124850278
Decay Widths of Excited Heavy Mesons from Quantum Chromodynamics Sum Rules in the Infinite Mass Limit
The widths for pionic decays of the lowest two excited doublets (0(+), 1(+)) and (1(+), 2(+)) of heavy mesons are studied with quantum Chromodynamics sum rules in the heavy quark effective theory. The interpolating currents used allow us to distinguish the two 1(+) states without contamination in the infinite mass Limit. The soft pion approximation is not used in the calculations.
119384069
Supersymmetry for Fermion Masses
It is proposed that supersymmetry (SUSY) maybe used to understand fermion mass hierarchies. A family symmetry Z_{3L} is introduced, which is the cyclic symmetry among the three generation SU(2) doublets. SUSY breaks at a high energy scale ~ 10^{11} GeV. The electroweak energy scale ~ 100 GeV is unnaturally small. No additional global symmetry, like the R-parity, is imposed. The Yukawa couplings and R-parity violating couplings all take their natural values which are about (10^0-10^{-2}). Under the family symmetry, only the third generation charged fermions get their masses. This family symmetry is broken in the soft SUSY breaking terms which result in a hierarchical pattern of the fermion masses. It turns out that for the charged leptons, the tau mass is from the Higgs vacuum expectation value (VEV) and the sneutrino VEVs, the muon mass is due to the sneutrino VEVs, and the electron gains its mass due to both Z_{3L} and SUSY breaking. The large neutrino mixing are produced with neutralinos playing the partial role of right-handed neutrinos. |V_{e3}| which is for nu_e-nu_{tau} mixing is expected to be about 0.1. For the quarks, the third generation masses are from the Higgs VEVs, the second generation masses are from quantum corrections, and the down quark mass due to the sneutrino VEVs. It explains m_c/m_s, m_s/m_e, m_d>m_u and so on. Other aspects of the model are discussed.
118790054
Phenomenological aspects of R-parity violating supersymmetry with a vectorlike extra generation
Phenomenological analysis to the R-parity violating supersymmetry with a vectorlike extra generation is performed in detail. It is found that, via the trilinear couplings, the correct neutrino spectrum can be obtained. The Higgs mass rises to 125 GeV by new up-type Yukawa couplings of vectorlike quarks with no need of very heavy superpartners. Phenomena of new heavy fermions at LHC are predicted. DOI: 10.1103/PhysRevD.87.075012
119216988
LHCb $\bigtriangleup A_{CP}$ of $D$ Meson and R-Parity Violation
LHCb collaboration has recently announced a measurement of the difference of time-integrated CP asymmetries between $D\rightarrow K^+K^-$ and $D \rightarrow \pi^+\pi^-$. This result provides the evidence of large direct CP violation in $D$ meson and reveals some important implications on underlying new physics. It is shown that the direct CP violation in $D$ meson can be enhanced by R-parity violating supersymmetry, while CP violations in $K$ and $B$ mesons are suppressed by this new physics, which is in consistence with previous experiments. Constraints on the model parameters and some consequences are also discussed.
117463737
A Supersymmetric model with the gauge symmetry SU(3)(1) x SU(2)(1) x U(1)(1) x SU(3)(2) x SU(2)(2) x U(1)(2)
A supersymmetric model with two copies of the Standard Model gauge groups is constructed in the gauge mediated supersymmetry breaking scenario. The supersymmetry breaking messengers axe in a simple form. The Standard Model is obtained after first step gauge symmetry breaking. In the case of one copy of the gauge interactions being strong, a scenario of electroweak symmetry breaking is discussed, and the gauginos are generally predicted to be heavier than the sfermions.
14586429
QCD sum rule analysis for the Lambda(b)->Lambda(c) semileptonic decay
Abstract The 1 m c and 1 m b corrections to the Λ b → Λ c semileptonic decay are analyzed by QCD sum rules. Within the framework of heavy quark effective theory, the subleading baryonic Isgur-Wise function of Λ b → Λ c has been calculated. It is shown that the corrections due to the 1 m Lagrangian insertion are negligibly small. The sizable 1 m Q effect to the decay lies only in the weak current. The decay spectrum and the branching ratio are given.
