Observations of accreting pulsars
We summarize 5 years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20-70 keV observations have determined or refined the orbital parameters of 13 binaries, discovered five new transient accreting pulsars, measured the pulsed flux history during outbursts of 12 transients (GRO J1744-28, 4U 0115+634, GRO J1750-27, GS 0834-430, 2S 1417-624, GRO J1948+32, EXO 2030+375, GRO J1008-57, A0535+26, GRO J2058+42, 4U 1145-619, and A1118-616), and also measured the accretion torque history during outbursts of six of those transients whose orbital parameters were also known. We have also continuously measured the pulsed flux and spin frequency for eight persistently accreting pulsars (Her X-1, Cen X-3, Vela X-1, OAO 1657-415, GX 301-2, 4U 1626-67, 4U 1538-52, and GX 1+4). Because of their continuity and uniformity over a long baseline, BATSE observations have provided new insights into the long-term behavior of accreting magnetic neutron stars. We have found that all accreting pulsars show stochastic variations in their spin frequencies and luminosities, including those displaying secular spin-up or spin-down on long timescales, which blurs the conventional distinction between disk-fed and wind-fed binaries. Pulsed flux and accretion torque are strongly correlated in outbursts of transient accreting pulsars but are uncorrelated, or even anticorrelated, in persistent sources. We describe daily folded pulse profiles, frequency, and flux measurements that are available through the Compton Observatory Science Support Center at NASA/Goddard Space Flight Center.

title: On the Dramatic Spin-up/Spin-down Torque Reversals in Accreting Pulsars
abstract: Dramatic torque reversals between spin-up and spin-down have been observed in half of the persistent X-ray 
pulsars monitored by the BATSE all-sky monitor on the Compton Gamma Ray Observatory. Theoretical models 
developed to explain early pulsar timing data can explain spin-down torques via a disk-magnetosphere interaction 
if the star nearly corotates with the inner accretion disk. To produce the observed BATSE torque reversals, however, these equilibrium models require the disk to alternate between two mass accretion rates, with ˙M5 producing accretion torques of similar magnitude but always of opposite sign. Moreover, in at least one pulsar (GX 114) undergoing secular spin-down, the neutron star spins down faster during brief (~20 day) hard X-ray flares—this is opposite the correlation expected from standard theory, assuming that BATSE pulsed flux increases with mass accretion rate. The 10 day to 10 yr intervals between torque reversals in these systems are much longer than any characteristic magnetic or viscous timescale near the inner disk boundary and are more suggestive of a global disk phenomenon. 
 
We discuss possible explanations of the observed torque behavior. Despite the preferred sense of rotation defined by the binary orbit, the BATSE observations are urprisingly consistent with an earlier suggestion for GX 1+4: the disks in these systems somehow alternate between episodes of prograde and retrograde rotation. We are unaware of any mechanism that could produce a stable retrograde disk in a binary undergoing Roche lobe overflow, but such flip-flop behavior does occur in numerical simulations of wind-fed systems. One possibility is that the disks in some of these binaries are fed by an X-ray–excited wind.

title: Chandra Observations of the Anomalous X-ray Pulsar 4U 0142+61
abstract: We present X-ray imaging, timing, and phase-resolved spectroscopy of the anomalous X-ray pulsar 4U 0142+61 using the Chandra X-Ray Observatory. The spectrum is well described by a power-law plus blackbody model with Γ = 3.35(2), kTBB = 0.458(3) keV, and NH = 0.91(2) × 1022 cm-2; we find no significant evidence for spectral features (0.5-7.0 keV). Time-resolved X-ray spectroscopy shows evidence for evolution in phase in either Γ, kTBB, or some combination thereof as a function of pulse phase. We derive a precise X-ray position for the source and determine its spin period, P = 8.68866(30) s. We have detected emission beyond 4'' from the central source and extending beyond 100'', likely due to dust scattering in the interstellar medium.

title: Characterization of the Crab Pulsar's Timing Noise
abstract: We present a power spectral analysis of the Crab pulsar’s timing noise, mainly using radio measurements from Jodrell Bank taken over the period 1982-1989, an interval bounded by sparse data sampling and a large glitch. The power spectral analysis is complicated by nonuniform data sampling and the presence of a steep red power spectrum that can distort power spectra measurement by causing severe power “leakage”. We develop a simple windowing method for computing red noise power spectra of uniformly sampled data sets and test it on Monte Carlo generated sample realizations of red power-law noise. We generalize time-domain methods of generating power-law red noise with even integer spectral indices to the case of noninteger spectral indices. The Jodrell Bank pulse phase residuals are dense and smooth enough that an interpolation onto a uniform time series is possible. A windowed power spectrum is computed revealing a periodic or nearly periodic component with a period of 568± 10 days and a 1/f 3 power-law noise component in pulse phase with a noise strength Sφ = (1.24±0.067)×10−16 cycles/sec over the analysis frequency range f = 0.003 − 0.1 cycles/day. This result deviates from past analyses which characterized the pulse phase timing residuals as either 1/f 4 power-law noise or a quasiperiodic process. The analysis was checked using the Deeter polynomial method of power spectrum estimation that was developed for the case of nonuniform sampling, but has lower spectral resolution. The timing noise is consistent with a torque noise spectrum rising with analysis frequency as f implying blue torque noise, a result not predicted by current models of pulsar timing noise. If the periodic or nearly periodic component is due to a binary companion, we find a mass function f(M) = (6.8 ± 2.4) × 10−16 M⊙ and a companion mass, Mc ≥ 3.2M⊕ assuming a Crab pulsar mass of 1.4M⊙.

