Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSUSY Higgs at the LHC: Effects of light charginos and neutralinos
52
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In view of the latest LEP data we consider the effects of charginos and neutralinos on the two-photon and bbbar signatures of the Higgs at the LHC. Assuming the usual GUT inspired relation between M_1 and M_2 we show that there are only small regions with moderate tanbeta and large stop mixings that may be dangerous. Pathological models not excluded by LEP which have degeneracy between the sneutrino and the chargino are however a real danger because of large branching fraction of the Higgs into invisibles. We have also studied models where the gaugino masses are not unified at the GUT scale. We take M_1=M_2/10 as an example where large reductions in the signal at the LHC can occur. However we argue that such models with a very light neutralino LSP may give a too large relic density unless the sleptons are light. We then combine this cosmological constraint with neutralino production with light sfermions to further reduce the parameter space that precludes observability of the Higgs at the LHC. We still find regions of parameter space where the drops in the usual Higgs signals at the LHC can be drastic. Nonetheless, in such scenarios where Higgs may escape detection we show that one should be able to produce all charginos and neutralinos. Although the heavier of these could cascade into the Higgs, the rates are not too high and the Higgs may not always be recovered this way.
rate research
Read More
Recent results on MSSM Higgs physics at the LHC are reviewed. The dependence of the LHC discovery reach in the bbar b H/A, H/A to tau^+tau^- channel on the underlying SUSY scenario is analysed. This is done by combining the latest results for the prospective CMS experimental sensitivities for an integrated luminosity of 30 or 60 fb^-1 with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in terms of the parameters governing the MSSM Higgs sector at lowest order, M_A and tan_beta. While the higgsino mass parameter mu has a significant impact on the prospective discovery reach (and correspondingly the ``LHC wedge region), it is found that the discovery reach is rather stable with respect to variations of other supersymmetric parameters. Within the discovery region a determination of the masses of the heavy neutral Higgs bosons with an accuracy of 1-4% seems feasible. It is furthermore shown that Higgs-boson production in central exclusive diffractive channels can provide important information on the properties of the neutral MSSM Higgs bosons.
The region of the supersymmetry parameter space, in which charginos decay predominantly into sneutrinos and leptons: chi+ -> tilde{ u} + l+, is not excluded experimentally for small mass differences between charginos and sneutrinos. The decay sneutrinos are invisible in R-parity conserving theories since they are either the lightest supersymmetric particles or they decay primarily into the channel: neutrino + lightest neutralino. If the energy of the decay leptons is so small that they escape detection, chargino events e+e- -> chi+chi- in e+e- collisions remain invisible, eroding the excluded chargino mass range at LEP. This region of the supersymmetry parameter space can partly be covered by searching for single W events in e+e- -> W+W-$, with one W boson decaying to leptons or quark jets, but the second W boson decaying to (undetected) charginos and neutralinos.
We study the muon $(g-2)_{mu}$ anomaly in light of neutralino dark matter and the LHC. We scan the MSSM parameters relevant to $(g-2)_{mu}$ and focus on three distinct cases with different neutralino compositions. We find that the 2$sigma$ range of $(g-2)_{mu}$ requires the smuon ($tilde{mu}_1$) to be lighter than $sim$ 500 (1000) GeV for $tan beta=10,(50)$. Correspondingly the two lightest neutralinos, $tilde{chi}_{1}^0, tilde{chi}_{2}^0$, have to be lighter than $sim$ 300 (650) GeV and 900 (1000) GeV respectively. We explore the prospects of searching the light smuon and neutralinos at the LHC, in conjunction with constraints arising from indirect dark matter (DM) detection experiments. The upcoming run of the LHC will be able to set $95%$ CL exclusion limit on $M_{tilde{chi}_{2}^0}$ ($sim 475 - 1300$ GeV) and $m_{tilde{l}}$ ($sim 670-775$ GeV) with $M_{tilde{chi}_{1}^0} sim 100-250$ GeV at 3000 fb$^{-1}$ luminosity in multi-lepton + missing energy channel.
We discuss the production of charginos, neutralinos, and third generation sfermions in $e^+e^-$ annihilation in the energy range $sqrt{s} = 0.2-1$ TeV. We present numerical predictions within the Minimal Supersymmetric Standard Model for the cross sections and study the importance of beam polarization for the determination of the underlying SUSY parameters.
We review the most relevant LHC searches at $sqrt{s}$ = 8 TeV looking for low mass bosons arising from exotic decay of the Standard Model Higgs and highlighting their impact on both supersymmetric and not supersymmetric Beyond the Standard Model scenarios.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
