameters to the data. We observe that the Upsilon(4s) state has an abnormally large amount of mesonmeson components in the wave function, while the other states are largely b (b) over bar. We predict branching ratios for the different decay channels which can be contrasted with experiment for the case of the Upsilon(5s) state. While globally the agreement is fair, we call the attention to some disagreement that could be a warning for the existence of more elaborate components in the state.
Address [Liang, Wei-Hong; Oset, Eulogio] Guangxi Normal Univ, Dept Phys, Guilin 541004, Peoples R China, Email: liangwh@gxnu.edu.cn;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000521730300046 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4355
Permanent link to this record
 
 
Author Cañas, B.C.; Miranda, O.G.; Parada, A.; Tortola, M.; Valle, J.W.F.
Title (down) Updating neutrino magnetic moment constraints Type Journal Article
Year 2016 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 753 Issue Pages 191-198
Keywords
Abstract In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Lambda(i) and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1 x 10(-11) mu(B) at 90% C.L. This corresponds to the individual transition magnetic moment constraints: vertical bar Lambda(1)vertical bar <= 5.6 x10(-11)mu(B), vertical bar Lambda(2)vertical bar <= 4.0 x10(-11)mu(B), and vertical bar Lambda(3)vertical bar <= 3.1 x10(-11)mu B(90% C. L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.
Address [Canas, B. C.; Miranda, O. G.] Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Fis, Apdo Postal 14-740, Mexico City 07000, DF, Mexico, Email: bcorduz@fis.cinvestav.mx;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000368783600029 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2551
Permanent link to this record
 
 
Author T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Molina Bueno, L.; Novella, P.
Title (down) Updated T2K measurements of muon neutrino and antineutrino disappearance using 3.6 x 10^21 protons on target Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 108 Issue 7 Pages 072011 - 10pp
Keywords
Abstract Muon neutrino and antineutrino disappearance probabilities are identical in the standard three-flavor neutrino oscillation framework, but CPT violation and nonstandard interactions can violate this symmetry. In this work we report the measurements of sin2 theta 23 and Delta m232 independently for neutrinos and antineutrinos. The aforementioned symmetry violation would manifest as an inconsistency in the neutrino and antineutrino oscillation parameters. The analysis discussed here uses a total of 1.97 x 1021 and 1.63 x 1021 protons on target taken with a neutrino and antineutrino beam respectively, and benefits from improved flux and cross section models, new near-detector samples and more than double the data reducing the overall uncertainty of the result. No significant deviation is observed, consistent with the standard neutrino oscillation picture.
Address [Labarga, L.; Ospina, N.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid 28049, Spain
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:001102916000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5846
Permanent link to this record
 
 
Author Estienne, M.; Fallot, M.; Algora, A.; Briz-Monago, J.; Bui, V.M.; Cormon, S.; Gelletly, W.; Giot, L.; Guadilla, V.; Jordan, D.; Le Meur, L.; Porta, A.; Rice, S.; Rubio, B.; Tain, J.L.; Valencia, E.; Zakari-Issoufou, A.A.
Title (down) Updated Summation Model: An Improved Agreement with the Daya Bay Antineutrino Fluxes Type Journal Article
Year 2019 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 123 Issue 2 Pages 022502 - 6pp
Keywords
Abstract A new summation method model of the reactor antineutrino energy spectrum is presented. It is updated with the most recent evaluated decay databases and with our total absorption gamma-ray spectroscopy measurements performed during the last decade. For the first time, the spectral measurements from the Daya Bay experiment are compared with the antineutrino energy spectrum computed with the updated summation method without any renormalization. The results exhibit a better agreement than is obtained with the Huber-Mueller model in the 2-5 MeV range, the region that dominates the detected flux. A systematic trend is found in which the antineutrino flux computed with the summation model decreases with the inclusion of more pandemonium-free data. The calculated flux obtained now lies only 1.9% above that detected in the Daya Bay experiment, a value that may be reduced with forthcoming new pandemonium-free data, leaving less room for a reactor anomaly. Eventually, the new predictions of individual antineutrino spectra for the U-235, Pu-239, Pu-241, and U-238 are used to compute the dependence of the reactor antineutrino spectral shape on the fission fractions.
Address [Estienne, M.; Fallot, M.; Briz-Monago, J.; Bui, V. M.; Cormon, S.; Giot, L.; Guadilla, V.; Le Meur, L.; Porta, A.; Zakari-Issoufou, A. -A.] Univ Nantes, CNRS, IN2P3, SUBATECH,IMT Atlantique, F-44307 Nantes, France, Email: magali.estienne@subatech.in2p3.fr
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000474894200010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4078
Permanent link to this record
 
 
Author LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title (down) Updated search for B-c(+) decays to two charm mesons Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 12 Issue 12 Pages 117 - 23pp
Keywords B physics; Branching fraction; Flavor physics; Hadron-Hadron scattering (experiments)
Abstract A data set corresponding to an integrated luminosity of 9 fb(-1) of proton-proton collisions collected by the LHCb experiment has been analysed to search for D-(s)(()*())+ ((D) over bar)(*)0 decays. The decays are fully or partially reconstructed, where one or two (8) missing neutral pions or photons from the decay of an excited charm meson are allowed. Upper limits for the branching fractions, normalised to B+ decays to final states with similar topologies, are obtained for sixteen B-c(+) decay modes. For the decay B-c(+) -> D-s(+)(D) over bar (0), an excess with a significance of 3.4 standard deviations is found.
Address [Baptista Leite, J.; Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, C.; Gomes, A.; Massafferri, A.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: fionn.caitlin.ros.bishop@cern.ch
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:000732953900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5056
Permanent link to this record
 
 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title (down) Updated measurement of time-dependent CP-violating observables in B-s(0) -> J/psi K+K- decays Type Journal Article
Year 2019 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 79 Issue 8 Pages 706 - 26pp
Keywords
Abstract The decay-time-dependent CP asymmetry in B0 s. J/. K + K-decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 1.9 fb-1, collected with the LHCb detector at a centre-ofmass energy of 13 TeV in 2015 and 2016. Using a sample of approximately 117 000 signal decays with an invariant K + K-mass in the vicinity of the f( 1020) resonance, the CP-violating phase fs is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B0 s-B0s system, s. The difference of the average B0 s and B0 meson decay widths, s-d, is determined using in addition a sample of B0. J/. K + p-decays. The values obtained are fs =-0.083 +/- 0.041 +/- 0.006 rad, s = 0.077 +/- 0.008 +/- 0.003 ps-1 and s-d = -0.0041 +/- 0.0024 +/- 0.0015 ps-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of these quantities to date and are consistent with expectations based on the Standard Model and with a previous LHCb analysis of this decay using data recorded at centre-of-mass energies 7 and 8 TeV. Finally, the results are combined with recent results from B0 s. J/. p + p-decays obtained using the same dataset as this analysis, and with previous independent LHCb results.
Address [Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Reis, A. C. dos; Lavra, l. Soares] Ctr Brasileiro Pesquisas Fisicas CBPF, Rio De Janeiro, Brazil, Email: veronika.chobanova@cern.ch;
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:000482401700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4121
Permanent link to this record