The production cross-sections of $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S)$ mesons in proton-proton collisions at $\sqrt{s}$= 13 TeV are measured with a data sample corresponding to an integrated luminosity of $277 \pm 11$ $\rm pb^{-1}$ recorded by the LHCb experiment in 2015. The $\Upsilon$ mesons are reconstructed in the decay mode $\Upsilon\to\mu^{+}\mu^{-}$. The differential production cross-sections times the dimuon branching fractions are measured as a function of the $\Upsilon$ transverse momentum, $p_{\rm T}$, and rapidity, $y$, over the range $0 < p_{\rm T}< 30$ GeV/c and $2.0 < y < 4.5$. The ratios of the cross-sections with respect to the LHCb measurement at $\sqrt{s}$= 8 TeV are also determined. The measurements are compared with theoretical predictions based on NRQCD.

The polarization of the $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S) $mesons, produced in $pp$ collisions at centre-of-mass energies $\sqrt{s}$=7 and 8TeV, is measured using data samples collected by the LHCb experiment, corresponding to integrated luminosities of 1 and 2fb$^{-1}$, respectively. The measurements are performed in three polarization frames, using $\Upsilon\to\mu^+\mu^-$ decays in the kinematic region of the transverse momentum $p_{T}(\Upsilon)<30GeV/c$, and rapidity $2.2<y(\Upsilon)<4.5$. No large polarization is observed.

Measurements of the cross-section for producing \bquark quarks in the reaction $pp\to b\bar{b} X$ are reported in 7 and 13 TeV collisions at the LHC as a function of the pseudorapidity $\eta$ in the range $2<\eta<5$ covered by the acceptance of the LHCb experiment. The measurements are done using semileptonic decays of $b$-flavored hadrons decaying into a ground-state charmed hadron in association with a muon. The cross-sections in the covered $\eta$ range are $72.0\pm 0.3\pm6.8~\mu$b and $144\pm 1\pm 21~\mu$b for 7 and 13 TeV. The ratio is $2.00\pm0.02\pm0.26$, where the quoted uncertainties are statistical and systematic, respectively. The agreement with theoretical expectation is good at 7 TeV, but differs somewhat at 13 TeV. The measured ratio of cross-sections is larger at lower $\eta$ than the model prediction.

Production cross-sections of prompt charm mesons are measured using data from $pp$ collisions at the LHC at a centre-of-mass energy of $5\,$TeV. The data sample corresponds to an integrated luminosity of $8.60\pm0.33\,$pb$^{-1}$ collected by the LHCb experiment. The production cross-sections of $D^0$, $D^+$, $D_s^+$, and $D^{*+}$ mesons are measured in bins of charm meson transverse momentum, $p_{\text{T}}$, and rapidity, $y$. They cover the rapidity range $2.0<y<4.5$ and transverse momentum ranges $0 < p_{\text{T}} < 10\, \text{GeV}/c$ for $D^0$ and $D^+$ and $1 < p_{\text{T}} < 10\, \text{GeV}/c$ for $D_s^+$ and $D^{*+}$ mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of $1 < p_{\text{T}} < 8\, \text{GeV}/c$ are determined to be \sigma(pp\rightarrow D^0 X) = 1004 \pm 3 \pm 54\,\mu\text{b} \sigma(pp\rightarrow D^+ X) = 402 \pm 2 \pm 30\,\mu\text{b} \sigma(pp\rightarrow D_s^+ X) = 170 \pm 4 \pm 16\,\mu\text{b} \sigma(pp\rightarrow D^{*+} X)= 421 \pm 5 \pm 36\,\mu\text{b} where the uncertainties are statistical and systematic, respectively.

The inclusive $D_s^{\pm}$ production asymmetry is measured in $pp$ collisions collected by the LHCb experiment at centre-of-mass energies of $\sqrt{s} =7$ and 8 TeV. Promptly produced $D_s^{\pm}$ mesons are used, which decay as $D_s^{\pm}\to\phi\pi^{\pm}$, with $\phi\to K^+K^-$. The measurement is performed in bins of transverse momentum, $p_{\rm T}$, and rapidity, $y$, covering the range $2.5

A measurement of the production cross-section of Z bosons in pp collisions at $\sqrt{s} = 13$ TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range $2.0 < \eta < 4.5$, transverse momenta $p_\text{T} > 20$ GeV and dilepton invariant mass in the range $60<m(\ell\ell)<120$ GeV. The integrated cross-section from averaging the two final states is \begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm 7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable $\phi^*_\eta$.

