Development of novel n+-in-p Silicon Planar Pixel Sensors for HL-LHC
We have been developing highly radiation-tolerant n + -in-p planar pixel sensors for use in the high-luminosity LHC. Novel n + -in-p structures were made using various combinations of the bias structures (punch-through or polysilicon resistor), isolation structures (p-stop or p-spray), and thicknesses ( 320 μ m or 150 μ m ). The 1-chip pixel modules with thin FE-I4 pixel sensors were evaluated using test beams, before and after 2 × 10 15 n eq / cm 2 irradiation. The full depletion voltages were estimated to be 44±10 V and 380±70 V, in the non-irradiated and the irradiated modules, respectively. A reduction of efficiency was observed in the vicinity of the four pixel corners and underneath the bias rail after the irradiation. The global efficiencies were > 99 % and > 95 % in the non-irradiated and the irradiated modules, respectively. The collected charges were uniform in the depth direction at bias voltages well above the full depletion voltages. The encapsulation of vulnerable edges with adhesive or parylene prevented HV sparking. Bump bonding with the SnAg solder bumps was performed at HPK with 150 μ m - and 320 μ m - thick sensors and chips. No disconnection of bumps was observed after 10 thermal cycles between −40 and +50 °C, with a temperature slew rate of > 70 K / min .

title: Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using 4.7 fb-1 of √s = 7 TeV proton-proton collision data
abstract: A search for squarks and gluinos in final states containing jets, missing transverse momentum and no high-p(T) electrons or muons is presented. The data represent the complete sample recorded in 2011 by the ATLAS experiment in 7 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 4.7 fb(-1). No excess above the Standard Model background expectation is observed. Gluino masses below 860 GeV and squark masses below 1320 GeV are excluded at the 95% confidence level in simplified models containing only squarks of the first two generations, a gluino octet and a massless neutralino, for squark or gluino masses below 2 TeV, respectively. Squarks and gluinos with equal masses below 1410 GeV are excluded. In minimal supergravity/constrained minimal supersymmetric Standard Model models with tan beta = 10, A(0) = 0 and mu > 0, squarks and gluinos of equal mass are excluded for masses below 1360 GeV. Constraints are also placed on the parameter space of supersymmetric models with compressed spectra. These limits considerably extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.

title: Effective theories for dark matter nucleon scattering
abstract: A bstractWe reformulate the calculation of the dark matter-nucleon scattering cross sections based on the method of effective field theories. We assume that the scatterings are induced by the exchange of colored mediators, and construct the effective theories by integrating out the colored particles. All of the leading order matching conditions as well as the renormalization group equations are presented. We consider a Majorana fermion, and real scalar and vector bosons for the dark matter and show the results for each case. The treatment for the twist-2 operators is discussed in detail, and it is shown that the scale of evaluating their nucleon matrix elements does not have to be the hadronic scale. The effects of the QCD corrections are evaluated on the assumption that the masses of the colored mediators are much heavier than the electroweak scale. Our formulation is systematic and model-independent, and thus suitable to be implemented in numerical packages, such as micrOMEGAs and DarkSUSY.