Evidence for collectivity in pp collisions at the LHC

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Lett. B765 (2017) 193-220, 2017.
Inspire Record 1471287 DOI 10.17182/hepdata.76506

Measurements of two- and multi-particle angular correlations in pp collisions at s=5,7, and 13TeV are presented as a function of charged-particle multiplicity. The data, corresponding to integrated luminosities of 1.0pb−1 (5 TeV), 6.2pb−1 (7 TeV), and 0.7pb−1 (13 TeV), were collected using the CMS detector at the LHC. The second-order ( v2 ) and third-order ( v3 ) azimuthal anisotropy harmonics of unidentified charged particles, as well as v2 of KS0 and Λ/Λ‾ 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 v2 values of charged hadrons (mostly pions), KS0 , and Λ/Λ‾ , with lighter particle species exhibiting a stronger azimuthal anisotropy signal below pT≈2GeV/c . For 13 TeV data, the v2 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.

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D-meson production in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV and in pp collisions at $\sqrt{s}=7$ TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
2016.
Inspire Record 1465513 DOI 10.17182/hepdata.73941

The production cross sections of the prompt charmed mesons D$^0$, D$^+$, D$^{*+}$ and D$_s$ were measured at mid-rapidity in p-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}}=5.02$ TeV with the ALICE detector at the LHC. D mesons were reconstructed from their decays D$^0\rightarrow{\rm K}^-\pi^+$, D$^+\rightarrow{\rm K}^-\pi^+\pi^+$, D$^{*+}\rightarrow D^0\pi^+$, D$_s^+\rightarrow\phi\pi^+\rightarrow{\rm K}^-{\rm K}^+\pi^+$, and their charge conjugates. The $p_{\rm T}$-differential production cross sections were measured at mid-rapidity in the interval $1<p_{\rm T}<24$ GeV/$c$ for D$^0$, D$^+$ and D$^{*+}$ mesons and in $2<p_{\rm T}<12$ GeV/$c$ for D$_s$ mesons, using an analysis method based on the selection of decay topologies displaced from the interaction vertex. The production cross sections of the D$^0$, D$^+$ and D$^{*+}$ mesons were also measured in three $p_{\rm T}$ intervals as a function of the rapidity $y_{\rm cms}$ in the centre-of-mass system in $-1.26<y_{\rm cms}<0.34$. In addition, the prompt D$^0$ cross section was measured in pp collisions at $\sqrt{s}=7$ TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV down to $p_{\rm T}=0$ using an analysis technique that is based on the estimation and subtraction of the combinatorial background, without reconstruction of the D$^0$ decay vertex. The nuclear modification factor $R_{\rm pPb}(p_{\rm T})$, defined as the ratio of the $p_{\rm T}$-differential D-meson cross section in p-Pb collisions and that in pp collisions scaled by the mass number of the Pb nucleus, was calculated for the four D-meson species and found to be compatible with unity within experimental uncertainties. The results are compared to theoretical calculations that include cold-nuclear-matter effects and to transport model calculations incorporating the interactions of charm quarks with an expanding deconfined medium.

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Dijet Azimuthal Decorrelations in $pp$ Collisions at $\sqrt{s} = 7$~TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M. ; Tumasyan, Armen ; et al.
Phys.Rev.Lett. 106 (2011) 122003, 2011.
Inspire Record 885663 DOI 10.17182/hepdata.57051
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Prompt charm production in pp collisions at sqrt(s)=7 TeV

The LHCb collaboration Aaij, R ; Abellan Beteta, C ; Adametz, A ; et al.
Nucl.Phys. B871 (2013) 1-20, 2013.
Inspire Record 1218996 DOI 10.17182/hepdata.60321
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Measurement of Upsilon production in 7 TeV pp collisions at ATLAS

The ATLAS collaboration Aad, Georges ; Abajyan, Tatevik ; Abbott, Brad ; et al.
Phys.Rev. D87 (2013) 052004, 2013.
Inspire Record 1204994 DOI 10.17182/hepdata.60219