The production cross-section of $J/\psi$ pairs is measured using a data sample of $pp$ collisions collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s} = 13 \,{\mathrm{TeV}}$, corresponding to an integrated luminosity of $279 \pm 11 \,{\mathrm{pb^{-1}}}$. The measurement is performed for $J/\psi$ mesons with a transverse momentum of less than $10 \,{\mathrm{GeV}}/c$ in the rapidity range $2.0<y<4.5$. The production cross-section is measured to be $15.2 \pm 1.0 \pm 0.9 \,{\mathrm{nb}}$. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the $J/\psi$ pair are measured and compared to theoretical predictions.

Forward top quark pair production is studied in $pp$ collisions in the $\mu eb$ final state using a data sample corresponding to an integrated luminosity of 1.93 fb$^{-1}$ collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The cross-section is measured in a fiducial region where both leptons have a transverse momentum greater than 20 GeV and a pseudorapidity between 2.0 and 4.5. The quadrature sum of the azimuthal separation and the difference in pseudorapidities, denoted $\Delta R$, between the two leptons must be larger than 0.1. The $b$-jet axis is required to be separated from both leptons by a $\Delta R$ of 0.5, and to have a transverse momentum in excess of 20 GeV and a pseudorapidity between 2.2 and 4.2. The cross-section is measured to be $$\sigma_{t\bar{t}}= 126\pm19\,(\mathrm{stat})\pm16\,(\mathrm{syst})\pm5\,(\mathrm{lumi})\,\,\mathrm{ fb}$$ where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measurement is compatible with the Standard Model prediction.

The production of $B^{\pm}$ mesons is studied in $pp$ collisions at centre-of-mass energies of 7 and 13 TeV, using $B^{\pm}\rightarrow J/\psi K^{\pm}$ decays and data samples corresponding to 1.0 fb$^{-1}$ and 0.3 fb$^{-1}$, respectively. The production cross-sections summed over both charges and integrated over the transverse momentum range $0<p_{\text{T}}< 40$ GeV/$c$ and the rapidity range $2.0<y<4.5$ are measured to be $\sigma(pp \rightarrow B^{\pm} X, \sqrt{s} = \text{7 TeV}) = 43.0 \pm 0.2 \pm 2.5 \pm 1.7\mu b,$ $\sigma(pp \rightarrow B^{\pm} X, \sqrt{s} = \text{13 TeV}) = 86.6 \pm 0.5 \pm 5.4 \pm 3.4\mu b,$ where the first uncertainties are statistical, the second are systematic, and the third are due to the limited knowledge of the $B^{\pm}\rightarrow J/\psi K^{\pm}$ branching fraction. The ratio of the cross-section at 13 TeV to that at 7 TeV is determined to be $2.02\pm0.02\text{(stat)}\pm0.12\text{(syst)}$. Differential cross-sections are also reported as functions of $p_{\text{T}}$ and $y$. All results are in agreement with theoretical calculations based on the state-of-art fixed next-to-leading order quantum chromodynamics.

Measurements are presented of electroweak boson production using data from $pp$ collisions at a centre-of-mass energy of $\sqrt{s} = 8\mathrm{\,Te\kern -0.1em V}$. The analysis is based on an integrated luminosity of $2.0\mathrm{\,fb}^{-1}$ recorded with the LHCb detector. The bosons are identified in the $W\rightarrow\mu\nu$ and $Z\rightarrow\mu^{+}\mu^{-}$ decay channels. The cross-sections are measured for muons in the pseudorapidity range $2.0 < \eta < 4.5$, with transverse momenta $p_{\rm T} > 20{\mathrm{\,Ge\kern -0.1em V\!/}c}$ and, in the case of the $Z$ boson, a dimuon mass within $60 < M_{\mu^{+}\mu^{-}} < 120{\mathrm{\,Ge\kern -0.1em V\!/}c^{2}}$. The results are \begin{align*} \sigma_{W^{+}\rightarrow\mu^{+}\nu} &= 1093.6 \pm 2.1 \pm 7.2 \pm 10.9 \pm 12.7{\rm \,pb} \, , \sigma_{W^{-}\rightarrow\mu^{-}\bar{\nu}} &= \phantom{0}818.4 \pm 1.9 \pm 5.0 \pm \phantom{0}7.0 \pm \phantom{0}9.5{\rm \,pb} \, , \sigma_{Z\rightarrow\mu^{+}\mu^{-}} &= \phantom{00}95.0 \pm 0.3 \pm 0.7 \pm \phantom{0}1.1 \pm \phantom{0}1.1{\rm \,pb} \, , \end{align*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. The evolution of the $W$ and $Z$ boson cross-sections with centre-of-mass energy is studied using previously reported measurements with $1.0\mathrm{\,fb}^{-1}$ of data at $7\mathrm{\,Te\kern -0.1em V}$. Differential distributions are also presented. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.

