Phenomenlogical Aspects of Mirage Mediation Yeong Gyun Kim (Sejong U. & KAIST) Neutralino Dark Matter in Mirage Mediation (thermal relic density, direct detection) LHC signature of Mirage Mediation

Neutralino Dark Matter in Mirage Mediation In collaboration with K.Choi, K.Y.Lee, Y.Shimizu (KAIST) K.Okumura (Tohoku University) Ref. JCAP 0612 (2006) 017

In KKLT-type moduli stabilization scenario  Modulus mediated contribution to SSB parameters at M GUT Mirage Mediation can be comparable to the anomaly mediated one O (m 3/2 /4pi 2 ) when the gravitino mass m 3/2 ~ 10 TeV.  Depending upon the anomaly to modulus mediation ratio the model can lead to a highly distinctive pattern of superpaticle masses at low energy scale.

 The soft parameters at M GUT are determined to be where a ijk = a i + a j + a k, and c i parameterize the pattern of the pure modulus mediated soft masses. b a and gamma i : beta function and anomalous dim.

 An interesting consequence of this mixed modulus-anomaly mediation is that soft masses are unified at a mirage messenger scale For instance,

The original KKLT compactification of IIB theory gives (T : Calabi-Yau volume modulus) modulus Kahler potential modulus superpotential matter Kahler metric gauge kinetic function uplifting potential n i are rational numbers depending on the origin of matter superfield. (e.g, n i =0 for matter fields living on D7 brane)

(alpha, M 0 ) parameter space with a H =c H =0 and a M =c M =1/2 tan(beta)=10 tan(beta)=35 small alpha : Bino-like, large alpha : Higgsino-like Alpha > 2 : No EWSB, Bino-Higgsino Mixing Region appear Choi, YGK, Lee, Okumura, Shimizu (2006)

When alpha increases, the lightest neutralino is changed from Bino- like to Higgsino-like via Bino-Higgsino mixed region Larger alpha  smaller M 3 (relative to M 1 )  reduced mu at EW scale M 3 ~M 0 (1-0.3 alpha), while M 1 ~M 0 (1+0.7 alpha) at GUT scale

tan(beta)=10tan(beta)=35 and Direct detection (SI cross section vs. m LSP )

Summary of the neutralino DM part  Depending upon the model parameters, especially the anomaly to modulus mediation ratio, the nature of the LSP is changed from Bino-like neutralino to Higgsino-like one via Bino-Higgsino mixing region.  For the Bino-like LSP, the standard thermal production mechanism can give a right amount of relic DM density through pseudo-scalar Higgs resonance effect or the stau-neutralino or stop-neutralino coannihilation process.  Neutralino DM might be detected by near future direct detection experiments, especially in the case of Bino-Higgsino mixed LSP.

LHC signature of Mirage Mediation In collaboration with W.Cho, K.Y.Lee, C.Park, Y.Shimizu (KAIST) Ref. JHEP 0704 (2007) 054

Large Hadron Collider (LHC) : 2007 ~ : not only a discovery machine but also a precision physics tool  proton-proton at 14 TeV  10 fb -1 integrated luminosity per year (first few years)  100 fb -1 per year (designed)

A benchmark point for collider study alpha = 1 M0 = 500 GeV a M =c M =1/2 a H =c H =0 tan(beta)=10 K.Choi, YGK, K.Y.Lee, K.Okumura, Y.Shimizu (2006)

 Mirage benchmark point alpha=1, M 0 =500 GeV, a M =c M =1/2, a H =c H =0, tanb=10 (M1=367 GeV, M2=461 GeV, mu=475 GeV at EW scale) m_gluino= 884 GeV, m_dL=776 GeV, m_t1=545 GeV m_N1 = 355 GeV, m_N2 = 416 GeV, m_eR = 382 GeV  The cascade decay is open ! (m_N2 > m_eR)  Cross section for SUSY events ~ 6 pb We generated SUSY events ( ~ 30 fb -1 luminosity) using PYTHIA (event generator) + PGS (detector simulation)  (cf. mSUGRA )

Precision measurements of sparticle masses at the LHC When the cascade decay is open, a clean SUSY signal is l l + jets + missing events.

Polesello at Paris (Nov. 06)

Event Selection Cuts.

Di-lepton invariant mass distribution for the mirage point with 30 fb -1 lumi. M ll (max) ~ 60 GeV well matched with the generated value

Various distributions for the mirage point m_squark, m_slepton, m_N2, and m_N1 can be determined.

Gluino and squark mass measurement Di-jet invariant mass

Gluino and squark mass measurement Di-jet invariant mass

Squark mass measurement Stransverse mass m_qR vs m_N1

where For  Stransverse mass Lester and Summers (1999)

‘Model-Independent’ Masses

 The mass ratio of gluino to LSP which is quite distinctive from the predictions of mSUGRA type and AMSB type gaugino masses.

Determination of model parameters  Gluino, squark and slepton masses  M 0, alpha and c M  Neutralino masses  Mu (EW scale), tan(beta)  c H and tan(beta)

Determination of model parameters

Conclusions  We have investigated LHC signature of mirage mediation by performing a Monte Carlo study for a benchmark point.  SUSY particle masses are determined in a model independent way. In particular, the measured ratio well reproduce theoretical input value of the benchmark point. Therefore, the benchmark scenario may be distinguishable experimentally from other SUSY scenarios, for example, in which gaugino masses are unified at GUT scale.  Model parameters were obtained from a global fit to observable and well agree with the input values.