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Author Archidiacono, M.; Giusarma, E.; Melchiorri, A.; Mena, O. url  doi
openurl 
  Title Dark radiation in extended cosmological scenarios Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 86 Issue 4 Pages 043509 - 7pp  
  Keywords  
  Abstract (up) Recent cosmological data have provided evidence for a “dark” relativistic background at high statistical significance. Parameterized in terms of the number of relativistic degrees of freedom N-eff, however, the current data seem to indicate a higher value than the one expected in the standard scenario based on three active neutrinos. This dark radiation component can be characterized not only by its abundance but also by its clustering properties, as its effective sound speed and its viscosity parameter. It is therefore crucial to study the correlations among the dark radiation properties and key cosmological parameters, as the dark energy equation of state or the running of the scalar spectral index, with current and future cosmic microwave background data. We find that dark radiation with viscosity parameters different from their standard values may be misinterpreted as an evolving dark energy component or as a running spectral index in the power spectrum of primordial fluctuations.  
  Address [Archidiacono, Maria; Melchiorri, Alessandro] Univ Roma La Sapienza, Dept Phys, I-00185 Rome, 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:000307276500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1122  
Permanent link to this record
 

 
Author Boucenna, M.S.; Morisi, S.; Tortola, M.; Valle, J.W.F. url  doi
openurl 
  Title Bilarge neutrino mixing and the Cabibbo angle Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 86 Issue 5 Pages 051301 - 4pp  
  Keywords  
  Abstract (up) Recent measurements of the neutrino mixing angles cast doubt on the validity of the so-far popular 2 tribimaximal mixing Ansatz. We propose a parametrization for the neutrino mixing matrix where the reactor angle seeds the large solar and atmospheric mixing angles, equal to each other in first approximation. We suggest such a bilarge mixing pattern as a model-building standard, realized when the leading order value of theta(13) equals the Cabibbo angle lambda(C).  
  Address [Boucenna, S. M.; Morisi, S.; Tortola, M.; Valle, J. W. F.] Univ Politecn Valencia, Inst Fis Corpuscular, CSIC, AHEP Grp, E-46071 Valencia, Spain, Email: boucenna@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:000308690400001 Approved no  
  Is ISI yes International Collaboration  
  Call Number IFIC @ pastor @ Serial 1147  
Permanent link to this record
 

 
Author Lu, J.X.; Chen, H.X.; Guo, Z.H.; Nieves, J.; Xie, J.J.; Geng, L.S. url  doi
openurl 
  Title Lambda(c)(2595) resonance as a dynamically generated state: The compositeness condition and the large N-c evolution Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 11 Pages 114028 - 16pp  
  Keywords  
  Abstract (up) Recent studies have shown that the well-established Lambda(c) (2595) resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors (N-c) expansion. We examine three different models fulfilling two body unitarily in coupled-channels, and adopting renormalization schemes where the mass of the Lambda(c)(2595) resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the Lambda(c)(2595) depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the Lambda(c)(2595) in the large N-c expansion, within a scheme involving only the pi Sigma(c) and K Xi(c)', channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of N-c, we show that for moderate N-c > 3 values, the mass and width of the Lambda(c)(2595) deviate from those of a genuine qqq baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the Lambda(c)(2595), in the strict N-c -> infinity limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) subdominant qqq component in the Lambda(c)(2595) resonance wave function, which would become dominant when the number of colors gets sufficiently large.  
  Address [Lu, Jun-Xu; Chen, Hua-Xing; Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@buaa.edu.cn  
  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:000378306600004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2745  
Permanent link to this record
 