The production of $W$ and $Z$ bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 fb$^{-1}$. The $W$ boson is identified using its decay to a muon and a neutrino, while the $Z$ boson is identified through its decay to a muon pair. Total cross-sections are measured and combined into charge ratios, asymmetries, and ratios of $W+$jet and $Z$+jet production cross-sections. Differential measurements are also performed as a function of both boson and jet kinematic variables. All results are in agreement with Standard Model predictions.

The production of $\Upsilon (nS)$ mesons ($n=1,2,3$) in $p$Pb and Pb$p$ collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{NN}}=8.16$ TeV is measured by the LHCb experiment, using a data sample corresponding to an integrated luminosity of 31.8 nb$^{-1}$. The $\Upsilon (nS)$ mesons are reconstructed through their decays into two opposite-sign muons. The measurements comprise the differential production cross-sections of the $\Upsilon (1S)$ and $\Upsilon (2S)$ states, their forward-to-backward ratios and nuclear modification factors, performed as a function of the transverse momentum $p_{\mathrm{T}}$ and rapidity in the nucleon-nucleon centre-of-mass frame $y^*$ of the $\Upsilon (nS)$ states, in the kinematic range $p_{\rm{T}}<25$ GeV/$c$ and $1.5<y^*<4.0$ ($-5.0<y^*<-2.5$) for $p$Pb (Pb$p$) collisions. In addition, production cross-sections for $\Upsilon (3S)$ are measured integrated over phase space and the production ratios between all three $\Upsilon (nS)$ states are determined. The measurements are compared to theoretical predictions and suppressions for quarkonium in $p$Pb collisions are observed.

The cross-section for prompt antiproton production in collisions of protons with an energy of $6.5$ TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of $0.5\,nb^{-1}$. The target is provided by injecting helium gas into the LHC beam line at the LHCb interaction point. The reported results, covering antiproton momenta between $12$ and $110\,\mathrm{GeV/}c$, represent the first direct determination of the antiproton production cross-section in ${\rm p He}$ collisions, and impact the interpretation of recent results on antiproton cosmic rays from space-borne experiments.

Using a data sample corresponding to an integrated luminosity of $2.0\,fb^{-1}$, collected by the LHCb experiment, the production of the $\eta_c(1S)$ state in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13 \text{ TeV}$ is studied in the rapidity range ${2.0 < y < 4.5}$ and in the transverse momentum range ${6.5 < p_{T} < 14.0\text{ GeV}}$. The cross-section for prompt production of $\eta_c(1S)$ mesons relative to that of the $J/\psi$ meson is measured using the ${p\bar{p}}$ decay mode and is found to be ${\sigma_{\eta_c(1S)}/\sigma_{J/\psi} = 1.69 \pm 0.15 \pm 0.10 \pm 0.18}$. The quoted uncertainties are, in order, statistical, systematic and due to uncertainties on the branching fractions of the ${J/\psi\to p \bar{p}}$ and ${\eta_c\to p \bar{p}}$ decays. The prompt $\eta_c(1S)$ production cross-section is determined to be ${\sigma_{\eta_c(1S)} = 1.26 \pm 0.11\pm 0.08 \pm 0.14 \,\mu b}$, where the last uncertainty includes that on the ${J/\psi}$ meson cross-section. The ratio of the branching fractions of $b$-hadron decays to the $\eta_c(1S)$ and ${J/\psi}$ states is measured to be ${\mathcal{B}_{b\to\eta_c X}/\mathcal{B}_{b\to J/\psi X} = 0.48 \pm 0.03 \pm 0.03 \pm 0.05}$, where the last uncertainty is due to those on the branching fractions of the ${J/\psi \to p \bar{p}}$ and ${\eta_c\to p \bar{p}}$ decays. The difference between the ${J/\psi}$ and $\eta_c(1S)$ masses is also determined to be ${113.0 \pm 0.7 \pm 0.1\text{ MeV}}$, which is the most precise single measurement of this quantity to date.

