Abstract
The Minimal Dilaton Model (MDM) extends the Standard Model (SM) by a singlet scalar, which can be viewed as a linear realization of general dilaton field. This new scalar field mixes with the SM Higgs field to form two mass eigenstates with one of them corresponding to the 125 GeV SM-like Higgs boson reported by the LHC experiments. In this work, under various theoretical and experimental constrains, we perform fits to the latest Higgs data and then investigate the phenomenology of Higgs boson in both the heavy dilaton scenario and the light dilaton scenario of the MDM. We find that: (i) If one considers the ATLAS and CMS data separately, the MDM can explain each of them well, but refer to different parameter space due to the apparent difference in the two sets of data. If one considers the combined data of the LHC and Tevatron, however, the explanation given by the MDM is not much better than the SM, and the dilaton component in the 125-GeV Higgs is less than about 20% at 2 sigma level. (ii) The current Higgs data have stronger constrains on the light dilaton scenario than on the heavy dilaton scenario. (iii) The heavy dilaton scenario can produce a Higgs triple self coupling much larger than the SM value, and thus a significantly enhanced Higgs pair cross section at hadron colliders. With a luminosity of 100 fb^{-1} (10 fb^{-1}) at the 14-TeV LHC, a heavy dilaton of 400 GeV (500 GeV) can be examined. (iv) In the light dilaton scenario, the Higgs exotic branching ratio can reach 43% (60%) at 2 sigma (3 sigma) level when considering only the CMS data, which may be detected at the 14-TeV LHC with a luminosity of 300 fb^{-1} and the Higgs Factory.
Highlights
JHEP01(2014)150 violation of the scale invariance in the Standard Model (SM), i.e., to the fermions and W, Z bosons with strength proportional to their masses, and mimics the behavior of the SM Higgs boson at Run I of the LHC
This new scalar field mixes with the SM Higgs field to form two mass eigenstates with one of them corresponding to the 125 GeV SM-like Higgs boson reported by the LHC experiments
If one considers the combined data of the LHC and Tevatron, the explanation given by the Minimal Dilaton Model (MDM) is not much better than the SM, and the dilaton component in the 125GeV Higgs is less than about 20% at 2σ level. (ii) The current Higgs data have stronger constrains on the light dilaton scenario than on the heavy dilaton scenario. (iii) The heavy dilaton scenario can produce a Higgs triple self coupling much larger than the SM value, and a significantly enhanced Higgs pair cross section at hadron colliders
Summary
The Minimal Dilaton Model extends the SM by one gauge singlet scalar field S which represents a linearized dilaton field, and one fermion field T with the same quantum number as the right-handed top quark which is usually called the top quark partner. Where q3L is the SU(2)L left-handed quark doublet of the third generation, M the scale of the strong dynamics, and LSM is the SM Lagrangian without Higgs potential. Where mS, λS, κ, mH and λH are all free real parameters With such potential, the field S and H will mix to form two CP-even mass eigenstates, i.e. the Higgs boson h and the dilaton s, and the mixing angle θS is defined by. As for the potential, it is more convenient to use f , v, θS, mh and ms as input parameters. In this case, κ, λH and λS can be re-expressed as κ. Where V denotes either W ± or Z boson, f the fermions except for top quark, and Ai is the loop function presented in [50] with particle i running in the loop
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