Using 1.8 fb-1 of pp collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the Large Hadron Collider, we present measurements of the production cross sections of Upsilon(1S,2S,3S) mesons. Upsilon mesons are reconstructed using the di-muon decay mode. Total production cross sections for p_T<70 GeV and in the rapidity interval |Upsilon|<2.25 are measured to be 8.01+-0.02+-0.36+-0.31 nb, 2.05+-0.01+-0.12+-0.08 nb, 0.92+-0.01+-0.07+-0.04 nb respectively, with uncertainties separated into statistical, systematic, and luminosity measurement effects. In addition, differential cross section times di-muon branching fractions for Upsilon(1S), Upsilon(2S), and Upsilon(3S) as a function of Upsilon transverse momentum p_T and rapidity are presented. These cross sections are obtained assuming unpolarized production. If the production polarization is fully transverse or longitudinal with no azimuthal dependence in the helicity frame the cross section may vary by approximately +-20%. If a non-trivial azimuthal dependence is considered, integrated cross sections may be significantly enhanced by a factor of two or more. We compare our results to several theoretical models of Upsilon meson production, finding that none provide an accurate description of our data over the full range of Upsilon transverse momenta accessible with this dataset.

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$J/\psi$ polarization in $pp$ collisions at $\sqrt{s}=7$ TeV

The ALICE collaboration Abelev, Betty ; Abrahantes Quintana, Arian ; Adamova, Dagmar ; et al.
Phys.Rev.Lett. 108 (2012) 082001, 2012.
Inspire Record 944730 DOI 10.17182/hepdata.73005

The ALICE Collaboration has studied J/psi production in pp collisions at $\sqrt{s}$=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/$\psi$ polarization parameters lambda_theta and lambda_phi were obtained. The study was performed in the kinematic region 2.5 < y < 4, 2 < $p_t$ < 8 GeV/c, in the helicity and Collins-Soper reference frames. The results for lambda_theta in the helicity frame show a longitudinal polarization at low $p_t$, vanishing with increasing transverse momentum. All the other polarization parameters are consistent with zero, within uncertainties.

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Dielectron production in proton-proton collisions at $\sqrt{s}$ = 7 TeV

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
2018.
Inspire Record 1672792 DOI 10.17182/hepdata.83913

The first measurement of e$^+$e$^-$ pair production at mid-rapidity ($|\eta_{{\rm e}}|$ $<$ 0.8) in pp collisions at $\sqrt{s} = 7$ TeV with ALICE at the LHC is presented. The dielectron production is studied as a function of the invariant mass ($m_{\rm ee}$ $<$ 3.3 GeV/$c^{2}$), the pair transverse momentum ($p_{\rm T,ee}$ $<$ 8 GeV/$c$), and the pair transverse impact parameter (DCA$_{{\rm ee}}$), i.e., the average distance of closest approach of the reconstructed electron and positron tracks to the collision vertex, normalised to its resolution. The results are compared with the expectations from a cocktail of known hadronic sources and are well described when PYTHIA is used to generate the heavy-flavour contributions. In the low-mass region (0.14 $<$ $m_{\rm ee}$ $<$ 1.1 GeV/$c^{2}$), prompt and non-prompt e$^+$e$^-$ sources can be separated via the DCA$_{\rm ee}$. In the intermediate-mass region (1.1 $<$ $m_{\rm ee}$ $<$ 2.7 GeV/$c^{2}$), a double-differential fit to the data in $m_{\rm ee}$ and $p_{\rm T,ee}$ and a fit of the DCA$_{\rm ee}$ distribution allow the total ${\rm c\overline c}$ and ${\rm b\overline b}$ cross sections to be extracted. Two different event generators, PYTHIA and POWHEG, can reproduce the shape of the two-dimensional $m_{\rm ee}$ and $p_{\rm T,ee}$ spectra, as well as the shape of the DCA$_{\rm ee}$ distribution, reasonably well. However, differences in the ${\rm c\overline c}$ and ${\rm b\overline b}$ cross sections are observed when using the generators to extrapolate to full phase space. Finally, the ratio of inclusive to decay photons is studied via the measurement of virtual direct photons in the transverse-momentum range 1 $<$ $p_{\rm T}$ $<$ 8 GeV/$c$. This is found to be unity within the statistical and systematic uncertainties and consistent with expectations from next-to-leading order perturbative quantum chromodynamic calculations.

