Searches for new phenomena inspired by supersymmetry in final states containing an $e^+e^-$ or $\mu^+\mu^-$ pair, jets, and missing transverse momentum are presented. These searches make use of proton-proton collision data with an integrated luminosity of 139 $\text{fb}^{-1}$, collected during 2015-2018 at a centre-of-mass energy $\sqrt{s}=13 $TeV by the ATLAS detector at the Large Hadron Collider. Two searches target the pair production of charginos and neutralinos. One uses the recursive-jigsaw reconstruction technique to follow up on excesses observed in 36.1 $\text{fb}^{-1}$ of data, and the other uses conventional event variables. The third search targets pair production of coloured supersymmetric particles (squarks or gluinos) decaying through the next-to-lightest neutralino $(\tilde\chi_2^0)$ via a slepton $(\tilde\ell)$ or $Z$ boson into $\ell^+\ell^-\tilde\chi_1^0$, resulting in a kinematic endpoint or peak in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectations. Results are interpreted using simplified models and exclude masses up to 900 GeV for electroweakinos, 1550 GeV for squarks, and 2250 GeV for gluinos.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>EWK SR distributions:</b> <a href="116034?version=1&table=Figure 11a">SR-High_8-EWK</a>; <a href="116034?version=1&table=Figure 11b">SR-ℓℓ𝑏𝑏-EWK</a>; <a href="116034?version=1&table=Figure 11c">SR-Int-EWK</a>; <a href="116034?version=1&table=Figure 11d">SR-Low-EWK</a>; <a href="116034?version=1&table=Figure 11e">SR-OffShell-EWK</a><br/><br/> <b>Strong SR distributions:</b> <a href="116034?version=1&table=Figure 13a">SRC-STR</a>; <a href="116034?version=1&table=Figure 13b">SRLow-STR</a>; <a href="116034?version=1&table=Figure 13c">SRMed-STR</a>; <a href="116034?version=1&table=Figure 13d">SRHigh-STR</a><br/><br/> <b>RJR SR Yields:</b> <a href="116034?version=1&table=Table 16">SR2l-Low-RJR, SR2l-ISR-RJR</a><br/><br/> <b>EWK SR Yields:</b> <a href="116034?version=1&table=Table 18">SR-High_16a-EWK, SR-High_8a-EWK, SR-1J-High-EWK, SR-ℓℓ𝑏𝑏-EWK, SR-High_16b-EWK, SR-High_8b-EWK</a>; <a href="116034?version=1&table=Table 19">SR-Int_a-EWK, SR-Low_a-EWK, SR-Low-2-EWK, SR-OffShell_a-EWK, SR-Int_b-EWK, SR-Low_b-EWK, SR-OffShell_b-EWK </a><br/><br/> <b>Strong SR Yields:</b> <a href="116034?version=1&table=Table 21">SRC-STR, SRLow-STR, SRMed-STR, SRHigh-STR</a>; <a href="116034?version=1&table=Table 22">SRZLow-STR, SRZMed-STR, SRZHigh-STR</a><br/><br/> <b>C1N2 Model Limits:</b> <a href="116034?version=1&table=Table 15a C1N2 Observed Limit">Obs</a>; <a href="116034?version=1&table=Table 15a C1N2 Expected Limit">Exp</a>; <a href="116034?version=1&table=Auxiliary Figure 34a C1N2 Expected XS Upper Limit">Upper Limits</a><br/><br/> <b>GMSB Model Limits:</b> <a href="116034?version=1&table=Table 15b GMSB Observed Limit">Obs</a>; <a href="116034?version=1&table=Table 15b GMSB Expected Limit">Exp</a>; <a href="116034?version=1&table=Auxiliary Figure 34b GMSB Expected XS Upper Limit">Upper Limits</a><br/><br/> <b>Gluon-Slepton Model Limits:</b> <a href="116034?version=1&table=Figure 16a Observed Limit">Obs</a>; <a href="116034?version=1&table=Figure 16a Expected Limit">Exp</a>; <a href="116034?version=1&table=Auxiliary Figure 23a XS Upper Limit">Upper Limits</a><br/><br/> <b>Gluon-Z* Model Limits:</b> <a href="116034?version=1&table=Figure 16b Observed Limit">Obs</a>; <a href="116034?version=1&table=Figure 16b Expected Limit">Exp</a>; <a href="116034?version=1&table=Auxiliary Figure 23b XS Upper Limit">Upper Limits</a><br/><br/> <b>Squark-Z* Model Limits:</b> <a href="116034?version=1&table=Figure 16c Observed Limit">Obs</a>; <a href="116034?version=1&table=Figure 16c Expected Limit">Exp</a>; <a href="116034?version=1&table=Auxiliary Figure 23c XS Upper Limit">Upper Limits</a><br/><br/> <b>EWK VR distributions:</b> <a href="116034?version=1&table=Figure 4a S_ETmiss in VR-High-Sideband-EWK">VR-High-Sideband-EWK</a>; <a href="116034?version=1&table=Figure 4b S_Etmiss in VR-High-R-EWK">VR-High-R-EWK</a>; <a