 
Author Hirsch, M.; Wang, Z.S. url  doi
openurl 
  Title Heavy neutral leptons at ANUBIS Type Journal Article
  Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 101 Issue 5 Pages 055034 - 9pp  
  Keywords  
  Abstract (up) Recently Bauer et al. [arXiv:1909.13022] proposed ANUBIS, an auxiliary detector to be installed in one of the shafts above the ATLAS or CMS interaction point, as a tool to search for long-lived particles. Here, we study the sensitivity of this proposal for long-lived heavy neutral leptons (HNLs) in both minimal and extended scenarios. We start with the minimal HNL model where both production and decay of the HNLs are mediated by active-sterile neutrino mixing, before studying the case of right-handed neutrinos in a leftright symmetric model. We then consider a U(1)(B-L) extension of the Standard Model (SM). In this model HNLs are produced from the decays of the mostly SM-like Higgs boson, via mixing in the scalar sector of the theory. In all cases, we fmd that ANUBIS has sensitivity reach comparable to the proposed MATHUSLA detector. For the minimal HNL scenario, the contributions from W's decaying to HNLs are more important at ANUBIS than at MATHUSLA, extending the sensitivity to slightly larger HNL masses at ANUBIS.  
  Address [Hirsch, Martin] Univ Valencia Calle, Inst Fis Corpuscular, CSIC, AHEP Grp, Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: mahirsch@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:000522163200007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4358  
Permanent link to this record
 

 
Author Dercks, D.; Dreiner, H.K.; Hirsch, M.; Wang, Z.S. url  doi
openurl 
  Title Long-lived fermions at AL3X Type Journal Article
  Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 99 Issue 5 Pages 055020 - 10pp  
  Keywords  
  Abstract (up) Recently Gligorov et al. [V. V. Gligorov et al., Phys. Rev. D 99, 015023 (2019)] proposed to build a cylindrical detector named AL3X close to the ALICE experiment at interaction point (IP) 2 of the LHC, aiming for discovery of long-lived particles (LLPs) during Run 5 of the HL-LHC. We investigate the potential sensitivity reach of this detector in the parameter space of different new-physics models with long-lived fermions namely heavy neutral leptons (HNLs) and light supersymmetric neutralinos, which have both not previously been studied in this context. Our results show that the AL3X reach can be complementary or superior to that of other proposed detectors such as CODEX-b, FASER, MATHUSLA and SHiP.  
  Address [Dercks, Daniel] DESY, Notkestr 85, D-22607 Hamburg, Germany, Email: daniel.dercks@desy.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:000461906400007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3949  
Permanent link to this record
 

 
Author Arbelaez, C.; Gonzalez, M.; Hirsch, M.; Kovalenko, S.G. url  doi
openurl 
  Title QCD corrections and long-range mechanisms of neutrinoless double beta decay Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 94 Issue 9 Pages 096014 - 5pp  
  Keywords  
  Abstract (up) Recently it has been demonstrated that QCD corrections are numerically important for short-range mechanisms (SRM) of neutrinoless double beta decay (0 nu beta beta) mediated by heavy particle exchange. This is due to the effect of color mismatch for certain effective operators, which leads to mixing between different operators with vastly different nuclear matrix elements (NMEs). In this note we analyze the QCD corrections for long-range mechanisms (LRM), due to diagrams with light-neutrino exchange between a Standard Model (V-A)chi(V-A) and a beyond the SM lepton number violating vertex. We argue that in contrast to the SRM in the LRM case, there is no operator mixing from color-mismatched operators. This is due to a combined effect of the nuclear short-range correlations and color invariance. As a result, the QCD corrections to the LRM amount to an effect no more than 60%, depending on the operator in question. Although less crucial, taken into account QCD running makes theoretical predictions for 0 nu beta beta-decay more robust also for LRM diagrams. We derive the current experimental constraints on the Wilson coefficients for all LRM effective operators.  
  Address [Arbelaez, C.; Gonzalez, M.; Kovalenko, S. G.] Univ Tecn Federico Santa Maria, Ctr Cient Tecnol Valparaiso, Casilla 110-V, Valparaiso, Chile, Email: carolina.arbelaez@usm.cl;  
  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:000388823800017 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2888  
Permanent link to this record
 

