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Physics letters / B B 802, 135217 - (2020). doi:10.1016/j.physletb.2020.135217, Recently, the Belle Collaboration has updated the analysis of the cross sections for the processes e+e−→ϒ(nS)π+π− ( n=1,2,3 ) in the e+e− center-of-mass energy range from 10.52 to 11.02 GeV. A new structure, called here Yb(10750) , with the mass M(Yb)=(10752.7±5.9−1.1+0.7) MeV and the Breit-Wigner width Γ(Yb)=(35.5−11.3−3.3+17.6+3.9) MeV was observed [1] . We interpret Yb(10750) as a compact JPC=1−− state with a dominant tetraquark component. The mass eigenstate Yb(10750) is treated as a linear combination of the diquark-antidiquark and bb¯ components due to the mixing via gluonic exchanges shown recently to arise in the limit of large number of quark colors. The mixing angle between Yb and ϒ(5S) can be estimated from the electronic width, recently determined to be Γee(Yb)=(13.7±1.8) eV. The mixing provides a plausible mechanism for Yb(10750) production in high energy collisions from its bb¯ component and we work out the Drell-Yan and prompt production cross sections for pp→Yb(10750)→ϒ(nS)π+π− at the LHC. The resonant part of the dipion invariant mass spectrum in Yb(10750)→ϒ(1S)π+π− and the corresponding angular distribution of π+ -meson in the dipion rest frame are presented as an example., Published by North-Holland Publ., Amsterdam

Physical review letters 121(23), 231602 (2018). doi:10.1103/PhysRevLett.121.231602, We propose an integrability setup for the computation of correlation functions of gauge-invariant operators in $\mathcal{N}=4$ supersymmetric Yang-Mills theory at higher orders in the large $N_c$ genus expansion and at any order in the ’t Hooft coupling $g_{YM}^{2}N_c$. In this multistep proposal, one polygonizes the string world sheet in all possible ways, hexagonalizes all resulting polygons, and sprinkles mirror particles over all hexagon junctions to obtain the full correlator. We test our integrability-based conjecture against a nonplanar four-point correlator of large 1/2 Bogomol’nyi-Prasad-Sommerfield operators at one and two loops., Published by APS, College Park, Md.

Physical review / D 60(1), 014010 (1999). doi:10.1103/PhysRevD.60.014010, The amplitude for hard exclusive pseudoscalar meson electroproduction off nucleon (nuclear) targets is computed in QCD within the leading $\alpha_s \ln {Q^2/\lambda_{QCD}^{2}}$ approximation. We show that the distribution of recoil nucleons depends strongly on the angle between the momentum of the recoil nucleon and the polarization vector of the target (or outgoing nucleon). This dependence is especially sensitive to the spin flip skewed parton distribution (SPD) $\widetilde E$. We argue also that the scaling for this spin asymmetry sets in at lower Q^2 than that for the absolute cross section. Basing on the chiral quark-soliton model of the nucleon we estimate quantitatively the spin asymmetry. In the case of pi+ production this asymmetry is dominated at small t by the contribution of the pion pole in the isovector SPD $\widetilde E$ as required by PCAC. In the case of K0 production off a proton we find a large enhancement of the cross section as compared to the case of pi0 production. For the forward production of neutral pseudoscalar mesons off a deuteron target we find the cross section should be zero for the zero deuteron helicity (along the $\gamma^*D$ direction). We consider also cross sections of quasielastic processes off nuclei including the feasibility to implant K+,rho-mesons into nuclear volume., Published by Inst., Woodbury, NY