href="116034?version=1&table=Figure 4c S_Etmiss in VR-1J-High-EWK">VR-1J-High-EWK</a>; <a href="116034?version=1&table=Figure 4d S_Etmiss in VR-llbb-EWK">VR-ℓℓ𝑏𝑏-EWK</a>; <a href="116034?version=1&table=Figure 5a S_Etmiss in VR-Int-EWK">VR-Int-EWK</a>; <a href="116034?version=1&table=Figure 5b S_Etmiss in VR-Low-EWK">VR-Low-EWK</a>; <a href="116034?version=1&table=Figure 5c S_Etmiss in VR-Low-2-EWK">VR-Low-2-EWK</a>; <a href="116034?version=1&table=Figure 5d S_Etmiss in VR-OffShell-EWK">VR-OffShell-EWK</a><br/><br/> <b>Strong VR distributions:</b> <a href="116034?version=1&table=Figure 6a">VRC-STR</a>; <a href="116034?version=1&table=Figure 6b">VRLow-STR</a>; <a href="116034?version=1&table=Figure 6c">VRMed-STR</a>; <a href="116034?version=1&table=Figure 6d">VRHigh-STR</a>; <a href="116034?version=1&table=Figure 8">VR3L-STR</a><br/><br/> <b>Other Strong distributions:</b> <a href="116034?version=1&table=Auxiliary Figure 17a">SRLow-STR + VRLow-STR</a><br/><br/> <b>Other EWK distributions:</b> <a href="116034?version=1&table=Auxiliary Figure 33a Mjj in CR-Z-EWK and SR-Low-EWK">CR-Z-EWK + SR-Low-EWK</a>; <a href="116034?version=1&table=Auxiliary Figure 33b S_ETmiss in CR-Z-met-EWK">CR-Z-met-EWK</a><br/><br/> <b>Strong Signal Cutflows:</b> <a href="116034?version=1&table=Auxiliary Table 30-31 SRC-STR Cutflow">SRC-STR GG_N2_ZN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRMed-STR Cutflow">SRC-STR SS_N2_ZN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRLow-STR Cutflow">SRLow-STR GG_N2_SLN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRHigh-STR Cutflow">SRC-STR GG_N2_SLN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRZLow-STR Cutflow">SRZLow-STR SS_N2_ZN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRZMed-STR Cutflow">SRZMed-STR SS_N2_ZN1</a>; <a href="116034?version=1&table=Auxiliary Table 30-31 SRZHigh-STR Cutflow">SRZHigh-STR SS_N2_ZN1</a><br/><br/> <b>EWK Signal Cutflows:</b> <a href="116034?version=1&table=Auxiliary Table 36 SR-OffShell_a-EWK Cutflow"> SR-OffShell_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 37 SR-OffShell_b-EWK Cutflow"> SR-OffShell_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 38 SR-Low_a-EWK Cutflow"> SR-Low_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 39 SR-Low_b-EWK Cutflow"> SR-Low_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 40 SR-Low-2-EWK Cutflow"> SR-Low-2-E</a>; <a href="116034?version=1&table=Auxiliary Table 41 SR-Int_a-EWK Cutflow"> SR-Int_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 42 SR-Int_b-EWK Cutflow"> SR-Int_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 43 SR-High_16a-EWK Cutflow"> SR-High_16a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 44 SR-High_16b-EWK Cutflow"> SR-High_16b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 45 SR-High_8a-EWK Cutflow"> SR-High_8a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 46 SR-High_8b-EWK Cutflow"> SR-High_8b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 47 SR-1J-High-EWK Cutflow"> SR-1J-Hig</a>; <a href="116034?version=1&table=Auxiliary Table 48 SR-llbb-EWK Cutflow"> SR-llbb-EWK</a><br/><br/> <b>EWK Signal Number of MC Events:</b> <a href="116034?version=1&table=Auxiliary Table 36 SR-OffShell_a-EWK Generated"> SR-OffShell_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 37 SR-OffShell_b-EWK Generated"> SR-OffShell_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 38 SR-Low_a-EWK Generated"> SR-Low_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 39 SR-Low_b-EWK Generated"> SR-Low_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 40 SR-Low-2-EWK Generated"> SR-Low-2-E</a>; <a href="116034?version=1&table=Auxiliary Table 41 SR-Int_a-EWK Generated"> SR-Int_a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 42 SR-Int_b-EWK Generated"> SR-Int_b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 43 SR-High_16a-EWK Generated"> SR-High_16a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 44 SR-High_16b-EWK Generated"> SR-High_16b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 