{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.70016.v1","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/1346844"}},{"@id":"https://doi.org/10.1140/epjc/s10052-015-3644-x","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"ATLAS Collaboration"},"creator":{"@type":"Organization","name":"ATLAS Collaboration"},"datePublished":"2016","description":"CERN-LHC. Studies of Bose-Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range $p_{T} > 100\\ MeV$ and $|\\eta| < 2.5$ in proton-proton collisions at centre-of-mass energies of $0.9$ and $7\\ TeV$ with the ATLAS detector at the CERN Large Hadron Collider are presented. In addition to minimum-bias data, high-multiplicity data recorded at $7\\ TeV$ using a dedicated trigger are investigated. The integrated luminosities are approximately $7\\ \\mu$$b^{-1}$ (2009), $190\\ \\mu$$b^{-1}$ (2010) and $12.4\\ nb^{-1}$ (2010) for $0.9\\ TeV$, $7\\ TeV$ minimum-bias and $7\\ TeV$ high-multiplicity (HM) data samples, respectively. \n\nBose-Einstein correlations are measured in terms of a two-particle correlation function. The density function is parameterized in terms of the Lorentz-invariant four-momentum difference squared, $Q^{2}$, of the two particles. The studies were performed using the double-ratio correlation function $R_{2}(Q)$. In the double-ratio method, the single-ratio correlation function $C_{2}(Q)$ obtained from the data is divided by a similar single-ratio calculated using Monte Carlo events, which do not have BEC effects. The reference sample for each of the two single-ratios is constructed from unlike-sign charged-particle pairs. \n\nA clear signal of Bose-Einstein correlations is observed in the region of small four-momentum difference. The BEC effect is usually described by a function with two parameters: the effective radius $R$ and the strength parameter $\\lambda$ (incoherence or chaoticity parameter). To quantitatively characterize the BEC effect, the Gaussian $\\Omega^{(G)}$ and the Exponential $\\Omega^{(E)} $parametrizations are fit to the measured correlation functions. As the Gaussian parametrization provides a poor description of the BEC-enhanced region and hence the Exponential parametrization is used for the final results. The fits are performed in the $Q$ range $0.02\\ GeV$ to $2\\ GeV$ and with a bin width of $0.02\\ GeV$. Around $Q \\sim 0.7\\ GeV$ there is a visible bump which is due to an overestimate of $\\rho \\to \\pi^{+}\\pi^{-}$ decays in the Monte Carlo simulation. Therefore the region $0.5 \\le Q \\le 0.9\\ GeV$ is excluded from the fits.\n\nThe BEC parameters characterizing the correlation strength $\\lambda$ and the correlation source size $R$ are measured for $0.9\\ TeV$, $7\\ TeV$ minimum-bias charged-particle events and $7\\ TeV$ high-multiplicity charged-particle events with multiplicities $n_{ch} \\ge 2$, $n_{ch} \\ge 2$ and $n_{ch} \\ge 150$, respectively. The average transverse momentum $k_{T}$ and the multiplicity $n_{ch}$ dependences of the BEC parameters are investigated for charged-particle multiplicities of up to $240$. A saturation effect in the multiplicity dependence of the correlation source size is observed using the high-multiplicity $7\\ TeV$ data samples.\n \nSee Eur. Phys. J. C75 (2015) 466 for more details.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t1","@type":"Dataset","description":"Systematic uncertainties on $\\lambda$ and $R$ for the exponential fit of the two-particle double-ratio correlation function $R_{2}(Q)$ in the full...","name":"Table 1"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t2","@type":"Dataset","description":"Results of fitting the multiplicity, $n_{ch}$, dependence of the BEC parameters $R$ and $\\lambda$ with different functional forms for $\\sqrt{s}...","name":"Table 2"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t3","@type":"Dataset","description":"Results of fitting the transverse momentum of the pair, $k_{T}$, dependence of the BEC parameters $R$ and $\\lambda$ with the...","name":"Table 3"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t4","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 0.9\\ TeV$ events with the...","name":"Table 4"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t5","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 7\\ TeV$ events with the...","name":"Table 5"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t6","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 7\\ TeV\\ HM$ events with...","name":"Table 6"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t7","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 0.9\\ TeV$ ($n_{ch} \\ge 2$)...","name":"Table 7"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t8","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 7\\ TeV$ ($n_{ch} \\ge 2$)...","name":"Table 8"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t9","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 7\\ TeV\\ HM$ ($n_{ch} \\ge...","name":"Table 9"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t10","@type":"Dataset","description":"The results of fits of the two-particle double-ratio correlation function $R_{2} (Q)$ for $\\sqrt{s} = 7\\ TeV$ events with the...","name":"Table 10"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t11","@type":"Dataset","description":"The $Q$ distribution measured at $0.9\\ TeV$ for unlike-sign pairs for $p_{T} > 100\\ MeV$ and $|\\eta|<2.5$, renormalized to the...","name":"Table 11"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t12","@type":"Dataset","description":"The $Q$ distribution measured at $0.9\\ TeV$ for like-sign pairs for $p_{T} > 100\\ MeV$ and $|\\eta|<2.5$, renormalized to the...","name":"Table 12"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t13","@type":"Dataset","description":"The $Q$ distribution measured at $7\\ TeV$ for unlike-sign pairs for $p_{T} > 100\\ MeV$ and $|\\eta|<2.5$, renormalized to the...","name":"Table 13"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t14","@type":"Dataset","description":"The $Q$ distribution measured at $7\\ TeV$ for like-sign pairs for $p_{T} > 100\\ MeV$ and $|\\eta|<2.5$, renormalized to the...","name":"Table 14"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t15","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $0.9\\ TeV$ using unlike-charge particle reference sample for different $n_{ch}$ intervals $p_{T} > 100\\...","name":"Table 15"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t16","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $0.9\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals with multiplicity $n_{ch}...","name":"Table 16"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t17","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different multiplicity intervals $n_{ch}$ with $p_{T}...","name":"Table 17"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t18","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals with multiplicity $n_{ch}...","name":"Table 18"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t19","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV\\ HM$ using unlike-charge particle reference sample for different $n_{ch}$ intervals $p_{T} >...","name":"Table 19"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t20","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured with $7\\ TeV\\ HM$ data using unlike-charge particle reference sample for different $k_{T}$ intervals with...","name":"Table 20"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t21","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals within multiplicity interval...","name":"Table 21"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t22","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals within multiplicity interval...","name":"Table 22"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t23","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals within multiplicity interval...","name":"Table 23"},{"@id":"https://doi.org/10.17182/hepdata.70016.v1/t24","@type":"Dataset","description":"The $R_{2}(Q)$ correlation function measured at $7\\ TeV$ using unlike-charge particle reference sample for different $k_{T}$ intervals within multiplicity interval...","name":"Table 24"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins1346844?version=1"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/70016"}],"inLanguage":"en","name":"Two-particle Bose-Einstein correlations in $pp$ collisions at $\\mathbf {\\sqrt{s} =}$ 0.9 and 7 TeV measured with the ATLAS detector","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins1346844?version=1","version":1}