相关论文: Constraints on the $\chi_\mathrm{c1}$ versus $\chi…
The production mechanisms of charmonium states in both hadronic and heavy-ion collisions hold great significance for investigating the hot and dense QCD matter. Studying charmonium polarization in ultra-relativistic collisions can also…
The polarizations of Y(nS) (n=1,2,3) and prompt J/\psi and \psi(2S), as well as the differential cross section of the Y(nS), are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a dimuon data sample collected by the CMS…
We analyze the first LHC data on $\chi_{c1}$ and $\chi_{c2}$ polarization obtained very recently by the CMS Collaboration at $\sqrt s = 8$~TeV. We describe the perturbative production of $c\bar c$ pair with $k_T$-factorization approach and…
The measurement of polarization serves as an important probe to investigate the production mechanism of quarkonia, the bound state of heavy quark anti-quark (charm or bottom) pairs, in hadronic collisions. In experimental invesigations, the…
The polarization of inclusive J/$\psi$ and $\Upsilon(1{\rm S})$ produced in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=5.02$ TeV at the LHC is measured with the ALICE detector. The study is carried out by reconstructing the quarkonium through…
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$^{-1}$,…
We have 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…
Several topics of relevance to low transverse momentum $\psi$ and $\chi_{1,2}(c\overline{c})$ production in polarized proton-proton collisions are discussed. The leading ${\cal O}(\alpha_S^3)$ contributions to the low $p_T$ $\chi_1$…
The polarizations of prompt J/psi and psi(2S) mesons are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9…
The polarizations of the Y(1S), Y(2S), and Y(3S) mesons are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a data sample of Y(nS) to oppositely charged muon pair decays collected by the CMS experiment, corresponding to an…
We study the polarization of inclusive J/$\psi$ produced in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in…
We have measured the polarizations of $\jpsi$ and $\psiprime$ mesons as functions of their transverse momentum $\pt$ when they are produced promptly in the rapidity range $|y|<0.6$ with $\pt \geq 5 \pgev$. The analysis is performed using a…
The polarizations of prompt and non-prompt J$/\psi$ and $\psi$(2S) mesons are measured in proton-proton collisions at $\sqrt{s}$ = 13 TeV, using data samples collected by the CMS experiment in 2017 and 2018, corresponding to a total…
The prompt and non-prompt production cross-sections for the chi_c1 and chi_c2 charmonium states are measured in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector at the LHC using 4.5 fb^-1 of integrated luminosity. The chi_c states…
The first measurement of the polarisation of coherently photoproduced J$/\psi$ mesons in ultra-peripheral Pb-Pb collisions, using data at $\sqrt{s_{\rm NN}}$ = 5.02 TeV, is presented. The J/$\psi$ meson is measured via its dimuon decay…
A measurement is presented of the relative prompt production rate of chi(c2) and chi(c1) with 4.6 inverse femtobarns of data collected by the CMS experiment at the LHC in pp collisions at sqrt(s) = 7 TeV. The two states are measured via…
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…
A polarization measurement carried out for the $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S)$ mesons produced in pp collisions at $\sqrt{s}=$ 7 and 8 TeV is presented. Data samples used for the polarization measurement were collected by…
Prompt $\chi_c$ production at hadron colliders may provide a unique test for the color-octet mechanism in nonrelativistic QCD. We present an analysis for the polarization observables of $\chi_{c1}$ and $\chi_{c2}$ at next-to-leading order…
Prompt production of charmonium $\chi_{c0}$, $\chi_{c1}$ and $\chi_{c2}$ mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of $\sqrt{s}=7$TeV. The $\chi_{c}$ mesons are identified through their decay to…