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Title: Search for new physics in final states with low transverse energy photon and missing transverse energy in proton-proton collisions at $$\sqrt{s} = 8$$ TeV

A search for new physics in the γ+E T final state is performed using pp collision data corresponding to an integrated luminosity of 7.3 fb -1 collected at √s = 8 TeV using low threshold triggers in a phase space region defined by E T > 45 GeV and E-slash T > 40 GeV. The data are also examined using optimized selections for maximum sensitivity to an exotic (gravitino/neutralino) decay of the Higgs boson predicted in a low-scale SUSY breaking scenario. The results are found to be compatible with the Standard Model hypothesis. These results are the first limits on this model from collider searches. Furthermore, proton-proton collision events containing high-energy photon and missing transverse momentum have been investigated. No deviations from the standard model have been observed using the √s = 8 TeV data set corresponding to 19.6 fb -1 of integrated luminosity. Further constraints are set on χ production and translated into upper limits on vector and axial-vector contributions to the χ-nucleon scattering cross section. For M χ = 10 GeV, the χ-nucleon cross section is constrained to be 2.6 x 10 -39 cm 2 (9.6 x 10 -41 cm 2) for a spin-independent (spin-dependent) interaction at 90%more » confidence level. In addition the most stringent limits to date are obtained on the effective Planck scale in the ADD model with large spatial extra dimensions and on the brane tension scale in the branon model.« less
Authors:
 [1]
  1. Brown Univ., Providence, RI (United States)
Publication Date:
OSTI Identifier:
1182548
Report Number(s):
FERMILAB-THESIS-2015-02
TRN: US1601289
DOE Contract Number:
AC02-07CH11359
Resource Type:
Thesis/Dissertation
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PROTON-PROTON INTERACTIONS; TRANSVERSE MOMENTUM; TEV RANGE 01-10; PHOTONS; CROSS SECTIONS; SUPERSYMMETRY; SYMMETRY BREAKING; HIGGS BOSONS; DECAY; LIMITING VALUES; STANDARD MODEL; PARTICLE PRODUCTION; GRAVITINOS; NEUTRALINOS