Limits...
Search for resonant diboson production in the [Formula: see text] final state in [Formula: see text] collisions at [Formula: see text] TeV with the ATLAS detector.

- Eur Phys J C Part Fields (2015)

Bottom Line: No significant excess of data events over the Standard Model expectation is observed.Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza-Klein gravitons predicted by the Randall-Sundrum model and for Extended Gauge Model [Formula: see text] bosons.These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and [Formula: see text] boson respectively.

View Article: PubMed Central - PubMed

Affiliation: CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France.

ABSTRACT

This paper reports on a search for narrow resonances in diboson production in the [Formula: see text] final state using [Formula: see text] collision data corresponding to an integrated luminosity of [Formula: see text] fb[Formula: see text] collected at [Formula: see text] TeV with the ATLAS detector at the Large Hadron Collider. No significant excess of data events over the Standard Model expectation is observed. Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza-Klein gravitons predicted by the Randall-Sundrum model and for Extended Gauge Model [Formula: see text] bosons. These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and [Formula: see text] boson respectively.

No MeSH data available.


Related in: MedlinePlus

Reconstructed  or  mass distributions in the data and for background after all the selection cuts are applied in the three kinematic regions referred to as the LR (top), HR (middle) and MR (bottom) in the text. The shaded regions show the full background uncertainty obtained by adding statistical and systematic uncertainties in quadrature, including the constraints on the background from the data control regions and before the fit to the data in the signal regions (cf. unconstrained case in Table 2). Also shown are the  signal yields expected for masses of 500, 800 and 1400 GeV with the production cross sections scaled by a factor 10
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Fig1: Reconstructed or mass distributions in the data and for background after all the selection cuts are applied in the three kinematic regions referred to as the LR (top), HR (middle) and MR (bottom) in the text. The shaded regions show the full background uncertainty obtained by adding statistical and systematic uncertainties in quadrature, including the constraints on the background from the data control regions and before the fit to the data in the signal regions (cf. unconstrained case in Table 2). Also shown are the signal yields expected for masses of 500, 800 and 1400 GeV with the production cross sections scaled by a factor 10

Mentions: The invariant mass of the diboson system is reconstructed from the or system. The reconstructed distributions for data and simulated background events in the three signal regions are shown in Fig. 1 for the combined electron and muon channels. Good agreement is observed between the data and the background predictions, with value2 ranging from 0.98 to 0.10, and the results are presented as 95 % confidence level upper limits on the production cross section times branching ratio for the and models. The upper limits are determined using the modified frequentist formalism [59] with a profile likelihood test statistic [60]. The test statistic is evaluated with a maximum likelihood fit of signal models and background predictions to the reconstructed spectra shown in Fig. 1. Systematic uncertainties and their correlations are taken into account as nuisance parameters with Gaussian constraints. The likelihood fit, which takes into account correlations between the systematic uncertainties, is performed for signal pole masses ranging between 300 and 850 GeV for the LR, 550 and 1800 GeV for the HR and 800 and 2000 GeV for the MR. Overlapping regions are fit simultaneously.


Search for resonant diboson production in the [Formula: see text] final state in [Formula: see text] collisions at [Formula: see text] TeV with the ATLAS detector.

- Eur Phys J C Part Fields (2015)

Reconstructed  or  mass distributions in the data and for background after all the selection cuts are applied in the three kinematic regions referred to as the LR (top), HR (middle) and MR (bottom) in the text. The shaded regions show the full background uncertainty obtained by adding statistical and systematic uncertainties in quadrature, including the constraints on the background from the data control regions and before the fit to the data in the signal regions (cf. unconstrained case in Table 2). Also shown are the  signal yields expected for masses of 500, 800 and 1400 GeV with the production cross sections scaled by a factor 10
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4376397&req=5

Fig1: Reconstructed or mass distributions in the data and for background after all the selection cuts are applied in the three kinematic regions referred to as the LR (top), HR (middle) and MR (bottom) in the text. The shaded regions show the full background uncertainty obtained by adding statistical and systematic uncertainties in quadrature, including the constraints on the background from the data control regions and before the fit to the data in the signal regions (cf. unconstrained case in Table 2). Also shown are the signal yields expected for masses of 500, 800 and 1400 GeV with the production cross sections scaled by a factor 10
Mentions: The invariant mass of the diboson system is reconstructed from the or system. The reconstructed distributions for data and simulated background events in the three signal regions are shown in Fig. 1 for the combined electron and muon channels. Good agreement is observed between the data and the background predictions, with value2 ranging from 0.98 to 0.10, and the results are presented as 95 % confidence level upper limits on the production cross section times branching ratio for the and models. The upper limits are determined using the modified frequentist formalism [59] with a profile likelihood test statistic [60]. The test statistic is evaluated with a maximum likelihood fit of signal models and background predictions to the reconstructed spectra shown in Fig. 1. Systematic uncertainties and their correlations are taken into account as nuisance parameters with Gaussian constraints. The likelihood fit, which takes into account correlations between the systematic uncertainties, is performed for signal pole masses ranging between 300 and 850 GeV for the LR, 550 and 1800 GeV for the HR and 800 and 2000 GeV for the MR. Overlapping regions are fit simultaneously.

Bottom Line: No significant excess of data events over the Standard Model expectation is observed.Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza-Klein gravitons predicted by the Randall-Sundrum model and for Extended Gauge Model [Formula: see text] bosons.These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and [Formula: see text] boson respectively.

View Article: PubMed Central - PubMed

Affiliation: CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France.

ABSTRACT

This paper reports on a search for narrow resonances in diboson production in the [Formula: see text] final state using [Formula: see text] collision data corresponding to an integrated luminosity of [Formula: see text] fb[Formula: see text] collected at [Formula: see text] TeV with the ATLAS detector at the Large Hadron Collider. No significant excess of data events over the Standard Model expectation is observed. Upper limits at the 95 % confidence level are set on the production cross section times branching ratio for Kaluza-Klein gravitons predicted by the Randall-Sundrum model and for Extended Gauge Model [Formula: see text] bosons. These results lead to the exclusion of mass values below 740 and 1590 GeV for the graviton and [Formula: see text] boson respectively.

No MeSH data available.


Related in: MedlinePlus