The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in pPb and PbPb collisions over a wide pseudorapidity (eta) range based on correlations among six or more charged particles. The pPb data, corresponding to an integrated luminosity of 35 inverse nanobarns, were collected during the 2013 LHC pPb run at a nucleon-nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. A sample of semi-peripheral PbPb collision data at sqrt(s[NN])= 2.76 TeV, corresponding to an integrated luminosity of 2.5 inverse microbarns and covering a similar range of particle multiplicities as the pPb data, is also analyzed for comparison. The six- and eight-particle cumulant and the Lee-Yang zeros methods are used to extract the v2 coefficients, extending previous studies of two- and four-particle correlations. For both the pPb and PbPb systems, the v2 values obtained with correlations among more than four particles are consistent with previously published four-particle results. These data support the interpretation of a collective origin for the previously observed long-range (large Delta[eta]) correlations in both systems. The ratios of v2 values corresponding to correlations including different numbers of particles are compared to theoretical predictions that assume a hydrodynamic behavior of a pPb system dominated by fluctuations in the positions of participant nucleons. These results provide new insights into the multi-particle dynamics of collision systems with a very small overlapping region.

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.

A measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2 TeV. The analysis is based on the proton-proton collision data collected with the CMS experiment at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 inverse femtobarns. The dijet azimuthal decorrelation is caused by the radiation of additional jets and probes the dynamics of multijet production. The results are compared to fixed-order predictions of perturbative quantum chromodynamics (QCD), and to simulations using Monte Carlo event generators that include parton showers, hadronization, and multiparton interactions. Event generators with only two outgoing high transverse momentum partons fail to describe the measurement, even when supplemented with next-to-leading-order QCD corrections and parton showers. Much better agreement is achieved when at least three outgoing partons are complemented through either next-to-leading-order predictions or parton showers. This observation emphasizes the need to improve predictions for multijet production.

Results are presented from a search for new decaying massive particles whose presence is inferred from an imbalance in transverse momentum and which are produced in association with a single top quark that decays into a bottom quark and two light quarks. The measurement is performed using 19.7 inverse femtobarns of data from proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No deviations from the standard model predictions are observed and lower limits are set on the masses of new invisible bosons. In particular, scalar and vector particles, with masses below 330 and 650 GeV, respectively, are excluded at 95% confidence level, thus substantially extending a previous limit published by the CDF Collaboration.

The production cross sections of the B+, B0, and B0s mesons, and of their charge conjugates, are measured via exclusive hadronic decays in pPb collisions at the center-of-mass energy sqrt(s_NN) = 5.02 TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6 inverse nanobarns. The production cross sections are measured in the transverse momentum range between 10 and 60 GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in PbPb collisions.

Azimuthal angle (Delta phi) correlations are presented for a broad range of transverse momentum (0.4 < pT < 10 GeV/c) and centrality (0-92%) selections for charged hadrons from di-jets in Au+Au collisions at sqrt(s_NN) = 200 GeV. With increasing pT, the away-side Delta phi distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons to p+p data suggest that the away-side distribution can be divided into a partially suppressed head region centered at Delta phi ~ \pi, and an enhanced shoulder region centered at Delta phi ~ \pi \pm 1:1. The pT spectrum for the associated hadrons in the head region softens toward central collisions. The spectral slope for the shoulder region is independent of centrality and trigger pT . The properties of the near-side distributions are also modified relative to those in p + p collisions, reflected by the broadening of the jet shape in Delta phi and Delta eta, and an enhancement of the per-trigger yield. However, these modifications seem to be limited to pT < 4 GeV/c, above which both the dihadron pair shape and per-trigger yield become similar to p + p collisions. These observations suggest that both the away- and near-side distributions contain a jet fragmentation component which dominates for pT \ge 5GeV and a medium-induced component which is important for pT \le 4 GeV/c. We also quantify the role of jets at intermediate and low pT through the yield of jet-induced pairs in comparison to binary scaled p + p pair yield. The yield of jet-induced pairs is suppressed at high pair proxy energy (sum of the pT magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The former is consistent with jet quenching/ the latter is consistent with the enhancement of soft hadron pairs due to transport of lost energy to lower pT.

The production of Z bosons in pPb collisions at sqrt(s[NN]) = 5.02 TeV is studied by the CMS experiment via the electron and muon decay channels. The inclusive cross section is compared to pp collision predictions, and found to scale with the number of elementary nucleon-nucleon collisions. The differential cross sections as a function of the Z boson rapidity and transverse momentum are measured. Though they are found to be consistent within uncertainty with theoretical predictions both with and without nuclear effects, the forward-backward asymmetry suggests the presence of nuclear effects at large rapidities. These results provide new data for constraining nuclear parton distribution functions.

