Extracting limits on dark matter annihilation from gamma ray observations towards dwarf spheroidal galaxies

Dwarf spheroidal galaxies compose one of the most dark matter dominated classes of objects, making them a set of targets to search for signals of dark matter annihilation. Recent developments in gamma-ray astronomy, most importantly the launch of the Fermi-LAT instrument, have brought those targets into attention. Yet, no clear excess of gamma-rays has been confirmed from these targets, resulting in some of the tightest limits on dark matter annihilation from indirect searches. In extracting limits from dwarf spheroidal galaxies, it is of great importance, to properly take into account all relevant uncertainties. Those include the dark matter distribution properties of the dwarf spheroidals and the uncertainties on the underlying background. We revisit the limits on dark matter annihilation, from gamma-rays studying a set of close-by dwarf spheroidal galaxies, for which, we have good understanding of the uncertainties in the dark matter distribution. For those targets, we perform and compare results for alternative methods in extracting the background gamma-ray flux. This provides a method to discriminate among the dark matter annihilation targets, those that can give robust constraints. We finally present our tightest limits on dark matter annihilation, that come only from the targets that ensure accurate understanding of both the gamma-ray background and the dark matter distribution uncertainties

Dark Matter in the Singlet Extension of MSSM: Explanation of Pamela and Implication on Higgs Phenomenology

As discussed recently by Hooper and Tait, the singlino-like dark matter in the Minimal Supersymmetric Standard Model (MSSM) extended by a singlet Higgs superfield can give a perfect explanation for both the relic density and the Pamela result through the Sommerfeld-enhanced annihilation into singlet Higgs bosons ($a$ or $h$ followed by $h->a a$) with $a$ being light enough to decay dominantly to muons or electrons. In this work we analyze the parameter space required by such a dark matter explanation and also consider the constraints from the LEP experiments. We find that although the light singlet Higgs bosons have small mixings with the Higgs doublets in the allowed parameter space, their couplings with the SM-like Higgs boson $h_{SM}$ (the lightest doublet-dominant Higgs boson) can be enhanced by the soft parameter $A_\kappa$ and, in order to meet the stringent LEP constraints, the $h_{SM}$ tends to decay into the singlet Higgs pairs $aa$ or $hh$ instead of $b\bar b$. So the $h_{SM}$ produced at the LHC will give a multi-muon signal, h_{SM} -> aa -> 4 muons or h_{SM} -> hh -> 4 a -> 8 muons.Comment: Version in JHE

Teachers’ Perception of Teaching and Learning During to Post Covid-19 Pandemic Era: A Case of Indonesian Mathematics Teachers

This study explores secondary school mathematics teachers’ perceptions of teaching and learning during to post the COVID-19 Pandemic. The Quantitative data were collected through a survey of 45 secondary school mathematics teachers (34 females and 11 males). Moreover, the qualitative data were collected through semi-structured interviews with four secondary school mathematics teachers (2 females and two males). The quantitative data were analysed statistically. Moreover, thematic analysis was used to analyse the qualitative data. The quantitative results indicate a significant connection between teachers’ difficulties in teaching and learning and their profiles: their school type, academic degree, and professional qualification. The secondary mathematics teachers of public schools faced more obstacles than the teachers of private schools. The qualitative analysis showed that five main instructional aspects might affect teaching and learning success during the pandemic era: learning modes, learning activities, learning media, learning tools, assessment, and time consumption

PAMELA, DAMA, INTEGRAL and Signatures of Metastable Excited WIMPs

Models of dark matter with ~ GeV scale force mediators provide attractive explanations of many high energy anomalies, including PAMELA, ATIC, and the WMAP haze. At the same time, by exploiting the ~ MeV scale excited states that are automatically present in such theories, these models naturally explain the DAMA/LIBRA and INTEGRAL signals through the inelastic dark matter (iDM) and exciting dark matter (XDM) scenarios, respectively. Interestingly, with only weak kinetic mixing to hypercharge to mediate decays, the lifetime of excited states with delta < 2 m_e is longer than the age of the universe. The fractional relic abundance of these excited states depends on the temperature of kinetic decoupling, but can be appreciable. There could easily be other mechanisms for rapid decay, but the consequences of such long-lived states are intriguing. We find that CDMS constrains the fractional relic population of ~100 keV states to be <~ 10^-2, for a 1 TeV WIMP with sigma_n = 10^-40 cm^2. Upcoming searches at CDMS, as well as xenon, silicon, and argon targets, can push this limit significantly lower. We also consider the possibility that the DAMA excitation occurs from a metastable state into the XDM state, which decays via e+e- emission, which allows lighter states to explain the INTEGRAL signal due to the small kinetic energies required. Such models yield dramatic signals from down-scattering, with spectra peaking at high energies, sometimes as high as ~1 MeV, well outside the usual search windows. Such signals would be visible at future Ar and Si experiments, and may be visible at Ge and Xe experiments. We also consider other XDM models involving ~ 500 keV metastable states, and find they can allow lighter WIMPs to explain INTEGRAL as well.Comment: 22 pages, 7 figure

Pengaruh Penambahan Kultur Azotobacter Pada Feses Kambing Terhadap Kualitas Media Dan Produktivitas Cacing Tanah (Lumbricus Rubellus)