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$\Lambda_{\rm c}^+$ production in pp collisions at $\sqrt{s} = 7$ TeV and in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV

The ALICE collaboration Acharya, Shreyasi ; Torales - Acosta, Fernando ; Adamova, Dagmar ; et al.
2017.
Inspire Record 1645239 DOI 10.17182/hepdata.81727

The $p_{\rm T}$-differential production cross section of prompt $\Lambda_{\rm c}^+$ charmed baryons was measured with the ALICE detector at the Large Hadron Collider (LHC) in pp collisions at $\sqrt{s} = 7$ TeV and in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV at midrapidity. The $\Lambda_{\rm c}^+$ and ${\overline{\Lambda}}_{\rm c}^-$ were reconstructed in the hadronic decay modes $\Lambda_{\rm c}^+\rightarrow {\rm p}{\rm K^-}\pi^+$, $\Lambda_{\rm c}^+\rightarrow {\rm p}{\rm K_{\rm S}^0}$ and in the semileptonic channel $\Lambda_{\rm c}^+\rightarrow {\rm e^+}\nu_{\rm e}\Lambda$ (and charge conjugates). The measured values of the $\Lambda_{\rm c}^+/{\rm D_0}$ ratio, which is sensitive to the c-quark hadronisation mechanism, and in particular to the production of baryons, are presented and are larger than those measured previously in different colliding systems, centre-of-mass energies, rapidity and $p_{\rm T}$ intervals, where the $\Lambda_{\rm c}^+$ production process may differ. The results are compared with the expectations obtained from perturbative Quantum Chromodynamics calculations and Monte Carlo event generators. Neither perturbative QCD calculations nor Monte Carlo models reproduce the data, indicating that the fragmentation of heavy-flavour baryons is not well understood. The first measurement at the LHC of the $\Lambda_{\rm c}^+$ nuclear modification factor, $R_{\rm pPb}$, is also presented. The $R_{\rm pPb}$ is found to be consistent with unity and with that of D mesons within the uncertainties, and consistent with a theoretical calculation that includes cold nuclear matter effects and a calculation that includes charm quark interactions with a deconfined medium.

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Inclusive $b$-jet production in $pp$ collisions at $\sqrt{s}=7$ TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
JHEP 1204 (2012) 084, 2012.
Inspire Record 1089835 DOI 10.17182/hepdata.58503
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Measurement of Upsilon production in pp collisions at $\sqrt{s}$ = 7 TeV

The LHCb collaboration Aaij, R. ; Abellan Beteta, C. ; Adeva, B. ; et al.
Eur.Phys.J. C72 (2012) 2025, 2012.
Inspire Record 1091071 DOI 10.17182/hepdata.58651

The production of Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons in proton-proton collisions at the centre-of-mass energy of sqrt(s)=7 TeV is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The Upsilon mesons are reconstructed in the decay mode Upsilon -&gt; mu+ mu- and the signal yields are extracted from a fit to the mu+ mu- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the Upsilon transverse momentum pT and rapidity y, over the range pT &lt; 15 GeV/c and 2.0 &lt; y &lt; 4.5. The cross-sections times branching fractions, integrated over these kinematic ranges, are measured to be sigma(pp -&gt; Upsilon(1S) X) x B(Upsilon(1S)-&gt;mu+ mu-) = 2.29 {\pm} 0.01 {\pm} 0.10 -0.37 +0.19 nb, sigma(pp -&gt; Upsilon(2S) X) x B(Upsilon(2S)-&gt;mu+ mu-) = 0.562 {\pm} 0.007 {\pm} 0.023 -0.092 +0.048 nb, sigma(pp -&gt; Upsilon(3S) X) x B(Upsilon(3S)-&gt;mu+ mu-) = 0.283 {\pm} 0.005 {\pm} 0.012 -0.048 +0.025 nb, where the first uncertainty is statistical, the second systematic and the third is due to the unknown polarisation of the three Upsilon states.

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Light vector meson production in $pp$ collisions at $\sqrt{s}=7$ TeV

The ALICE collaboration Abelev, B. ; Abrahantes Quintana, A. ; Adamova, D. ; et al.
Phys.Lett. B710 (2012) 557-568, 2012.
Inspire Record 1080945 DOI 10.17182/hepdata.58629

