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Author (up) Bombacigno, F.; Boudet, S.; Olmo, G.J.; Montani, G.
Title Big bounce and future time singularity resolution in Bianchi I cosmologies: The projective invariant Nieh-Yan case Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 12 Pages 124031
Keywords
Abstract We extend the notion of the Nieh-Yan invariant to generic metric-affine geometries, where both torsion and nonmetricity are taken into account. Notably, we show that the properties of projective invariance and topologicity can be independently accommodated by a suitable choice of the parameters featuring this new Nieh-Yan term. We then consider a special class of modified theories of gravity able to promote the Immirzi parameter to a dynamical scalar field coupled to the Nieh-Yan form, and we discuss in more detail the dynamics of the effective scalar tensor theory stemming from such a revised theoretical framework. We focus, in particular, on cosmological Bianchi I models and we derive classical solutions where the initial singularity is safely removed in favor of a big bounce, which is ultimately driven by the nonminimal coupling with the Immirzi field. These solutions, moreover, turn out to be characterized by finite time singularities, but we show that such critical points do not spoil the geodesic completeness and wave regularity of these spacetimes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language 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:000661819200005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4870
Permanent link to this record
 
 
Author (up) Bonilla, C.; Centelles Chulia, S.; Cepedello, R.; Peinado, E.; Srivastava, R.
Title Dark matter stability and Dirac neutrinos using only standard model symmetries Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 3 Pages 033011 - 5pp
Keywords
Abstract We provide a generic framework to obtain stable dark matter along with naturally small Dirac neutrino masses generated at the loop level. This is achieved through the spontaneous breaking of the global U(1)(B-L) symmetry already present in the standard model. The U(1)(B-L) symmetry is broken down to a residual even Z(n) (n >= 4) subgroup. The residual Z(n) symmetry simultaneously guarantees dark matter stability and protects the Dirac nature of neutrinos. The U(1)(B-L) symmetry in our setup is anomaly free and can also be gauged in a straightforward way. Finally, we present an explicit example using our framework to show the idea in action.
Address [Bonilla, Cesar] Tech Univ Munich, Phys Dept T30d, James Franck Str, D-85748 Garching, Germany, Email: cesar.bonilla@tum.de;
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:000517243100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4308
Permanent link to this record
 
 
Author (up) Bonilla, C.; Fonseca, R.M.; Valle, J.W.F.
Title Consistency of the triplet seesaw model revisited Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 92 Issue 7 Pages 075028 - 7pp
Keywords
Abstract Adding a scalar triplet to the Standard Model is one of the simplest ways of giving mass to neutrinos, providing at the same time a mechanism to stabilize the theory's vacuum. In this paper, we revisit these aspects of the type-II seesaw model pointing out that the bounded-from-below conditions for the scalar potential in use in the literature are not correct. We discuss some scenarios where the correction can be significant and sketch the typical scalar boson profile expected by consistency.
Address [Bonilla, Cesar; Fonseca, Renato M.; Valle, J. W. F.] CSIC Univ Valencia, AHEP Grp, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: cbonilla@ific.uv.es;
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000363237400013 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2423
Permanent link to this record
 
 
Author (up) Bonilla, C.; Modak, T.; Srivastava, R.; Valle, J.W.F.
Title U(1)(B3-3L2) gauge symmetry as a simple description of b -> s anomalies Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 9 Pages 095002 - 11pp
Keywords
Abstract We present a simple U(1)(B3-3L2) gauge standard model extension that can easily account for the anomalies in R(K) and R(K*) reported by LHCb. The model is economical in its setup and particle content. Among the standard model fermions, only the third generation quark family and the second generation leptons transform nontrivially under the new U(1)(B3-3L2) symmetry. This leads to lepton nonuniversality and flavor changing neutral currents involving the second and third quark families. We discuss the relevant experimental constraints and some implications.
Address [Bonilla, Cesar] Tech Univ Munich, Phys Dept T30d, James Franck Str, D-85748 Garching, Germany, Email: cesar.bonilla@tum.de;
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:000448926500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3785
Permanent link to this record
 