45 SR-High_8a-EWK Generated"> SR-High_8a-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 46 SR-High_8b-EWK Generated"> SR-High_8b-EWK</a>; <a href="116034?version=1&table=Auxiliary Table 47 SR-1J-High-EWK Generated"> SR-1J-Hig</a>; <a href="116034?version=1&table=Auxiliary Table 48 SR-llbb-EWK Generated"> SR-llbb-EWK</a><br/><br/> <b>SRC-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_SLN1 acc in SRC">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 acc in SRC">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRC">SS_N2_ZN1</a><br/><br/> <b>SRLow-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_SLN1 acc in SRLow">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 acc in SRLow">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRLow">SS_N2_ZN1</a><br/><br/> <b>SRMed-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_SLN1 acc in SRMed">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 acc in SRMed">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRMed">SS_N2_ZN1</a><br/><br/> <b>SRHigh-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_SLN1 acc in SRHigh">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 acc in SRHigh">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRHigh">SS_N2_ZN1</a><br/><br/> <b>SRZLow-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_ZN1 acc in SRZLow">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRZLow">SS_N2_ZN1</a><br/><br/> <b>SRZMed-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_ZN1 acc in SRZMed">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRZMed">SS_N2_ZN1</a><br/><br/> <b>SRZHigh-STR Signal Acceptance:</b> <a href="116034?version=1&table=GG_N2_ZN1 acc in SRZHigh">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 acc in SRZHigh">SS_N2_ZN1</a><br/><br/> <b>SRC-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_SLN1 eff in SRC">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 eff in SRC">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRC">SS_N2_ZN1</a><br/><br/> <b>SRLow-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_SLN1 eff in SRLow">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 eff in SRLow">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRLow">SS_N2_ZN1</a><br/><br/> <b>SRMed-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_SLN1 eff in SRMed">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 eff in SRMed">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRMed">SS_N2_ZN1</a><br/><br/> <b>SRHigh-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_SLN1 eff in SRHigh">GG_N2_SLN1</a>; <a href="116034?version=1&table=GG_N2_ZN1 eff in SRHigh">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRHigh">SS_N2_ZN1</a><br/><br/> <b>SRZLow-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_ZN1 eff in SRZLow">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRZLow">SS_N2_ZN1</a><br/><br/> <b>SRZMed-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_ZN1 eff in SRZMed">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRZMed">SS_N2_ZN1</a><br/><br/> <b>SRZHigh-STR Signal Efficiency:</b> <a href="116034?version=1&table=GG_N2_ZN1 eff in SRZHigh">GG_N2_ZN1</a>; <a href="116034?version=1&table=SS_N2_ZN1 eff in SRZHigh">SS_N2_ZN1</a><br/><br/> <b>SR-OffShell_a-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-OffShell_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-OffShell_a-EWK">C1N2</a>; <br/><br/> <b>SR-OffShell_b-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-OffShell_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-OffShell_b-EWK">C1N2</a>; <br/><br/> <b>SR-Low_a-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in C1N2 acc in SR-Low_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in C1N2 acc in