Top-antitop resonance searches beyond 1 TeV

Abstract

We perform a general parton level analysis for the search of heavy resonant states in the production of tt pairs at the LHC with an integrated luminosity of 30 fb −1 . We assume the existence of resonances that only couple to quarks and propose kinematic cuts in order to increase the amount of events produced through quark-annihilation. We study the interplay between different variables and their impact on the purity of the selected sample. We make focus on the longitudinal (β) and transverse (p T ) momentum of the tt pair, and the scattering angle (θ) in the center of mass reference frame. We observe that β is replaced by θ as a suitable discriminating variable of quark-annihilation processes for invariant masses above 1 TeV. Finally, we illustrate the analysis with a gluon resonance of 1.5 TeV and show the improvement in the sensitivity of the signal when cuts on θ are imposed.

Improving top quark induced charge asymmetries at the LHC usingtt¯transverse momentum

“…From the previous results we may see that, considering N AE as binomial random variables, the ratio between the statistical significances of the first and second sample is given by [18] …”

“…This proposal was advantageous in the sense of having many events, but disadvantageous in having too many gluon-fusion events which dilute the asymmetry. Hence, it is more useful in a statistic regime rather than in a systematic one [18]. A second kind of example is the one that looks for boosted t " t pairs [10,15], which has the convenience of reaching a high quark-fusion fraction, but with the fault of making strong cuts which may raise the statistic error above the desired limit.…”

“…We will restrict our analysis to N AE as excluding variables, since it is shown in [18] that any case can be reduced to the excluding case and that the significance of the asymmetry is always enhanced when this is done. The measuring of the asymmetry carries an error which consists of systematic ( syst ) and statistic ( stat ) parts.…”

“…For an in-depth analysis, diagnosis, and comparison of general and particular proposals to induce an asymmetry in a pp collider the reader should refer to [18].…”

The Spinning Motions of All Fermions and Bosons as Implied by Pauli Matrices Containing Complex Conjugates in a Combined Spacetime Four-Manifold

“…4; To prepare for the ensuing analysis of particle collisions, we will use the symbol ⊞ for field superpositions, and we note that the mixing angles among the colliding fields determine the outcomes, a well-observed fact (cf. Alvarez et al, 2013;Tayduganov et al, 2012 to result in two photon-waves (noting here that the angle of 180 degrees of separation refers to the final state of field superposition, which is not to be identified with the mixing angle responsible for arriving at this state). Here and after we will use the square brackets for particle-waves resulting from a combination of particles and anti-particles.…”