Heavy quarkonium production at the LHC throughWboson decays

Abstract

The production of the heavy (cc)-quarkonium, (cb)-quarkonium and (bb)-quarkonium states [(QQ ′ ) quarkonium for short], via the W + semi-inclusive decays, has been systematically studied within the framework of the non-relativistic QCD. In addition to the two color-singlet S-wave states, we also discuss the production of the four color-singlet P -wave states |(QQ ′ )( 1 P1)1 and |(QQ ′ )( 3 PJ )1 [with J = (0, 1, 2)] together with the two color-octet components |(QQ ′ )( 1 S0)8 and |(QQ ′ )( 3 S1)8 . Improved trace technology is adopted to derive the simplified analytic expressions at the amplitude level, which shall be useful for dealing with the following cascade decay channels. At the LHC with the luminosity L ∝ 10 34 cm −2 s −1 and the center-of-mass energy √ S = 14 TeV, sizable heavy-quarkonium events can be produced through the W + boson decays, i.e. 2.57 × 10 6 ηc, 2.65 × 10 6 J/Ψ and 2.40 × 10 6 P -wave charmonium events per year can be obtained; and 1.01 × 10 5 Bc, 9.11 × 10 4 B * c and 3.16 × 10 4 P -wave (cb)-quarkonium events per year can be obtained. Main theoretical uncertainties have also been discussed. By adding the uncertainties caused by the quark masses in quadrature, we obtain Γ W + →(cc)+cs = 524.8 +396.3 −258.4 KeV, Γ W + →(cb)+bs = 13.5 +4.73 −3.29 KeV, Γ W + →(cb)+cc = 1.74 +1.98 −0.73 KeV and Γ W + →(bb)+cb = 38.6 +13.4 −9.69 eV.

Bcproduction in Higgs boson decays

“…It can inform us not only the nature B c itself, but also the properties of the parent particles. Study of B c production through W boson decays [22,23], top quark decays [24][25][26] and Z 0 boson decays [27][28][29][30] have been studied systematically and carefully. Particularly, Ref.…”

Excited heavy quarkonium production at the LHC throughWboson decays

“…[2], we have carried out an investigation on the higher-excited |(QQ) -quarkonium states' production through W + -boson semiinclusive decays.…”

“…The compact and complex expressions for the amplitudes of the S-wave and P -wave cases can be found in the appendix of Ref. [2].…”

“…the Power-Law model [22], the Logarithmic model [23] and the Cornell model [24], will be adopted as an error analysis. Furthermore, similar to our previous treatment [2], we adopt the same constitute quark masses for the same n-th level Fock states. To ensure the gauge invariance of the hard amplitude, we set the |(QQ ′ ) -quarkonium mass M to be m Q + m Q ′ .…”

“…If assuming all excited heavy-quarkonium states decay to the ground spin-singlet [ 3 P J ] (J = 0, 1, 2)) via the W + semi-inclusive decays has been done in Ref. [2]. Here |(QQ ′ ) -quarkonium stands for the |(cc) -charmonium, |(cb) -quarkonium and |(bb) -bottomonium respectively.…”