On the Kinetic Energy and Radiative Efficiency of Gamma-Ray Bursts

Using measured X-ray luminosities to 17 Gamma-Ray Bursts (GRBs) during the afterglow phase and accounting for radiative losses, we calculate the kinetic energy of these bursts and investigate its relation to other GRB properties. We then use the observed radiated energy during the prompt phase to determine the radiative efficiency of these bursts, and explore how the efficiency relates to other GRB observables. We find that the kinetic energy in the afterglow phase is directly correlated with the radiated energy, total energy as well as possibly the jet opening angle and spectral peak energy. More importantly, we find the intriguing fact that the efficiency is correlated with the radiated energy, and mildly with the total energy, jet opening angle and spectral peak energy. XRF020903 also seems to follow the trends we find for our GRB sample. We discuss the implications of these results for the GRB radiation and jet models.Comment: 9 pages, 7 figures; Revised version, accepted to Ap

Effects of density-dependent quark mass on phase diagram of three-flavor quark matter

Considering the density dependence of quark mass, we investigate the phase transition between the (unpaired) strange quark matter and the color-flavor-locked matter, which are supposed to be two candidates for the ground state of strongly interacting matter. We find that if the current mass of strange quark $m_s$ is small, the strange quark matter remains stable unless the baryon density is very high. If $m_s$ is large, the phase transition from the strange quark matter to the color-flavor-locked matter in particular to its gapless phase is found to be different from the results predicted by previous works. A complicated phase diagram of three-flavor quark matter is presented, in which the color-flavor-locked phase region is suppressed for moderate densities.Comment: 4 figure

Standard convolution description of deuteron tensor spin structure

Spin-1 hadrons have additional structure functions not present for spin 1/2 hadrons. These could probe novel aspects of hadron structure and QCD dynamics. For the deuteron, the tensor structure function $b_1$ inherently mixes quark and nuclear degrees of freedom. These proceedings discuss two standard convolution models applied to calculations of the deuteron $b_1$ structure functions. We find large differences with the existing HERMES data and other convolution model calculations. This leaves room for non-standard contributions to $b_1$ in the deuteron. We also discuss the influence of higher twist nuclear effects in the model calculations and data extraction at kinematics covered in HERMES and Jefferson Lab.Comment: Proceedings of 25th International Workshop on Deep Inelastic Scattering and Related Topics, 3-7 April 2017 University of Birmingha

Qubit measurement using a quantum point contact with a quantum Langevin equation approach

We employ a quantum Langevin equation approach to establish non-Markovian dynamical equations, on a fully microscopic basis, to investigate the measurement of the state of a coupled quantum dot qubit by a nearby quantum point contact. The ensuing Bloch equations allow us to examine qubit relaxation and decoherence induced by measurement, and also the noise spectrum of meter output current with the help of a quantum regression theorem, at arbitrary bias-voltage and temperature. Our analyses provide a clear resolution of a recent debate concerning the occurrence of a quantum oscillation peak in the noise spectrum.Comment: 5 pages, 3 figures, submitted, published version in Phys. Rev.

Probing the Electroweak Phase Transition at the LHC

We study the correlation between the value of the triple Higgs coupling and the nature of the electroweak phase transition. We use an effective potential approach, including higher order, non-renormalizable terms coming from integrating out new physics. We show that if only the dimension six operators are considered, large positive deviations of the triple Higgs coupling from its Standard Model (SM) value are predicted in the regions of parameter space consistent with a strong first order electroweak phase transition (SFOEPT). We also show that at higher orders sizable and negative deviations of the triple Higgs coupling may be obtained, and the sign of the corrections tends to be correlated with the order of the phase transition. We also consider a singlet extension of the SM, which allows us to establish the connection with the effective field theory (EFT) approach and analyze the limits of its validity. Furthermore, we study how to probe the triple Higgs coupling from the double Higgs production at the LHC. We show that selective cuts in the invariant mass of the two Higgs bosons should be used, to maximize the sensitivity for values of the triple Higgs coupling significantly different from the Standard Model one.Comment: 43 pages, 4 figure

ALMA Observations of Ethyl Formate toward Orion KL

Orion KL is one of the prime templates of astrochemical and prebiotic chemical studies. We wish to explore more organic molecules with increasing complexity in this region. In particular, we have searched for one of the most complex organic molecules detected in space so far, ethyl formate (C$_{2}$H$_{5}$OCHO). This species is the next step in chemical complexity after the simplest member of esters (methyl formate, CH$_{3}$OCHO). The mechanisms leading to its formation are still poorly known. We have used high angular resolution ($\sim$ 1.$^{\prime\prime}$5) ALMA observations covering a large bandwidth from 214 to 247 GHz. We have detected 82 unblended lines of C$_{2}$H$_{5}$OCHO (49 and 33 of the trans and gauche conformers, respectively). The line images showed that C$_{2}$H$_{5}$OCHO arises mainly from the compact ridge and the hot core-southwest regions. The derived rotational temperatures and column densities are 122 $\pm$ 34 K, (0.9 $\pm$ 0.3) $\times$ 10$^{16}$ cm$^{-2}$ for the hot core-SW, and 103 $\pm$ 13 K, (0.6 $\pm$ 0.3) $\times$ 10$^{16}$ cm$^{-2}$ for the compact ridge. The comparison of spatial distribution and abundance ratios with chemically related molecules (methyl formate, ethanol and formic acid) indicates that C$_{2}$H$_{5}$OCHO is likely formed on the surface of dust grains by addition of CH$_{3}$ to functional-group radicals (CH$_{2}$OCHO) derived from methyl formate (CH$_{3}$OCHO)

Probing the birth of fast rotating magnetars through high-energy neutrinos

We investigate the high-energy neutrino emission expected from newly born magnetars surrounded by their stellar ejecta. Protons might be accelerated up to 0.1-100 EeV energies possibly by, e.g., the wave dissipation in the winds, leading to hadronic interactions in the stellar ejecta. The resulting PeV-EeV neutrinos can be detected by IceCube/KM3Net with a typical peak time scale of a few days after the birth of magnetars, making the characteristic soft-hard-soft behavior. Detections would be important as a clue to the formation mechanism of magnetars, although there are ambiguities coming from uncertainties of several parameters such as velocity of the ejecta. Non-detections would also lead to useful constraints on the scenario.Comment: 5 pages, 3 figures, accepted for publication in PR