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Author Chiang, C.W.; Cottin, G.; Eberhardt, O.
Title Global fits in the Georgi-Machacek model Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 1 Pages 015001 - 21pp
Keywords
Abstract Off the beaten track of scalar singlet and doublet extensions of the Standard Model, triplets combine an interesting LHC phenomenology with an explanation for neutrino masses. The Georgi-Machacek model falls into this category, but it has never been fully explored in a global fit. We use the HEPfit package to combine recent experimental Higgs data with theoretical constraints and obtain strong limits on the mixing angles and mass differences between the heavy new scalars as well as their decay widths. We also find that the current signal strength measurements allow for a Higgs to vector boson coupling with an opposite sign to the Standard Model, but this possibility can be ruled out by the lack of direct evidence for heavy Higgs states. For these hypothetical particles, we identify the dominant decay channels and extract bounds on their branching ratios from the global fit, which can be used to single out the decay patterns relevant for the experimental searches.
Address [Chiang, Cheng-Wei; Cottin, Giovanna] Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan, Email: chengwei@phys.ntu.edu.tw;
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000454768700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3862
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Author Heisenberg, L.; Ramirez, H.; Tsujikawa, S.
Title Inflation with mixed helicities and its observational imprint on CMB Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 2 Pages 023505 - 14pp
Keywords
Abstract In the framework of effective field theories with prominent helicity-0 and helicity-1 fields coupled to each other via a dimension-3 operator, we study the dynamics of inflation driven by the helicity-0 mode, with a given potential energy, as well as the evolution of cosmological perturbations, influenced by the presence of a mixing term between both helicities. In this scenario, the temporal component of the helicity-1 mode is an auxiliary field and can be integrated out in terms of the time derivative of the helicity-0 mode, so that the background dynamics effectively reduces to that in single-field inflation modulated by a parameter beta associated to the coupling between helicity-0 and helicity-1 modes. We discuss the evolution of a longitudinal scalar perturbation psi and an inflaton fluctuation delta phi, and we explicitly show that a particular combination of these two, which corresponds to an isocurvature mode, is subject to exponential suppression by the vector mass comparable to the Hubble expansion rate during inflation. Furthermore, we find that the effective single-field description corrected by beta also holds for the power spectrum of curvature perturbations generated during inflation. We compute the standard inflationary observables such as the scalar spectral index n(s), and the tensorto-scalar ratio r and confront several inflaton potentials with the recent observational data provided by Planck 2018. Our results show that the coupling between helicity-0 and helicity-1 modes can lead to a smaller value of the tensor-to-scalar ratio especially for small-field inflationary models, so our scenario exhibits even better compatibility with the current observational data.
Address [Heisenberg, Lavinia] Swiss Fed Inst Technol, Inst Theoret Phys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000454769400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3864
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Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.
Title Study of the reactions e(+)e(-) -> pi(+)pi(-)pi(0)pi(0)pi(0) and pi(+)pi(-) pi(0)pi(0)eta at center-of-mass energies from threshold to 4.35 GeV using initial-state radiation Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 11 Pages 112015 - 23pp
Keywords
Abstract We study the processes e(+)e--> pi(+)pi(-)pi(0)pi(0)pi(0)gamma and pi(+)pi(-)pi(0)pi(0)eta gamma in which an energetic photon is radiated from the initial state. The data are collected with the BABAR detector at SLAC. About 14 000 and 4700 events, respectively, are selected from a data sample corresponding to an integrated luminosity of 469 fb(-1). The invariant mass of the hadronic final state defines the effective e(+)e(-) center-of-mass energy. From the mass spectra, the first precise measurement of the e(+)e--> pi(+)pi(-)pi(0)pi(0)pi(0) cross section and the first measurement ever of the e(+)e--> pi(+)pi(-)pi(0)pi(0)pi(0)eta cross section are performed. The center-of-mass energies range from threshold to 4.35 GeV. The systematic uncertainty is typically between 10% and 13%. The contributions from omega pi(0)pi(0), eta pi(+)pi(-) and other intermediate states are presented. We observe the J/psi and psi(2S) in most of these final states and measure the corresponding branching fractions, many of them for the first time.
Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, Lab Annecy Le Vieux Phys Particules LAPP, F-74941 Annecy Le Vieux, France
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000454634400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3866
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Author Carames, T.F.; Vijande, J.; Valcarce, A.
Title Exotic bc(q)over-bar(q)over-bar four-quark states Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 1 Pages 014006 - 9pp
Keywords
Abstract We carry out a systematic study of exotic QQ'(q) over bar(q) over bar four-quark states containing distinguishable heavy flavors, b and c. Different generic constituent models are explored in an attempt to extract general conclusions. The results are robust, predicting the same sets of quantum numbers as the best candidates to lodge bound states independently of the model used, the isoscalar J(P) = 0(+) and J(P) = 1(+) states. The first state would be strong and electromagnetic-interaction stable, while the second would decay electromagnetically to (B) over barD gamma. Isovector states are found to be unbound, preventing the existence of charged partners. The interest on exotic heavy-light tetraquarks with nonidentical heavy flavors comes reinforced by the recent estimation of the production rate of the isoscalar bc (u) over bar(d) over bar J(P) = 1(+) state, 2 orders of magnitude larger than that of the bb (u) over bar(d) over bar analogous state.
Address [Carames, T. F.; Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: carames@usal.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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000455060900002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3874
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Author Lopez-Honorez, L.; Mena, O.; Villanueva-Domingo, P.
Title Dark matter microphysics and 21 cm observations Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 2 Pages 023522 - 12pp
Keywords
Abstract Dark matter interactions with massless or very light standard model particles, as photons or neutrinos, may lead to a suppression of the matter power spectrum at small scales and of the number of low mass haloes. Bounds on the dark matter scattering cross section with light degrees of freedom in such interacting dark matter (IDM) scenarios have been obtained from e.g., early time cosmic microwave background physics and large scale structure observations. Here we scrutinize dark matter microphysics in light of the claimed 21 cm EDGES 78 MHz absorption signal. IDM is expected to delay the 21 cm absorption features due to collisional damping effects. We identify the astrophysical conditions under which the existing constraints on the dark matter scattering cross section could be largely improved due to the IDM imprint on the 21 cm signal, providing also an explicit comparison to the WDM scenario.
Address [Lopez-Honorez, Laura] Univ Libre Bruxelles, Serv Phys Theor, CP225,Blvd Triomphe, B-1050 Brussels, Belgium, Email: llopezho@ulb.ac.be;
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000456291400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3885
Permanent link to this record