Fully charmed tetraquarks from LHC to FCC: natural stability from fragmentation
Francesco Giovanni Celiberto, Gabriele Gatto, Alessandro Papa
Abstract
Abstract We investigate the inclusive production of fully charmed tetraquarks, $$T_{4c}(0^{++})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> <mml:mi>c</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msup> <mml:mn>0</mml:mn> <mml:mrow> <mml:mo>+</mml:mo> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> or $$T_{4c}(2^{++})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> <mml:mi>c</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msup> <mml:mn>2</mml:mn> <mml:mrow> <mml:mo>+</mml:mo> <mml:mo>+</mml:mo> </mml:mrow> </mml:msup> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> radial excitations, in high-energy proton collisions. We build our study upon the collinear fragmentation of a single parton in a variable-flavor number scheme, suited to describe the tetraquark formation mechanism from moderate to large transverse-momentum regimes. To this extent, we derive a novel set of DGLAP-evolving collinear fragmentation functions, named determinations. They encode initial-scale inputs corresponding to both gluon and heavy-quark fragmentation channels, defined within the context of quark-potential and spin-physics inspired models, respectively. We work within the NLL/ $$\hbox {NLO}^+$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mtext>NLO</mml:mtext> <mml:mo>+</mml:mo> </mml:msup> </mml:math> hybrid factorization and make use of the numeric interface along with the symbolic calculation plugin. With these tools, we provide predictions for high-energy observables sensitive to $$T_{4c}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> <mml:mi>c</mml:mi> </mml:mrow> </mml:msub> </mml:math> plus jet emissions at center-of-mass energies ranging from 14 TeV at the LHC to the 100 TeV nominal energy of the FCC.