Phenomenological implications of the new Littlest Higgs model with T-parity
Metadatos
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Springer Nature
Materia
Compositeness Models for Dark Matter Specific BSM Phenomenology Vector-Like Fermions
Fecha
2022-11-10Referencia bibliográfica
Illana, J.I., Pérez-Poyatos, J.M. Phenomenological implications of the new Littlest Higgs model with T-parity. J. High Energ. Phys. 2022, 55 (2022). [https://doi.org/10.1007/JHEP11(2022)055]
Patrocinador
Spanish Ministry of Science, Innovation and Universities (PID2019-107844GB-C21/AEI/10.13039/501100011033); Junta de Andalucía (FQM 101, SOMM17/6104/UGR, P18-FR-5057)Resumen
We investigate the parameter space of the new Littlest Higgs model with
T-parity (NLHT) recently introduced to cure some pathologies of the original LHT. The
model requires extra fermion content and additional pseudo-Goldstone bosons. While the
heavy top quark sector is similar, there are both T-odd and T-even heavy quarks and leptons
with masses proportional to just two sets of Yukawa matrices in flavor space, one more than
in the LHT. The new scalars are a singlet and real triplet, T-odd, with masses controlled
by gauge and Yukawa couplings, independent of the spontaneous symmetry breaking scale
f, and hence potentially light. Imposing that no mass exceeds the cutoff scale, applying
current lower bounds on vector-like quarks and assuming a simplified model with mass
degenerate heavy fermions compatible with the heavy photon as dark matter constituent,
we find that f gets constrained within the interval between 2 and 3TeV, the common
Yukawa coupling of heavy leptons gets fixed and the Yukawa coupling of heavy quarks
becomes greatly correlated to the top quark Yukawa couplings. The particle spectrum is
then bounded from below and above, with the (lightest) heavy photon at about 0.5TeV, not
far from the heavy leptons, the new scalars below 1TeV, the usual complex scalar triplet
close to the heavy weak bosons at about 1.5 to 2.5TeV, and the heavy quarks and top
quark partners between 2 and 5TeV. The new scalars decay predominantly to a standard
and a T-odd lepton and have a width comparable to that of the Higgs.