678 research outputs found

### Dominant Spin-Flip Effects for the Hadronic Produced $J/\psi$ Polarization at TEVATRON

Dominant spin-flip effects for the direct and prompt $J/\psi$ polarizations
at TEVATRON run II with collision energy 1.96 TeV and rapidity cut
$|y^{J/\psi}|<0.6$, have been systematically studied, especially, the spin-flip
effect for the transition of $(c\bar{c})_8[^3S_1]$ into $J/\psi$ has been
carefully discussed. It is found that the spin-flip effect shall always dilute
the $J/\psi$ polarization, and with a suitable choice of the parameters
$a_{0,1}$ and $c_{0,1,2}$, the $J/\psi$ polarization puzzle can be solved to a
certain degree. At large transverse momentum $p_t$, $\alpha$ for the prompt
$J/\psi$ is reduced by $\sim50%$ for $f_0 = v^2$ and by $\sim80%$ for $f_0=1$.
We also study the indirect $J/\psi$ polarization from the $b$-decays, which
however is slightly affected by the same spin-flip effect and then shall
provide a better platform to determine the color-octet matrix elements.Comment: 19 pages, 5 figures. References added. Revised version to be
published in Phys.Rev.

### Electromagnetic counterparts of high-frequency gravitational waves having additional polarization states: distinguishing and probing tensor-mode, vector-mode and scalar-mode gravitons

GWs from extra dimensions, very early universe, and some high-energy
astrophysical process, might have at most six polarizations: plus- and
cross-type (tensor-mode gravitons), x-, y-type (vector-mode), and b-, l-type
(scalar-mode). Peak or partial peak regions of some of such GWs are just
distributed in GHz or higher frequency band, which would be optimal band for
electromagnetic(EM) response. In this paper we investigate EM response to such
high-frequency GWs(HFGWs) having additional polarizations. For the first time
we address:(1)concrete forms of analytic solutions for perturbed EM fields
caused by HFGWs having all six possible polarizations in background stable EM
fields; (2)perturbed EM signals of HFGWs with additional polarizations in
three-dimensional-synchro-resonance-system(3DSR system) and in
galactic-extragalactic background EM fields. These perturbative EM fields are
actually EM counterparts of HFGWs, and such results provide a novel way to
simultaneously distinguish and display all possible six polarizations. It is
also shown: (i)In EM response, pure cross-, x-type and pure y-type
polarizations can independently generate perturbative photon fluxes(PPFs,
signals), while plus-, b- and l-type polarizations produce PPFs in different
combination states. (ii) All such six polarizations have separability and
detectability. (iii)In EM response to HFGWs from extra-dimensions,
distinguishing and displaying different polarizations would be quite possible
due to their very high frequencies, large energy densities and special
properties of spectrum. (iv)Detection band(10^8 to 10^12 Hz or higher) of PPFs
by 3DSR and observation range(7*10^7 to 3*10^9 Hz) of PPFs by FAST
(Five-hundred-meter-Aperture-Spherical Telescope, China), have a certain
overlapping property, so their coincidence experiments will have high
complementarity.Comment: 27 pages, 16 figure

### Effective SU(2)_L x U(1) theory and the Higgs boson mass

We assume the stability of vacuum under radiative corrections in the context
of the standard electroweak theory. We find that this theory behaves as a good
effective model already at cut off energy scales as low as 0.7 TeV. This
stability criterion allows to predict m_H= 318 +- 13 GeV for the Higgs boson
mass.Comment: Latex, 5 pages, 1 Postscript figure include

### $B\to K$ Transition Form Factor with Tensor Current within the $k_T$ Factorization Approach

In the paper, we apply the $k_T$ factorization approach to deal with the
$B\to K$ transition form factor with tensor current in the large recoil
regions. Main uncertainties for the estimation are discussed and we obtain
$F_T^{B\to K}(0)=0.25\pm0.01\pm0.02$, where the first error is caused by the
uncertainties from the pionic wave functions and the second is from that of the
B-meson wave functions. This result is consistent with the light-cone sum rule
results obtained in the literature.Comment: 8 pages, 4 figures, references adde

