Kansas State Institutional Dairy Heards 22nd Annual Report

A large report on the 14 heards assessed by the Sunflower Testing Program in July 1, 1940-June 30, 1941.https://scholars.fhsu.edu/buildings/1220/thumbnail.jp

SUSY backgrounds to Standard Model calibration processes at the LHC

One of the first orders of business for LHC experiments after beam turn-on will be to calibrate the detectors using well understood Standard Model (SM) processes such as W and Z production and ttbar production. These familiar SM processes can be used to calibrate the electromagnetic and hadronic calorimeters, and also to calibrate the associated missing transverse energy signal. However, the presence of new physics may already affect the results coming from these standard benchmark processes. We show that the presence of relatively low mass supersymmetry (SUSY) particles may give rise to significant deviations from SM predictions of Z+jets and W+jets events for jet multiplicity $\ge 4$ or $\ge 5$, respectively. Furthermore, the presence of low mass SUSY may cause non-standard deviations to appear in top quark invariant and transverse mass distributions. Thus, effects that might be construed as detector mal-performance could in fact be the presence of new physics. We advocate several methods to check when new physics might be present within SM calibration data.Comment: 14 pages, 6 figures, 3 table

Discovery potential for SUSY at a high luminosity upgrade of LHC14

After completion of the LHC8 run in 2012, the plan is to upgrade the LHC for operation close to its design energy sqrt{s}=14 TeV, with a goal of collecting hundreds of fb^{-1} of integrated luminosity. The time is propitious to begin thinking of what is gained by even further LHC upgrades. In this report, we compute an LHC14 reach for SUSY in the mSUGRA/CMSSM model with an anticipated high luminosity upgrade. We find that LHC14 with 300 (3000) fb^{-1} has a reach for SUSY via gluino/squark searches of m(gluino)\sim3.2 TeV (3.6 TeV) for m(squark)\sim m)gluino), and a reach of m(gluino)\sim1.8 TeV (2.3 TeV) for m(squark)>> m(gluino). In the case where m(squark)>> m(gluino), then the LHC14 reach for chargino-neutralino production with decay into the Wh+MET final state reaches to m(gluino)\sim2.6 TeV for 3000 fb^{-1}.Comment: 9 pages with 4 .eps figure

Is natural higgsino-only dark matter excluded?

The requirement of electroweak naturalness in supersymmetric (SUSY) models of particle physics necessitates light higgsinos not too far from the weak scale characterized by m(weak)~ m(W,Z,h)~100 GeV. On the other hand, LHC Higgs mass measurements and sparticle mass limits point to a SUSY breaking scale in the multi-TeV regime. Under such conditions, the lightest SUSY particle is expected to be a mainly higgsino-like neutralino with non-negligible gaugino components (required by naturalness). The computed thermal WIMP abundance in natural SUSY models is then found to be typically a factor 5-20 below its measured value. To gain concordance with observations, either an additional DM particle (the axion is a well-motivated possibility) must be present or additional non-thermal mechanisms must augment the neutralino abundance. We compare present direct and indirect WIMP detection limits to three natural SUSY models based on gravity-, anomaly- and mirage-mediation. We show that the case of natural higgsino-only dark matter where non-thermal production mechanisms augment its relic density, is essentially excluded by a combination of direct detection constraints from PandaX-II, LUX and Xenon-1t experiments, and by bounds from Fermi-LAT/MAGIC observations of gamma rays from dwarf spheroidal galaxies.Comment: 16 pages with 6 .png figures; some added references for version