Search for the production of dark matter in association with top-quark pairs in the single-lepton final state in proton-proton collisions at sqrt(s) = 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 06 (2015) 121, 2015.
Inspire Record 1359293 DOI 10.17182/hepdata.70231

A search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of sqrt(s) = 8 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 19.7 inverse femtobarns. This search requires the presence of one lepton, multiple jets, and large missing transverse energy. No excess of events is found above the SM expectation, and upper limits are derived on the production cross section. Interpreting the findings in the context of a scalar contact interaction between fermionic dark matter particles and top quarks, lower limits on the interaction scale are set. These limits are also interpreted in terms of the dark matter-nucleon scattering cross sections for the spin-independent scalar operator and they complement direct searches for dark matter particles in the low mass region.

4 data tables

Systematic uncertainties from various sources and their impact on the total background prediction.

Expected number of background events in the SR, expected number of signal events for a DM particle with the mass $M_{\chi}$ = 1 GeV, assuming an interaction scale $M_{*}$ = 100 GeV, and observed data. The statistical and systematic uncertainties are given on the expected yields.

Expected number of signal events in SR assuming an interaction scale $M_{*}$ = 100 GeV, signal efficiencies, and observed and expected limits at 90% CL on production cross sections for $\mathrm{pp \rightarrow t\bar{t} + \chi\bar{\chi}}$, for various DM particle masses.

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Measurement of the Z gamma production cross section in pp collisions at 8 TeV and search for anomalous triple gauge boson couplings

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 04 (2015) 164, 2015.
Inspire Record 1345354 DOI 10.17182/hepdata.66985

The cross section for the production of Z gamma in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 inverse femtobarns. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. The differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. The observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. Limits on anomalous triple gauge couplings of Z Z gamma and Z gamma gamma are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.

4 data tables

Inclusive fiducial cross sections in bins of pT(gamma) with statistical, systematic, and luminosity uncertainties, respectivley. Results are not divided by bin-widths. The last bin is the cross section for pT(gamma) > 120 GeV. Combined result of electron and muon channels.

Fiducial cross sections with jet-veto in bins of pT(gamma) with statistical, systematic, and luminosity uncertainties, respectivley. Results are not divided by bin-widths. The last bin is the cross section for pT(gamma) > 120 GeV. Combined result of electron and muon channels.

Ratio of fiducial cross section with jet-veto and the inclusive cross section in bins of pT(gamma). The last bin is the cross section for pT(gamma) > 120 GeV. Combined result of electron and muon channels.

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Evidence for collective multi-particle correlations in pPb collisions

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Rev.Lett. 115 (2015) 012301, 2015.
Inspire Record 1345262 DOI 10.17182/hepdata.67530

The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in pPb and PbPb collisions over a wide pseudorapidity (eta) range based on correlations among six or more charged particles. The pPb data, corresponding to an integrated luminosity of 35 inverse nanobarns, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. A sample of semi-peripheral PbPb collision data at sqrt(s[NN])= 2.76 TeV, corresponding to an integrated luminosity of 2.5 inverse microbarns and covering a similar range of particle multiplicities as the pPb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the pPb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large Delta[eta]) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a pPb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multi-particle dynamics of collision systems with a very small overlapping region.

14 data tables

The cumulant $c_2\{6\}$ extracted for all charged particles with $0.3 < p_T < 3.0$ GeV/c as a function of $N_{trk}^{offline}$ in PbPb collisions.

The cumulant $c_2\{8\}$ extracted for all charged particles with $0.3 < p_T < 3.0$ GeV/c as a function of $N_{trk}^{offline}$ in PbPb collisions.

The cumulant $c_2\{6\}$ extracted for all charged particles with $0.3 < p_T < 3.0$ GeV/c as a function of $N_{trk}^{offline}$ in pPb collisions.

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Evidence of a broad structure at an invariant mass of 4.32- GeV/c**2 in the reaction e+ e- ---> pi+ pi- psi(2S) measured at BaBar

The BaBar collaboration Aubert, Bernard ; Barate, R. ; Bona, M. ; et al.
Phys.Rev.Lett. 98 (2007) 212001, 2007.
Inspire Record 729388 DOI 10.17182/hepdata.19344

We present a measurement of the cross section of the process $e^+e^-\to\pi^+pi^-\psi(2S)$ from threshold up to 8 GeV center-of-mass energy using events containing initial-state radiation, produced at the PEP-II $e^+e^-$ storage rings. The study is based on 298 fb$^{-1}$ of data recorded with the BaBar detector. A structure is observed in the cross-section not far above threshold, near 4.32 GeV. We also investigate the compatibility of this structure with the Y(4260) previously reported by this experiment.