The pseudorapidity distribution of charged hadrons in pp collisions at sqrt(s) =13 TeV is measured using a data sample obtained with the CMS detector, operated at zero magnetic field, at the CERN LHC. The yield of primary charged long-lived hadrons produced in inelastic pp collisions is determined in the central region of the CMS pixel detector (abs(eta)<2) using both hit pairs and reconstructed tracks. For central pseudorapidities (abs(eta)<0.5), the charged-hadron multiplicity density is dN/d(eta)[charged,abs(eta) < 0.5] = 5.49 +/- 0.01 (stat) +/- 0.17 (sys), a value obtained by combining the two methods. The result is compared to predictions from Monte Carlo event generators and to similar measurements made at lower collision energies.

The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 inverse nanobarns at a nucleon-nucleon centre-of-mass energy of sqrt(s[NN]) = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV, and as a function of the lepton pseudorapidity in the abs(eta[lab]) < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.

Production of prompt J/$\psi$ meson pairs in proton-proton collisions at $\sqrt{s}$ = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 inverse-femtobarns. The two J/$\psi$ mesons are fully reconstructed via their decays into $\mu^+\mu^-$ pairs. This observation provides for the first time access to the high-transverse-momentum region of J/$\psi$ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/$\psi$ transverse momentum ($p_T^{J/\psi}$) and rapidity (|$y^{J/\psi}$|): |$y^{J/\psi}$| lower than 1.2 for $p_T^{J/\psi}$ greater than 6.5 GeV/c; |$y^{J/\psi}$| in [1.2,1.43] for a $p_T$ threshold that scales linearly with |$y^{J/\psi}$| from 6.5 to 4.5 GeV/c; and |$y^{J/\psi}$| in [1.43,2.2] for $p_T^{J/\psi}$ greater than 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/$\psi$ pair production is 1.49 $\pm$ 0.07 (stat.) $\pm$ 0.13 (syst.) nb. Different assumptions about the J/$\psi$ polarization imply modifications to the cross section ranging from -31% to +27%.

The WZ production cross section in proton-proton collisions at sqrt(s) = 13 TeV is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in the leptonic decay modes WZ to l nu l' l', where l, l'= e, mu. The measured cross section for the range 60 < m[l'l'] < 120 GeV is sigma(pp to WZ) = 39.9 +/- 3.2 (stat) +2.9/-3.1 (syst) +/- 0.4 (theo) +/- 1.3 (lumi) pb, consistent with the standard model prediction.

The double-differential inclusive jet cross section is measured as a function of jet transverse momentum pT and absolute rapidity y, using proton-proton collision data collected with the CMS experiment at the LHC, at a center-of-mass energy of sqrt(s) = 2.76 TeV and corresponding to an integrated luminosity of 5.43 inverse picoboarns. Jets are reconstructed within the pT range of 74 to 592 GeV and the rapidity range |y| < 3.0. The reconstructed jet spectrum is corrected for detector resolution. The measurements are compared to the theoretical prediction at next-to-leading-order QCD using different sets of parton distribution functions. This inclusive cross section measurement explores a new kinematic region and is consistent with QCD predictions.

The polarizations of the Y(1S), Y(2S), and Y(3S) mesons are measured as a function of the charged particle multiplicity in proton-proton collisions at sqrt(s) = 7 TeV. The measurements are performed with a dimuon data sample collected in 2011 by the CMS experiment, corresponding to an integrated luminosity of 4.9 inverse femtobarns. The results are extracted from the dimuon decay angular distributions, in two ranges of Y(nS) transverse momentum (10-15 and 15-35 GeV), and in the rapidity interval abs(y) < 1.2. The results do not show significant changes from low- to high-multiplicity pp collisions, although large uncertainties preclude definite statements in the Y(2S) and Y(3S) cases.

A systematic study of the factorization of long-range azimuthal two-particle correlations into a product of single-particle anisotropies is presented as a function of pt and eta of both particles, and as a function of the particle multiplicity in PbPb and pPb collisions. The data were taken with the CMS detector for PbPb collisions at sqrt(s[NN]) = 2.76 TeV and pPb collisions at sqrt(s[NN]) = 5.02 TeV, covering a very wide range of multiplicity. Factorization is observed to be broken as a function of both particle pt and eta. When measured with particles of different pt, the magnitude of the factorization breakdown for the second Fourier harmonic reaches 20% for very central PbPb collisions but decreases rapidly as the multiplicity decreases. The data are consistent with viscous hydrodynamic predictions, which suggest that the effect of factorization breaking is mainly sensitive to the initial-state conditions rather than to the transport properties (e.g., shear viscosity) of the medium. The factorization breakdown is also computed with particles of different eta. The effect is found to be weakest for mid-central PbPb events but becomes larger for more central or peripheral PbPb collisions, and also for very high-multiplicity pPb collisions. The eta-dependent factorization data provide new insights to the longitudinal evolution of the medium formed in heavy ion collisions.