SR-Low_a-EWK">C1N2</a>; <br/><br/> <b>SR-Low_b-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-Low_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-Low_b-EWK">C1N2</a>; <br/><br/> <b>SR-Int_a-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-Int_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-Int_a-EWK">C1N2</a>; <br/><br/> <b>SR-Int_b-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-Int_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-Int_b-EWK">C1N2</a>; <br/><br/> <b>SR-High_16a-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-High_16a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-High_16a-EWK">C1N2</a>; <br/><br/> <b>SR-High_16b-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-High_16b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-High_16b-EWK">C1N2</a>; <br/><br/> <b>SR-High_8a-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-High_8a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-High_8a-EWK">C1N2</a>; <br/><br/> <b>SR-High_8b-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-High_8b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-High_8b-EWK">C1N2</a>; <br/><br/> <b>SR-1J-High-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-1J-High-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-1J-High-EWK">C1N2</a>; <br/><br/> <b>SR-llbb-EWK Signal Acceptance:</b><a href="116034?version=1&table=GMSB acc in SR-llbb-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 acc in SR-llbb-EWK">C1N2</a>; <br/><br/> <b>SR-OffShell_a-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-OffShell_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-OffShell_a-EWK">C1N2</a>; <br/><br/> <b>SR-OffShell_b-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-OffShell_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-OffShell_b-EWK">C1N2</a>; <br/><br/> <b>SR-Low_a-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in C1N2 eff in SR-Low_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in C1N2 eff in SR-Low_a-EWK">C1N2</a>; <br/><br/> <b>SR-Low_b-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-Low_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-Low_b-EWK">C1N2</a>; <br/><br/> <b>SR-Int_a-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-Int_a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-Int_a-EWK">C1N2</a>; <br/><br/> <b>SR-Int_b-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-Int_b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-Int_b-EWK">C1N2</a>; <br/><br/> <b>SR-High_16a-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-High_16a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-High_16a-EWK">C1N2</a>; <br/><br/> <b>SR-High_16b-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-High_16b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-High_16b-EWK">C1N2</a>; <br/><br/> <b>SR-High_8a-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-High_8a-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-High_8a-EWK">C1N2</a>; <br/><br/> <b>SR-High_8b-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-High_8b-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-High_8b-EWK">C1N2</a>; <br/><br/> <b>SR-1J-High-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-1J-High-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-1J-High-EWK">C1N2</a>; <br/><br/> <b>SR-llbb-EWK Signal Efficiency:</b><a href="116034?version=1&table=GMSB eff in SR-llbb-EWK">GMSB</a>; <a href="116034?version=1&table=C1N2 eff in SR-llbb-EWK">C1N2</a>; <br/><br/> <b>Truth Code snippets</b>, <b>SLHA files</b>, and <b>PYHF json likelihoods</b> are available under "Resources" (purple button on the left) ---- Record created with hepdata_lib 0.7.0: https://zenodo.org/record/4946277 and PYHF: https://doi.org/10.5281/zenodo.1169739
Breakdown of expected and observed yields in the two recursive-jigsaw reconstruction signal regions after a simultaneous fit of the the CRs. The two sets of regions are fit separately. The uncertainties include both statistical and systematic sources.
Breakdown of expected and observed yields in the electroweak search High and $\ell\ell bb$ signal regions after a simultaneous fit to the signal regions and control regions. All statistical and systematic uncertainties are included.
