Measurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector

We present a systematic comparison of jet predictions at the LHC and the Tevatron, with accuracy up to next-to-next-to-leading order (NNLO). The exact computation at NNLO is completed for the gluons-only channel, so we compare the exact predictions for this channel with an approximate prediction based on threshold resummation, in order to determine the regions where this approximation is reliable at NNLO. The kinematic regions used in this study are identical to the experimental setup used by recently published jet data from the ATLAS and CMS experiments at the LHC, and CDF and D0 experiments at the Tevatron. We study the effect of choosing different renormalisation and factorisation scales for the NNLO exact prediction and as an exercise assess their impact on a PDF fit including these corrections. Finally we provide numerical values of the NNLO k-factors relevant for the LHC and Tevatron experiments.

“…We have also included the ATLAS measurements of inclusive jet cross sections at √ s = 7 TeV [26] and √ s = 2.76 TeV [27], where the rapidity coverage reaches |η| < 4.4.…”

Section: Jhep10(2014)145mentioning

confidence: 99%

“…Numerical results for the gluons-only exact and approximate NNLO k-factors as described in section A for the ATLAS 2010 √ s = 7 TeV dataset [26] in the rapidity slice |η| < 0.3. Table 12.…”

Section: Jhep10(2014)145mentioning

confidence: 99%

Perturbative QCD description of jet data from LHC Run-I and Tevatron Run-II

Carrazza

Pires

2014

“…The latest tt narrow resonance searches with 200 pb −1 at Atlas [47] do not constrain our model parameter space, because of the suppressed branching ratio of ρ G → tt seen in figure 1. However, the dijet resonance searches [48][49][50][51] our model is not completely straightforward, as there will be some nonzero efficiency for ρ G → π G π G events to be reconstructed in the ρ G → jj sample. This efficiency depends on the mass ratio m π G /m ρ G and on the jet algorithm used by Atlas.…”

Section: )mentioning

confidence: 99%

“…We use the leading order cross-section as calculated in MadGraph [55], as comparison with measured dijet cross-sections [48,49] indicates good agreement (i.e., K-factors near unity) in the high-p T , large invariant mass regime of interest. Renormalization and factorization scales are set at µ = m ρ G .…”

Section: Jhep07(2012)067mentioning

confidence: 99%

Composite octet searches with jet substructure

Bai

Shelton

2012

Abstract:Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 a simple dijet analysis with only the jet mass variable provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the full jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.

“…Note that the leading order cross section is O(α 2 s ). The single-jet inclusive and dijet cross sections have been studied at NLO [1][2][3][4][5][6] and successfully compared with data from the high energy frontier at the TEVATRON [7][8][9] and at the LHC [10,11]. A particular success is the determination of the strong coupling constant as a function of the jet transverse energy [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Real-virtual corrections for gluon scattering at NNLO

Ridder

Glover

Pires

2012

We use the antenna subtraction method to isolate the mixed real-virtual infrared singularities present in gluonic scattering amplitudes at next-to-next-to-leading order. In a previous paper, we derived the subtraction term that rendered the double real radiation tree-level process finite in the single and double unresolved regions of phase space. Here, we show how to construct the real-virtual subtraction term using antenna functions with both initial-and final-state partons which removes the explicit infrared poles present in the one-loop amplitude, as well as the implicit singularities that occur in the soft and collinear limits. As an explicit example, we write down the subtraction term that describes the single unresolved contributions from the five-gluon one-loop process. The infrared poles are explicitly and locally cancelled in all regions of phase space prior to integration, leaving a finite remainder that can be safely evaluated numerically in four-dimensions. We show numerically that the subtraction term correctly approximates the matrix elements in the various single unresolved configurations.