We present a measurement of b jet transverse momentum (pt) spectra in proton-lead (pPb) collisions using a dataset corresponding to about 35 inverse nanobarns collected with the CMS detector at the LHC. Jets from b quark fragmentation are found by exploiting the long lifetime of hadrons containing a b quark through tagging methods using distributions of the secondary vertex mass and displacement. Extracted cross sections for b jets are scaled by the effective number of nucleon-nucleon collisions and are compared to a reference obtained from PYTHIA simulations of pp collisions. The PYTHIA-based estimate of the nuclear modification factor is found to be 1.22 +/- 0.15 (stat + syst pPb) +/- 0.27 (syst PYTHIA) averaged over all jets with pt between 55 and 400 GeV/c and with abs(eta[lab]) < 2. We also compare this result to predictions from models using perturbative calculations in quantum chromodynamics.

The differential and total cross sections for kaon pair production in the pp->ppK+K- reaction have been measured at three beam energies of 2.65, 2.70, and 2.83 GeV using the ANKE magnetic spectrometer at the COSY-Juelich accelerator. These near-threshold data are separated into pairs arising from the decay of the phi-meson and the remainder. For the non-phi selection, the ratio of the differential cross sections in terms of the K-p and K+p invariant masses is strongly peaked towards low masses. This effect can be described quantitatively by using a simple ansatz for the K-p final state interaction, where it is seen that the data are sensitive to the magnitude of an effective K-p scattering length. When allowance is made for a small number of phi events where the K- rescatters from the proton, the phi region is equally well described at all three energies. A very similar phenomenon is discovered in the ratio of the cross sections as functions of the K-pp and K+pp invariant masses and the identical final state interaction model is also very successful here. The world data on the energy dependence of the non-phi total cross section is also reproduced, except possibly for the results closest to threshold.

The cross section for K + meson production in collisions of 36 Ar ions on a 48 Ti target has been measured at an incident energy of 92 MeV per nucleon. A description of the experimental set-up is given. Twelve events attributed to monoenergetic muons following the decay of stopped kaons have been identified. From these events, one infers a production cross section of 240 pb. Data are briefly discussed.

The TPC/Two-Gamma Collaboration has measured the inclusive cross section for production of charmed D ∗± mesons in photon-photon collisions. The reaction utilized was e + e - →e + e - D ∗± X, with D ∗± →D O π +- , D O →K -+ π ± , and either zero or one outgoing e ± detected. The result, σ(e + e - → e + e - D ∗± X) = 74±26±19 pb , is in agreement with the quark parton mo del prediction for e + e - → e + e - c c , combined with a Lund model for the hadronization of the charmed quarks.

Double differential K+cross sections have been measured in p+C collisions at 1.2, 1.5 and 2.5 GeV beam energy and in p+Pb collisions at 1.2 and 1.5 GeV. The K+ spectrum taken at 2.5 GeV can be reproduced quantitatively by a model calculation which takes into account first chance proton-nucleon collisions and internal momentum with energy distribution of nucleons according to the spectral function. At 1.2 and 1.5 GeV beam energy the K+ data excess significantly the model predictions for first chance collisions. When taking secondary processes into account the results of the calculations are in much better agreement with the data.

The system created in non-central relativistic nucleus-nucleus collisions possesses large orbital angular momentum. Due to spin-orbit coupling, particles produced in such a system could become globally polarized along the direction of the system angular momentum. We present the results of Lambda and anti-Lambda hyperon global polarization measurements in Au+Au collisions at sqrt{s_NN}=62.4 GeV and 200 GeV performed with the STAR detector at RHIC. The observed global polarization of Lambda and anti-Lambda hyperons in the STAR acceptance is consistent with zero within the precision of the measurements. The obtained upper limit, |P_{Lambda,anti-Lambda}| <= 0.02, is compared to the theoretical values discussed recently in the literature.

A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 inverse femtobarns. By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68 +/- 0.20 (stat) +1.58 -0.97 (syst) GeV is measured. The overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark.

