A search is presented for flavour-changing neutral-current interactions involving the top quark, the Higgs boson and an up-type quark ($q=u,c$) with the ATLAS detector at the Large Hadron Collider. The analysis considers leptonic decays of the top quark along with Higgs boson decays into two $W$ bosons, two $Z$ bosons or a $\tau^{+}\tau^{-}$ pair. It focuses on final states containing either two leptons (electrons or muons) of the same charge or three leptons. The considered processes are $t\bar{t}$ and $Ht$ production. For the $t\bar{t}$ production, one top quark decays via $t\to Hq$. The proton-proton collision data set analysed amounts to 140 fb$^{-1}$ at $\sqrt{s}=13$ TeV. No significant excess beyond Standard Model expectations is observed and upper limits are set on the $t\to Hq$ branching ratios at 95% confidence level, amounting to observed (expected) limits of $\mathcal{B}(t\to Hu)<2.8\,(3.0) \times 10^{-4}$ and $\mathcal{B}(t\to Hc)<3.3\,(3.8) \times 10^{-4}$. Combining this search with other searches for $tHq$ flavour-changing neutral-current interactions previously conducted by ATLAS, considering $H\to b\bar{b}$ and $H\to\gamma\gamma$ decays, as well as $H\to\tau^{+}\tau^{-}$ decays with one or two hadronically decaying $\tau$-leptons, yields observed (expected) upper limits on the branching ratios of $\mathcal{B}(t\to Hu)<2.6\,(1.8) \times 10^{-4}$ and $\mathcal{B}(t\to Hc)<3.4\,(2.3) \times 10^{-4}$.
Pre-fit background composition of the SR$2\ell$ Dec. The table shows the event yields as opposed to just the percentages of the relevant background processes.
Pre-fit background composition of the SR$2\ell$ Prod. The table shows the event yields as opposed to just the percentages of the relevant background processes.
Pre-fit background composition of the SR$3\ell$ Dec. The table shows the event yields as opposed to just the percentages of the relevant background processes.
The production of single top quarks and top antiquarks via the $t$-channel exchange of a virtual $W$ boson is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV at the LHC using $140\,\mathrm{fb^{-1}}$ of ATLAS data. The total cross-sections are determined to be $\sigma(tq)=137^{+8}_{-8}\,\mathrm{pb}$ and $\sigma(\bar{t}q)=84^{+6}_{-5}\,\mathrm{pb}$ for top-quark and top-antiquark production, respectively. The combined cross-section is found to be $\sigma(tq+\bar{t}q)=221^{+13}_{-13}\,\mathrm{pb}$ and the cross-section ratio is $R_{t}=\sigma(tq)/\sigma(\bar{t}q)=1.636^{+0.036}_{-0.034}$. The predictions at next-to-next-to-leading-order in quantum chromodynamics are in good agreement with these measurements. The predicted value of $R_{t}$ using different sets of parton distribution functions is compared with the measured value, demonstrating the potential to further constrain the functions when using this result in global fits. The measured cross-sections are interpreted in an effective field theory approach, setting limits at the 95% confidence level on the strength of a four-quark operator and an operator coupling the third quark generation to the Higgs boson doublet: $-0.37 < C_{Qq}^{3,1}/\Lambda^2 < 0.06$ and $-0.87 < C_{\phi Q}^{3}/\Lambda^2 < 1.42$. The constraint $|V_{tb}|>0.95$ at the 95% confidence level is derived from the measured value of $\sigma(tq+\bar{t}q)$. In a more general approach, pairs of CKM matrix elements involving top quarks are simultaneously constrained, leading to confidence contours in the corresponding two-dimensional parameter spaces.
The 17 variables used for the training of the NN ordered by their discriminating power. The jet that is not \(b\)-tagged is referred to as the untagged jet. The charged lepton is denoted \(\ell\). The sphericity tensor \(S^{\alpha\beta}\) used to define the sphericity \(S\) is formed with the three-momenta \(\vec{p}_i\) of the reconstructed objects, namely the jets, the charged lepton and the reconstructed neutrino. The tensor is given by \(S^{\alpha\beta}=\frac{\sum_i p_i^\alpha p_i^\beta}{\sum_i |\vec{p}_i|^2}\) where \(\alpha\) and \(\beta\) correspond to the spatial components $x$, $y$ and $z$.
