Search for Scalar Charm Quark Pair Production inppCollisions ats=8  TeVwith the ATLAS Detector

Abstract

The results of a dedicated search for pair production of scalar partners of charm quarks are reported. The search is based on an integrated luminosity of 20.3 fb^{-1} of pp collisions at sqrt[s]=8 TeV recorded with the ATLAS detector at the LHC. The search is performed using events with large missing transverse momentum and at least two jets, where the two leading jets are each tagged as originating from c quarks. Events containing isolated electrons or muons are vetoed. In an R-parity-conserving minimal supersymmetric scenario in which a single scalar-charm state is kinematically accessible, and where it decays exclusively into a charm quark and a neutralino, 95% confidence-level upper limits are obtained in the scalar-charm-neutralino mass plane such that, for neutralino masses below 200 GeV, scalar-charm masses up to 490 GeV are excluded.

Sensitivity of the intensity frontier experiments for neutrino and scalar portals: analytic estimates

“…Predictions of FONLL have been calibrated against the accelerator data and were found to be in very good agreement, see e.g. [65,66,[73][74][75]. In particular, comparison of the FONLL simulations of the production of the B + s with the measurements at the Tevatron and at the LHC showed that FONLL predicts the low p T distribution accurately.…”

Measurement of differential cross sections of isolated-photon plus heavy-flavour jet production in pp collisions at s=8 TeV using the ATLAS detector

“…This stage can be inverted to populate background enriched sideband regions. These two stages, which together are referred to as the tight criteria, are used in previous ATLAS prompt-photon analyses [4][5][6][7][8][9][10][11]. In the simulation, the distributions of the shower-shape variables used for photon identification are corrected to reproduce those observed in the data.…”

“…The uncertainties related to the analysis techniques are similar to those in the ATLAS inclusive photon and γ+jet analyses at 8 TeV [8,9]. Specifically, the assumption that the photon background regions are uncorrelated in the two-dimensional sideband method is assessed by varying the correlation by 10%.…”

“…Compared to the proton-antiproton collisions of the Tevatron, these collisions exhibit smaller contributions from t-channel quark-antiquark processes, allowing other processes sensitive to the heavyquark content of the proton to play a more significant role. 1 Prompt photons (γ) can be used as a colourless non-hadronizing probe of parton dynamics that yields a clean experimental signature [4][5][6][7][8][9][10][11][12][13][14][15][16]. Processes containing final state bor c-quarks play an important role in many LHC physics analyses and therefore the accuracy of the description of this heavy-flavour (HF) content of the proton must be investigated [17][18][19][20][21].…”

First steps towards the reconstruction of the squark flavour structure

“…Among the numerous extensions addressing the shortcomings of the Standard Model, Supersymmetry ranks among the most attractive solutions. However, if Nature is indeed supersymmetric, it is reasonable to assume that its exact realization is situated beyond the "vanilla" Minimal Supersymmetric Standard Model (MSSM) or its simplified realizations which are typically searched for in current experimental analyses [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. To give an example, experimental studies typically are based on the Minimal Flavour Violation (MFV) paradigm assuming that all flavour-violating interactions stem from the Yukawa couplings alone, as it is the case in the Standard Model.…”