Υ\Upsilon radiative decays to light quark jets and color octet mechanism

We study radiative decays of $\Upsilon$ to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet $b\bar b$ operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about $36^\circ$, the branching ratio for $\Upsilon\to\gamma q\bar q$ is found to be $8.2\times 10^{-4}$ from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.Comment: journal version; a few references adde

J/psi Pair Production at the Tevatron

The double J/psi production in p\bar{p} collision is revisited. It is found that the J/\psi pair production rate at leading order with p_T > 4 GeV in conventional scheme is larger than the rate derived from color-octet mechanism by a factor of five. As the double J/psi production is shown to be attainable with data yet collected at the Tevatron detectors, experimental study on it would be helpful to clarify the validity of the conventional color-singlet description for heavy quarkonium production

Reexamining radiative decays of 1−−1^{--} quarkonium into η′\eta' and η\eta

Recently CLEO has studied the radiative decay of $\Upsilon$ into $\eta'$ and an upper limit for the decay has been determined. Confronting with this upper limit,most of theoretical predictions for the decay fails. After briefly reviewing these predictions we re-examine the decay by separating nonperturbative effect related to the quarkonium and that related to $\eta'$ or $\eta$, in which the later is parameterized by distribution amplitudes of gluons in $\eta'$. With this factorization approach we obtain theoretical predictions which are in agreement with experiment. Uncertainties in our predictions are discussed. The possibly largest uncertainties are from relativistic corrections for $J/\Psi$ and the value of the charm quark mass. We argue that the effect of these uncertainties can be reduced by using quarkonium masses instead of using quark masses. An example of the reduction is shown with an attempt to explain the violation of the famous 14% rule in radiative decays of charmonia.Comment: 9 Pages, Latex fil

Serum N-Terminal propeptide of collagen type I is associated with the number of bone Metastases in breast and prostate cancer and correlates to other bone related markers

Background A number of biomarkers have been proven potentially useful for their ability to indicate bone metastases (BM) in cancer patients. The aim of this study was to investigate the relative utility of a newly developed N-terminal propeptide of collagen type I (PINP) human serum assay for the detection of BM in cancer patients. This assay has a corresponding rat PINP assay which in the future might help in translational science between rodent and human trials. Methods Participants were 161 prostate, lung and breast cancer patients stratified by number of BM(Soloway score). PINP was assessed and correlated to number of BM. Additionally, the PINP marker was correlated to bone resorption of young (ALPHA CTX-I)- and aged bone (BETA CTX-I); number of osteoclasts (Tartrate-resistant acid phosphatase 5b, TRACP5B) and osteoclast activity (CTX-I/TRACP5B). Results PINP was significantly elevated in breast- and prostate cancer patients +BM, compared to –BM ( P < 0.001), however not in lung cancer patients. A strong linear association was seen between PINP and the number of BMs. Significant elevation of PINP was observed at Soloway scores 1–4 (<0 BM) compared with score 0 (0 BM) ( P < 0.001). The correlation between bone resorption of young bone or aged bone and bone formation was highly significant in patients +BM and –BM ( P < 0.0001). Conclusions Data suggest that the present PINP potentially could determine skeletal involvement in patients with breast or prostate cancer. Correlations suggested that coupling between bone resorption and bone formation was maintained in breast- and prostate cancer patients

Quarkonium+γ\gamma production in coherent hadron - hadron interactions at LHC energies

In this paper we study the $H + \gamma$ ($H = J/\Psi$ and $\Upsilon$) production in coherent hadron - hadron interactions at LHC energies. Considering the ultrarelativistic protons as a source of photons, we estimate the $\gamma + p \rightarrow H + \gamma + X$ cross section using the non-relativistic QCD (NRQCD) factorization formalism and considering different sets of values for the matrix elements. Our results for the total $p + p \rightarrow p + H + \gamma + X$ cross sections and rapidity distributions at $\sqrt{s} = 7$ and 14 TeV demonstrate that the experimental analysis of the $J/\Psi + \gamma$ production at LHC is feasible.Comment: 6 pages, 3 figures, 1 table. Improved version with a new figure. Version to be published in European Physical Journal