1 data table

The measured c.m. energy dependence of the cross section with statistical errors only.. Bins with no recorded data are shown as a 'dash'.


Measurement of the $Q~{2}$ dependence of the Charged and Neutral Current Cross Sections in $e~{\pm}p$ Scattering at HERA

The H1 collaboration Aid, S. ; Andreev, V. ; Andrieu, B. ; et al.
Phys.Lett.B 379 (1996) 319-329, 1996.
Inspire Record 417155 DOI 10.17182/hepdata.44768

The $Q~{2}$ dependence and the total cross sections for charged and neutral current processes are measured in $e~{\pm}p$ reactions for transverse momenta of the outgoing lepton larger than 25 GeV. Comparable size of cross sections for the neutral current process and for the weak charged current process are observed above $Q~2\approx5000$GeV$~2$. Using the shape and magnitude of the charged current cross section we determine a propagator mass of $m_{W} = 84\ ~{+10}_{-7}$ GeV.

4 data tables

No description provided.

No description provided.

Total cross-section for E-P events.

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High $p_T$ Hadron Production in Photon - Photon Collisions

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 107 (1981) 290-296, 1981.
Inspire Record 167417 DOI 10.17182/hepdata.31027

We have studied the properties of hadron production in photon-photon scattering with tagged photons at the e + e − storage ring PETRA. A tail in the p T distribution of particles consistent with p T −4 has been observed. We show that this tail cannot be due to the hadronic part of the photon. Selected events with high p T particles are found to be consistent with a two-jet structure as expected from a point-like coupling of the photons to quarks. The lowest-order cross section predicted for γγ → q q , σ = 3 Σ e q 4 · σ γγ → μμ , is approached from above by the data at large transverse momenta.

1 data table

No description provided.


Production Characteristics of the F Meson

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Phys.Lett.B 80 (1979) 412-418, 1979.
Inspire Record 132410 DOI 10.17182/hepdata.27370

Inclusive cross sections of η production by e + e - annihilation for c.m. energies between 4.0 and 5.0 GeV are presented. The η production is shown to be correlated with the production of a weakly decaying particle, indicating that its main source is F production. At the 4.42 GeV resonance it is correlated with a low energy photon, suggesting F F ∗ or F ∗ F ∗ production. A mass determination of the F is made at 4.42 GeV using the F → ηπ decay channel.

1 data table

NUMERICAL VALUES MEASURED FROM GRAPH IN PREPRINT. A CHARM MODEL (METHOD 2) GAVE CONSISTENT RESULTS FOR BACKGROUND SEPARATION.


Charged Pion, Kaon and Nucleon Production by e+ e- Annihilation for C.M. Energies Between 3.6-GeV and 5.2-GeV

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Nucl.Phys.B 148 (1979) 189-227, 1979.
Inspire Record 132045 DOI 10.17182/hepdata.34826

Inclusive production of ifπ ± , K ± and p has been studied near charm threshold for c.m. energies between 3.6 and 5.2 GeV. Differential and scaling cross sections together with particle multiplicities have been determinated. By comparing data below and above charm threshold the charm contribution to if π ± and K ± production has been extracted. A comparison has been made between inclusice p production and inelastic electron-proton scattering. To study differences between three-gluon annihilation and two-quark production of the spectra from J/ decay and from non-resonant production at 3.6 GeV has been compared.

35 data tables

No description provided.

No description provided.

No description provided.

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Total Cross-section for Hadron Production by $e^+ e^-$ Annihilation at Center-of-mass Energies Between 3.6-{GeV} and 5.2-{GeV}

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Phys.Lett.B 76 (1978) 361, 1978.
Inspire Record 129715 DOI 10.17182/hepdata.27431

The total cross section for e + e − annihilation into hadronic final states between 3.6 and 5.2 GeV was measured by the nonmagnetic inner detector of DASP, which has similar trigger and detection efficiencies for photons and charged particles. The measured difference in R = σ had / σμμ between 3.6 GeV and 5.2 GeV is ΔR = 2.1 ± 0.3. We observe three peaks at cm energies of 4.04, 4.16 and 4.417 GeV, the parameters of which, when interpreted as resonances, are given.

2 data tables

EXCLUDING CONTRIBUTION OF TAU HEAVY LEPTON.

INCLUDING CONTRIBUTION OF TAU HEAVY LEPTON.