### Two body final states production in electron-positron annihilation and their contributions to $(g-2)_{\mu}$

In this paper, we study the processes of $e^{+}e^{-}$ annihilation into two
body final states, either two pseudoscalar mesons or one meson with a photon.
The hadronic vacuum polarization form factors are calculated within the
framework of resonance chiral theory in the energy region of $E \lesssim 2$
GeV, with final state interactions taken into account. A joint analysis on the
processes of $e^{+}e^{-} \rightarrow \pi^{+}\pi^{-}$, $K^{+}K^{-}$,
$K_{L}^{0}K_{S}^{0}$, $\pi^{0}\gamma$, and $\eta\gamma$ has been performed, and
the latest experimental data are included. Based on the vacuum polarization
form factors of these processes, we estimate their contributions to the lowest
order of anomalous magnetic moment of the muon, $(g-2)_\mu$. Combined with
other contributions from hadronic vacuum polarization and other interactions
from the standard model, the discrepancy between theoretical prediction and
experimental measurement is $\Delta a_{\mu}=(24.1\pm5.4)\times 10^{-10}$, i.e.,
4.5$\sigma$.Comment: 45 pages, 6 figures, to be the same as the published versio

### Excited Heavy Quarkonium Production at the LHC through $W$-Boson Decays

Sizable amount of heavy-quarkonium events can be produced through $W$-boson
decays at the LHC. Such channels will provide a suitable platform to study the
heavy-quarkonium properties. The "improved trace technology", which disposes
the amplitude ${\cal M}$ at the amplitude-level, is helpful for deriving
compact analytical results for complex processes. As an important new
application, in addition to the production of the lower-level Fock states
$|(Q\bar{Q'})[1S]>$ and $|(Q\bar{Q'})[1P]>$, we make a further study on the
production of higher-excited $|(Q\bar{Q'})>$-quarkonium Fock states
$|(Q\bar{Q'})[2S]>$, $|(Q\bar{Q'})[3S]>$ and $|(Q\bar{Q'})[2P]>$. Here
$|(Q\bar{Q'})>$ stands for the $|(c\bar{c})>$-charmonium,
$|(c\bar{b})>$-quarkonium and $|(b\bar{b})>$-bottomonium respectively. We show
that sizable amount of events for those higher-excited states can also be
produced at the LHC. Therefore, we need to take them into consideration for a
sound estimation.Comment: 7 pages, 9 figures and 6 tables. Typo errors are corrected, more
discussions and two new figures have been adde

### Doubly Heavy Baryon Production at A High Luminosity $e^+ e^-$ Collider

Within the framework of nonrelativistic QCD, we make a detailed discussion on
the doubly heavy baryon production through the $e^+ e^-$ annihilation channel,
$e^{+}e^{-}\rightarrow\gamma/Z^0 \rightarrow \Xi_{QQ^{\prime}} +\bar{Q}
+\bar{Q^{\prime}}$, at a high luminosity $e^{+}e^{-}$ collider. Here
$Q^{(\prime)}$ stands for the heavy $b$ or $c$ quark. In addition to the
channel through the usually considered diquark state
$(QQ^{\prime})[^3S_1]_{\bf\bar{3}}$, contributions from the channels through
other same important diquark states such as $(QQ^{\prime})[^1S_0]_{\bf 6}$ have
also been discussed. Uncertainties for the total cross sections are predicted
by taking $m_c=1.80\pm0.30$ GeV and $m_b=5.10\pm0.40$ GeV. At a super
$Z$-factory running around the $Z^0$ mass and with a high luminosity up to
${\cal L} \propto 10^{34}\sim 10^{36}{\rm cm}^{-2} {\rm s}^{-1}$, we estimate
that about $1.1\times10^{5 \sim 7}$ $\Xi_{cc}$ events, $2.6\times10^{5 \sim 7}$
$\Xi_{bc}$ events and $1.2\times 10^{4 \sim 6}$ $\Xi_{bb}$ events can be
generated in one operation year. Such a $Z$-factory, thus, will provide a good
platform for studying the doubly heavy baryons in comparable to the CERN large
hadronic collider.Comment: 9 pages, 4 figures. To be published in Phys.Rev.

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