A search for partonic collective effects inside jets produced in proton-proton collisions is performed via correlation measurements of charged constituents using the CMS detector at the CERN LHC. The analysis uses data collected at a center-of-mass energy of $\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. Jets are reconstructed with the anti-$k_\mathrm{T}$ algorithm with a distance parameter of 0.8 and are required to have transverse momentum greater than 550 GeV and pseudorapidity $\lvert\eta\rvert$$\lt$ 1.6. Two-particle correlations among the charged constituents within the jets are studied as functions of the particles' azimuthal angle and pseudorapidity separations ($\Delta\phi^*$ and $\Delta\eta^*$) in a jet coordinate basis, where constituents' $\eta^*$, $\phi^*$ are defined relative to the direction of the jet. The correlation functions are studied in classes of in-jet charged-particle multiplicity up to $N_\text{ch}^\mathrm{j}$$\approx$ 100. Fourier harmonics are extracted from long-range azimuthal correlation functions to characterize azimuthal anisotropy for $\lvert\Delta\eta^*\rvert$$\gt$ 2. For low-multiplicity jets, the long-range elliptic anisotropic harmonic, $v^*_2$, is observed to decrease with $N_\text{ch}^\mathrm{j}$. This trend is well described by Monte Carlo event generators. However, a rising trend for $v^*_2$ emerges at $N_\text{ch}^\mathrm{j}$$\gtrsim$ 80, hinting at a possible onset of collective behavior, which is not reproduced by the models tested. This observation yields new insights into the dynamics of parton fragmentation processes in the vacuum.
Examples of two-particle angular correlations projected onto 1D $\Delta\phi^*$ for $\abs{\Delta\eta^*}>2$.
A continuous evolution of extracted two-particle Fourier coefficients $V^*_{N\Delta}$ as a function of $N_{ch}^{j}$.
The single-particle elliptic anisotropies $v^*_2$, as a function of $N_{ch}^{j}$.
The ALICE Collaboration reports three measurements in ultra-peripheral proton$-$lead collisions at forward rapidity. The exclusive two-photon process \ggmm and the exclusive photoproduction of J/$\psi$ are studied. J/$\psi$ photoproduction with proton dissociation is measured for the first time at a hadron collider. The cross section for the two-photon process of dimuons in the invariant mass range from 1 to 2.5 GeV/$c^2$ agrees with leading order quantum electrodynamics calculations. The exclusive and dissociative cross sections for J/$\psi$ photoproductions are measured for photon$-$proton centre-of-mass energies from 27 to 57 GeV. They are in good agreement with HERA results.
Differential cross sections DSIGMA/DM for exclusive GAMMA* GAMMA* to MU+ MU- production in p–Pb UPCs for each mass and rapidity interval
Exclusive J/psi photoproduction cross section in p-Pb UPC.
Dissociative J/psi photoproduction cross section in p-Pb UPC.
We present results on transverse momentum ($p_{\rm T}$) and rapidity ($y$) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive J/$\psi$ and $\psi(2S)$ at forward rapidity ($2.5<y<4$) as well as $\psi(2S)$-to-J/$\psi$ cross section ratios. These quantities are measured in pp collisions at center of mass energies $\sqrt{s}=5.02$ and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at $\sqrt{s}=2.76$, 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full $p_{\rm T}$ range, provided that both contributions are summed. In particular, it is found that for $p_{\rm T}>15$ GeV/$c$ the non-prompt contribution reaches up to 50% of the total charmonium yield.
Differential production cross sections of $J/\psi$ as a function of $p_{\rm T}$.
Differential production cross sections of $J/\psi$ as a function of rapidity.
Differential production cross sections of $\psi(2S)$ as a function of $p_{\rm T}$.
We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the first to use a complete next to leading order QCD d escription of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma . We also report a new measurement of the charm mass.
Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 88.
Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 174.
Neutrino forward dimuon cross sections for Y bins 0.32, 0.56 and 0.77 as a function of X for neutrino energy 247.
Measurements of the production of high transverse momentum direct photons by a 515 GeV/c piminus beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5 < p_T < 12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k_T model.
Invariant cross sections per nucleon for P BE collisions at 800 GeV.
