Autor(es): Fichet, Sylvain [UNESP] ; von Gersdorff, Gero [UNESP]
Data: 2018
Identificador Persistente: http://hdl.handle.net/11449/161086
Origem: Oasisbr
Assunto(s): Beyond Standard Model; Field Theories in Higher Dimensions; Effective field theories; Beyond Standard Model; Beyond Standard Model; Field Theories in Higher Dimensions; Field Theories in Higher Dimensions; Effective field theories; Effective field theories
Made available in DSpace on 2018-11-26T16:19:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-12-15
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
We classify the complete set of dimension-5 operators relevant for the resonant production of a singlet of spin 0 or 2 linearly coupled to the Standard Model (SM). We compute the decay width of such states as a function of the effective couplings, and provide the matching to various well-motivated New Physics scenarios. We then investigate the possibility that one of these neutral resonances be at the origin of the excess in diboson production recently reported by the ATLAS collaboration. We perform a shape analysis of the excess under full consideration of the systematic uncertainties to extract the width inverted right perpendicular(tot) of the hypothetical resonance, finding it to be in the range 26 GeV < inverted right perpendicular(tot) < 144 GeV at 95% C.L. We then point out that the three overlapping selections W W , W Z, ZZ reported by ATLAS follow a joint trivariate Poisson distribution, which opens the possibility of a thorough likelihood analysis of the event rates. The background systematic uncertainties are also included in our analysis. We show that the data do not require WZ production and could thus in principle be explained by neutral resonances. We then use both the information on the width and the cross section, which prove to be highly complementary, to test the effective Lagrangians of singlet resonances. Regarding specific models, we find that neither scalars coupled via the Higgs-portal nor the Randall-Sundrum (RS) radion can explain the ATLAS anomaly. The RS graviton with all matter on the infrared (IR) brane can in principle fit the observed excess, while the RS model with matter propagating in the bulk requires the presence of IR brane kinetic terms for the gauge fields.
Sao Paulo State Univ, Inst Fis Teor, ICTP South Amer Inst Fundamental Res, Sao Paulo, Brazil
Sao Paulo State Univ, Inst Fis Teor, ICTP South Amer Inst Fundamental Res, Sao Paulo, Brazil
