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.
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
118615785
Dense baryonic matter in conformally-compensated hidden local symmetry: Vector manifestation and chiral symmetry restoration
We find that, when the dilaton is implemented as a (pseudo-)Nambu-Goldstone boson using a conformal compensator or "conformon" in a hidden gauge symmetric Lagrangian written to $O(p^4)$ from which baryons arise as solitons, namely, skyrmions, the vector manifestation and chiral symmetry restoration at high density predicted in hidden local symmetry theory --- which is consistent with Brown-Rho scaling --- are lost or sent to infinite density. It is shown that they can be restored if in medium the behavior of the $\omega$ field is taken to deviate from that of the $\rho$ meson in such a way that the flavor $U(2)$ symmetry is strongly broken at increasing density. The hitherto unexposed crucial role of the $\omega$ meson in the structure of elementary baryon and multibaryon systems is uncovered in this work. In the state of half-skyrmions to which the skyrmions transform at a density $n_{1/2}^{} \gtrsim n_0^{}$ (where $n_0^{}$ is the normal nuclear matter density), characterized by the vanishing (space averaged) quark condensate but nonzero pion decay constant, the nucleon mass remains more or less constant at a value $\gtrsim$ 60 \% of the vacuum value indicating a large component of the nucleon mass that is not associated with the spontaneous breaking of chiral symmetry. We discuss its connection to the chiral-invariant mass $m_0^{}$ that figures in the parity-doublet baryon model.
118662330
Dense baryonic matter in the hidden local symmetry approach
The dense baryonic matter and hadron properties in medium were simulated by using a Skyrme model including the ground state vector mesons introduced from the hidden local symmetry approach up to the next to leading order. We found that both the $\rho$ and $\omega$ mesons affect the baryonic matter and medium modified hadron properties dramatically. The most remarkable observation is that, the pion decay constant and the nucleon mass have the similar density dependence which agrees with the large $N_c$ argument. Explicitly, they drop with increasing density in the Skyrmion phase and stop decreasing at $n_{1/2}^{}$ at which the skyrmions in medium fractionize into half-skyrmions and remains nearly constants in the half-skyrmion phase. This density dependence in the half-skyrmion phase indicates that, although $\langle \bar{q}q\rangle \neq 0$ on average in this phase, chiral symmetry is not restored since hadrons are still massive and there exist pions. In addition, the nearly constant nucleon mass means that it could has a non-vanishing component up to the chiral transition, which might shed light on the origin of the nucleon mass.
121260659
Open and hidden charm hadronic molecules
Properties of some open and hidden charm exotic states which have been studied using the composite model are summarized. It is found that, their decay properties are consistent with the data and further data are necessary to discriminate the hadronic molecular interpretation from other interpretations.
119182023
Skyrmions, half-skyrmions and nucleon mass in dense baryonic matter
We explore the hadron properties in dense baryonic matter in a unified way by using a Skyrme model constructed with an effective Lagrangian which includes the ρ and ω vector mesons as hidden gauge bosons and is valid up to O(p4) in chiral expansion including the homogeneous Wess-Zumino terms. With the two input values of pion decay constant and the lowest lying vector meson mass which can be fixed in free space, all the other low energy constants in the effective Lagrangian are determined by their master formulas derived from holographic QCD models, which allows us to study the baryonic matter properties with no additional free parameters and thus without ambiguities. We find that the ω field that figures in the homogeneous Wess-Zumino term plays a crucial role in the skyrmion structure and its matter properties. The most striking and intriguing observation is that the pion decay constant that smoothly drops with increasing density in the Skyrmion phase stops decreasing at n1/2 at which the skyrmions in medium fractionize into half-skyrmions and remains nearly constant in the half-skyrmion phase. In accordance with the large Nc consideration, the baryon mass also stays non-scaling in the half-skyrmion phase. This feature is supported by the nuclear effective field theory with the parameters of the Lagrangian scaling modified at the skyrmion–half-skyrmion phase transition. Our exploration also uncovers the crucial role of the ω meson in multi-baryon systems as well as in the structure of a single skyrmion.
119262831
Properties of X(3872) as a hadronic molecule with a negative parity
We discuss the possible interpretation of X(3872) as a DD ∗ hadronic molecule with J PC = 2 −+ . Using the phenomenological Lagrangian approach, we studied its radiative and strong decay properties. We find that our model with about 97.6% isospin zero component explains the existing data nicely. We predict the partial widths of the radiative and strong decays of X(3872) and show that the measurement of the ratio B(X(3872) → �c0�0)/B(X(3872) → �c1�0) may signal the nature of X(3872).