117504817
The X-ray spectra and XUV excess of some AGNs.
121855913
Possibility to Detect Upgoing Sleptons
Some supersymmetric models predict long lived charged sleptons. If they are exist, the τ ˜ , the supersymmetry partner of τ lepton, could be produced inside the earth by collisions of high energy neutrinos with nucleons. The possible signals of upgoing τ ˜ have been studied in various ways. Taking the atmospheric neutrino flux into account, the muon flux as main background is also estimated. By using the Waxman-Bahcall limit on the extraterrestrial neutrino flux, the resultant spectra show that there are about 70 events per year passing a km-scale underground experiment, such as ICECUBE.
12058058
Detectability of Upgoing Sleptons
Some supersymmetric models predicted long lived charged sleptons. Following Albuquerque, Burdman and Chacko \cite{albu}, we consider an exact process where the $ \widetilde{\tau}$, the supersymmetry partner of $\tau$ lepton, are produced inside the earth by collisions of high energy neutrinos with nucleons. We detailedly investigate the possible signals of upgoing $ \widetilde{\tau}$ by comparing with the background muons where atmospheric neutrino flux is taken into account. The realistic spectra shows that km-scale experiments could see as many as 69 events a year by using the Waxman-Bahcall limit on the extraterrestrial neutrino flux.
118365916
Geminga Pulsar in Cos-B and Heao-B Observations
115136998
Search for a Muon Flux Enhancement During the Solar Flare of 14 July 2000 with the L3+C Data
The solar slare of the 14 July 2000 offers a unique opportunity for the L3+C experiment at CERN to search for a correlated enhancement in the flux of muons using the precision spectrometer. The search for a directional excess in the flux of muons between 15 and 25 GeV, corresponding to primary proton energies above 40 GeV, is presented. We report an excess with a chance probability of 2.7 · 10−3 at a time coincident with the peak increase of solar protons observed with neutron monitors and satellites. At higher energies no significant signal has been observed up to 1.5 hours after the Solar flare time.
119273980
Hidden Local Symmetry and Infinite Tower of Vector Mesons for Baryons
In an effort to access dense baryonic matter relevant for compact stars in a unified framework that handles both single baryon and multibaryon systems on the same footing, we first address a holographic dual action for a single baryon focusing on the role of the infinite tower of vector mesons deconstructed from five dimensions. To leading order in 't Hooft coupling $\lambda=N_c g_{\rm YM}^2$, one has the Bogomol'nyi-Prasad-Sommerfield (BPS) Skyrmion that results when the warping of the bulk background and the Chern-Simons term in the Sakai-Sugimoto D4/D8-${\bar{\rm D8}}$ model are ignored. The infinite tower was found by Sutcliffe to induce flow to a conformal theory, i.e., the BPS. We compare this structure to that of the SS model consisting of a 5D Yang-Mills action in warped space and the Chern-Simons term in which higher vector mesons are integrated out while preserving hidden local symmetry and valid to $O(\lambda^0)$ and $O(p^4)$ in the chiral counting. We point out the surprisingly important role of the $\omega$ meson that figures in the Chern-Simons term that encodes chiral anomaly in the baryon structure and that may be closely tied to short-range repulsion in nuclear interactions.
118902741
Anomalous Action of QCD from the General Quark Propagator
The anomalous action of the chiral effective theory to O(p 4 ) is investigated by generalizing the consideration in [1] with including the wave function part in the general quark propagator. It is found that the QCD dynamics dependence of the Wess-Zumino term is explicit and this dependence means that the QCD chiral symmetry must be broken dynamically in the low energy region for dynamically generating the Wess-Zumino term. In addition, we found that the next to leading order anomalous action in the momentum expansion of the chiral perturbation theory is gauge invariant and QCD dynamics dependent.
118351603
Strong and radiative decays of X(3872) as a hadronic molecule with a negative parity
Properties of X(3872) are studied by regarding it as a $DD^{\ast}$ hadronic molecule with $J^{PC} = 2^{-+}$ in the phenomenological Lagrangian approach. We find that our model with about 97.6% isospin zero component explains the existing data nicely, for example, the ratio $\mathcal{B}(X(3872) \to J/\psi\pi^+\pi^-\pi^0)/\mathcal{B}(X(3872) \to J/\psi\pi^+\pi^-)$. We predict the partial widths of the radiative decays of $X(3872) \to \gamma J/\psi$, $\gamma \psi(2S) $ and the strong decays of $X(3872) \to J/\psi \pi^+ \pi^-$, $J/\psi \pi^+\pi^-\pi^0$ as well as $X(3872) \to \chi_{cJ}\pi^0$. Our analysis shows that the measurement of the ratio $\mathcal{B}(X(3872) \to \chi_{c0}\pi^0)/\mathcal{B}(X(3872) \to \chi_{c1}\pi^0)$ may signal the nature of X(3872).
59430684
Chiral partner structure of heavy baryons from the bound state approach with hidden local symmetry
The chiral partner structure of heavy baryons is studied using the bound state approach by binding the heavy-light mesons to the nucleon as the soliton in an effective Lagrangian for the pseudoscalar and vector mesons based on hidden local symmetry. In the heavy-light meson sector, we regard the $H$ doublet and $G$ doublet as chiral partners and couple them to light mesons with a minimal derivative. We find that the chiral partner of ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},2286)$ is the ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},\frac{3}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{})$ heavy quark doublet with a mass of about 3.1 GeV but not (${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},2595)$, ${\ensuremath{\Lambda}}_{c}(\frac{3}{2}\genfrac{}{}{0}{}{{}^{\ensuremath{-}}}{},2625)$), which might be interpreted as an orbital excitation of ${\ensuremath{\Lambda}}_{c}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},2286)$. The same model is applied to the bottom sector, and the chiral partner of ${\ensuremath{\Lambda}}_{b}(\frac{1}{2}\genfrac{}{}{0}{}{{}^{+}}{},5625)$ is shown to have a mass of about 6.5 GeV. We also discuss the chiral partner structures for the isospin vector heavy baryons. For the pentaquark states, we find that the masses of the pentaquark state made of a ground state heavy-light meson and its chiral partner are similar, and both of them are below the $Dp$ threshold, which therefore cannot be ruled out by the present data.
119298268
Lepton-number-violating decays of B+, D+, and D+s mesons induced by the doubly charged Higgs boson
The lepton-number-violating decays of B+, D+, and D-s(+) mesons induced by the doubly charged Higgs boson have been studied. It is found that although the yielded results of the branch ratio are much smaller than the present limits from the data, they are consistent with the previous conclusions calculated in the framework of the relativistic quark model where the processes happened via light Majorana neutrinos.