Limits...
Search for supersymmetry in hadronic final states with missing transverse energy using the variables α T and b-quark multiplicity in pp collisions at [Formula: see text].

- Eur Phys J C Part Fields (2013)

Bottom Line: No significant excess of events over the standard model expectation is found.For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model.For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

View Article: PubMed Central - PubMed

Affiliation: Yerevan Physics Institute, Yerevan, Armenia.

ABSTRACT

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb(-1) collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, α T, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

No MeSH data available.


Related in: MedlinePlus

The αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorised according to 2≤njet≤3 (left) and njet≥4 (right). An inclusive set of trigger conditions is used to collect the events in data (black solid circles with error bars). Expected yields as given by simulation are also shown for multijet events (green dash-dotted line), non-multijet backgrounds with genuine  as described in Sect. 5 (blue long-dashed line), the sum of all aforementioned SM processes (cyan solid line) and the reference signal model D2 (left, red dotted line) or G2 (right, red dotted line). The statistical uncertainties for the multijet and SM expectations are represented by the hatched areas (visible only for statistically limited bins). The final bin contains all events with αT>3 (Color figure online)
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Fig1: The αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorised according to 2≤njet≤3 (left) and njet≥4 (right). An inclusive set of trigger conditions is used to collect the events in data (black solid circles with error bars). Expected yields as given by simulation are also shown for multijet events (green dash-dotted line), non-multijet backgrounds with genuine as described in Sect. 5 (blue long-dashed line), the sum of all aforementioned SM processes (cyan solid line) and the reference signal model D2 (left, red dotted line) or G2 (right, red dotted line). The statistical uncertainties for the multijet and SM expectations are represented by the hatched areas (visible only for statistically limited bins). The final bin contains all events with αT>3 (Color figure online)

Mentions: Figure 1 shows the αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorized according to njet. An inclusive set of trigger conditions is used in order to show the full αT distribution. The analysis relies on data control samples to estimate the contributions from the multijet and non-multijet backgrounds, as described in Sects. 5 and 6. However, for illustration, the expected yields from simulation of multijet events, non-multijet backgrounds with genuine , the sum of these SM backgrounds, and an example signal model, are also shown in Fig. 1. The expected yield for multijet events that satisfy αT>0.55, as given by simulation, is less than ten events and is negligible with respect to all other SM backgrounds. Figure 1 highlights the ability of the αT variable to discriminate between multijet events and all other SM or new physics processes with genuine in the final state. Fig. 1


Search for supersymmetry in hadronic final states with missing transverse energy using the variables α T and b-quark multiplicity in pp collisions at [Formula: see text].

- Eur Phys J C Part Fields (2013)

The αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorised according to 2≤njet≤3 (left) and njet≥4 (right). An inclusive set of trigger conditions is used to collect the events in data (black solid circles with error bars). Expected yields as given by simulation are also shown for multijet events (green dash-dotted line), non-multijet backgrounds with genuine  as described in Sect. 5 (blue long-dashed line), the sum of all aforementioned SM processes (cyan solid line) and the reference signal model D2 (left, red dotted line) or G2 (right, red dotted line). The statistical uncertainties for the multijet and SM expectations are represented by the hatched areas (visible only for statistically limited bins). The final bin contains all events with αT>3 (Color figure online)
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4371056&req=5

Fig1: The αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorised according to 2≤njet≤3 (left) and njet≥4 (right). An inclusive set of trigger conditions is used to collect the events in data (black solid circles with error bars). Expected yields as given by simulation are also shown for multijet events (green dash-dotted line), non-multijet backgrounds with genuine as described in Sect. 5 (blue long-dashed line), the sum of all aforementioned SM processes (cyan solid line) and the reference signal model D2 (left, red dotted line) or G2 (right, red dotted line). The statistical uncertainties for the multijet and SM expectations are represented by the hatched areas (visible only for statistically limited bins). The final bin contains all events with αT>3 (Color figure online)
Mentions: Figure 1 shows the αT distributions of events with HT>375 GeV that satisfy all the selection criteria described above except the αT requirement, categorized according to njet. An inclusive set of trigger conditions is used in order to show the full αT distribution. The analysis relies on data control samples to estimate the contributions from the multijet and non-multijet backgrounds, as described in Sects. 5 and 6. However, for illustration, the expected yields from simulation of multijet events, non-multijet backgrounds with genuine , the sum of these SM backgrounds, and an example signal model, are also shown in Fig. 1. The expected yield for multijet events that satisfy αT>0.55, as given by simulation, is less than ten events and is negligible with respect to all other SM backgrounds. Figure 1 highlights the ability of the αT variable to discriminate between multijet events and all other SM or new physics processes with genuine in the final state. Fig. 1

Bottom Line: No significant excess of events over the standard model expectation is found.For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model.For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

View Article: PubMed Central - PubMed

Affiliation: Yerevan Physics Institute, Yerevan, Armenia.

ABSTRACT

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb(-1) collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, α T, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

No MeSH data available.


Related in: MedlinePlus