Cosmological relic density from minimal supergravity with implications for collider physics

Abstract

We review the gauging of an R-symmetry in local and global susy. We then construct the first anomaly-free models. We break the R-symmetry and susy at the Planck scale and discuss the low-energy effects. We include a solution to the mu-problem, and the prediction of observable effects at HERA. The models also nicely allow for GUT-scale baryogenesis and R-parity violation without the sphaleron interactions erasing the baryon-asymmetry.

Collider signals and neutralino dark matter detection in relic-density-consistent models without universality

“…Here, we see that it is quite easy to evade the ILC reach and still have a neutralino relic density consistent with (1.1). This is in contrast to prejudices from studies in the mid-1990s which favored the bulk annihilation region of mSUGRA, which then implied sparticle mass ought to be quite light, and likely accessible to LEP2 and ILC500 searches [9]. The upper bands of mSUGRA model parameter points correspond to the stau co-annihilation region in mSUGRA or in MWDM1 models.…”

“…As a result, only special regions of the mSUGRA parameter space where the annihilation rate for neutralinos is enhanced are compatible with the measured value of the relic density. 1 In early work on the mSUGRA model, the low m 0 , low m 1/2 region (so-called "bulk region"), where sparticles are indeed very light, was favored [9] in that neutralino annihilation into leptons via light t−channel slepton exchange occurred at large rates, leading to relic densities Ω e Z 1 h 2 ∼ 0.3−1. The rather lower measured abundance in (1.1), however, favors even lower values of m 0 and m 1/2 , resulting in considerable tension with the negative search results from LEP2 for chargino and slepton pair production.…”

Mixed higgsino dark matter from a large SU(2) gaugino mass

“…(1.1). For instance, in the mSUGRA model [6], almost all of parameter space is excluded by the precisely measured abundance, and only a few distinct regions where neutralino annihilation is enhanced survive: the nearly excluded bulk region with low masses already mentioned above [7], the stau [8] or stop [9] co-annihilation regions, the hyperbolic branch/focus point (HB/FP) region at large m 0 [10], where the Z 1 becomes mixed higgsino dark matter (with enhanced annihilation to W and Z particles via its higgsino component), or the A or h resonance annihilation (Higgs funnel) region [11,12]. Within the mSUGRA framework, each of these regions leads to characteristic patterns in collider signals at the soon-to-be-operational CERN Large Hadron Collider (LHC), and also to differences in signals in direct and indirect DM search experiments under way.…”

“…We compute the spin independent neutralino-proton scattering cross-section (used as the figure of merit in these experiments), and compare it to projections for the sensitivity of Stage 2 detectors (CDMS2 [48], Edelweiss2 [49], CRESST2 [50], ZEPLIN2 [51]) which are expected to probe a factor of ∼ 5 below the XENON-10 bound. 7 We also compare expectations in the HM2DM model with the projected sensitivity of the proposed SuperCDMS detector with 25 kg of Ge, and with proposed ton-size noble liquid detectors (XENON [53], LUX, WARP [54] and CLEAN [55]), for which we use the sensitivity of Warm Argon Project, with 1400 kg of argon as the benchmark.…”

The soft supersymmetry-breaking Lagrangian: theory and applications

“…There has been a great deal of activity in computing the relic density for various regions of MSSM parameter space [415,416,417,418,419,414,413,420,421,422,423,424,425,426,106,427,428,429,430,431,432,433,434,435,436,437,438,439,440,441,442,443,444,445,446,447,448,449]. The state of the art numerical programs take into account nearly 8000 Feynman diagrams.…”