 
Author Morisi, S.; Patel, K.M.; Peinado, E. url  doi
openurl 
  Title Model for T2K indication with maximal theta(23) and trimaximal theta(12) Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 5 Pages 053002 - 6pp  
  Keywords  
  Abstract (up) Recently T2K experiment gives hint in favor of large reactor angle theta(13). Most of the models, with tribimaximal mixing at the leading order, can not reproduce such a large mixing angle since they predict typically corrections for the reactor angle of the order theta(13) similar to lambda(2)(C), where lambda(C) similar to 0.2. In this paper, we discuss the possibility to achieve large theta(13) within the T2K region with maximal atmosphericmixing angle, sin(2)theta(23) = 1/2, and trimaximal solar mixing angle, sin(2)theta(12) = 1/3, through the deviation from the exact tribimaximal mixing. We derive the structure of neutrino mass matrix that leads to the large theta(13) leaving maximal theta(23) and trimaximal theta(12). It is shown that such a structure of neutrino mass matrix can arise in a model with S(4) flavor symmetry.  
  Address [Morisi, S; Peinado, E] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: morisi@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:000294567400006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 726  
Permanent link to this record
 

 
Author Capozziello, S.; Harko, T.; Koivisto, T.S.; Lobo, F.S.N.; Olmo, G.J. url  doi
openurl 
  Title Wormholes supported by hybrid metric-Palatini gravity Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 86 Issue 12 Pages 127504 - 5pp  
  Keywords  
  Abstract (up) Recently, a modified theory of gravity was presented, which consists of the superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini. The theory possesses extremely interesting features such as predicting the existence of a long-range scalar field, that explains the late-time cosmic acceleration and passes the local tests, even in the presence of a light scalar field. In this brief report, we consider the possibility that wormholes are supported by this hybrid metric-Palatini gravitational theory. We present here the general conditions for wormhole solutions according to the null energy conditions at the throat and find specific examples. In the first solution, we specify the redshift function, the scalar field and choose the potential that simplifies the modified Klein-Gordon equation. This solution is not asymptotically flat and needs to be matched to a vacuum solution. In the second example, by adequately specifying the metric functions and choosing the scalar field, we find an asymptotically flat spacetime.  
  Address [Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy, Email: capozzie@na.infn.it;  
  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:000312446600010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1280  
Permanent link to this record
 

 
Author Papoulias, D.K. url  doi
openurl 
  Title COHERENT constraints after the COHERENT-2020 quenching factor measurement Type Journal Article
  Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 102 Issue 11 Pages 113004 - 10pp  
  Keywords  
  Abstract (up) Recently, an improved quenching factor (QF) measurement for low-energy nuclear recoils in CsI[Na] has been reported by the COHERENT Collaboration. The new energy-dependent QF is characterized by a reduced systematic uncertainty and leads to a better agreement between the experimental COHERENT data and the Standard Model (SM) expectation. In this work, we report updated constraints on parameters that describe the process of coherent elastic neutrino-nucleus scattering within and beyond the SM, and we also present how the new QF affects their interpretation.  
  Address [Papoulias, D. K.] Univ Valencia, CSIC, AHEP Grp, Inst Fis Corpuscular, Parc Cient Paterna,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: dipapou@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:000599092900001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4651  
Permanent link to this record
 

 
Author Guevara, A.; Lopez Castro, G.; Roig, P. url  doi
openurl 
  Title Improved description of dilepton production in tau(-) -> nu(tau)P(- )decays Type Journal Article
  Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 105 Issue 7 Pages 076007 - 15pp  
  Keywords  
  Abstract (up) Recently, the Belle Collaboration reported the first measurements of the tau(-) -> nu(tau)pi(-) e(+) e(-) branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvement on our previous evaluation of tau(-) -> nu(tau)pi(-) l(+) l(-) decays (l = e, mu). In this paper we improve our calculation of the WP-gamma* vertex by including flavor-symmetry breaking effects in the framework of the resonance chiral theory. We impose QCD short-distance behavior to constrain most parameters and data on the pi(-) e(+) e(-) spectrum reported by the Belle Collaboration to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, which are in good agreement with observations. Analogous calculations for the strangeness-changing tau(-) -> nu(tau) K- l(+) l(-) transitions are reported for the first time. Albeit one expects the m(pi mu+ mu- )spectrum to be measured in Belle-II and the observables with l = e can be improved, it is rather unlikely that the K channels can be measured due to the suppression factor vertical bar V-ud/V-us vertical bar(2) = 0.05.  
  Address [Guevara, Adolfo] Univ Granada, Dept Fis Atom Mol & Nucl, E-18071 Granada, 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:000789304200003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5212  
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