A combined analysis technique for the search for fast magnetic monopoles with the MACRO detector

We describe a search method for fast moving ($\beta > 5 \times 10^{-3}$) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confirmation. Using this technique, a first sample of more than two years of data has been analyzed without any evidence of a magnetic monopole. We set a 90% CL upper limit to the local monopole flux of $1.5 \times 10^{-15} cm^{-2} s^{-1} sr^{-1}$ in the velocity range $5 \times 10^{-3} \le \beta \le 0.99$ and for nucleon decay catalysis cross section smaller than $\sim 1 mb$.Comment: 29 pages (12 figures). Accepted by Astroparticle Physic

Final results of magnetic monopole searches with the MACRO experiment

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range $4\times 10^{-5}< \beta < 1$. Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined ways. No candidates were detected and a 90% Confidence Level (C.L.) upper limit to the local magnetic monopole flux was set at the level of $1.4\times 10^{-16}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$. This result is the first experimental limit obtained in direct searches which is well below the Parker bound in the whole $\beta$ range in which GUT magnetic monopoles are expected.Comment: 12 pages, Latex, 9 figures and 2 Table

The Observation of Up-going Charged Particles Produced by High Energy Muons in Underground Detectors

An experimental study of the production of up-going charged particles in inelastic interactions of down-going underground muons is reported, using data obtained from the MACRO detector at the Gran Sasso Laboratory. In a sample of 12.2 10^6 single muons, corresponding to a detector livetime of 1.55 y, 243 events are observed having an up-going particle associated with a down-going muon. These events are analysed to determine the range and emission angle distributions of the up-going particle, corrected for detection and reconstruction efficiency. Measurements of the muon neutrino flux by underground detectors are often based on the observation of through-going and stopping muons produced in $\nu_\mu$ interactions in the rock below the detector. Up-going particles produced by an undetected down-going muon are a potential background source in these measurements. The implications of this background for neutrino studies using MACRO are discussed.Comment: 18 pages, 9 figures. Accepted by Astrop. Physic

Nuclearite search with the MACRO detector at Gran Sasso

In this paper we present the results of a search for nuclearites in the penetrating cosmic radiation using the scintillator and track-etch subdetectors of the MACRO apparatus. The analyses cover the beta =v/c range at the detector depth (3700 hg/cm^2) 10^-5 < beta < 1; for beta = 2 x 10^-3 the flux limit is 2.7 x 10^-16 cm^-2 s^-1 sr^-1 for an isotropic flux of nuclearites, and twice this value for a flux of downgoing nuclearites.Comment: 16 pages, 4 Encapsulated Postscript figures, uses article.sty. Submitted to The European Physical Journal

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

New MACRO results on atmospheric neutrino oscillations

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200

Moon and Sun shadowing effect in the MACRO detector

Using data collected by the MACRO experiment from 1989 to the end of its operations in 2000, we have studied in the underground muon flux the shadowing effects due to both the Moon and the Sun. We have observed the Moon shadowing effect with a significance of 6.5 sigma and the Sun shadowing effect with a significance of 4.3 sigma. The observed displacement of the Sun shadow, due to the configurations of the solar and interplanetary magnetic fields, has been used to quote the antiproton/proton flux limits for primaries of about 20 TeV energy.Comment: 23 pages, 11 figures, submitted to Astrop.Phy

SEARCH FOR SLOWLY MOVING MAGNETIC MONOPOLES WITH THE MACRO DETECTOR

A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6 x 10(-15) cm-2 sr-1 s-1 at 90% confidence level in the velocity range of 10(-4) less than or similar to beta < 4 x 10(-3). This result places a new constraint on the abundance of monopoles trapped in our solar system

EFEKTIVITAS PENGAWASAN UNIT KERJA ANTI FRAUD PADA BANK MUAMALAT INDONESIA

Perkembangan perbankan syari‟ah di Indonesia demikian pesat yang ditandai dengan berdirinya Bank Muamalat Indonesia. Perkembangan ini berimplikasi pada besarnya tantangan perbankan syari‟ah di Indonesia terutama dalam mempertahankan identitasnya sebagai perusahaan yang bergerak berlandaskan prinsip-prinsip syari‟ah. Sejak berdirinya perbankan syariah,berbagai kontroversi muncul dari masyarakat, masalah yang paling banyak disorot adalah pelekatan label syariah pada institusi keuangan Islam yang masih dianggap belum layak. Keraguan masyarakat tersebut seolah terjawab dengan munculnya kasus yang cukup menggemparkan yakni kasus fraud (tindak kecurangan) yang terjadi di lembaga syariah. Bank Muamalat Indonesia merupakan bank syari‟ah pertama yang muncul dengan gagasan bank murni syari‟ah. Akan tetapi, bank Muamalat Indonesia juga tak luput dari kasus fraud yang dilakukan oleh karyawan bank tersebut. Berdasarkan Laporan Tahunan BMI menyebutkan bahwa telah terjadi peningkatan kasus fraud dari tahun sebelumnya yang berjumlah 18 kasus menjadi 82 kasus pada tahun 2016. Padahal perusahaan yang menggunakan identitas syariah seharusnya dapat lebih meminimalisir bahkan meniadakan resiko terjadinya kasus fraud dengan adanya internal control perusahaan. Dari latar belakang tersebut, peneliti berusaha mendalami peran pengawasan Unit Kerja Anti Fraud dalam fraud preventive pada Bank Muamalat Indonesia. Penelitian ini merupakan penelitin pustaka yang bersifat deskriptif analisis dengan pendekatan kualitatif. Adapun sumber bahan hukum primer yang dipakai yaitu berdasarkan Laporan Tahunan Bank Muamalat Indonesia Tahun 2016. Sedangkan sumber bahan hukum sekunder berupa buku-buku, jurnal,karya ilmiah, artikel, terkait dengan strategi anti fraud perbankan syariah. Dari hasil penelitian dikemukakan bahwa peningkatan kasus fraud yang terjadi pada Bank Muamalat Indonesia disebabkan kurang efektifnya pengawasan Unit Kerja Anti Fraud. Hal ini dikarenakan kegiatan yang dilakukan selama tahun 2016 belum menujukkan adanya usaha preventif terhadap kasus fraud. Sedangkan pencegahan merupakan pilar penting dalam keefektivan sebuah pengawasan. Tujuan perusahaan dalam mencegah fraud dapat tercapai, jika fungsi pengawasan dilakukan sebelum terjadinya penyimpangan-penyimpangan sehingga lebih bersifat mencegah (prefentive control). Oleh karena itu, keefektivan pengawasan Unit Kerja Anti Fraud diharapkan dapat meminimalisir tindak kecurangan demi mewujudkan perusahaan yang patuh terhadap ketentuan syariah sesuai dengan identitas perusahaan. vii Usaha pencegahan terjadinya kasus pada Bank Muamalat Indonesia diharapkan dapat menjadi bukti terlaksananya tatakelola perusahaan (Good Corporate Governance) pada Bank Syari‟ah dengan baik. Hal ini berdasarkan dalam dalam perbankan syariah dikenal adanya prinsip-prinsip syariah yang mendukung bagi terlaksananya prinsip GCG yakni keharusan bagi subjek hukum termasuk bank untuk menerapkan prinsip kejujuran (shiddiq), edukasi kepada masyarakat (tabligh), kepercayaan (amanah), dan pengelolaan secara profesional (fathanah)