The impact of different groups of systematic uncertainties on the \(\sigma(tq)\) , \(\sigma(\bar t q)\), \(\sigma(tq + \bar t q)\) and \(R_t\), given in %.
The impact of the eight most important systematic uncertainties on the \(\sigma(tq)\) , \(\sigma(\bar t q)\) and \(\sigma(tq + \bar t q)\), given in %. The sequence of the uncertainties is given by the impact on \(\sigma(tq + \bar t q)\)
A search for a heavy CP-odd Higgs boson, $A$, decaying into a $Z$ boson and a heavy CP-even Higgs boson, $H$, is presented. It uses the full LHC Run 2 dataset of $pp$ collisions at $\sqrt{s}=13$ TeV collected with the ATLAS detector, corresponding to an integrated luminosity of $140$ fb$^{-1}$. The search for $A\to ZH$ is performed in the $\ell^+\ell^- t\bar{t}$ and $\nu\bar{\nu}b\bar{b}$ final states and surpasses the reach of previous searches in different final states in the region with $m_H>350$ GeV and $m_A>800$ GeV. No significant deviation from the Standard Model expectation is found. Upper limits are placed on the production cross-section times the decay branching ratios. Limits with less model dependence are also presented as functions of the reconstructed $m(t\bar{t})$ and $m(b\bar{b})$ distributions in the $\ell^+\ell^- t\bar{t}$ and $\nu\bar{\nu}b\bar{b}$ channels, respectively. In addition, the results are interpreted in the context of two-Higgs-doublet models.
<b><u>Overview of HEPData Record</u></b><br> <b>Upper limits on cross-sections:</b> <ul> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=0.5">95% CL upper limit on ggF A->ZH(tt) production for tanb=0.5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=1">95% CL upper limit on ggF A->ZH(tt) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20ggF,%20tanbeta=5">95% CL upper limit on ggF A->ZH(tt) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=1">95% CL upper limit on bbA A->ZH(tt) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=5">95% CL upper limit on bbA A->ZH(tt) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20lltt,%20bbA,%20tanbeta=10">95% CL upper limit on bbA A->ZH(tt) production for tanb=10</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=0.5">95% CL upper limit on ggF A->ZH(bb) production for tanb=0.5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=1">95% CL upper limit on ggF A->ZH(bb) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20ggA,%20tanbeta=5">95% CL upper limit on ggF A->ZH(bb) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=1">95% CL upper limit on bbA A->ZH(bb) production for tanb=1</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=5">95% CL upper limit on bbA A->ZH(bb) production for tanb=5</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=10">95% CL upper limit on bbA A->ZH(bb) production for tanb=10</a> <li><a href="?table=Cross-section%20limits%20for%20vvbb,%20bbA,%20tanbeta=20">95% CL upper limit on bbA A->ZH(bb) production for tanb=20</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=m(tt),L3hi_Zin,ggF-production">m(tt) distribution in the L3hi_Zin region of the lltt channel</a> <li><a href="?table=m(bb),2tag,0L,ggF-production">m(bb) distribution in the 2 b-tag 0L region of the vvbb channel</a> <li><a href="?table=m(bb),3ptag,0L,bbA-production">m(bb) distribution in the 3p b-tag 0L region of the vvbb channel</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin450,bbA-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis with the bbA signal shown</a> <li><a href="?table=m(tt),L3hi_Zin,bbA-production">m(tt) distribution in the L3hi_Zin region of the lltt channel with the bbA signal shown</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin350,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=350 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin400,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=400 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin450,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin500,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=500 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin550,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=550 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin600,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=600 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin700,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=700 GeV hypothesis</a> <li><a href="?table=m(lltt)-m(tt),L3hi_Zin_Hin800,ggF-production">Fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin130,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=130 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin150,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=150 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin200,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=200 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin250,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=250 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin300,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin350,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=350 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin400,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=400 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin450,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=450 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin500,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=500 