The ALICE experiment has measured low-mass dimuon production in pp collisions at $\sqrt{s}$ = 7 TeV in the dimuon rapidity region 2.5 < y < 4. The observed dimuon mass spectrum is described as a superposition of resonance decays ($\eta, \rho, \omega, \eta^{'}, \phi$) into muons and semi-leptonic decays of charmed mesons. The measured production cross sections for $\omega$ and $\phi$ are $\sigma_\omega (1 < p_t < 5$ GeV/c,2.5 < y < 4) = 5.28 $\pm$ 0.54 (stat) $\pm$ 0.50 (syst) mb and $\sigma_\phi$(1 < $p_t$ < 5 GeV/c,2.5 < y < 4)=0.940 $\pm$ 0.084 (stat) $\pm$ 0.078 (syst) mb. The differential cross sections $d^2\sigma/dy dp_t$ are extracted as a function of $p_t$ for $\omega$ and $\phi$. The ratio between the $\rho$ and $\omega$ cross section is obtained. Results for the $\phi$ are compared with other measurements at the same energy and with predictions by models.

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Upsilon Production Cross-Section in pp Collisions at $sqrt{s}=7$ TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M. ; Tumasyan, Armen ; et al.
Phys.Rev. D83 (2011) 112004, 2011.
Inspire Record 882871 DOI 10.17182/hepdata.57722

The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}\pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.

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Measurement of Dijet Azimuthal Decorrelations in $pp$ Collisions at $\sqrt{s}=7$ TeV

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 106 (2011) 172002, 2011.
Inspire Record 889546 DOI 10.17182/hepdata.58478

Azimuthal decorrelations between the two central jets with the largest transverse momenta are sensitive to the dynamics of events with multiple jets. We present a measurement of the normalized differential cross section based on the full dataset (L=36/pb) acquired by the ATLAS detector during the 2010 sqrt(s)=7 TeV proton-proton run of the LHC. The measured distributions include jets with transverse momenta up to 1.3 TeV, probing perturbative QCD in a high energy regime.

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Probing color coherence effects in pp collisions at $\sqrt{s}=7\,\text {TeV} $

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Eur.Phys.J. C74 (2014) 2901, 2014.
Inspire Record 1265659 DOI 10.17182/hepdata.65178

A study of color coherence effects in pp collisions at a center-of-mass energy of 7 TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 inverse picobarns. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementations of color coherence. None of the models describe the data satisfactorily.

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Measurement of $\psi(2S)$ polarisation in $pp$ collisions at $\sqrt{s}=7$ TeV

The LHCb collaboration Aaij, Roel ; Adeva, Bernardo ; Adinolfi, Marco ; et al.
Eur.Phys.J. C74 (2014) 2872, 2014.
Inspire Record 1283844 DOI 10.17182/hepdata.64674

The polarisation of prompt $\psi(2S)$ mesons is measured by performing an angular analysis of $\psi(2S)\rightarrow \mu^{+} \mu^{-}$ decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum $p_\mathrm{T}$ and rapidity $y$ in the kinematic region $3.5<p_\mathrm{T}<15$ GeV$/c$ and $2.0<y<4.5$, and is compared to theoretical models. No significant polarisation is observed.

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Multiplicity dependence of two-particle azimuthal correlations in pp collisions at the LHC

The ALICE collaboration Abelev, Betty ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
JHEP 1309 (2013) 049, 2013.
Inspire Record 1241570 DOI 10.17182/hepdata.62319
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$J/\psi$ and $\psi_{2S}$ production in $pp$ collisions at $\sqrt{s}=7$ TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
JHEP 1202 (2012) 011, 2012.
Inspire Record 944755 DOI 10.17182/hepdata.58303

A measurement of the J/psi and psi(2S) production cross sections in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC is presented. The data sample corresponds to an integrated luminosity of 37 inverse picobarns. Using a fit to the invariant mass and decay length distributions, production cross sections have been measured separately for prompt and non-prompt charmonium states, as a function of the meson transverse momentum in several rapidity ranges. In addition, cross sections restricted to the acceptance of the CMS detector are given, which are not affected by the polarization of the charmonium states. The ratio of the differential production cross sections of the two states, where systematic uncertainties largely cancel, is also determined. The branching fraction of the inclusive B to psi(2S) X decay is extracted from the ratio of the non-prompt cross sections to be: BR(B to psi(2S) X) = (3.08 +/- 0.12(stat.+syst.) +/- 0.13(theor.) +/- 0.42(BR[PDG])) 10^-3

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Observation of $J/\psi$ pair production in $pp$ collisions at $\sqrt{s}=7 TeV$

