Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userWalking from 750 GeV to 950 GeV in the Technipion Zoo
52
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
If the 750 GeV diphoton excess is identified with the color-singlet isosinglet-technipion, $P^0$ (750), in the one-family walking technicolor, as in our previous paper, then there should exist another color-singlet technipion, isotriplet one, $P^{pm,3}$, definitely predicted at around 950 GeV independently of the dynamical details. The $P^{pm,3}(950)$ are produced at the LHC via vector boson and photon fusion processes, predominantly decaying to $W gamma$, and $gammagamma$, respectively. Those walking technicolor signals can be explored at the Run 2, or 3, which would further open a way to a plethora of yet other (colored) technipions.
rate research
Read More
We study kinematic distributions that may help characterise the recently observed excess in diphoton events at 750 GeV at the LHC Run 2. Several scenarios are considered, including spin-0 and spin-2 750 GeV resonances that decay directly into photon pairs as well as heavier parent resonances that undergo three-body or cascade decays. We find that combinations of the distributions of the diphoton system and the leading photon can distinguish the topology and mass spectra of the different scenarios, while patterns of QCD radiation can help differentiate the production mechanisms. Moreover, missing energy is a powerful discriminator for the heavy parent scenarios if they involve (effectively) invisible particles. While our study concentrates on the current excess at 750 GeV, the analysis is general and can also be useful for characterising other potential diphoton signals in the future.
Motivated by the recent excess in the diphoton invariant mass near 750 GeV, we explore a supersymmetric extension of the Standard Model that includes the minimal set of superpartners as well as additional Dirac partner chiral superfields in the adjoint representation for each gauge group. The bino partner pseudoscalar is identified as the 750 GeV resonance, while superpotential interactions between it and the gluino (wino) partners yield production via gluon fusion (decay to photon pairs) at one-loop. The gauginos and these additional adjoint superpartners are married by a Dirac mass and must also have Majorana masses. While a large wino partner Majorana mass is necessary to explain the excess, the gluino can be approximately Dirac-like, providing benefits consistent with being both supersoft (loop corrections to the scalar masses from Dirac gauginos are free of logarithmic enhancements) and supersafe (the experimental limits on the squark/gluino masses can be relaxed due to the reduced production rate). Consistency with the measured Standard Model-like Higgs boson mass is imposed, and a numerical exploration of the parameter space is provided. Models that can account for the diphoton excess are additionally characterized by having couplings that can remain perturbative up to very high scales, while remaining consistent with experimental constraints, the Higgs boson mass, and an electroweak scale which is not excessively fine tuned.
We examine the scenario of a warped extra dimension containing bulk SM fields in light of the observed diphoton excess at 750 GeV. We demonstrate that a spin-2 graviton whose action contains localized kinetic brane terms for both gravity and gauge fields is compatible with the excess, while being consistent with all other constraints. The graviton sector of this model contains a single free parameter, once the mass of the graviton is fixed. The scale of physics on the IR-brane is found to lie in the range of a $sim$ few TeV, relevant to the gauge hierarchy. There remains significant flexibility in the coupled gauge/fermion KK sectors to address the strong constraints arising from precision measurements.
Pair production of colored particles is in general accompanied by production of QCD bound states (onia) slightly below the pair-production threshold. Bound state annihilation leads to resonant signals, which in some cases are easier to see than the decays of the pair-produced constituents. In a previous paper (arXiv:1204.1119) we estimated the bound state signals, at leading order and in the Coulomb approximation, for particles with various spins, color representations and electric charges, and used 7 TeV ATLAS and CMS resonance searches to set rough limits. Here we update our results to include 8 and 13 TeV data. We find that the recently reported diphoton excesses near 750 GeV could indeed be due to a bound state of this kind. A narrow resonance of the correct size could be obtained for a color-triplet scalar with electric charge -4/3 and mass near 375 GeV, if (as a recent lattice computation suggests) the wave function at the origin is somewhat larger than anticipated. Pair production of this particle could have evaded detection up to now. Other candidates may include a triplet scalar of charge 5/3, a triplet fermion of charge -4/3, and perhaps a sextet scalar of charge -2/3.
The recent diphoton excess at the LHC has been explained tentatively by a Standard Model (SM) singlet scalar of 750 GeV in mass, in the association of heavy particles with SM gauge charges. These new particles with various SM gauge charges induce loop-level couplings of the new scalar to $WW$, $ZZ$, $Zgamma$, $gammagamma$, and $gg$. We show that the strength of the couplings to the gauge bosons also determines the production mechanism of the scalar particle via $WW,, ZZ,, Zgamma,, gammagamma,, gg$ fusion which leads to individually distinguishable jet distributions in the final state where the statistics will be improved in the ongoing run. The number of jets and the leading jets transverse momentum distribution in the excess region of the diphoton signal can be used to determine the coupling of the scalar to the gauge bosons arising from the protons which subsequently determine the charges of the heavy particles that arise from various well-motivated models.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