118433133
Millisecond dips in the 2007–09 RXTE/PCA light curve of Sco X-1 and one possible occultation event
Serendipitous stellar occultation search is so far the only way to detect the existence of very small, very dim, remote objects in the Solar system. To date, however, there are only very few reported detections for trans-Neptunian objects (TNOs) in optical bands. In the X-ray band, with the RXTE/PCA data of Sco X-1 taken from 2007 June to 2009 October, we found one possible X-ray occultation event. We discuss the veracity and properties of this event, and suggest upper limits to the size distribution of TNOs at hectometre size and of main-belt asteroids at decametre size.
118652654
Energy dependence of normal branch oscillations in Scorpius X-1
We report the energy dependence of normal branch oscillations (NBOs) in Scorpius X-1, a low-mass X-ray binary Z-source. Three characteristic quantities (centroid frequency, quality factor, and fractional root-mean-squared (rms) amplitude) of a quasi-periodic oscillation signal as functions of photon energy are investigated. We found that, although it is not yet statistically well established, there is a signature indicating that the NBO centroid frequency decreases with increasing photon energy when it is below 6− 8k eV, which turns out to be positively correlated with the photon energy at the higher energy side. In addition, the rms amplitude increases significantly with the photon energy below 13 keV and then decreases in the energy band of 13−20 keV. There is no clear dependence on photon energy for the quality factor. Based on these results, we suggest that the NBO originates mainly in the transition layer.
119094676
Scalar and tensor slueballs on asymmetric coarse lattices
Abstract Scalar and tensor glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU (3) gauge theory. The smallest spatial lattice spacing is about 0.08 fm which makes the extrapolation to the continuum limit more reliable. In particular, attention is paid to the scalar glueball mass which is known to have problems in the extrapolation. Converting our lattice results to physical units using the scale set by the static quark potential, we obtain the following results for the glueball masses: M G (0 ++ ) = 1730(90) MeV for the scalar glueball mass and M G (2 ++ ) = 2400(95) MeV for the tensor glueball.
118572828
Glueballs at finite temperature inSU(3)Yang-Mills theory
Thermal properties of glueballs in SU(3) Yang-Mills theory are investigated in a large temperature range from $0.3T_c$ to $1.9T_c$ on anisotropic lattices. The glueball operators are optimized for the projection of the ground states by the variational method with a smearing scheme. Their thermal correlators are calculated in all 20 symmetry channels. It is found in all channels that the pole masses $M_G$ of glueballs remain almost constant when the temperature is approaching the critical temperature $T_c$ from below, and start to reduce gradually with the temperature going above $T_c$. The correlators in the $0^{++}$, $0^{-+}$, and $2^{++}$ channels are also analyzed based on the Breit-Wigner $\emph{Ansatz}$ by assuming a thermal width $\Gamma$ to the pole mass $\omega_0$ of each thermal glueball ground state. While the values of $\omega_0$ are insensitive to $T$ in the whole temperature range, the thermal widths $\Gamma$ exhibit distinct behaviors at temperatures below and above $T_c$. The widths are very small (approximately few percent of $\omega_0$ or even smaller) when $T T_c$ and reach values of roughly $\Gamma\sim \omega_0/2$ at $T\approx 1.9T_c$.
14759412
I=2 PION SCATTERING LENGTH WITH IMPROVED ACTIONS ON ANISOTROPIC LATTICES
ππ scattering length in the I=2 channel is calculated within quenched approximation using improved gauge and improved Wilson fermion actions on anisotropic lattices. The results are extrapolated towards the chiral, infinite volume and continuum limit. This result improves our previous result on the scattering length. In the chiral, infinite volume and continuum limit, we obtain , which is consistent with the result from Chiral Perturbation Theory, the experiment and results from other lattice calculations.