Dark Matter candidate in a Heavy Higgs Model - Direct Detection Rates

We investigate direct detection rates for Dark Matter candidates arise in a $SU(2)_L\times U(1)_Y$ with an additional doublet Higgs proposed by Barbieri, Hall and Rychkov. We refer this model as `Heavy Higgs Model'. The Standard Model Higgs mass comes out in this model very heavy adopting the few per cent chance that there is no Higgs boson mass below 200 GeV. The additional Higgs boson develops neither any VEV due to the choice of coefficient of the scalar potential of the model nor it has any coupling with fermions due to the incorporation of a discrete parity symmetry. Thus, the neutral components of the extra doublet are stable and can be considered as probable candidate of Cold Dark Matter. We have made calculations for three different types of Dark Matter experiments, namely, $^{76}$Ge (like GENIUS), DAMA (NaI) and XENON ($^{131}$Xe). Also demonstrated the annual variation of Dark Matter detection in case of all three detectors considered.Comment: 10 pages, 9 figures, figures unchanged, text modified, version to appear in Mod. Phys. Lett.

Effect of Salt Concentration on the Electrophoretic Speed of a Polyelectrolyte through a Nanopore

In a previous paper [S. Ghosal, Phys. Rev. E 74, 041901 (2006)] a hydrodynamic model for determining the electrophoretic speed of a polyelectrolyte through an axially symmetric slowly varying nanopore was presented in the limit of a vanishingly small Debye length. Here the case of a finite Debye layer thickness is considered while restricting the pore geometry to that of a cylinder of length much larger than the diameter. Further, the possibility of a uniform surface charge on the walls of the nanopore is taken into account. It is thereby shown that the calculated transit times are consistent with recent measurements in silicon nanopores.Comment: 4 pages, 2 figure

Anomaly Detection for Science DMZs Using System Performance Data

Science DMZs are specialized networks that enable large-scale distributed scientific research, providing efficient and guaranteed performance while transferring large amounts of data at high rates. The high-speed performance of a Science DMZ is made viable via data transfer nodes (DTNs), therefore they are a critical point of failure. DTNs are usually monitored with network intrusion detection systems (NIDS). However, NIDS do not consider system performance data, such as network I/O interrupts and context switches, which can also be useful in revealing anomalous system performance potentially arising due to external network based attacks or insider attacks. In this paper, we demonstrate how system performance metrics can be applied towards securing a DTN in a Science DMZ network. Specifically, we evaluate the effectiveness of system performance data in detecting TCP-SYN flood attacks on a DTN using DBSCAN (a density-based clustering algorithm) for anomaly detection. Our results demonstrate that system interrupts and context switches can be used to successfully detect TCP-SYN floods, suggesting that system performance data could be effective in detecting a variety of attacks not easily detected through network monitoring alone

Modulation of the local density of states within the dd-density wave theory in the underdoped cuprates

The low temperature scanning tunneling microscopy spectra in the underdoped regime is analyzed from the perspective of coexisting $d$-density wave and d-wave superconducting states. The calculations are carried out in the presence of a low concentration of unitary impurities and within the framework of the fully self-consistent Bogoliubov-de Gennes theory, which allows local modulations of the magnitude of the order parameters in response to the impurities. Our theory captures the essential aspects of the experiments in the underdoped BSCCO at very low temperatures.Comment: 4 pages, 4 eps figures, RevTex4. New added material as well as reference

Performance of well-known frequency reuse algorithms in LTE downlink 3GPP LTE systems

© 2015 IEEE. Intercell interference (ICI) is one of the major factors that limit the performance of wireless cellular network systems. Soft frequency reuse (SFR) as well as its modified algorithms such as Soft fractional frequency reuse (Soft FFR) and Distributed fractional frequency reuse (Distributed FFR) have been introduced as an effective way to optimize spectrum and control the ICI. However, the comparison between these algorithms has not fully been presented by the researchers proposing the models. This paper presents a comparison of the performance of well-known frequency reuse algorithms in term of system throughput, average packet loss ratio and average packet delay. The simulation results indicate that the simplest scheme, i.e. Soft FR, archives the highest system performance comparing to Soft FFR and Distributed FFR. Hence, it is noticed that one of the effective methods which optimize frequency reuse is to reduce the algorithm complexity

Lepton Flavor Violating Z Decays in the Zee Model

We calculate lepton flavor violating (LFV) Z decays Z \to {{e_i^\pm}}e_j^\mp (i, j = e, \mu, \tau ; i\neq j) in the Zee model keeping in view the radiative leptonic decays e_i\to e_j\gamma (i = \mu, \tau ; j = e, \mu ; i\neq j), \mu decay and anomalous muon magnetic moment (\mu AMM). We investigate three different cases of Zee f_{ij} coupling (A) f_{e\mu}^2 = f_{\mu\tau}^2= f_{\tau e}^2, (B) f_{e\mu}^2 \gg f_{\tau e}^2 \gg f_{\mu\tau}^2, and (C) f_{\mu\tau}^2 \gg f_{e\mu}^2 \gg f_{\tau e}^2 subject to the neutrino phenomenology. Interestingly, we find that, although the case (C) satisfies the large excess value of \mu AMM, however, it is unable to explain the solar neutrino experimental result, whereas the case (B) satisfies the bi-maximal neutrino mixing scenario, but confronts with the result of \mu AMM experiment. We also find that among all the three cases, only the case (C) gives rise to largest contribution to the ratio B(Z\to e^\pm\tau^\mp)/B(Z\to \mu^\pm \mu^\mp) \simeq {10}^{-8} which is still two order less than the accessible value to be probed by the future linear colliders, whereas for the other two cases, this ratio is too low to be observed even in the near future for all possible LFV Z decay modes.Comment: 12 pages, RevTex, 2 figures, 3 Tables, typos corrected, reference added, version to appear in Phys. Rev.

Long-term stability test of a triple GEM detector

The main aim of the study is to perform the long-term stability test of gain of the single mask triple GEM detector. A simple method is used for this long- term stability test using a radioactive X-ray source with high activity. The test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The details of the chamber fabrication, the test set-up, the method of measurement and the test results are presented in this paper.Comment: 8 pages, 5 figure