Comment on "Quantum dense key distribution"

In this Comment we question the security of recently proposed by Degiovanni et al. [Phys. Rev. A 69 (2004) 032310] scheme of quantum dense key distribution

Eavesdropping on the "ping-pong" quantum communication protocol

The proposed eavesdropping scheme reveals that the quantum communication protocol recently presented by Bostrom and Felbinger [Phys. Rev. Lett. 89, 187902 (2002)] is not secure as far as quantum channel losses are taken into account

KASCADE: Astrophysical results and tests of hadronic interaction models

KASCADE is a multi-detector setup to get redundant information on single air shower basis. The information is used to perform multiparameter analyses to solve the threefold problem of the reconstruction of (i)the unknown primary energy, (ii) the primary mass, and (iii) to quantify the characteristics of the hadronic interactions in the air-shower development. In this talk recent results of the KASCADE data analyses are summarized concerning cosmic ray anisotropy studies, determination of flux spectra for different primary mass groups, and approaches to test hadronic interaction models. Neither large scale anisotropies nor point sources were found in the KASCADE data set. The energy spectra of the light element groups result in a knee-like bending and a steepening above the knee. The topology of the individual knee positions shows a dependency on the primary particle. Though no hadronic interaction model is fully able to describe the multi-parameter data of KASCADE consistently, the more recent models or improved versions of older models reproduce the data better than few years ago.Comment: to appear in Nucl. Phys. B (Proc. Suppl.), Proc. of the XIII ISVHECRI, Pylos 2004 - with a better quality of the figure

Inventarisasi Arecaceae Di Kawasan Wisata Air Terjun Irenggolo Kediri

-Arecaceae is a monocot that grows in parts of the world from the tropics and sub-tropics, lowlands to highlands, on the mountains and the shore, in the lush and barren land. From the 215 genus of Arecaceae, the 46 genus is growing in Indonesia and 29 of them is endemic plant. Lately, Aracaceae research related to rare, whereas the benefits of it is good among other for drugs, cosmetics, building materials, and others. The study aims to determine the species of Arecaceae in the waterfall region of Irenggolo Kediri. Descriptive study was conducted with the observation and literature review technique. Samples were taken with a random roaming method which is divided into four zones according to the height of land. The Arecaceae found in Irenggolo waterfall Kediri as many as of six species, namely A. pinnata, P. roconata, Daemonorops sp., Calamus unifarius, Calamus sp., S. Zalampaicc

Towards symmetric scheme for superdense coding between multiparties

Recently Liu, Long, Tong and Li [Phys. Rev. A 65, 022304 (2002)] have proposed a scheme for superdense coding between multiparties. This scheme seems to be highly asymmetric in the sense that only one sender effectively exploits entanglement. We show that this scheme can be modified in order to allow more senders to benefit of the entanglement enhanced information transmission.Comment: 6 page

Exclusive meson pair production in proton-proton collisions

We present a study of the exclusive production of meson pairs in the four-body $pp \to pp \pi^{+} \pi^{-}$, $pp K^{+}K^{-}$ reactions at high energies which constitute an irreducible background to resonance states (e.g. $\phi$, $f_{2}(1270)$, $f_{0}(1500)$, $f_{2}'(1525)$, $\chi_{c0}$). We consider central diffractive contribution mediated by Pomeron and Reggeon exchanges and new diffractive mechanism of emission of pions/kaons from the proton lines. We include absorption effects due to proton-proton interaction and pion/kaon rescattering. Predictions for the total cross section and differential distributions in pion/kaon rapidity and transverse momentum as well as two-pion/kaon invariant mass are presented for the RHIC, Tevatron and LHC colliders. Finally we consider a measurement of exclusive production of a scalar $\chi_{c0}$ meson via $\chi_{c0} \to \pi^{+} \pi^{-}$, $K^{+} K^{-}$ decay.Comment: 4 pp., 4 figures, talk presented by PL at MESON2012 - 12th International Workshop on Meson Production, Properties and Interaction, Krakow, Poland, 31 May - 5 June 201

Canonical solution of a system of long-range interacting rotators on a lattice

The canonical partition function of a system of rotators (classical X-Y spins) on a lattice, coupled by terms decaying as the inverse of their distance to the power alpha, is analytically computed. It is also shown how to compute a rescaling function that allows to reduce the model, for any d-dimensional lattice and for any alpha<d, to the mean field (alpha=0) model.Comment: Initially submitted to Physical Review Letters: following referees' Comments it has been transferred to Phys. Rev. E, because of supposed no general interest. Divided into sections, corrections in (5) and (20), reference 5 updated. 8 pages 1 figur

Open charm meson production at LHC

We discuss charm production at the LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use Kimber-Martin-Ryskin unintegrated gluon distributions in the proton. The hadronization is included with the help of Peterson fragmentation functions. Transverse momentum and pseudorapidity distributions of charmed mesons are presented and compared to recent results of the ALICE, LHCb and ATLAS collaborations. Furthermore we discuss production of two pairs of $c \bar c$ within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS), are predicted for LHC energies. We discuss perspectives how to identify the double scattering contribution. We predict much larger cross section for large rapidity distance between charm quarks from different hard parton scatterings compared to single scattering.Comment: 5 pages, 4 figures, talk given by R. Maciula at the MESON2012 - 12th International Workshop on Meson Production, Properties and Interaction, 31 May - 5 June 2012, Krakow, Polan

Pengaplikasian Lumpur Sidoarjo Kadar Tinggi Pada Mortar Dan Beton

Berbagaipenelitian mengenai pemanfaatan material lumpur Sidoarjo, khususnya sebagai material pengganti semen (pozzolan) telah dilakukan. Penelitian ini berfokus pada penggunaan lumpur Sidoarjo dengan kadar yang tinggi, yaitu &gt;50%, serta membandingkan hasil tersebut dengan fly ash. Analisa terhadap materialdilakukan menggunakan XRF (X-Ray Flouresence) untuk mengetahui karakteristik dari material tersebut. Analisa juga dilakukan terhadap pengaruh ukuran butiranmenggunakan PSA (Particle Size Analysis).Lumpur dilakukan treatment dari pengeringan, pembakaran hingga digiling menggunakan bar-mill dengan lama penggilingan bervariasi untuk mendapatkan ukuran butiran berbeda. Presentase kadar yang digunakan adalah 50%, 55% dan 60% dari total cementitious material. Mortar dan beton digunakan ukuran 5x5x5 cm3 dan 15x15x15 cm3 lalu dilakukan pengujian berupa kuat tekan, workability dan setting time. Hasil menunjukkan semakin halus ukuran butiran, semakin tinggi kuat tekan dan workability-nya. Diantara kadar 50%-60% penggantian semen dengan lumpur Sidoarjo, kadar 50% merupakan yang paling efektif.Pada beton dengan lumpur Sidoarjo menghasilkan slump test sebesar 8,5 cm dengan kuat tekan 34,07 MPa pada umur 37 hari