 
Author (up) Bonilla, C.; Nebot, M.; Valle, J.W.F.; Srivastava, R.
Title Flavor physics scenario for the 750 GeV diphoton anomaly Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 93 Issue 7 Pages 073009 - 5pp
Keywords
Abstract A simple variant of a realistic flavor symmetry scheme for fermion masses and mixings provides a possible interpretation of the diphoton anomaly as an electroweak singlet “flavon.” The existence of TeV scale vectorlike T-quarks required to provide adequate values for Cabibbo-Kobayashi-Maskawa (CKM) parameters can also naturally account for the diphoton anomaly. Correlations between V-ub and V-cb with the vectorlike T-quark mass can be predicted. Should the diphoton anomaly survive in a future run, our proposed interpretation can also be tested in upcoming B and LHC studies.
Address [Bonilla, Cesar; Nebot, Miguel; Valle, Jose W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient Paterna C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: cesar.bonilla@ific.uv.es;
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:000374548300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2669
Permanent link to this record
 
 
Author (up) Bonilla, C.; Romao, J.C.; Valle, J.W.F.
Title Neutrino mass and invisible Higgs decays at the LHC Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 91 Issue 11 Pages 113015 - 7pp
Keywords
Abstract The discovery of the Higgs boson suggests that neutrinos also get their mass from spontaneous symmetry breaking. In the simplest ungauged lepton-number scheme, the Standard Model Higgs now has two other partners: a massive CP-even scalar, and the massless Nambu-Goldstone boson, called the Majoron. For weak-scale breaking of lepton number the invisible decays of the CP-even Higgs bosons to the Majoron lead to potentially copious sources of events with large missing energy. Using LHC results, we study how the constraints on invisible decays of the Higgs boson restrict the relevant parameters, substantially extending those previously derived from LEP and potentially shedding light on the scale of spontaneous lepton-number violation.
Address [Bonilla, Cesar; Valle, Jose W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46980 Paterna, Valencia, Spain, Email: cesar.bonilla@ific.uv.es;
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000356928900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2285
Permanent link to this record
 
 
Author (up) Borexino Collaboration (Bellini, G. et al); Pena-Garay, C.
Title Final results of Borexino Phase-I on low-energy solar neutrino spectroscopy Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 89 Issue 11 Pages 112007 - 68pp
Keywords
Abstract Borexino has been running since May 2007 at the Laboratori Nazionali del Gran Sasso laboratory in Italy with the primary goal of detecting solar neutrinos. The detector a large unsegmented liquid scintillator calorimeter characterized by unprecedented low levels of intrinsic radioactivity is optimized for the study of the lower energy part of the spectrum. During Phase-I (2007-2010) Borexino first detected and then precisely measured the flux of the Be-7 solar neutrinos ruled out any significant day-night asymmetry of their interaction rate made the first direct observation of the pep neutrinos and set the tightest upper limit on the flux of solar neutrinos produced in the CNO cycle (carbon nitrogen oxigen) where carbon nitrogen and oxygen serve as catalysts in the fusion process. In this paper we discuss the signal signature and provide a comprehensive description of the backgrounds quantify their event rates describe the methods for their identification selection or subtraction and describe data analysis. Key features are an extensive in situ calibration program using radioactive sources the detailed modeling of the detector response the ability to define an innermost fiducial volume with extremely low background via software cuts and the excellent pulse-shape discrimination capability of the scintillator that allows particle identification. We report a measurement of the annual modulation of the Be-7 neutrino interaction rate. The period the amplitude and the phase of the observed modulation are consistent with the solar origin of these events and the absence of their annual modulation is rejected with higher than 99% C.L. The physics implications of Phase-I results in the context of the neutrino oscillation physics and solar models are presented.
Address [Bellini, G.; Avanzini, M. Buizza; Caccianiga, B.; D'Angelo, D.; Giammarchi, M.; Lombardi, P.; Ludhova, L.; Meroni, E.; Miramonti, L.; Ranucci, G.; Re, A.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000338663100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1856
Permanent link to this record
 