The LHCb collaboration Aaij, R. ; Adeva, B. ; Adinolfi, M. ; et al.
Phys.Lett. B707 (2012) 52-59, 2012.
Inspire Record 926280 DOI 10.17182/hepdata.58915

The production of $J/\psi$ pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of $37.5 pb^{-1}$ collected with the LHCb detector. The production cross-section for pairs with both \jpsi in the rapidity range $2&lt;y^{J/\psi}&lt;4.5$ and transverse momentum $p_{T}^{J/\psi}&lt;10 GeV/c$ is $$ \sigma^{J/\psi J/\psi} = 5.1\pm1.0\pm1.1 nb,$$ where the first uncertainty is statistical and the second systematic.

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Multi-strange baryon production in $pp$ collisions at $\sqrt{s} = 7$ TeV with ALICE

The ALICE collaboration Abelev, Betty ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
Phys.Lett. B712 (2012) 309-318, 2012.
Inspire Record 1097057 DOI 10.17182/hepdata.60477

A measurement of the multi-strange Xi- and Omega- baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for inelastic proton-proton collisions at centre of mass energy of 7 TeV. The transverse momentum (pt) distributions were studied at mid-rapidity (|y| < 0.5) in the range of 0.6 < pt < 8.5 GeV/c for Xi- and Xi+ baryons, and in the range of 0.8 < pt < 5 GeV/c for Omega- and Omega+. Baryons and antibaryons were measured as separate particles and we find that the baryon to antibaryon ratio of both particle species is consistent with unity over the entire range of the measurement. The statistical precision of the current LHC data has allowed us to measure a difference between the mean pt of Xi- (Xi+) and Omega- (Omega+). Particle yields, mean pt, and the spectra in the intermediate pt range are not well described by the PYTHIA Perugia 2011 tune Monte Carlo event generator, which has been tuned to reproduce the early LHC data. The discrepancy is largest for Omega- (Omega+). This PYTHIA tune approaches the pt spectra of Xi- and Xi+ baryons below pt < 0.85 GeV/c and describes the Xi- and Xi+ spectra above pt > 6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Omega-+Omega+)/(Xi-+Xi+) as a function of transverse mass.

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Measurement of $J/\psi$ production in $pp$ collisions at $\sqrt{s}=7~\rm{TeV}$

The LHCb collaboration Aaij, R. ; Adeva, B. ; Adinolfi, M. ; et al.
Eur.Phys.J. C71 (2011) 1645, 2011.
Inspire Record 891233 DOI 10.17182/hepdata.57066

The production of $J/\psi$ mesons in proton-proton collisions at $\sqrt{s}$= 7 tev is studied with the LHCb detector at the LHC. The differential cross-section for prompt $J/\psi$ production is measured as a function of the $J/\psi$ transverse momentum p_{\rm T}\ and rapidity $y$ in the fiducial region $p_{\rm T}\in[0;14]$ GeV/c and $y\in[2.0;4.5]$. The differential cross-section and fraction of \j psi\ from $b$-hadron decays are also measured in the same p_{\rm T}\ and $y$ range s. The analysis is based on a data sample corresponding to an integrated luminos ity of 5.2 pb$^{-1}$. The measured cross-sections integrated over the fiducial region are $10.52\pm 0. 04\pm 1.40^{+1.64}_{-2.20}\mu b$ for $\mathrm{prompt}~J/\psi$ production and $1.14 \pm 0. 01\pm 0.16 \mu b$ for $J/\psi$ from $b$-hadron decays, where the first uncertainty is statistical and the second systematic. The $\mathrm{prompt}~J/\psi$ production cross-section is obtained assuming no $J/\psi$ polarisation and the third error indicates the acceptance uncertainty due to this assumption.

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Measurement of associated W + charm production in pp collisions at $\sqrt{s}$ = 7 TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
JHEP 1402 (2014) 013, 2014.
Inspire Record 1256938 DOI 10.17182/hepdata.63113

