7 research outputs found

    Measurement of CP violation and constraints on the CKM angle Îł in B± → DK± with D → K0Sπ+π− decays

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    A model-dependent amplitude analysis of B± → DK± with D → K0 Sπ+π− decays is performed using proton–proton collision data, corresponding to an integrated luminosity of 1 fb−1, recorded by LHCb at a centre-of-mass energy of 7 TeV in 2011. Values of the CP violation observables x± and y±, which are sensitive to the CKM angle Îł, are measured to be x− = +0.027 ± 0.044+0.010 −0.008 ± 0.001, y− = +0.013 ± 0.048+0.009 −0.007 ± 0.003, x+ = −0.084 ± 0.045 ± 0.009 ± 0.005, y+ = −0.032 ± 0.048+0.010 −0.009 ± 0.008, where the first uncertainty is statistical, the second systematic and the third arises from the uncertainty of the D → K0 Sπ+π− amplitude model. The value of Îł is determined to be (84+49 −42)◩, including all sources of uncertainty. Neutral D meson mixing is found to have negligible effect

    Erratum: Measurement of the -Quark Production Cross Section in 7 and 13 TeV Collisions [Phys. Rev. Lett. 118 , 052002 (2017)]

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    Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

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    Measurements of anisotropic flow coefficients (vn) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at 1as=13\u2009\u2009TeV, p 12Pb at a center-of-mass energy per nucleon pair 1asNN=5.02\u2009\u2009TeV, Xe-Xe at 1asNN=5.44\u2009\u2009TeV, and Pb-Pb at 1asNN=5.02\u2009\u2009TeV recorded with the ALICE detector. The multiplicity dependence of vn is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |\u3b7|v3>v4 is found in pp and p 12Pb collisions, similar to that seen in large collision systems, while a weak v2 multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v2 measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p 12Pb collisions. The magnitude of the correlation between v2n and v2m, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v2 and v4, while for v2 and v3 it is negative and changes sign for multiplicities below 100, which may indicate a different vn fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p 12Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems

    Precision measurement of the ratio of the Lambda(0)(b) to (B)over-bar(0) lifetimes

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    The LHCb measurement of the lifetime ratio of the Lambda(0)(b) baryon to the (B) over bar (0) meson is updated using data corresponding to an integrated luminosity of 3.0 fb(-1) collected using 7 and 8 TeV centre-of-mass energy pp collisions at the LHC. The decay modes used are Lambda(0)(b) -> J/psi pK(-) and (B) over bar (0) -> J/psi pi K-+(-), where the pi K-+(-) mass is consistent with that of the (K) over bar*(0)(892) meson. The lifetime ratio is determined with unprecedented precision to be 0.974 +/- 0.006 +/- 0.004, where the first uncertainty is statistical and the second systematic. This result is in agreement with original theoretical predictions based on the heavy quark expansion. Using the current world average of the (B) over bar (0) lifetime, the Lambda(0)(b) lifetime is found to be 1.479 +/- 0.009 +/- 0.010 ps

    Precision measurement of the ratio of the Lambda(0)(b) to (B)over-bar(0) lifetimes

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    The LHCb measurement of the lifetime ratio of the Lambda(0)(b) baryon to the (B) over bar (0) meson is updated using data corresponding to an integrated luminosity of 3.0 fb(-1) collected using 7 and 8 TeV centre-of-mass energy pp collisions at the LHC. The decay modes used are Lambda(0)(b) -> J/psi pK(-) and (B) over bar (0) -> J/psi pi K-+(-), where the pi K-+(-) mass is consistent with that of the (K) over bar*(0)(892) meson. The lifetime ratio is determined with unprecedented precision to be 0.974 +/- 0.006 +/- 0.004, where the first uncertainty is statistical and the second systematic. This result is in agreement with original theoretical predictions based on the heavy quark expansion. Using the current world average of the (B) over bar (0) lifetime, the Lambda(0)(b) lifetime is found to be 1.479 +/- 0.009 +/- 0.010 ps. (C) 2014 The Authors. Published by Elsevier B.V

    Measurement of CP violation and constraints on the CKM angle gamma in B-+/- -> DK +/- with D -> K-s(0)pi(+)pi(-) decays

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    A model-dependent amplitude analysis of B-+/- -> DK +/- with D -> K-s(0)pi(+)pi(-) decays is performed using proton proton collision data, corresponding to an integrated luminosity of 1 fb(-1), recorded by LHCb at a centre-of-mass energy of 7 TeV in 2011. Values of the CP violation observables x +/- and y +/-, which are sensitive to the CKM angle gamma, are measured to be x- = +0.027 +/- 0.0441(-0.008)(+0.010) +/- 0.001, y- = +0.013 +/- 0.0481(-0.007)(+0.009) +/- 0.003, x+ = -0.084 +/- 0.045 +/- 0.009 +/- 0.005, y+ = -0.032 +/- 0.048(-0.009)(+0.010) +/- 0.008, where the first uncertainty is statistical, the second systematic and the third arises from the uncertainty of the D -> K-S(0)pi(+)pi(-) amplitude model. The value of gamma is determined to be (84(-42)(+49))degrees including all sources of uncertainty. Neutral D meson mixing is found to have negligible effect

    Evidence for CP Violation in B+→pp‟K+B^+\to p \overline p K^+ Decays

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