title: Large Torque Variations in Two Soft Gamma Repeaters
abstract: We have monitored the pulse frequencies of the two soft gamma repeaters SGR 1806-20 and SGR 1900+14 through the beginning of year 2001 using primarily Rossi X-Ray Timing Explorer Proportional Counter Array observations. In both sources, we observe large changes in the spin-down torque up to a factor of ~4, which persist for several months. Using long-baseline phase-connected timing solutions as well as the overall frequency histories, we construct torque noise power spectra for each SGR. The power spectrum of each source is very red (power-law slope ~-3.5). The torque noise power levels are consistent with some accreting systems on timescales of ~1 yr, yet the full power spectrum is much steeper in frequency than any known accreting source. To the best of our knowledge, torque noise power spectra with a comparably steep frequency dependence have been seen only in young, glitching radio pulsars (e.g., Vela). The observed changes in spin-down rate do not correlate with burst activity; therefore, the physical mechanisms behind each phenomenon are also likely unrelated. Within the context of the magnetar model, seismic activity cannot account for both the bursts and the long-term torque changes unless the seismically active regions are decoupled from one another.

title: Long-Term Spectral and Timing Behavior of the Black Hole Candidate XTE J1908+094
abstract: We present the long-term X-ray light curves and detailed spectral and timing analyses of XTE J1908+094 using the Rossi X-Ray Timing Explorer Proportional Counter Array observations covering two outbursts in 2002 and early 2003. At the onset of the first outburst, the source was found in a spectrally low/hard state lasting for ~40 days, followed by a 3 day long transition to the high/soft state. The source flux (in 2-10 keV) reached ~100 mcrab on 2002 April 6, then decayed rapidly. In power spectra, we detect strong band-limited noise and varying low-frequency quasi-periodic oscillations that evolved from ~0.5 to ~5 Hz during the initial low/hard state of the source. We find that the second outburst closely resembled the spectral evolution of the first. The X-ray transient's overall outburst characteristics led us to classify XTE J1908+094 as a black hole candidate. Here we also derive precise X-ray position of the source using Chandra observations that were performed during the decay phase of the first outburst and following the second outburst.

title: Search for new physics in events with same-sign dileptons and b jets in pp collisions at $ \sqrt{s}=8 $ TeV
abstract: A bstractA search for new physics is performed using events with isolated same-sign leptons and at least two bottom-quark jets in the final state. Results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 8 TeV with the CMS detector and corresponding to an integrated luminosity of 10.5 fb−1. No excess above the standard model background is observed. Upper limits are set on the number of events from non-standard-model sources and are used to constrain a number of new physics models. Information on acceptance and efficiencies is also provided so that the results can be used to confront an even broader class of new physics models.

title: Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at $ \sqrt{s}=7 $TeV
abstract: A bstractA search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 fb−1. Higgs boson decay modes to ττ and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H→ γγ and H→ b$ \overline{\mathrm{b}} $ decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV.

title: Search for light resonances decaying into pairs of muons as a signal of new physics
abstract: A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7TeV, and corresponding to an integrated luminosity of 35 pb−1. The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no excess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance areset, ranging from 0.1 to 0.5 pb at the 95% CL depending on event topology. In addition, the results are interpreted in several benchmark models in the context of supersymmetry with a new light dark sector exploring previously inaccessible parameter space.

title: Search for supersymmetry in hadronic final states with missing transverse energy using the variables alphaT and b-quark multiplicity in pp collisions at sqrt(s) = 8 TeV

title: Measurement of the Drell-Yan cross section in pp collisions at $ \sqrt {s} = 7 $ TeV
abstract: The Drell-Yan differential cross section is measured in pp collisions at $ \sqrt {s} = 7 $ TeV, from a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 36 pb−1. The cross section measurement, normalized to the measured cross section in the Z region, is reported for both the dimuon and dielectron channels in the dilepton invariant mass range 15–600 GeV. The normalized cross section values are quoted both in the full phase space and within the detector acceptance. The effect of final state radiation is also identified. The results are found to agree with theoretical predictions.