Top Quark Decays into Heavy Quark Mesons

For top quark decays into heavy quark mesons $\Upsilon$ and $\bar{B}_c^*$ , a complete calculation to the leading order both in QCD coupling constant $\alpha_s$ and in $v$, the typical velocity of the heavy quarks inside the mesons, is performed. Relatons between the top quark mass and the decay branching ratios are studied. Comparion with the results which are obtained by using the quark frangmentation functions is also discussed. The branching ratios are consistent (within a factor of $2\sim 3$) with that obtained using fragmentation functions at $m_t\sim 150$ GeV.Comment: 15 pages in LaTex form, 4 figures include

Fragmentation Function and Hadronic Production of the Heavy Supersymmetric Hadrons

The light top-squark \sto may be the lightest squark and its lifetime may be `long enough' in a kind of SUSY models which have not been ruled out yet experimentally, so colorless `supersymmetric hadrons (superhadrons)' (\sto \bar{q}) ($q$ is a quark except $t$-quark) may be formed as long as the light top-squark \sto can be produced. Fragmentation function of \sto to heavy `supersymmetric hadrons (superhadrons)' (\sto \bar{Q}) ($\bar{Q}=\bar{c}$ or $\bar{b}$) and the hadronic production of the superhadrons are investigated quantitatively. The fragmentation function is calculated precisely. Due to the difference in spin of the SUSY component, the asymptotic behavior of the fragmentation function is different from those of the existent ones. The fragmentation function is also applied to compute the production of heavy superhadrons at hadronic colliders Tevatron and LHC under the so-called fragmentation approach. The resultant cross-section for the heavy superhadrons is too small to observe at Tevatron, but great enough at LHC, even when all the relevant parameters in the SUSY models are taken within the favored region for the heavy superhadrons. The production of `light superhadrons' (\sto \bar{q}) ($q=u, d, s$) is also roughly estimated. It is pointed out that the production cross-sections of the light superhadrons (\sto \bar{q}) may be much greater than those of the heavy superhadrons, so that even at Tevatron the light superhadrons may be produced in great quantities.Comment: 20 pages, 9 figure

Inelastic J/ψJ/\psi production in polarized photon-hadron collisions

Presented here is a calculation of inelastic $J/\psi$ production in polarized photon-hadron collisions under the framework of NRQCD factorization formalism. We consider the photoproduction of \jpsi in the energy range relevant to HERA. The Weizs\"acker-Williams approximation is adopted in the evaluation of the cross sections for $ep$ collisions. We found that this process can give another independent test for the color-octet mechanism, and the different features for the two color-octet processes may provide further informations on the mechanism for inelastic \jpsi photoproduction. And the discrepancy on the production asymmetry $A$ between various sets of polarized gluon distribution functions is also found to be distinctive.Comment: 14pages, 6 PS figure

Determination of color-octet matrix elements from e^+e- process at low energies

We present an analysis of the preliminary experimental data of direct j/psi production in e^e- process at low energies. We find that the color-octet contributions are crucially important to the cross section at this energy region, and their inclusion produces a good description of the data. By fitting to the data, we extract the individual values of two color-octet matrix elements: \approx 1.1\times 10^{-2} GeV^3, <{\cal O}_8^{\psi}(^3P_0)> m_c^2\approx 7.4\times 10^{-3}GeV^3. We discuss the allowed range of the two matrix elements constrained by the theoretical uncertainties. We find that is poorly determined because it is sensitive to the variation of the choice of m_c, \alpha_s and <{\cal O}_1^{\psi}(^3S_1)>. However m_c^2 is quite stable (about (6-9)\times 10^{-3}GeV^3) when the parameters vary in reasonable ranges. The uncertainties due to large experimental errors are also discussed.Comment: 13 page, RevTex, 2 figures in postscript. To appear in Phys. Rev.

Narrow width of a glueball decay into two mesons

The widths of a glueball decay to two pions or kaons are analyzed in the pQCD framework. Our results show that the glueball ground state has small branching ratio for two-meson decay mode, which is around $10^{-2}$. The predicted values are consistent with the data of $\xi\to\pi\pi, KK$ if $\xi$ particle is a $2^{++}$ glueball. Applicability of pQCD to the glueball decay and comparison with $\chi_{cJ}$ decay are also discussed.Comment: 12 pages, revtex, 2 ps figure