Search for Heavy Long-Lived Particles that Decay to Photons at CDF II

Abstract

We present the first search for heavy, long-lived particles that decay to photons at a hadron collider. We use a sample of γ+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 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 χ˜01→γG˜ and place the world-best 95% C.L. lower limit on the χ˜01 mass of 101 GeV/c2 at τχ˜01=5 ns

Exotic decays of the 125 GeV Higgs boson

“…These signatures offer opportunities for LHCb [76,77] as well as ATLAS and CMS, but we do not cover them here. A number of relevant experimental searches have already been performed [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95]. In the following sections we examine most of the above decay modes in detail, outline their theoretical motivations, and review existing collider studies and relevant experimental searches.…”

“…An example of a natural theory where such particles may arise in Higgs decays [76] is the twin Higgs [226], though the details are still to be worked out. This issue takes us beyond our current purposes, but this possibility has already received some amount of experimental study, as in [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95]229,230] II. h → E T…”

Nuclear EGFR as Novel Therapeutic Target

“…The broad inducibility of EGFR activation and internalization by cellular stress suggest an essential role of EGFR during regulation of cellular survival. The special role of nuclear EGFR has been underlined by the clinical observation, that detection of nuclear EGFR in tumor biopsies is strongly correlated with treatment resistance and poor prognosis [2,23,24,31,48,49,64].…”

The Hunt for Supersymmetry at the Tevatron

“…As a result, in the SPS8 (Snowmass Points and Slopes, parameters in scenario 8) benchmark, the DØ collaboration excluded an effective Supersymmetry breaking scale below 124 TeV at 95% CL, as well as the lightest neutralino and lightest chargino masses below 175 GeV and 330 GeV, respectively. A search for a long-lived particle that decays into a pair of photons resulted in a 95% CL lower mass limit of 101 GeV on the lightest neutralino at a 5-ns lifetime [13]. Recently, updated results for searches for massive, long-lived particles that decay to photons in the exclusive photon and missing energy final state have been reported by the CDF collaboration [14].…”