The fixed-target MIPP experiment, Fermilab E907, was designed to measure the production of hadrons from the collisions of hadrons of momenta ranging from 5 to 120 GeV/c on a variety of nuclei. These data will generally improve the simulation of particle detectors and predictions of particle beam fluxes at accelerators. The spectrometer momentum resolution is between 3 and 4%, and particle identification is performed for particles ranging between 0.3 and 80 GeV/c using $dE/dx$, time-of-flight and Cherenkov radiation measurements. MIPP collected $1.42 \times10^6$ events of 120 GeV Main Injector protons striking a target used in the NuMI facility at Fermilab. The data have been analyzed and we present here charged pion yields per proton-on-target determined in bins of longitudinal and transverse momentum between 0.5 and 80 GeV/c, with combined statistical and systematic relative uncertainties between 5 and 10%.
The production yields of PI+ and PI- and the ratio of these yields. The first uncertainty given on each value combines statistical uncertainties and systematic uncertainties from backgrounds.
Dijet angular distributions from the first LHC pp collisions at center-of-mass energy sqrt(s) = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb-1. Dijet $\chi$ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the $\chi$ distributions excludes quark contact interactions with a compositeness scale $\Lambda$ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits.
CHI distribution for mass bin 340 to 520 GeV.
CHI distribution for mass bin 520 to 800 GeV.
CHI distribution for mass bin 800 to 1200 GeV.
A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the Large Hadron Collider (LHC) and correspond to an integrated luminosity of 315 nb^-1 collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% CL the q* mass interval 0.30 < mq* < 1.26 TeV, extending the reach of previous experiments.
The dijet mass distribution (NUMBER OF EVENTS).
95 PCT CL upper limit of the cross section x acceptance.
We present the first measurement of photoproduction of J/psi and of two-photon production of high-mass e+e- pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au+Au data at sqrt(s_NN) = 200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au^{star} nuclei. The event sample consists of 28 events with m_{e+e-} > 2 GeV/c^2 with zero like-sign background. The measured cross sections at midrapidity of d\sigma / dy (J/psi + Xn, y=0) = 76 +/- 33 (stat) +/- 11 (syst) micro b and d^2\sigma/dm dy (e^+e^- + Xn, y=0) = 86 +/- 23 (stat) +/- 16 (syst) micro b/(GeV/c^2) for m_{e+e-} \in [2.0,2.8] GeV/c^2 are consistent with various theoretical predictions.
J/PSI N for ultra peripheral Au+Au reactions. The values has been obtained from the fit of the number of counts as a function of the mass of the e+e- pairs detected. The J/PSI pick has been fixed at the known mass ofJ/PSI : 3.097 GeV/c2.
e+e- pairs N in ultra peripherals Au + Au reactions. The values has been obtained from the fit of the number of counts as a function of the mass of the e+e- pairs.The results are given for 3 intervals of masses of the electron pair : 2.0 to 2.3, 2.3 to 2.8 and 2.0 to 2.8 Gev/c2.
J/PSI production cross section at mid rapidity for ultra peripheral Au+Au reactions.
We present measurements of the total production rates and momentum distributions of the charmed baryon $\Lambda_c^+$ in $e^+e^- \to$ hadrons at a center-of-mass energy of 10.54 GeV and in $\Upsilon(4S)$ decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in $e^+e^- \to c\bar{c}$ events, allowing direct studies of $c$-quark fragmentation. We measure a momentum distribution for $\Lambda_c^+$ baryons that differs significantly from those measured previously for charmed mesons. Comparing with a number of models, we find none that can describe the distribution completely. We measure an average scaled momentum of $\left< x_p \right> = 0.574\pm$0.009 and a total rate of $N_{\Lambda c}^{q\bar{q}} = 0.057\pm$0.002(exp.)$\pm$0.015(BF) $\Lambda_c^+$ per hadronic event, where the experimental error is much smaller than that due to the branching fraction into the reconstructed decay mode, $pK^-\pi^+$. In $\Upsilon (4S)$ decays we measure a total rate of $N_{\Lambda c}^{\Upsilon} = 0.091\pm$0.006(exp.)$\pm$0.024(BF) per $\Upsilon(4S)$ decay, and find a much softer momentum distribution than expected from B decays into a $\Lambda_c^+$ plus an antinucleon and one to three pions.
LAMBDA/C+ differential production rate per hadronic event for the continuum at cm energy 10.54 GeV.
