اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدInterpreting a CMS $lljjp_T^{rm miss}$ Excess With the Golden Cascade of the MSSM
93
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The CMS experiment recently reported an excess consistent with an invariant mass edge in opposite-sign same flavor (OSSF) leptons, when produced in conjunction with at least two jets and missing transverse momentum. We provide an interpretation of the edge in terms of (anti-)squark pair production followed by the `golden cascade decay for one of the squarks: $tilde q rightarrow tildechi_2^0 q to tilde l l q to tildechi_1^0 q l l$ in the minimal supersymmetric standard model (MSSM). A simplified model involving binos, winos, an on-shell slepton, and the first two generations of squarks fits the event rate and the invariant mass edge. We check consistency with a recent ATLAS search in a similar region, finding that much of the good-fit parameter space is still allowed at the 95% confidence level (CL). However, a combination of other LHC searches, notably two-lepton stop pair searches and jets plus $p_T^{rm miss}$, rule out all of the remaining parameter space at the 95% CL.
قيم البحث
اقرأ أيضاً
The CMS and the ATLAS Collaborations have recently reported on the search for supersymmetry with 35 pb$^{-1}$ of data and have put independent limits on the parameter space of the supergravity unified model with universal boundary conditions at the G
UT scale for soft breaking, i.e., the mSUGRA model. We extend this study by examining other regions of the mSUGRA parameter space in $A_0$ and $tanbeta$. Further, we contrast the reach of CMS and ATLAS with 35 pb$^{-1}$ of data with the indirect constraints, i.e., the constraints from the Higgs boson mass limits, from flavor physics and from the dark matter limits from WMAP. Specifically it is found that a significant part of the parameter space excluded by CMS and ATLAS is essentially already excluded by the indirect constraints and the fertile region of parameter space has yet to be explored. We also emphasize that gluino masses as low as 400 GeV but for squark masses much larger than the gluino mass remain unconstrained and further that much of the hyperbolic branch of radiative electroweak symmetry breaking, with low values of the Higgs mixing parameter $mu$, is essentially untouched by the recent LHC analysis.
We interpret within the phenomenological MSSM (pMSSM) the results of SUSY searches published by the CMS collaboration based on the first ~1 fb^-1 of data taken during the 2011 LHC run at 7 TeV. The pMSSM is a 19-dimensional parametrization of the MSS
M that captures most of its phenomenological features. It encompasses, and goes beyond, a broad range of more constrained SUSY models. Performing a global Bayesian analysis, we obtain posterior probability densities of parameters, masses and derived observables. In contrast to constraints derived for particular SUSY breaking schemes, such as the CMSSM, our results provide more generic conclusions on how the current data constrain the MSSM.
We demonstrate that the $3sigma$ excess observed by ATLAS in the Z + MET channel can be explained within the context of the MSSM. Using the freedom inherent in the pMSSM, we perform a detailed analysis of the parameter space and find a scenario that
describes the excess while simultaneously complying with all other search constraints from the Run I data at 7 and 8 TeV, including the Z + MET analysis by CMS. We generate a small sample of simplified models, using promising models from our existing pMSSM sample as seeds, and study their properties. The successful region is described by the production of 1st/2nd generation squark pairs, followed by their decay into a bino-like neutralino which in turn decays into a Higgsino-like LSP triplet by emitting a Z boson, i.e., $tilde qtotilde Btotilde h$ with $tilde q = tilde Q_L,tilde u_R,$ or $tilde d_R$. The sweet spot for the sparticle spectrum is found to have squark masses in the 500-750 GeV range, with bino masses near 350 GeV with a mass splitting of 150-200 GeV with the Higgsino LSP. If this excess holds, then this scenario predicts that a signal will be observed in the 0l + jets and/or 1l + jets searches in the early operations of Run II.
A recent CMS search for the right handed gauge boson $W_R$ reports an interesting deviation from the Standard Model. The search has been conducted in the $eejj$ channel and has shown a 2.8$sigma$ excess around $m_{eejj} sim 2$ TeV. In this work, we e
xplain the reported CMS excess with R-parity violating supersymmetry (SUSY). We consider resonant selectron and sneutrino production, followed by the three body decays of the neutralino and chargino via an $mathcal{R}-$parity violating coupling. We fit the excess for slepton masses around 2 TeV. The scenario can further be tested in neutrinoless double beta decay ($0 u beta beta$) experiments. GERDA Phase-II will probe a significant portion of the good-fit parameter space.
The ACME collaboration has recently announced a new constraint on the electron EDM, $|d_e| < 1.1 times 10^{-29}, e, {rm cm}$, from measurements of the ThO molecule. This is a powerful constraint on CP-violating new physics: even new physics generatin
g the EDM at two loops is constrained at the multi-TeV scale. We interpret the bound in the context of different scenarios for new physics: a general order-of-magnitude analysis for both the electron EDM and the CP-odd electron-nucleon coupling; 1-loop SUSY, probing sleptons above 10 TeV; 2-loop SUSY, probing multi-TeV charginos or stops; and finally, new physics that generates the EDM via the charm quark or top quark Yukawa couplings. In the last scenario, new physics generates a QULE operator $(q_f bar{sigma}^{mu u}{bar u}_f) cdot (ell {bar{sigma}}_{mu u} {bar e})$, which in turn generates the EDM through RG evolution. If the QULE operator is generated at tree level, this corresponds to a previously studied leptoquark model. For the first time, we also classify scenarios in which the QULE operator is generated at one loop through a box diagram, which include SUSY and leptoquark models. The electron EDM bound is the leading constraint on a wide variety of theories of CP-violating new physics interacting with the Higgs boson or the top quark. We argue that any future nonzero measurement of an electron EDM will provide a strong motivation for constructing new colliders at the highest feasible energies.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
