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Author Reig, M.
Title The stochastic axiverse Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue (down) 9 Pages 207 - 40pp
Keywords Cosmology of Theories beyond the SM; Beyond Standard Model; Compactification and String Models
Abstract In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, the plenitude of axions appearing in the string axiverse may have potentially dangerous implications. An example is the cosmological overproduction of relic axions and moduli by the misalignment mechanism, more pronounced in regions where the signals mentioned above may be observable, that is for large axion decay constant. In this work, we study the minimal requirements to soften this problem and show that the fundamental requirement is a long period of low-scale inflation. However, in this case, if the inflationary Hubble scale is lower than around O(100) eV, no relic DM axion is produced in the early Universe. Cosmological production of some axions may be activated, via the misalignment mechanism, if their potential minimum changes between inflation and today. As a particular example, we study in detail how the maximal-misalignment mechanism dilutes the effect of dangerous axions and allows the production of axion DM in a controlled way. In this case, the potential of the axion that realises the mechanism shifts by a factor increment theta = pi between the inflationary epoch and today, and the axion starts to oscillate from the top of its potential. We also show that axions with masses m(a) similar to O(1 – 100) H-0 realising the maximal-misalignment mechanism generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales. Finally, we briefly study the basic phenomenological implications of the mechanism and comment on the compatibility of this type of maximally-misaligned quintessence with the swampland criteria.
Address [Reig, Mario] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedratico Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: mario.reig@ifis.uv.es
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:000702371800004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4977
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Author Edelhauser, L.; Porod, W.; Singh, R.K.
Title Spin discrimination in three-body decays Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue (down) 8 Pages 053 - 31pp
Keywords Beyond Standard Model; Supersymmetric Standard Model
Abstract The identification of the correct model for physics beyond the Standard Model requires the determination of the spin of new particles. We investigate to which extent the spin of a new particle X can be identified in scenarios where it decays dominantly in three-body decays X -> f (f) over barY. Here we assume that Y is a candidate for dark matter and escapes direct detection at a high energy collider such as the LHC. We show that in the case that all intermediate particles are heavy, one can get information on the spins of X and Y at the LHC by exploiting the invariant mass distribution of the two standard model fermions. We develop a model-independent strategy to determine the spins without prior knowledge of the unknown couplings and test it in a series of Monte Carlo studies.
Address [Edelhaeuser, Lisa; Porod, Werner; Singh, Ritesh K.] Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany, Email: ledelhaeuser@physik.uni-wuerzburg.de
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000282368500014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 355
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Author Barenboim, G.; Panotopoulos, G.
Title Direct neutralino searches in the NMSSM with gravitino LSP in the degenerate scenario Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue (down) 8 Pages 027 - 16pp
Keywords Beyond Standard Model; Cosmology of Theories beyond the SM; Supersymmetric Standard Model
Abstract In the present work a two-component dark matter model is studied adopting the degenerate scenario in the R-parity conserving NMSSM. The gravitino LSP and the neutralino NLSP are extremely degenerate in mass, avoiding the BBN bounds and obtaining a high reheating temperature for thermal leptogenesis. In this model both gravitino (absolutely stable) and neutralino (quasi-stable) contribute to dark matter, and direct detection searches for neutralino are discussed. Points that survive all the constraints correspond to a singlino-like neutralino.
Address [Barenboim, G] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: gabriela.barenboim@uv.es
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000294901400055 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 771
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Author Coloma, P.; Donini, A.; Lopez-Pavon, J.; Minakata, H.
Title Non-standard interactions at a neutrino factory: correlations and CP violation Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue (down) 8 Pages 036 - 41pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract We explore the potential of several Neutrino Factory (NF) setups to constrain, discover and measure new physics effects due to Non-Standard Interactions (NSI) in propagation through Earth matter. We first study the impact of NSI in the measurement of theta(13): we find that these could be large due to strong correlations of theta(13) with NSI parameters in the golden channel, and the inclusion of a detector at the magic baseline is crucial in order to reduce them as much as possible. We present, then, the sensitivity of the considered NF setups to the NSI parameters, paying special attention to correlations arising between them and the standard oscillation parameters, when all NSI parameters are introduced at once. Off-diagonal NSI parameters could be tested down to the level of 10(-3), whereas the diagonal combinations (epsilon(ee) – epsilon(tau tau)) and (epsilon(mu mu) – epsilon(tau tau)) can be tested down to 10(-1) and 10(-2), respectively. The possibilities of observing CP violation in this context are also explored, by presenting a first scan of the CP discovery potential of the NF setups to the phases phi(e mu), phi(e tau) and delta. We study separately the case where CP violation comes only from non-standard sources, and the case where it is entangled with the standard source, delta. In case delta turns out to be CP conserving, the interesting possibility of observing CP violation for reasonably small values of the NSI parameters emerges.
Address [Coloma, P] Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain, Email: p.coloma@uam.es
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000294901400046 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 772
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Author Li, X.Q.; Yang, Y.D.; Yuan, X.B.
Title Anomalous (t q photon) coupling effects in exclusive radiative B-meson decays Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue (down) 8 Pages 075 - 22pp
Keywords Beyond Standard Model; B-Physics
Abstract The top-quark FCNC processes will be searched for at the CERN LHC, which are correlated with the B-meson decays. In this paper, we study the e ff ects of top-quark anomalous interactions tq gamma in the exclusive radiative B --> K*gamma and B --> rho gamma decays. With the current experimental data of the branching ratios, the direct CP and the isospin asymmetries, bounds on the coupling kappa(gamma)(tcR) from B --> K*gamma and kappa(gamma)(tuR) from B --> rho gamma decays are derived, respectively. The bound on vertical bar kappa(gamma)(tcR)vertical bar from B (B --> K*gamma) is generally compatible with that from B (B --> X(s)gamma). However, the isospin asymmetry Delta (K*gamma) further restrict the phase of kappa(gamma)(tuR), and the combined bound results in the upper limit, B (t --> c gamma) < 0 : 21%, which is lower than the CDF result. For real kappa(gamma)(tuR), the upper bound on B (t --> c gamma) is about of the same order as the 5 sigma discovery potential of ATLAS with an integrated luminosity of 10 fb(-1). For B --> rho gamma decays, the NP contribution is enhanced by a large CKM factor vertical bar V(ud)/V(td)vertical bar, and the constraint on tu gamma coupling is rather restrictive, B (t --> u gamma) < 1 : 44 x 10(-5). With re fi ned measurements to be available at the LHCb and the future super-B factories, we can get close correlations between B --> V gamma and the rare t --> q gamma decays, which will be studied directly at the LHC ATLAS and CMS.
Address [Li, XQ] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: xqli@itp.ac.cn
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000294901400007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 773
Permanent link to this record