Search for stopped gluinos from pp̄ collisions at s=1.96TeV
Physical Review Letters 99:13 (2007)
Abstract:
Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410pb-1 of pp̄ collisions at s=1.96TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino (χ 10). Limits are placed on the (gluino cross section)×(probability to stop)×[BR(g →gχ 10)] as a function of the gluino and χ 10 masses, for gluino lifetimes from 30μs-100h. © 2007 The American Physical Society.Search for heavy long-lived particles that decay to photons at CDF II.
Phys Rev Lett 99:12 (2007) 121801
Abstract:
We present the first search for heavy, long-lived particles that decay to photons at a hadron collider. We use a sample of gamma + jet + missing transverse energy events in pp[over] collisions at square root[s] = 1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb(-1) of collision data, we observe 2 events, consistent with the background estimate of 1.3+/-0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits in a supersymmetric model with [Formula: see text] and place the world-best 95% C.L. lower limit on the [Formula: see text] mass of 101 GeV/c(2) at [Formula: see text].Combined D0 measurements constraining the CP-violating phase and width difference in the Bs0 system
Physical Review D - Particles, Fields, Gravitation and Cosmology 76:5 (2007)
Abstract:
We combine the D0 measurement of the width difference between the light and heavy Bs0 mass eigenstates and of the CP-violating mixing phase determined from the time-dependent angular distributions in the Bs0→J/ψ decays along with the charge asymmetry in semileptonic decays also measured with the D0 detector. With the additional constraint from the world average of the flavor-specific Bs0 lifetime, we obtain ΔΓs≡(ΓL- ΓH)=0.13±0.09ps-1 and | s|=0.70-0.47+0.39 or ΔΓs=-0. 13±0.09ps-1 and | s|=2.44-0.39+0.47. The data sample corresponds to an integrated luminosity of 1.1fb-1 accumulated with the D0 detector at the Fermilab Tevatron Collider. © 2007 The American Physical Society.Search for heavy long-lived particles that decay to photons at CDF II
Physical Review Letters 99:12 (2007)
Abstract:
We present the first search for heavy, long-lived particles that decay to photons at a hadron collider. We use a sample of Î+jet+missing transverse energy events in pp collisions at s=1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570pb-1 of collision data, we observe 2 events, consistent with the background estimate of 1.3 0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits in a supersymmetric model with I E 10 GE and place the world-best 95% C.L. lower limit on the χ˜10 mass of 101 GeV/c2 at Ï.,χ˜10=5ns. © 2007 The American Physical Society.International Linear Collider Reference Design Report Volume 2: PHYSICS AT THE ILC
ArXiv 0709.1893 (2007)