Study of the doubly charmed tetraquark T+cc

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

"Table 6" of "Prompt and nonprompt J/ψ production and nuclear modification in pPb collisions at sNN=8.16TeV"

The double-differential cross sections for $J/\psi$ production from $b$-hadron decays as a function of transverse momentum for the rapidity range -5.0 < y^* < -2.5 in the nucleon-nucleon centre-of-mass frame. The first quoted uncertainty indicates the bin-by-bin correlated systematic uncertainty and the second is the bin-by-bin uncorrelated systematic uncertainty

"Table 9" of "Prompt and nonprompt J/ψ production and nuclear modification in pPb collisions at sNN=8.16 TeV"

The nuclear modification factor $R_{p \mathrm{Pb}}$ of prompt $J/\psi$ for transverse momentum smaller than 14 GeV/c as a function of transverse momentum integrated over the rapidity ranges 1.5 < y^* < 4.0 for $p$Pb and -5.0 < y^* < -2.5 for Pb$p$. The quoted uncertainties are the quadratic sums of statistical and systematic uncertainties

"Table 5" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(1S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 8$ TeV

"Table 4" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(1S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 8$ TeV

"Table 2" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(2S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 7$ TeV

"Table 3" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(3S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 7$ TeV

Baseline Estimation Method

Data and Program for Baseline Estimation Methodbaseline-estimate-main.zip file was imported from GitHub. This file is a repository for Baseline Estimation Method. All information, including Prerequisites, Usage, and Example, is shown in READ.md.Other .npy files are spectrum data from the Schottky resonator at CSRe. All these data files were analyzed using the spectrum analysis method from the GitHub repository (https://github.com/SchottkySpectroscopyIMP/data-analysis). All these data files are only used for displaying the results in the article on the Bayesian reweighted Penalized Least Squares (BrPLS) method development.psd.npy: a matrix (row: time, column: frequency) to record power spectral density during the experiment.frequency.npy : an array to record the frequency range.time.npy : an array to record the time range

"Table 2" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(2S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 7$ TeV

"Table 4" of "Study of χb meson production in pp collisions at √s = 7 and 8 TeV and observation of the decay χb (3P) → ϒ(3S)γ"

Fractions $R_{\Upsilon(1S)}^{\chi_{b}(mP)}$ in bins of $p_{\mathrm{T}}^{\Upsilon}$, measured for data collected at $\sqrt{s}= 8$ TeV