Solar neutrino interactions: Using charged currents at SNO to tell neutral currents at Super-Kamiokande

In the presence of flavor oscillations, muon and tau neutrinos can contribute to the Super-Kamiokande (SK) solar neutrino signal through the neutral current process \nu_{\mu,\tau} e^{-}\to \nu_{\mu,\tau} e^{-}. We show how to separate the \nu_e and \nu_{\mu,\tau} event rates in SK in a model independent way, by using the rate of the charged current process \nu_e d \to p p e^{-} from the Sudbury Neutrino Observatory (SNO) experiment, with an appropriate choice of the SK and SNO energy thresholds. Under the additional hypothesis of no oscillations into sterile states, we also show how to determine the absolute ^{8}B neutrino flux from the same data set, independently of the \nu_e survival probability.Comment: 14 pages (RevTeX), incl. 3 figures (epsf), submitted to Phys. ReV.

A simple proof of the unconditional security of quantum key distribution

Quantum key distribution is the most well-known application of quantum cryptography. Previous proposed proofs of security of quantum key distribution contain various technical subtleties. Here, a conceptually simpler proof of security of quantum key distribution is presented. The new insight is the invariance of the error rate of a teleportation channel: We show that the error rate of a teleportation channel is independent of the signals being transmitted. This is because the non-trivial error patterns are permuted under teleportation. This new insight is combined with the recently proposed quantum to classical reduction theorem. Our result shows that assuming that Alice and Bob have fault-tolerant quantum computers, quantum key distribution can be made unconditionally secure over arbitrarily long distances even against the most general type of eavesdropping attacks and in the presence of all types of noises.Comment: 13 pages, extended abstract. Comments will be appreciate

Higgs particle detection using jets

We study the possibility of detecting the Higgs boson in the intermediate mass range via its two jet channel. We consider only Higgs bosons produced in association with a $t \bar{t}$ pair. Both $t$ and $\bar{t}$ are required to decay semileptonically to reduce the QCD background. The signal is compared with the main background, $t \bar{t} + 2$ jets, after appropriate cuts. A sizable signal above background is seen in our simulation at the parton level. Use of the $t\bar{t}Z$ channel with $Z$ decaying to $l^+ l^-$ is suggested for eliminating theoretical uncertainties in determining the $t \bar{t}H$ signal.Comment: 10 pages, Fig.1 a,b,c,d(surve on request), plain tex, PVAM-HEP-93-