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Evidence for collectivity in pp collisions at the LHC

The CMS collaboration
Phys.Lett. B765 (2017) 193-220, 2017

Abstract (data abstract)
CERN-LHC. Measurements of two- and multi-particle angular correlations in pp collisions at sqrt(s) = 5, 7, and 13 TeV are presented as a function of charged-particle multiplicity. The data, corresponding to integrated luminosities of 1.0 inverse picobarn (5 TeV), 6.2 inverse picobarns (7 TeV), and 0.7 inverse picobarns (13 TeV), were collected using the CMS detector at the LHC. The second-order (v[2]) and third-order (v[3]) azimuthal anisotropy harmonics of unidentified charged particles, as well as v[2] of K0 short and Lambda/anti-Lambda particles, are extracted from long-range two-particle correlations as functions of particle multiplicity and transverse momentum. For high-multiplicity pp events, a mass ordering is observed for the v[2] values of charged hadrons (mostly pions), K0 short, and Lambda/anti-Lambda, with lighter particle species exhibiting a stronger azimuthal anisotropy signal below pt of about 2 GeV/c. For 13 TeV data, the v[2] signals are also extracted from four- and six-particle correlations for the first time in pp collisions, with comparable magnitude to those from two-particle correlations. These observations are similar to those seen in pPb and PbPb collisions, and support the interpretation of a collective origin for the observed long-range correlations in high-multiplicity pp collisions.

  • Table 1

    Data from Figure 4

    10.17182/hepdata.76506.v1/t1

    The second-order Fourier coefficients, $V_{2\Delta}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 2

    Data from Figure 4

    10.17182/hepdata.76506.v1/t2

    The second-order Fourier coefficients, $V_{2\Delta}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged particles, after correcting for back-to-back...

  • Table 3

    Data from Figure 4

    10.17182/hepdata.76506.v1/t3

    The second-order Fourier coefficients, $V_{3\Delta}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 4

    Data from Figure 4

    10.17182/hepdata.76506.v1/t4

    The second-order Fourier coefficients, $V_{3\Delta}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged particles, after correcting for back-to-back...

  • Table 5

    Data from Figure 5

    10.17182/hepdata.76506.v1/t5

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 6

    Data from Figure 5

    10.17182/hepdata.76506.v1/t6

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 7

    Data from Figure 5

    10.17182/hepdata.76506.v1/t7

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 8

    Data from Figure 5

    10.17182/hepdata.76506.v1/t8

    The triangular flow after correcting for back-to-back jet correlations, $v_{3}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 9

    Data from Figure 5

    10.17182/hepdata.76506.v1/t9

    The triangular flow after correcting for back-to-back jet correlations, $v_{3}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 10

    Data from Figure 5

    10.17182/hepdata.76506.v1/t10

    The triangular flow after correcting for back-to-back jet correlations, $v_{3}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 11

    Data from Figure 6

    10.17182/hepdata.76506.v1/t11

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged particles.

  • Table 12

    Data from Figure 6

    10.17182/hepdata.76506.v1/t12

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged particles.

  • Table 13

    Data from Figure 6

    10.17182/hepdata.76506.v1/t13

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged particles.

  • Table 14

    Data from Figure 6

    10.17182/hepdata.76506.v1/t14

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged...

  • Table 15

    Data from Figure 6

    10.17182/hepdata.76506.v1/t15

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged...

  • Table 16

    Data from Figure 6

    10.17182/hepdata.76506.v1/t16

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged...

  • Table 17

    Data from Figure 7

    10.17182/hepdata.76506.v1/t17

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged particles.

  • Table 18

    Data from Figure 7

    10.17182/hepdata.76506.v1/t18

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $K^{0}_{S}$.

  • Table 19

    Data from Figure 7

    10.17182/hepdata.76506.v1/t19

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $\Lambda/\bar{\Lambda}$.

  • Table 20

    Data from Figure 7

    10.17182/hepdata.76506.v1/t20

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged particles.

  • Table 21

    Data from Figure 7

    10.17182/hepdata.76506.v1/t21

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $K^{0}_{S}$.

  • Table 22

    Data from Figure 7

    10.17182/hepdata.76506.v1/t22

    The elliptic flow, $v_{2}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $\Lambda/\bar{\Lambda}$.

  • Table 23

    Data from Figure 8

    10.17182/hepdata.76506.v1/t23

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for charged...

  • Table 24

    Data from Figure 8

    10.17182/hepdata.76506.v1/t24

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $K^{0}_{S}$.

  • Table 25

    Data from Figure 8

    10.17182/hepdata.76506.v1/t25

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $p_{T}$ for $\Lambda/\bar{\Lambda}$.

  • Table 26

    Data from Figure 8

    10.17182/hepdata.76506.v1/t26

    The elliptic flow per constituent quark after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)/n_{q}$, as a function of...

  • Table 27

    Data from Figure 8

    10.17182/hepdata.76506.v1/t27

    The elliptic flow per constituent quark after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of...

  • Table 28

    Data from Figure 9

    10.17182/hepdata.76506.v1/t28

    The four-particle cumulant, $c_{2}(4)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 29

    Data from Figure 9

    10.17182/hepdata.76506.v1/t29

    The four-particle cumulant, $c_{2}(4)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 30

    Data from Figure 9

    10.17182/hepdata.76506.v1/t30

    The four-particle cumulant, $c_{2}(4)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 31

    Data from Figure 9

    10.17182/hepdata.76506.v1/t31

    The six-particle cumulant, $c_{2}(6)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 32

    Data from Figure 10

    10.17182/hepdata.76506.v1/t32

    The elliptic flow after correcting for back-to-back jet correlations, $v_{2}^{sub}(2, |\Delta\eta| > 2)$, as a function of $N_{offline}^{trk}$ for charged...

  • Table 33

    Data from Figure 10

    10.17182/hepdata.76506.v1/t33

    The elliptic flow, $v_{2}(4)$, as a function of $N_{offline}^{trk}$ for charged particles.

  • Table 34

    Data from Figure 10

    10.17182/hepdata.76506.v1/t34

    The elliptic flow, $v_{2}(6)$, as a function of $N_{offline}^{trk}$ for charged particles.

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