118462613
M5-branes in AdS$_4 \times Q^{1,1,1}$ spacetime
In this paper, we study the M5-brane configurations in AdS$_4 \times Q^{1,1,1}$ spacetime. We consider the configurations with an AdS$_2$ factor embedding into AdS$_4$, and manage to construct two solutions, which could be dual to line defects in the boundary gauge theory. Moreover we discuss their BPS nature and find that neither of them is supersymmetric. We show that the M5-brane with a R$_t$ or an AdS$_3$ factor found before is half-BPS.
118514316
Soft theorems in maximally supersymmetric theories
In this paper we study the supersymmetric generalization of the new soft theorem which was proposed by Cachazo and Strominger recently. At tree level, we prove the validity of the super soft theorems in both $$\mathcal{N}=4$$N=4 super-Yang-Mills theory and $$\mathcal{N}=8$$N=8 supergravity using super-BCFW recursion relations. We verify these theorems exactly by showing some examples.
14513092
Determination of the number of light neutrino species from single photon production at LEP
A determination of the number of light neutrino families performed by measuring the cross section of single photon production in \ee\ collision near the \Zo\ resonance is reported. From an integrated luminosity of $100~\mathrm{pb^{-1}}$, collected during the years 1991--94, we have observed 2091 single photon candidates with an energy above 1~\GeV\ in the polar angular region $45^\circ \theta_\gamma 135^\circ$. From a maximum likelihood fit to the single photon cross section, the \Zo\ decay width into invisible particles is measured to be $\Ginv = 498 \pm 12 \mathrm{(stat)} \pm 12 \mathrm{(sys)~MeV}$. Using the Standard Model couplings of neutrinos to the \Zo, the number of light neutrino species is determined to be $N_\nu = 2.98 \pm 0.07 (\mathrm{stat}) \pm 0.07 (\mathrm{sys}).$
14588649
Production of e, mu and tau pairs in untagged two-photon collisions at LEP
The two-photon collision reaction e+e- --> e+e-l+l- has been studied at root(s) ~ 91 GeV using the L3 detector at LEP for l = e, muon , tau. We have analysed untagged configurations where the two photons are quasi-real. Good agreement is found between our measurements and the order alpha**4 QED expectation.
121457351
Boson-Fermion Duality in A2 Toda Field Theory
In this paper, we consider a two-dimensional integrable and conformal invariant field theory with two Dirac spinors and two scalar fields. This model has chiral symmetry and CP-like symmetry. Moreover, this model also has a Neother current depending only on the matter field. At last, we bosonize the spinor fields.
67819117
Pseudoscalar Mesons Scattering off D*-mesons with Chiral Perturbation Theory
We have systematically calculated the s-wave pseudoscalar mesons and D*- mesons scattering lengths to the third order with chiral perturbation theory, which will be helpful to reveal their strong interaction. We present the scattering lengths (1) in the framework of the heavy meson chiral perturbation theory and (2) in the framework of the infrared regularization.
116994417
Measurement of $\eta^\prime\rightarrow \pi^+\pi^- e^+e^-$ and $\eta^\prime\rightarrow \pi^+\pi^-\mu^+\mu^-$
Based on a sample of 225.3 million J/\psi events accumulated with the BESIII detector at the BEPCII, the decays of \eta' to pi+pi-l+l- are studied via J/\psi to \gamma\eta'. A clear \eta' signal is observed in the pi+pi-e+e- mass spectrum, and the branching fraction is measured to be \BR(\eta' to pi+pi-e+e-) = (2.11\pm0.12 (stat.)\pm0.15 (syst.))\times10^{-3}, which is in good agreement with theoretical predictions and the previous measurement, but is determined with much higher precision. No \eta' signal is found in the pi+ pi- mu+ mu- mass spectrum, and the upper limit is determined to be \BR(\eta' to pi+ pi- mu+ mu-)<2.9\times10^{-5} at the 90% confidence level.