Measurements are presented of the associated production of a W boson and a charm-quark jet (W + c) in pp collisions at a center-of-mass energy of 7 TeV. The analysis is conducted with a data sample corresponding to a total integrated luminosity of 5 inverse femtobarns, collected by the CMS detector at the LHC. W boson candidates are identified by their decay into a charged lepton (muon or electron) and a neutrino. The W + c measurements are performed for charm-quark jets in the kinematic region $p_T^{jet} \gt$ 25 GeV, $|\eta^{jet}| \lt$ 2.5, for two different thresholds for the transverse momentum of the lepton from the W-boson decay, and in the pseudorapidity range $|\eta^{\ell}| \lt$ 2.1. Hadronic and inclusive semileptonic decays of charm hadrons are used to measure the following total cross sections: $\sigma(pp \to W + c + X) \times B(W \to \ell \nu)$ = 107.7 +/- 3.3 (stat.) +/- 6.9 (syst.) pb ($p_T^{\ell} \gt$ 25 GeV) and $\sigma(pp \to W + c + X) \times B(W \to \ell \nu)$ = 84.1 +/- 2.0 (stat.) +/- 4.9 (syst.) pb ($p_T^{\ell} \gt$ 35 GeV), and the cross section ratios $\sigma(pp \to W^+ + \bar{c} + X)/\sigma(pp \to W^- + c + X)$ = 0.954 +/- 0.025 (stat.) +/- 0.004 (syst.) ($p_T^{\ell} \gt$ 25 GeV) and $\sigma(pp \to W^+ + \bar{c} + X)\sigma(pp \to W^- + c + X)$ = 0.938 +/- 0.019 (stat.) +/- 0.006 (syst.) ($p_T^{\ell} \gt$ 35 GeV). Cross sections and cross section ratios are also measured differentially with respect to the absolute value of the pseudorapidity of the lepton from the W-boson decay. These are the first measurements from the LHC directly sensitive to the strange quark and antiquark content of the proton. Results are compared with theoretical predictions and are consistent with the predictions based on global fits of parton distribution functions.

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Measurement of the forward energy flow in $pp$ collisions at $\sqrt{s}=7$ TeV

The LHCb collaboration Aaij, R ; Abellan Beteta, C ; Adametz, A ; et al.
Eur.Phys.J. C73 (2013) 2421, 2013.
Inspire Record 1208105 DOI 10.17182/hepdata.61691

The energy flow created in pp collisions at is studied within the pseudorapidity range 1.9<η<4.9 with data collected by the LHCb experiment. The measurements are performed for inclusive minimum-bias interactions, hard scattering processes and events with an enhanced or suppressed diffractive contribution. The results are compared to predictions given by Pythia-based and cosmic-ray event generators, which provide different models of soft hadronic interactions.

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First Measurement of Hadronic Event Shapes in $pp$ Collisions at $\sqrt {s}=7$ TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M. ; Tumasyan, Armen ; et al.
Phys.Lett. B699 (2011) 48-67, 2011.
Inspire Record 886332 DOI 10.17182/hepdata.63817
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Forward production of $\Upsilon$ mesons in $pp$ collisions at $\sqrt{s}=7$ and 8TeV

The LHCb collaboration Aaij, Roel ; Adeva, Bernardo ; Adinolfi, Marco ; et al.
JHEP 1511 (2015) 103, 2015.
Inspire Record 1392456 DOI 10.17182/hepdata.249

The production of Υ mesons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV is studied with the LHCb detector using data samples corresponding to an integrated luminosity of 1 fb$^{−1}$ and 2 fb$^{−1}$ respectively. The production cross-sections and ratios of cross-sections are measured as functions of the meson transverse momentum p and rapidity y, for p < 30 GeV/c and 2.0 < y < 4.5.

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Measurement of four-jet production in proton-proton collisions at $\sqrt{s}=7$  TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Phys.Rev. D89 (2014) 092010, 2014.
Inspire Record 1273574 DOI 10.17182/hepdata.66510

Measurements of the differential cross sections for the production of exactly four jets in proton-proton collisions are presented as a function of the transverse momentum pt and pseudorapidity eta, together with the correlations in azimuthal angle and the pt balance among the jets. The data sample was collected in 2010 at a center-of-mass energy of 7 TeV with the CMS detector at the LHC, with an integrated luminosity of 36 inverse picobarns. The cross section for a final state with a pair of hard jets with pt > 50 GeV and another pair with pt > 20 GeV within abs(eta) < 4.7 is measured to be sigma = 330 +- 5 (stat.) +- 45 (syst.) nb. It is found that fixed-order matrix element calculations including parton showers describe the measured differential cross sections in some regions of phase space only, and that adding contributions from double parton scattering brings the Monte Carlo predictions closer to the data.

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