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin600,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=600 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin700,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=700 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,0L_Hin800,ggF-production">Fit discriminant mT(VH) in the 2 b-tag signal region of the vvbb channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin130,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=130 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin150,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=150 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin200,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=200 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin250,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=250 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin300,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin350,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=350 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin400,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=400 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin450,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=450 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin500,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=500 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin600,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=600 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin700,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=700 GeV hypothesis</a> <li><a href="?table=mTVH,3ptag,0L_Hin800,bbA-production">Fit discriminant mT(VH) in the 3p b-tag signal region of the vvbb channel for the mH=800 GeV hypothesis</a> <li><a href="?table=mTVH,2tag,2L">Fit discriminant mT(VH) in the 2L region of the vvbb channel</a> <li><a href="?table=mTVH,2tag,em">Fit discriminant mT(VH) in the em region of the vvbb channel</a> <li><a href="?table=mTVH,3ptag,2L">Fit discriminant mT(VH) in the 2L region of the vvbb channel</a> <li><a href="?table=mTVH,3ptag,em">Fit discriminant mT(VH) in the em region of the vvbb channel</a> <li><a href="?table=lep3pt,L3hi_Zin">pT(lepton,3) distribution in the L3hi_Zin region of the lltt channel</a> <li><a href="?table=etaHrestVH,L3hi_Zin">eta(H,VH rest frame) distribution in the signal region of the lltt channel</a> <li><a href="?table=ETmiss,2tag,0L">ETmiss distribution in the 2 b-tag signal region of the vvbb channel</a> <li><a href="?table=mtopnear,2tag,0L">m(top,near) distribution in the 2 b-tag signal region of the vvbb channel</a> <li><a href="?table=ETmiss,3ptag,0L">ETmiss distribution in the 3p b-tag signal region of the vvbb channel</a> <li><a href="?table=mtopnear,3ptag,0L">m(top,near) distribution in the 3p b-tag signal region of the vvbb channel</a> </ul> <b>Observed local significance:</b> <ul> <li><a href="?table=Local%20significance,%20lltt,%20ggF%20production">ggF A->ZH->lltt signals</a> <li><a href="?table=Local%20significance,%20lltt,%20bbA%20production">bbA A->ZH->lltt signals</a> <li><a href="?table=Local%20significance,%20vvbb,%20ggF%20production">ggF A->ZH->vvbb signals</a> <li><a href="?table=Local%20significance,%20vvbb,%20bbA%20production">bbA A->ZH->vvbb signals</a> </ul> <b>Acceptance and efficiency:</b> <ul> <li><a href="?table=Acceptance*efficiency,%20lltt,%20ggF%20production">ggF A->ZH->lltt signals</a> <li><a href="?table=Acceptance*efficiency,%20lltt,%20bbA%20production">bbA A->ZH->lltt signals</a> <li><a href="?table=Acceptance*efficiency,%20vvbb,%20ggF%20production">ggF A->ZH->vvbb signals</a> <li><a href="?table=Acceptance*efficiency,%20vvbb,%20bbA%20production">bbA A->ZH->vvbb signals</a> </ul>
The distribution of the fit discriminant m(lltt)-m(tt) in the signal region of the lltt channel for the mH=450 GeV hypothesis. <br><br><a href="?table=overview">return to overview</a>
The distribution of the fit discriminant mTVH in the 2 b-tag signal region of the vvbb channel for the mH=300 GeV hypothesis. <br><br><a href="?table=overview">return to overview</a>
This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139 fb$^{-1}$ of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688 $\pm$ 23 (stat.) $^{+75}_{-71}$ (syst.) fb, to be compared with the standard model prediction of 515 $^{+36}_{-42}$ fb at next-to-leading order in QCD.
This table shows the values for $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)$ and $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)+\sigma_{t(\rightarrow l\nu b\gamma)q}$ obtained by a profile-likelihood fit in the fiducial parton-level phase space (defined in Table 1) and particle-level phase space (defined in Table 2), respectively.
Distribution of the reconstructed top-quark mass in the $W\gamma\,$CR before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the NN output in the 0fj$\,$SR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.
The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity $|y_{ee}|<1$ in minimum-bias Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened $\rho$ spectral function for $M_{ee}<1.1$ GeV/$c^{2}$. The integrated dielectron excess yield at $\sqrt{s_{NN}}$ = 19.6 GeV for $0.4
Reconstructed dielectron unlike-sign pairs, like-sign pairs and signal distributions, together with the signal to background ratio (S/B). All columns are presented as a function of dielectron invariant mass in Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV.