A measurement of the forward-backward asymmetry A[FB] of oppositely charged lepton pairs (mu mu and e e) produced via Z/gamma* boson exchange in pp collisions at sqrt(s) = 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.7 inverse femtobarns collected with the CMS detector at the LHC. The measurement of A[FB] is performed for dilepton masses between 40 GeV and 2 TeV and for dilepton rapidity up to 5. The A[FB] measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.

A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb$^{-1}$, with 4.9 fb$^{-1}$ at 7 TeV and 19.7 fb$^{-1}$ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSM parameter space for different benchmark scenarios, $m_\mathrm{h}^\text{max}$, $m_\mathrm{h}^{\text{mod}+}$, $m_\mathrm{h}^{\text{mod}-}$, light-stop, light-stau, $\tau$-phobic, and low-$m_\mathrm{H}$. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.

The spectra of charged particles produced within the pseudorapidity window abs(eta) < 1 at sqrt(s[NN]) = 5.02 TeV are measured using 404 inverse microbarns of PbPb and 27.4 inverse picobarns of pp data collected by the CMS detector at the LHC in 2015. The spectra are presented over the transverse momentum ranges spanning 0.5 < pt < 400 GeV in pp and 0.7 < pt < 400 GeV in PbPb collisions. The corresponding nuclear modification factor, R[AA], is measured in bins of collision centrality. The R[AA] in the 5% most central collisions shows a maximal suppression by a factor of 7-8 in the pt region of 6-9 GeV. This dip is followed by an increase, which continues up to the highest pt measured, and approaches unity in the vicinity of pt = 200 GeV. The R[AA] is compared to theoretical predictions and earlier experimental results at lower collision energies. The newly measured pp spectrum is combined with the pPb spectrum previously published by the CMS Collaboration to construct the pPb nuclear modification factor, R[pA], up to 120 GeV. For pt > 20 GeV, R[pA] exhibits weak momentum dependence and shows a moderate enhancement above unity.

The NA44 Collaboration has measured yields and differential distributions of K+, K-, pi+, pi- in transverse kinetic energy and rapidity, around the center-of-mass rapidity in 158 A GeV/c Pb+Pb collisions at the CERN SPS. A considerable enhancement of K+ production per pi is observed, as compared to p+p collisions at this energy. To illustrate the importance of secondary hadron rescattering as an enhancement mechanism, we compare strangeness production at the SPS and AGS with predictions of the transport model RQMD.

Measurements of the differential and double-differential Drell-Yan cross sections in the dielectron and dimuon channels are presented. They are based on proton-proton collision data at sqrt(s) = 8 TeV recorded with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 inverse femtobarns. The measured inclusive cross section in the Z peak region (60-120 GeV), obtained from the combination of the dielectron and dimuon channels, is 1138 +/- 8 (exp) +/- 25 (theo) +/- 30 (lumi) pb, where the statistical uncertainty is negligible. The differential cross section d(sigma)/d(m) in the dilepton mass range 15 to 2000 GeV is measured and corrected to the full phase space. The double-differential cross section d2(sigma)/d(m)d(abs(y)) is also measured over the mass range 20 to 1500 GeV and absolute dilepton rapidity from 0 to 2.4. In addition, the ratios of the normalized differential cross sections measured at sqrt(s) = 7 and 8 TeV are presented. These measurements are compared to the predictions of perturbative QCD at next-to-leading and next-to-next-to-leading (NNLO) orders using various sets of parton distribution functions (PDFs). The results agree with the NNLO theoretical predictions computed with FEWZ 3.1 using the CT10 NNLO and NNPDF2.1 NNLO PDFs. The measured double-differential cross section and ratio of normalized differential cross sections are sufficiently precise to constrain the proton PDFs.

A search for the production of a heavy B quark, having electric charge -1/3 and vector couplings to W, Z, and H bosons, is carried out using proton-proton collision data recorded at the CERN LHC by the CMS experiment, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The B quark is assumed to be pair produced and to decay in one of three ways: to tW, bZ, or bH. The search is carried out in final states with one, two, and more than two charged leptons, as well as in fully hadronic final states. Each of the channels in the exclusive final-state topologies is designed to be sensitive to specific combinations of the B quark-antiquark pair decays. The observed event yields are found to be consistent with the standard model expectations in all the final states studied. A statistical combination of these results is performed and upper limits are set on the cross section of the strongly produced B quark-antiquark pairs as a function of the B quark mass. Lower limits on the B quark mass between 740 and 900 GeV are set at a 95% confidence level, depending on the values of the branching fractions of the B quark to tW, bZ, and bH. Overall, these limits are the most stringent to date.

Inclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV, collected with the CMS detector at the LHC, are presented. Jets are reconstructed with three different distance parameters (R = 0.2, 0.3, and 0.4) for transverse momentum (pT) greater than 70 GeV and pseudorapidity abs(eta) < 2. Next-to-leading-order quantum chromodynamic calculations with non-perturbative corrections are found to over-predict jet production cross sections in pp for small distance parameters. The jet nuclear modification factors for PbPb compared to pp collisions, show a steady decrease from peripheral to central events, along with a weak dependence on the jet pT. They are found to be independent of the distance parameter in the measured kinematic range.

Interactions between jets and the quark-gluon plasma produced in heavy ion collisions are studied via the angular distributions of summed charged-particle transverse momenta (pt) with respect to both the leading and subleading jet axes in high-pt dijet events. The contributions of charged particles in different momentum ranges to the overall event pt balance are decomposed into short-range jet peaks and a long-range azimuthal asymmetry in charged-particle pt. The results for PbPb collisions are compared to those in pp collisions using data collected in 2011 and 2013, at collision energy sqrt(s[NN]) = 2.76 TeV with integrated luminosities of 166 inverse microbarns and 5.3 inverse picobarns, respectively, by the CMS experiment at the LHC. Measurements are presented as functions of PbPb collision centrality, charged-particle pt, relative azimuth, and radial distance from the jet axis for balanced and unbalanced dijets.

The quark-gluon plasma is studied via medium-induced changes to correlations between jets and charged particles in PbPb collisions compared to pp reference data. This analysis uses data sets from PbPb and pp collisions with integrated luminosities of 166 inverse microbarns and 5.3 inverse picobarns, respectively, collected at sqrt(s[NN]) = 2.76 TeV. The angular distributions of charged particles are studied as a function of relative pseudorapidity (Delta eta) and relative azimuthal angle (Delta phi) with respect to reconstructed jet directions. Charged particles are correlated with all jets with transverse momentum (pt) above 120 GeV, and with the leading and subleading jets (the highest and second-highest in pt, respectively) in a selection of back-to-back dijet events. Modifications in PbPb data relative to pp reference data are characterized as a function of PbPb collision centrality and charged particle pt. A centrality-dependent excess of low-pt particles is present for all jets studied, and is most pronounced in the most central events. This excess of low-pt particles follows a Gaussian-like distribution around the jet axis, and extends to large relative angles of Delta eta approximately 1 and Delta phi approximately 1.

Measurements of strange hadron (K0s, Lambda + anti-Lambda, and Xi+ + Xi-) transverse momentum spectra in pp, pPb, and PbPb collisions are presented over a wide range of rapidity and event charged-particle multiplicity. The data were collected with the CMS detector at the CERN LHC in pp collisions at sqrt(s) = 7 TeV, pPb collisions at sqrt(s[NN]) = 5.02 TeV, and PbPb collisions at sqrt(s[NN]) = 2.76 TeV. The average transverse kinetic energy is found to increase with multiplicity, at a faster rate for heavier strange particle species in all systems. At similar multiplicities, the difference in average transverse kinetic energy between different particle species is observed to be larger for pp and pPb events than for PbPb events. In pPb collisions, the average transverse kinetic energy is found to be slightly larger in the Pb-going direction than in the p-going direction for events with large multiplicity. The spectra are compared to models motivated by hydrodynamics.

We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$ particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions.

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb^-1. The events are of the type ep -> eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x_gamma of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models.

A measurement of continuum dimuon production in proton-copper collisions at 800-GeV incident energy is presented. The dimuons observed in this experiment cover the mass range from 6.5 to 18 GeV near y=0 in the proton-nucleon center-of-momentum frame. Scaling forms of the cross section for the continuum are compared with the results of other experiments in the context of the parton model and quantum chromodynamics. The present limitations of such scaling comparisons are discussed.

The inclusive production of D ∗± mesons in single tagged photon-photon collisions is investigated using the JADE detector at PETRA. D ∗± mesons are reconstructed through their decay into D 0 +π ± where the D 0 decays via D 0 →Kππ 0 . The event rate and topology are compared to the expectations of c quark production in the quark-parton model: γγ→c c .

The transverse energy cross-sectiondσ/dET has been measured in the pseudorapidity region 0.6<η<2.4 for hadron-lead collisions at 200 GeV/c incident hadron momentum. TheET distribution extends to 40 GeV, which is twice the kinematic limit forp-p collisions at the same incident beam momentum. The distribution ofET is found to shift towards low pseudorapidities with increasing total transverse energy.