10,074 research outputs found
Short-range force between two Higgs bosons
The -wave scattering length and the effective range of the Higgs boson in
Standard Model are studied using effective-field-theory approach. After
incorporating the first-order electroweak correction, the short-range force
between two Higgs bosons remains weakly attractive for GeV. It is
interesting to find that the force range is about two order-of-magnitude larger
than the Compton wavelength of the Higgs boson, almost comparable with the
typical length scale of the strong interaction.Comment: v2, 11 pages, 2 figures, the version accepted for publication in
Phys. Lett.
Reconciling the nonrelativistic QCD prediction and the data
It has been a long-standing problem that the rare electromagnetic decay
process is plagued with both large and negative radiative
and relativistic corrections. To date it remains futile to make a definite
prediction to confront with the branching fraction of
recently measured by the \textsf{CLEO-c} and \textsf{BESIII} Collaborations. In
this work, we investigate the joint perturbative and relativistic correction
(i.e. the correction, where denotes the
characteristic velocity of the charm quark inside the ) for this decay
process, which turns out to be very significant. After incorporating the
contribution from this new ingredient, with the reasonable choice of the input
parameters, we are able to account for the measured decay rates in a
satisfactory degree.Comment: 7 pages, 1 figure, version accepted for publication in PRD R
Inclusive production at factories
Within the nonrelativistic QCD (NRQCD) factorization framework, we
investigate the inclusive production of the meson associated with either
light hadrons or charmed hadrons at factory energy GeV.
Both the leading color-singlet and color-octet channels are included. For the
production associated with light hadrons, the total production rate is
dominated by the color-octet channel, thus the future measurement of this
process may impose useful constraint on the value of the color-octet matrix
element ; for the production associated with
charmed hadrons, the total production rate is about one order of magnitude
smaller, and dominated by the color-singlet channel.Comment: v2, 23 pages, 1 table, 6 figures. Minor corrections, and a note
added, accepted for publication in PR
Can NRQCD explain the transition form factor data?
Unlike the bewildering situation in the form factor,
a widespread view is that perturbative QCD can decently account for the recent
\textsc{BaBar} measurement of transition form
factor. The next-to-next-to-leading order (NNLO) perturbative correction to the
form factor, is investigated in the NRQCD
factorization framework for the first time. As a byproduct, we obtain by far
the most precise order- NRQCD matching coefficient for the
process. After including the substantial negative
order- correction, the good agreement between NRQCD prediction and
the measured form factor is completely ruined over a
wide range of momentum transfer squared. This eminent discrepancy casts some
doubts on the applicability of NRQCD approach to hard exclusive reactions
involving charmonium.Comment: 6 pages, 3 figures and 1 table; adding Eqs.(8) and (9) as well as
some references, correcting errors in Table 1, updating Fig.3 to include the
"light-by-light" contributions, devoting a paragraph to discuss why our
strategy of interpreting the NNLO corrections is justified; Accepted by PR
Next-to-next-to-leading-order QCD corrections to at factories
Within the nonrelativistic QCD (NRQCD) factorization framework, we compute
the long-awaited correction for the exclusive double
charmonium production process at factories, i.e.,
at GeV. For the first time, we confirm that NRQCD
factorization does hold at next-to-next-to-leading-order (NNLO) for exclusive
double charmonium production. It is found that including the NNLO QCD
correction greatly reduces the renormalization scale dependence, and also
implies the reasonable perturbative convergence behavior for this process. Our
state-of-the-art prediction is consistent with the BaBar measurement.Comment: 6 pages, 2 figures, 1 tabl
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