 
Author (up) Botella, F.J.; Branco, G.C.; Nebot, M.; Sanchez, A.
Title Mixing asymmetries in B meson systems, the D0 like-sign dimuon asymmetry, and generic new physics Type Journal Article
Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 91 Issue 3 Pages 035013 - 14pp
Keywords
Abstract The measurement of a large like-sign dimuon asymmetry A(SL)(b) by the D0 experiment at the Tevatron departs noticeably from Standard Model (SM) expectations and it may be interpreted as a hint of physics beyond the Standard Model contributing to Delta B not equal 0 transitions. In this work we analyze how the natural suppression of A(SL)(b) in the SM can be circumvented by new physics. We consider generic Standard Model extensions where the charged current mixing matrix is enlarged with respect to the usual 3 x 3 unitary Cabibbo-Kobayashi-Maskawa matrix, and show how, within this framework, a significant enhancement over Standard Model expectations for Ab SL is easily reachable through enhancements of the semileptonic asymmetries A(SL)(d) and A(SL)(s) of both B-d(0)- (B) over bar (0)(d) and B-s(0)- (B) over bar (0)(s) systems. Despite being insufficient to reproduce the D0 measurement, such deviations from SM expectations may be probed by the LHCb experiment.
Address [Botella, F. J.; Sanchez, A.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: fbotella@uv.es;
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000349918300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2137
Permanent link to this record
 
 
Author (up) Botella, F.J.; Branco, G.C.; Rebelo, M.N.; Silva-Marcos, J.I.
Title What if the masses of the first two quark families are not generated by the standard model Higgs boson? Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 94 Issue 11 Pages 115031 - 6pp
Keywords
Abstract We point out that in the standard model there is meaningful quark mixing even in the extreme chiral (EC) limit, where only the third generation of quarks acquires mass. This mixing is in general expected to be of order 1 and the fact that |V-13|(2) + |V-23|(2) approximate to 1.6 x 10(-3) implies a novel fine-tuning problem in the SM which we point out for the first time. We propose a possible way of avoiding this fine-tuning by introducing a symmetry S which leads to V-CKM = 1, with only the third generation of quarks acquiring mass. We consider two scenarios for generating the mass of the first two quark generations and full quark mixing based on the assumption that the masses of the first two quark families are not generated by the standard Higgs. One consists of the introduction of a second Higgs doublet which is neutral under S. The second scenario consists of assuming new physics at a high energy scale, contributing to the masses of light quark generations, in an effective field theory approach. This last scenario leads to couplings of the Higgs particle to s (s) over bar and c (c) over tilde which are significantly enhanced with respect to those of the SM. In both schemes, one has scalar-mediated flavor-changing neutral currents which are naturally suppressed. Flavor-violating top decays are predicted in the second scenario at the level Br(t -> hc) >= 5 x 10(-5).
Address [Botella, F. J.] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: fbotella@uv.es;
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:000391016600004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2931
Permanent link to this record
 
 
Author (up) Botella, F.J.; Cornet-Gomez, F.; Nebot, M.
Title Electron and muon g-2 anomalies in general flavor conserving two-Higgs-doublet models Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 102 Issue 3 Pages 035023 - 19pp
Keywords
Abstract In general two-Higgs-doublet models (2HDMs) without scalar flavor changing neutral couplings (SFCNC) in the lepton sector, the electron, muon, and tau interactions can be decoupled in a robust framework, stable under renormalization group evolution. In this framework, the breaking of lepton flavor universality (LFU) goes beyond the mass proportionality, opening the possibility to accommodate in a simple manner a different behavior among charged leptons. We analyze simultaneously the electron and muon (g – 2) anomalies in the context of these general flavor conserving models in the leptonic sector (gtlFC). We consider two different models, I-gtlFC and II-gelFC, in which the quark Yukawa couplings coincide, respectively, with the ones in type I and in type II 2HDMs. We find two types of solutions that fully reproduce both (g – 2) anomalies, and which are compatible with experimental constraints from LEP and LHC, from LFU, from flavor and electroweak physics, and with theoretical constraints in the scalar sector. In the first type of solution, all the new scalars have masses in the 1-2.5 TeV range, the vacuum expectation values (vevs) of both doublets are quite similar in magnitude, and both anomalies are dominated by two loop Barr-Zee contributions. This solution appears in both models. There is a second type of solution, where one loop contributions are dominant in the muon anomaly, all new scalars have masses below 1 TeV, and the ratio of vevs is in the range 10-100. The second neutral scalar H is the lighter among the new scalars, with a mass in the 210-390 GeV range while the pseudoscalar A is the heavier, with a mass in the range 400-900 GeV. The new charged scalar H-+/- is almost degenerate either with the scalar or with the pseudoscalar. This second type of solution only appears in the I-gelFC model. Both solutions require the soft breaking of the Z(2) symmetry of the Higgs potential.
Address [Botella, Francisco J.; Cornet-Gomez, Fernando] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: Francisco.J.Botella@uv.es;
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000562002500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4508
Permanent link to this record