Invariant cross sections per nucleon for P BE collisions at 530 GeV.
Invariant cross sections per nucleon for PI- BE collisions at 515 GeV.
We present results on the production of high transverse momentum pizero and eta mesons in pi-p and pi-Be interactions at 515 GeV/c. The data span the kinematic ranges 1 < p_T < 11 GeV/c in transverse momentum and -0.75 < y < 0.75 in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.
Invariant differential cross section per nucleon for inclusive PI0 production in PI- BE collisions at 515 GeV averaged over the cm rapidity interval -0.75 to 0.75.
Invariant differential cross section for inclusive PI0 production in PI- P collisions at 515 GeV averaged over the cm rapidity interval -0.75 to 0.75.
The averaged invariant differential cross section per nucleon as a functionof rapidity in the PT intervals 1.00 to 1.50 and 1.50 to 2.00 GeV for PI0 produ ction in PI- BE interactions at 515 GeV.
We present results on the production of high transverse momentum pizero and eta mesons in pp and pBe interactions at 530 and 800 GeV/c. The data span the kinematic ranges: 1 < p_T < 10 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.
Invariant differetrial cross sections/nucleon for the inclusive reaction p Be --> pi0 X at 530 and 800 GEV, averaged over the c.m. rapidity interval -0.75 to 0.75 and -1.0 to 0.5 respectively.
Invariant differetrial cross sections/nucleon for the inclusive reaction p p --> pi0 X at 530 and 800 GEV, averaged over the c.m. rapidity interval -0.75 to 0.75 and -1.0 to 0.5 respectively.
The averaged invariant differential cross section/nucleon as a function of rapidity in the PT intervals 1.0-1.5, 1.5-2.0 and 2.0-2.5 GeV for the inclusive reaction p BE --> pi0 X at 530 and 800 GeV GeV.
We present a search for new heavy particles, $X$, which decay via $X \to WZ \to e\nu +jj$ in $p{\bar p}$ collisions at $\sqrt{s}$ = 1.8 TeV. No evidence is found for production of $X$ in 110 pb$^{-1}$ of data collected by the Collider Detector at Fermilab. Limits are set at the 95% C.L. on the mass and the production of new heavy charged vector bosons which decay via $W'\to WZ$ in extended gauge models as a function of the width, $\Gamma (W')$, and mixing factor between the $W'$ and the Standard Model $W$ bosons.
CONST(NAME=XI) is the mixing factor between WPRIME and W-boson.
We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 $pb^{-1}$ of $p\bar{p}$ collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both $p\bar{p} \to \gamma \gamma + X$ and $p \bar{p} \to \gamma \gamma + W/Z$. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale $\sqrt{F}$ in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for $H \to \gamma \gamma$. Finally, we set a lower limit on the mass of a 'bosophilic' Higgs boson (e.g. one which couples only to $\gamma, W,$ and $Z$ bosons with standard model couplings) of 82 GeV/$c^2$ at 95% confidence level.
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We present measurements of the semi-inclusive cross sections for νμ- and ν¯μ-nucleon deep inelastic scattering interactions with two oppositely charged muons in the final state. These events dominantly arise from the production of a charm quark during the scattering process. The measurement was obtained from the analysis of 5102 νμ-induced and 1458 ν¯μ-induced events collected with the NuTeV detector exposed to a sign-selected beam at the Fermilab Tevatron. We also extract a cross-section measurement from a reanalysis of 5030 νμ-induced and 1060 ν¯μ-induced events collected from the exposure of the same detector to a quad-triplet beam by the Chicago Columbia Fermilab Rochester (CCFR) experiment. The results are combined to obtain the most statistically precise measurement of neutrino-induced dimuon production cross sections to date. These measurements should be of broad use to phenomenologists interested in the dynamics of charm production, the strangeness content of the nucleon, and the Cabibbo-Kobayashi-Maskawa matrix element Vcd.
NuTeV forward cross section of neutrino induced events at mean energy of 90.18 GeV.
NuTeV forward cross section of neutrino induced events at mean energy of 174.37 GeV.
NuTeV forward cross section of neutrino induced events at mean energy of 244.72 GeV.
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