Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userNMSSM extended with vectorlike particles and the diphoton excess at the LHC
63
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We investigate the parameter space of a model which extends next to minimal supersymmetric standard model (NMSSM) with the vectorlike (VL) particles. We find that the $10+overline{10}$ model can explain the possible diphoton excess recently revealed by the ATLAS and CMS collaborations, although the predicted signal strength is a little smaller than the observed one.
rate research
Read More
We propose an NMSSM scenario that can explain the excess in the diphoton spectrum at 750 GeV recently observed by ATLAS and CMS. We show that in a certain limit with a very light pseudoscalar one can reproduce the experimental results without invoking exotic matter. The 750 GeV excess is produced by two resonant heavy Higgs bosons with masses ~750 GeV, that subsequently decay to two light pseudoscalars. Each of these decays to collimated photon pairs that appear as a single photon in the electromagnetic calorimeter. A mass gap between heavy Higgses mimics a large width of the 750 GeV peak. The production mechanism, containing a strong component via initial b quarks, ameliorates a possible tension with 8 TeV data compared to other production modes. We also discuss other constraints, in particular from low energy experiments. Finally, we discuss possible methods that could distinguish our proposal from other physics models describing the diphoton excess in the Run-II of the LHC.
We explore the detection possibility of light pseudoscalar Higgs boson in the next-to-minimal supersymmetric Standard Model(NMSSM) at the LHC with the center of mass energy, $sqrt{S}=13$ TeV. We focus on the parameter space which provides one of the Higgs boson as the SM-like with a mass of 125 GeV and some of the non-SM-like Higgs bosons can be light having suppressed couplings with fermions and gauge bosons due to their singlet nature. It is observed that for certain region of model parameter space, the singlet like light pseudoscalar can decay to di-photon($gammagamma$) channel with a substantial branching ratio. In this study, we consider this di-photon signal of light pseudoscalar Higgs boson producing it through the chargino-neutralino production and the subsequent decay of neutralino. We consider signal consisting of two photons plus missing energy along with a lepton from the chargino decay. Performing a detailed simulation of the signal and backgrounds including detector effects, we present results for a few benchmark points corresponding to the pseudoscalar Higgs boson mass in the range 60 -100 GeV. Our studies indicate that some of the benchmark points in the parameter space can be probed with a reasonable significance for 100 fb$^{-1}$ integrated luminosity. We also conclude that exploiting this channel it is possible to distinguish the NMSSM from the other supersymmetric models.
Motivated by the possible diphoton excess around $750~rm{GeV}$ observed by ATLAS and CMS at $13~rm{TeV}$, we consider a coloron model from $rm{SU}(3)_1 times rm{SU}(3)_2$ spontaneously breaking to the Standard Model $rm{SU}(3)_C$. A colored massive vector boson is resonantly produced by $q bar q $ in proton collision, followed by a colored scalar cascade decay. This process gives two photons and one jet in the final states. And the kinetic edge of the two photons can be an interpretation of the diphoton excess, while satisfying the dijet, $rm{t}bar{t}$, jet+photon resonance constraints. In this model, due to the large mass of vector resonance, the parton luminosity function ratio between $13~rm{TeV}$ and $8~rm{TeV}$ can be quite large. Therefore, the diphoton excess has not been observed at $8~rm{TeV}$ search. On the other hand, having all the new particles color-charged around $rm{TeV}$, this model predicts new signals at the LHC, which can be validated soon.
We study single production of exotic vectorlike $Y$ quark with electric charge $|Q_{Y}|=4/3$ and its subsequent decay at the High Luminosity LHC (HL-LHC). Most of the vector like quark (VLQ) decays have the electroweak $W$ bosons in the intermediate state. Besides their direct productions singly or pairs, the $W$-bosons are involved in decay chains as a result of the decay of a top quark which contributes to the background. This is particularly the case since vectorlike $Y$ quark, which is estimated to be produced with a high cross-section, can only decay via a $W$ boson and a down type quark ($d,s,b$). We calculate the cross sections of signal (for different couplings and mass values) and relevant Standard Model (SM) backgrounds. After a fast simulation of signal and background events, estimations of the sensitivity to the parameters (mass range 1000-2500 GeV for coupling value $kappa_{Y}=0.5$, and mass range 500-2000 GeV for coupling values $kappa_{Y}=0.3$ and $kappa_{Y}=0.15$) have been presented at the HL-LHC with center of mass energy $sqrt{s}=14$ TeV and integrated luminosity projections of 300 fb$^{-1}$, 1000 fb$^{-1}$ and 3000 fb$^{-1}$.
The next-to-minimal supersymmetric standard model (NMSSM) with an extended Higgs sector offers one of the Higgs boson as the Standard model (SM) like Higgs with a mass around 125 GeV along with other Higgs bosons with lighter and heavier masses and not excluded by any current experiments. At the LHC, phenomenology of these non SM like Higgs bosons is very rich and considerably different from the other supersymmetric models. In this work, assuming one of the Higgs bosons to be the SM like, we revisit the mass spectrum and couplings of non SM like Higgs bosons taking into consideration all existing constraints and identify the relevant region of parameter space. The discovery potential of these non SM like Higgs bosons, apart from their masses, is guided by their couplings with gauge bosons and fermions which are very much parameter space sensitive. We evaluate the rates of productions of these non SM like Higgs bosons at the LHC for a variety of decay channels in the allowed region of the parameter space. Although bb, {tau}{tau} decay modes appear to be the most promising, it is observed that for a substantial region of parameter space the two-photon decay mode has a remarkably large rate. In this work we emphasize that this diphoton mode can be exploited to find the NMSSM Higgs signal and can also be potential avenue to distinguish the NMSSM from the MSSM. In addition, we discuss briefly the various detectable signals of these non SM Higgs bosons at the LHC.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