The purposes of this research were to determine the effect of addition of Azotobacter bacterial culture into media of goat faeces on medium quality and earthworm productivity; and also to examine the best dose of Azotobacter bacterial cultures addition. The research material was 800 g earthworm aged 3 months old. The research method was experimental with Completely Randomized Design using 4 treatments and 4 replications. The results show that addition of Azotobacter bacterial culture had a significant effect (P&lt;0.01) on the medium quality and earthworm productivity (coccoon production, the number of juvenils per coccoon, coccoon hatching percentage, the numbers and weight of earthworm). The bacterial culture addition of 350 cc/100 kg goat faeces was found the best. We suggest to follow the study with observation about the effect of the length of fermentation to the medium quality and earthworm productivity

Sommerfeld enhancement from Goldstone pseudo-scalar exchange

We point out that the exchange of a Goldstone pseudo-scalar can provide an enhancement in the dark matter annihilation rate capable of explaining the excess flux seen in high energy cosmic ray data. The mechanism of enhancement involves the coupling of s and d waves through the tensor force that is very strong and, in fact, singular at short distances. The results indicate that large enhancements require some amount of fine tuning. We also discuss the enhancement due to other singular attractive potentials, such as WIMP models with a permanent electric dipole.Comment: 14 pages, 4 figures, v2 includes contact informatio

Level Berpikir Geometri Van Hiele Berdasarkan Gender pada Siswa Kelas VII SMP Islam Hasanuddin DAU Malang

Level of geomatri Van Hiele stated that a person will go through five level of development, those were; level 0 (visualization), level 1 (analysis), level 2 (informal deduction), level 3 (deduction), and level 4 (rigor). The purpose of this study was to determine and describe the Van Hiele geometric thinking levels by gender in class VII SMP Islam Hasanuddin Dau Malang. The method used in this research was descriptive qualitative. The instrument used was Van Hiele Geometry Test (VHGT) and interviews. The tests and interviews were conducted to 6 students which consited of 3 male and 3 female whose high, medium and low ability. The results showed that the student reached judging from the gender, female students whose high ability reached level 1 (analysis) while low ability female students were at level 0 (visualization). High ability male students were at level 1 (analysis) while male students whose low ability was at level 0 (visualization).Tahap perkembangan berpikir geomatri Van Hiele menyatakan bahwa seseorang akan melalui lima tahap perkembangan yaitu level 0 (visualisasi), level 1 (analisis), level 2 (deduksi informal), level 3 (deduksi), dan level 4 (rigor). Tujuan dari penelitian ini adalah untuk mengetahui dan mendeskripsikan level berpikir geometri Van Hiele berdasarkan gender pada siswa kelas VII SMP Islam Hasanuddin Dau Malang. Metode penelitian yang digunakan dalam penelitian ini adalah deskriptif kualitatif. Instrumen yang digunakan adalah tes berpikir geometri Van Hiele Geometry Test (VHGT) dan wawancara. Pemberian tes dan wawancara dilakukan kepada 6 orang siswa yaitu 3 siswa perempuan dan 3 siswa laki-laki yang masing-masing berkemampuan tinggi, sedang dan rendah. Hasil penelitian menunjukan bahwa ditinjau dari gender siswa perempuan berkemampuan tinggi dan sedang berada pada level 1 (analisis) sedangkan siswa perempuan berkemampuan rendah berada pada level 0 (visualisasi). Siswa laki-laki bekemampuan tinggi dan berada pada level 1 (analisis) sedangkan siswa laki-laki berkemampuan sedang dan rendah berada pada level 0 (visualisasi)

ASMARA DALAM LUKIS KACA BERLAPIS DENGAN PENCAHAYAAN LAMPU LED

Penelitian artistik yang berjudul “Asmara Dalam Lukis Kaca Berlapis Dengan Pencahayaan Lampu LED” ini merupakan penelitian kekaryaan yang dilakukan berdasarkan perkembangan seni lukis kaca dengan kaca berlapis sebagai media ekspresi.Menggabungkan seni dengan teknologi, menjadikan lukis kaca selain sebagai karya seni murni (fine art), sekaligus juga sebagai karya pakai (applied art). Menggunakan beberapa metode penelitian artistik (penciptaan seni), tahapantahapan tersebut antara lain: reset, eksperimen, perenungan, pembentukan kemudian hasil karya. Penelitian ini difokuskan pada penciptaan seni lukis kaca dengan kaca berlapis menggunakan pencahayaan Lampu LED dan mengangkat tema asmara (hubungan laki dan perempuan). Harapannya adalah dengan penciptaan karya seni lukis kaca ini selain untuk melakukan eksperimen atau eksplorasi untuk mencari kemungkinan-kemungkinan baru dalam penggabungan seni dengan teknologi, juga sebagai media untuk pelestarian budaya

Cosmic positron and antiproton constraints on the gauge-Higgs Dark Matter

We calculate the cosmic ray positron and antiproton spectra of a gauge-Higgs dark matter candidate in a warped five-dimensional $SO(5) \times U(1)$ gauge-Higgs unification model. The stability of the gauge-Higgs boson is guaranteed by the H parity under which only the Higgs boson is odd at low energy. The 4-point vertices of HHW^+W^- and HHZZ, allowed by H parity conservation, have the same magnitude as in the standard model, which yields efficient annihilation rate for $m_H > m_W$. The most dominant annihilation channel is $H H \to W^+ W^-$ followed by the subsequent decays of the $W$ bosons into positrons or quarks, which undergo fragmentation into antiproton. Comparing with the observed positron and antiproton spectra with the PAMALA and Fermi/LAT, we found that the Higgs boson mass cannot be larger than 90 GeV, in order not to overrun the observations. Together with the constraint on not overclosing the Universe, the valid range of the dark matter mass is restricted to 70-90 GeV.Comment: 13 pages, 3 figure