The integrated number of LAMBDA/C+'s per hadronic event for the continuum at cm energy 10.54 GeV.
LAMBDA/C+ differential production rate per UPSILON(4S) decay at cm energy 10.58 GeV.
We present a study of events with Z bosons and jets produced at the Fermilab Tevatron Collider in ppbar collisions at a center of mass energy of 1.96 TeV. The data sample consists of nearly 14,000 Z/G* -> e+e- candidates corresponding to the integrated luminosity of 0.4 fb-1 collected using the D0 detector. Ratios of the Z/G* + >= n jet cross sections to the total inclusive Z/G* cross section have been measured for n = 1 to 4 jet events. Our measurements are found to be in good agreement with a next-to-leading order QCD calculation and with a tree-level QCD prediction with parton shower simulation and hadronization.
Ratio of the cross sections.
Number of observed events per 5 GeV bin for the >=`1Jet sample. Data read from plots.
Number of observed events per 5 GeV bin for the >=2Jet sample. Data read from plots.
Measurements of the Xi- and anti-Xi+ masses, mass differences, lifetimes and lifetime differences are presented. The anti-Xi+ sample used is much larger than those used previously for such measurements. In addition, the Xi production rates in Z -> b anti-b and Z -> q anti-q events are compared and the position xi* of the maximum of the xi distribution in Z -> q anti-q events is measured.
Corrected LN(1/X) distribution for (XI- + XIBAR+) production.
Measured and extrapoplated production rates.
Extrapolated production rate in b-bbar events.
The PHENIX experiment has measured mid-rapidity transverse momentum spectra (0.4 < p_T < 4.0 GeV/c) of single electrons as a function of centrality in Au+Au collisions at sqrt(s_NN) = 200 GeV. Contributions to the raw spectra from photon conversions and Dalitz decays of light neutral mesons are measured by introducing a thin (1.7% X_0) converter into the PHENIX acceptance and are statistically removed. The subtracted ``non-photonic'' electron spectra are primarily due to the semi-leptonic decays of hadrons containing heavy quarks (charm and bottom). For all centralities, charm production is found to scale with the nuclear overlap function, T_AA. For minimum-bias collisions the charm cross section per binary collision is N_cc^bar/T_AA = 622 +/- 57 (stat.) +/- 160 (sys.) microbarns.
Value of the Alpha power as used in a fit of dN/dy versus Ncoll of the form A*Ncoll^Alpha, where N is the non photonic electron yield and Ncoll the number of p+p collisions This value only includes data from Au+Au collisions The value of Alpha = 1 is the expectation in the absence of medium effects.
Value of the Alpha power as used in a fit of dN/dy versus Ncoll, of the form A*Ncoll^Alpha, where N is the non photonic electron yield and Ncoll the number of p+p collisions This value is calculated including previous data of p+p collisions, measured by PHENIX, in addition of the Au+Au data The value of Alpha = 1 is the expectation in the absence of medium effects.
Spectrum in transverse momentum of electrons created in open heavy flavor decays, for minimum bias events.
The cross section for anti-deuteron photoproduction is measured at HERA at a mean centre-of-mass energy of W_{\gamma p} = 200 GeV in the range 0.2 < p_T/M < 0.7 and |y| < 0.4, where M, p_T and y are the mass, transverse momentum and rapidity in the laboratory frame of the anti-deuteron, respectively. The numbers of anti-deuterons per event are found to be similar in photoproduction to those in central proton-proton collisions at the CERN ISR but much lower than those in central Au-Au collisions at RHIC. The coalescence parameter B_2, which characterizes the likelihood of anti-deuteron production, is measured in photoproduction to be 0.010 \pm 0.002 \pm 0.001, which is much higher than in Au-Au collisions at a similar nucleon-nucleon centre-of-mass energy. No significant production of particles heavier than deuterons is observed and upper limits are set on the photoproduction cross sections for such particles.
The measured value of the invariant DEUTBAR production cross section. The data are normalized to a total photoproduction cross section of (164 +- 11 MUB).
The measured and weak decay corrected values of the DEUTBAR to PBAR cross sections.