Interpreting a CMS lljjP T Excess With the Golden Cascade of the MSSM October 1st, 2014 Journal Club Ben Allanach, Are R. Raklev, and Anders Kvellestad [ ] Natsumi Nagata

Motivation CMS (19.4 fb -1, 8 TeV) Opposite-sign same flavor (OSSF) leptons + 2 jets + missing E T CMS-PAS-SUS m ll [GeV]

Motivation CMS (19.4 fb -1, 8 TeV) Opposite-sign same flavor (OSSF) leptons + 2 jets + missing E T CMS-PAS-SUS σ excess !! m ll [GeV]

Samples and event selection Signal consists of a pair of opposite-sign same-flavor leptons e + e - or μ + μ - p T > 20 GeV and |η| < 2.4 Exclude 1.4 < |η| < 1.6 Opposite-sign opposite-flavor leptons (eμ) are used to estimate the background. Jets (at least two) anti-k T algorithm Jet radius parameter R = 0.5 p T > 40 GeV and |η| < 3.0 Missing energy N jets >= 2 and E T miss > 150 GeV, or N jets >= 3 and E T miss > 100 GeV

Background estimates Flavor-symmetric background - BGs that produce OF pairs as often as SF pairs - dominated by tt-bar processes - BGs in the signal regions estimated from events with OF pairs Drell-Yan events - Drell-Yan production of Z / γ * boson (with jets) - yield same-flavor events - estimated by a control region in the event kinematics which does not overlap with the signal region

Fit results CMS-PAS-SUS Right triangular shaped kinematic

CMS benchmark model CMS-PAS-SUS Roughly in agreement with data

Today’s topic Ben Allanach, Are R. Raklev, and Anders Kvellestad [ ] Interpretation in terms of the first two generation squark decay In this case, there exists an “edge” in m ll - due to kinematics - gives a constraint on parameter space with m ll max = 78.7 GeV

Constraint on SUSY particle masses m ll max = 78.7 GeV

Goal Look for parameter space which accounts for the excess

Strategy Free parameters M 2 Right-handed soft mass (Common to first and second generation) M 1 is determined by the condition for m ll max = 78.7 GeV Squark mass is taken such that the signal rate for the excess is realized Other assumptions All other soft masses decoupled tanβ = 10 (changing it has a negligible effect)

Constraints Jets + missing E T, simplified model (gluino decoupled) ATLAS slepton search ATLAS, CMS, ATLAS,

Results Some parameter region can explain the excess.

Example (fit)

Example (mass spectrum)

g-2

DM relic abundance Coannihilation with sleptons Wino dominate

Prospects More than 10 fb -1 is required to observe squarks

Note ATLAS has not provided a similar analysis of 8 TeV LHC data

Some ideas for future work Focusing on DM phenomenology (latter scenario) We have the neutralino DM. Coannihilation with sleptons play important role Indirect detection, direct detection, Lithium problem… Higgsino in less relevant to the excess g-2 is also interesting

Some ideas for future work Focusing on DM phenomenology (CMS interpretation) We have the neutralino DM, as well as light sbottom Direct detection may be promising Twist-2 interactions Scalar gluon interactions

Some ideas for future work SUSY breaking models ?? Light electroweak gauginos Light sleptons Heavy gluino 1 TeV squarks Heavy or extreemely degenerate staus Heavy or extreemely degenerate 3 rd generation squarks It may be impossible in CMSSM…

Backup

OPOF