Next-to-next-to-leading order matching of beauty-charmed meson B c and B c * decay constants

In this paper, we study the next-to-next-to-leading-order (NNLO) QCD corrections for the process e+e− → J/ψ + J/ψ at the B factories. By including the NNLO corrections, the cross section turns negative due to the poor convergence of perturbative expansion. Consequently, to obtain a reasonable estimation for the cross section, the square of the amplitude up to NNLO is used. In addition, the contributions from the bottom quark and the light-by-light part, which are usually neglected, are also included. The final cross section is obtained as $$ {1.76}_{-1.66}^{+2.42} $$ 1.76 − 1.66 + 2.42 fb at a center-of-mass energy of $$ \sqrt{s} $$ s = 10.58 GeV. Our result for total cross section and differential cross section could be compared with precise experimental measurement in future at the B factories.

Section: Calculation Of the Perturbative Sdcmentioning

confidence: 99%

Next-to-next-to-leading-order QCD corrections to double J/ψ production at the B factories

Huang,

Gong,

Niu

et al. 2024

“…[108,109]. Two-loop corrections to the matching coefficients for the heavy flavor-changing pseudo-scalar, spatial vector and temporal axial-vector currents are available in the literature [55,56,105,106,110,111,115]. At the N 3 LO of α s , the matching coefficients have been numerically computed for the seven heavy flavor-changing currents: scalar [56,115], pseudo-scalar [56,115], spatial vector [56,106,115], temporal axial-vector [56,105,115], spatial axial-vector [56], spatial-temporal tensor [112] and spatial-spatial axial-tensor [112].…”

Section: Jhep06(2024)012mentioning

confidence: 99%

“…[54,[102][103][104], and the S-wave B c and B * c meson decay constants involving the heavy flavor-changing pseudo-scalar, vector, axial-vector, tensor and axial-tensor currents were studied in refs. [55,56,[105][106][107][108][109][110][111][112].…”

Section: Introductionmentioning

confidence: 99%

Decay constants of $$ c\overline{b} $$ mesons involving the ten heavy flavor-changing currents at N3LO QCD

Tao,

Xiao

2024

Self Cite

Within the nonrelativistic QCD (NRQCD) framework, we complete the three-loop calculations of the NRQCD renormalization constants and the matching coefficients, for the heavy flavor-changing temporal vector, spatial-spatial tensor, spatial-temporal axial-tensor currents, which are coupled to the P-wave $$ c\overline{b} $$ c b ¯ mesons. We further study the ten decay constants for the $$ c\overline{b} $$ c b ¯ mesons (Bc, $$ {B}_c^{\ast } $$ B c ∗ , $$ {B}_{c0}^{\ast } $$ B c 0 ∗ , Bc1) coupled with the ten heavy flavor-changing currents involving (pseudo-)scalar, (axial-)vector and (axial-)tensor up to the next-to-next-to-next-to-leading order (N3LO) of αs. We obtain the six ratios of decay constants by approximating them to the corresponding ratios of matching coefficients. We find the N3LO perturbative QCD results for the six ratios of decay constants have good convergence and weak scale-dependence. We finally predict the hierarchical relationship among the ten decay constants for the $$ c\overline{b} $$ c b ¯ mesons coupled with the ten currents.

“…(4) From the tables 1 and 2, we also see the uncertainties of the matching coefficients and the matching coefficient (decay constant) ratio arising from the errors in the heavy quark masses m b and m c are relatively small compared to those resulting from the errors in µ f and µ (also see ref. [7]).…”

Section: Jhep12(2023)152mentioning

confidence: 99%

“…[3,4]. Two-loop corrections to the heavy flavor-changing pseudo-scalar, spatial vector and temporal axial-vector currents are available in the literature [5][6][7]. At the N 3 LO of α s , the matching coefficients for the heavy flavor-changing pseudo-scalar, spatial vector, scalar, temporal axial-vector and spatial axial-vector currents have been numerically JHEP12(2023)152 evaluated in refs.…”

Section: Introductionmentioning

confidence: 99%

Three-loop matching of heavy flavor-changing (axial-)tensor currents

Tao,

Xiao

2023

Self Cite

We present the three-loop calculations of the nonrelativistic QCD (NRQCD) current renormalization constants and corresponding anomalous dimensions, and the matching coefficients for the spatial-temporal tensor and spatial-spatial axial-tensor currents with two different heavy quark masses. We obtain the convergent decay constant ratio up to the next-to-next-to-next-to-leading order (N3LO) for the S-wave vector meson $$ {B}_c^{\ast } $$ B c ∗ involving the tensor and axial-tensor currents. We obtain the three-loop finite (ϵ0) term in the ratio of the QCD heavy flavor-changing tensor current renormalization constant in the on-shell (OS) scheme to that in the modified-minimal-subtraction ($$ \overline{\textrm{MS}} $$ MS ¯ ) scheme, which is helpful to obtain the three-loop matching coefficients for all heavy flavor-changing (axial-)tensor currents.