Dielectron invariant mass spectrum in the STAR acceptance (|$y_{ee}$| < 1, 0.2 < $p_T^e$ < 3 GeV/c, |$\eta^e$ | < 1) after efficiency correction in Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV.
Hadronic cocktail consisting of the decays of light hadrons and correlated decays of charm in Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV.
The results of mid-rapidity ($0 < y < 0.8$) neutral pion spectra over an extended transverse momentum range ($1 < p_T < 12$ GeV/$c$) in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured either by the STAR Barrel Electro-Magnetic Calorimeter (BEMC) or by the Time Projection Chamber (TPC) via tracking of conversion electron-positron pairs. Our measurements are compared to previously published $\pi^{\pm}$ and $\pi^0$ results. The nuclear modification factors $R_{\mathrm{CP}}$ and $R_{\mathrm{AA}}$ of $\pi^0$ are also presented as a function of $p_T$ . In the most central Au+Au collisions, the binary collision scaled $\pi^0$ yield at high $p_T$ is suppressed by a factor of about 5 compared to the expectation from the yield of p+p collisions. Such a large suppression is in agreement with previous observations for light quark mesons and is consistent with the scenario that partons suffer considerable energy loss in the dense medium formed in central nucleus-nucleus collisions at RHIC.
The diphoton invariant mass distributions using the EMC-TPC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.
The diphoton invariant mass distributions using the EMC-TPC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.
The diphoton invariant mass distributions using the EMC-EMC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.
The global topologies of inclusive three-- and four--jet events produced in $\pp$ interactions are described. The three-- and four--jet events are selected from data recorded by the D\O\ detector at the Tevatron Collider operating at a center--of--mass energy of $\sqrt{s} = 1800$ GeV. The measured, normalized distributions of various topological variables are compared with parton--level predictions of tree--level QCD calculations. The parton--level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well. The parton shower Monte Carlo generators provide a less satisfactory description of the topologies of the three-- and four--jet events.
The estimated systematic uncertainty is 6 PCT.
The estimated systematic uncertainty is 6 PCT.
The estimated systematic uncertainty is 6 PCT.
The properties of two-, three-, four-, five-, and six-jet events with multijet masses >600 GeV /c2 are compared with QCD predictions. The shapes of the multijet-mass and leading-jet-angular distributions are approximately independent of jet multiplicity and are well described by the NJETS matrix element calculation and the HERWIG parton shower Monte Carlo predictions. The observed jet transverse momentum distributions for three- and four-jet events discriminate between the matrix element and parton shower predictions, the data favoring the matrix element calculation.
Exclusive 2-jet mass distribution.
Exclusive 3-jet mass distribution.
Exclusive 4-jet mass distribution.
The production dynamics of baryon-antibaryon pairs are investigated using hadronic Z 0 decays, recorded with the OPAL detector, which contain at least two identified Λ baryons. The rapidly difference for Λ Λ pairs shows the correlations expected from models with a chain-like production of baryon-antibaryon pairs. If the baryon number of a Λ is compensated by a Λ , the Λ is found with a probability of 53% in an interval of ±0.6 around the Λ rapidity. This correlation strength is weaker than predicted by the Herwig Monte Carlo and the Jetset Monte Carlo with a production chain of baryon-antibaryon, and stronger than predicted by the UCLA model. The observed rapidity correlations can be described by the Jetset Monte Carlo with a dominant production chain of baryon-meson-antibaryon, the popcorn mechanism. In addition to the short range correlations, one finds an indication of a correlation of Λ Λ pairs in opposite hemispheres if both the Λ and the Λ have large rapidities. Such long range correlations are expected if the primary quark flavours are compensated in opposite hemispheres and if these quarks are found in energetic baryons. Rates for simultaneous baryon and strangeness number compensation for Λ Λ , Ξ − Ξ + and Ξ − Λ ( Λ + Λ ) are measured and compared with different Monte Carlo models.
No description provided.
Opposite and same baryon number invariant PI P mass distribuition for additional LAMBDA(LAMBDABAR) candidates in events with one identified LAMBDA(LAMBDABAR). CT.= Data read from plot.
Opposite and same baryon number invariant PI P mass distribuition for additional LAMBDA(LAMBDABAR) candidates in events with one identified XI-(XIBAR+). CT.= Data read from plot.
None
No description provided.
No description provided.
No description provided.
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