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Observation of triple J/$\psi$ meson production in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
Nature Phys. 19 (2023) 338 338-350, 2023.
Inspire Record 1965242 DOI 10.17182/hepdata.114984

Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering - referred to as single-parton scattering - leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/$\psi$ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process - reconstructed through the decays of J/$\psi$ mesons into pairs of oppositely charged muons - with a statistical significance above five standard deviations. We measured the inclusive fiducial cross section to be 272 $^{+141}_{-104}$ (stat) $\pm$ 17 (syst) fb, and compared it to theoretical expectations for triple-J/$\psi$ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross sections, double- and triple-parton scattering are the dominant contributions for the measured process.

6 data tables

Kinematic properties of each one of the three \JPsi mesons selected in the 5? 6? signal events.

Dimuon invariant mass ($m$), proper decay-length ($L$), transverse momentum ($p_{T}$), rapidity ($y$), and azimuthal angle ($\phi$) of each of the three $J/\psi$ candidates measured in the six triple-$J/\psi$ events passing our selection criteria.

DPS effective cross section

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Measurement of differential cross sections of isolated-photon plus heavy-flavour jet production in pp collisions at $\sqrt{s}=8$ TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 776 (2018) 295-317, 2018.
Inspire Record 1632756 DOI 10.17182/hepdata.79163

This Letter presents the measurement of differential cross sections of isolated prompt photons produced in association with a b-jet or a c-jet. These final states provide sensitivity to the heavy-flavour content of the proton and aspects related to the modelling of heavy-flavour quarks in perturbative QCD. The measurement uses proton-proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of up to 20.2 fb$^{-1}$. The differential cross sections are measured for each jet flavour with respect to the transverse energy of the leading photon in two photon pseudorapidity regions: $|\eta^\gamma|<1.37$ and $1.56<|\eta^\gamma|<2.37$. The measurement covers photon transverse energies $25 < E_\textrm{T}^\gamma<400$ GeV and $25 < E_\textrm{T}^\gamma<350$ GeV respectively for the two $|\eta^\gamma|$ regions. For each jet flavour, the ratio of the cross sections in the two $|\eta^\gamma|$ regions is also measured. The measurement is corrected for detector effects and compared to leading-order and next-to-leading-order perturbative QCD calculations, based on various treatments and assumptions about the heavy-flavour content of the proton. Overall, the predictions agree well with the measurement, but some deviations are observed at high photon transverse energies. The total uncertainty in the measurement ranges between 13% and 66%, while the central $\gamma+b$ measurement exhibits the smallest uncertainty, ranging from 13% to 27%, which is comparable to the precision of the theoretical predictions.

12 data tables

Measured fiducial integrated $\gamma+b$ and $\gamma+c$ cross sections for $|\eta^\gamma|<1.37$ and $1.56<|\eta^\gamma|<2.37$.

Measured $\gamma+b$ fiducial differential cross section as a function of $E_\text{T}^\gamma$ for $|\eta^\gamma|<1.37$.

Measured $\gamma+b$ fiducial differential cross section as a function of $E_\text{T}^\gamma$ for $1.56<|\eta^\gamma|<2.37$.

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Measurement of the differential cross-sections of inclusive, prompt and non-prompt J/psi production in proton-proton collisions at sqrt(s) = 7 TeV

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Nucl.Phys.B 850 (2011) 387-444, 2011.
Inspire Record 896268 DOI 10.17182/hepdata.61590

The inclusive J/psi production cross-section and fraction of J/psi mesons produced in B-hadron decays are measured in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector at the LHC, as a function of the transverse momentum and rapidity of the J/psi, using 2.3 pb-1 of integrated luminosity. The cross-section is measured from a minimum pT of 1 GeV to a maximum of 70 GeV and for rapidities within |y| < 2.4 giving the widest reach of any measurement of J/psi production to date. The differential production cross-sections of prompt and non-prompt J/psi are separately determined and are compared to Colour Singlet NNLO*, Colour Evaporation Model, and FONLL predictions.

27 data tables

Total cross section for inclusive andd non-prompt J/PSI (-> MU+MU-) production in the range |y| < 2.4 and pT > 7 GeV under the FLAT (ie isotropic) production scenario. The second (sys) error is the uncertainty assoicated with the spin and the third is the luminosity uncertainty.

Total cross section for inclusive and non-prompt J/PSI (-> MU+MU-) production in the range 1.5 < |y| < 2 and pT > 1 GeV under the FLAT (ie isotropic) production scenario. The second (sys) error is the uncertainty assoicated with the spin and the third is the luminosity uncertainty.

Inclusive J/psi production cross-section as a function of J/psi pT in the J/psi rapidity (|y|) bin 2<|y|<2.4. The first uncertainty is statistical, the second is systematic and the third encapsulates any possible variation due to spin-alignment from the unpolarised central value.

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Prompt K_short production in pp collisions at sqrt(s)=0.9 TeV

The LHCb collaboration Aaij, R ; Abellan Beteta, C ; Adeva, B ; et al.
Phys.Lett.B 693 (2010) 69-80, 2010.
Inspire Record 865584 DOI 10.17182/hepdata.55676

The production of K_short mesons in pp collisions at a centre-of-mass energy of 0.9 TeV is studied with the LHCb detector at the Large Hadron Collider. The luminosity of the analysed sample is determined using a novel technique, involving measurements of the beam currents, sizes and positions, and is found to be 6.8 +/- 1.0 microbarn^-1. The differential prompt K_short production cross-section is measured as a function of the K_short transverse momentum and rapidity in the region 0 &lt; pT &lt; 1.6 GeV/c and 2.5 &lt; y &lt; 4.0. The data are found to be in reasonable agreement with previous measurements and generator expectations.

3 data tables

The measured cross sections as a function of transverse momentum for prompt K0S production in three rapidity regions. The first systematic error is the uncorrelated systemtatic error and the second is the systematic error correlated across bins.

The double differential prompt K0S production cross section in three rapidity bands.

The double differential prompt K0S production cross section in the rapidity band 2.5 to 4.0.