1,859 research outputs found
NMSSM Higgs Discovery at the LHC
We demonstrate that Higgs discovery at the LHC is possible in the context of
the NMSSM even for those scenarios such that the only strongly produced Higgs
boson is a very SM-like CP-even scalar which decays almost entirely to a pair
of relatvely light CP-odd states. In combination with other search channels, we
are on the verge of demonstrating that detection of at least one of the NMSSM
Higgs bosons is guaranteed at the LHC for accumulated luminosity of .Comment: 8 pages, 1 figure, to appear in the Proceedings of the Les Houches
Workshop 2003: ``Physics at TeV Colliders'
Reinforcing the no-lose theorem for NMSSM Higgs discovery at the LHC
We show the potential of the LHC to detect a CP-even Higgs boson of the
NMSSM, or , decaying into two rather light CP-odd Higgs bosons,
, by exploiting the production mode based on Higgs-strahlung off
-quarks, i.e., the channel . We also consider the
case of decays. It is found that these decays have dominant
BRs over large regions of the NMSSM parameter space where tan is large,
a condition which also favours the production rates.
Further decays of the light Higgs boson pairs ( and ) into photon,
muon, tau and final states are also considered. The overall production and
decay rates for these processes at inclusive level are sizable and should help
extracting at least one Higgs boson signal over the NMSSM parameter space.Comment: 19 pages, 9 figures, added comments and corrected typo
The sustained post-outburst brightness of Nova Per 2018, the evolved companion, and the long orbital period
Nova Per 2018 (= V392 Per) halted the decline from maximum when it was 2mag
brighter than quiescence and since 2019 has been stable at such a plateau. The
ejecta have already fully diluted into the interstellar space. We obtained
BVRIgrizY photometry and optical spectroscopy of V392 Per during the plateau
phase and compared it with equivalent data gathered prior to the nova outburst.
We find the companion star to be a G9 IV/III and the orbital period to be
3.4118 days, making V392 Per the longest known period for a classical nova. The
location of V392 Per on the theoretical isochrones is intermediate between that
of classical novae and novae erupting within symbiotic binaries, in a sense
bridging the gap. The reddening is derived to be E(B-V)=0.72 and the fitting to
isochrones returns a 3.6 Gyr age for the system and 1.35 Msun, 5.3 Rsun, and 15
Lsun for the companion. The huge Ne overabundance in the ejecta and the very
fast decline from nova maximum both point to a massive white dwarf (M(WD) >=
1.1-1.2 Msun). The system is viewed close to pole-on conditions and the current
plateau phase is caused by irradiation of the CS by the WD still burning at the
surface.Comment: published in Astron.Astrophys. 639, L1
Exploring Sensitivity to NMSSM Signatures with Low Missing Transverse Energy at the LHC
We examine scenarios in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM), where pair-produced squarks and gluinos decay via two cascades, each
ending in a stable neutralino as Lightest Supersymmetric Particle (LSP) and a
Standard Model (SM)-like Higgs boson, with mass spectra such that the missing
transverse energy, , is very small. Performing
two-dimensional parameter scans and focusing on the hadronic decay giving a final state
we explore the sensitivity of a current LHC general-purpose
jets+ analysis to such scenarios.Comment: 17 pages, 17 figures, 6 table
A second black hole candidate in a M31 globular cluster is identified with XMM-Newton
We use arguments developed in previous work to identify a second black hole
candidate associated with a M31 globular cluster, Bo 144, on the basis of X-ray
spectral and timing properties. The 2002 XMM-Newton observation of the
associated X-ray source (hereafter XBo 144) revealed behaviour that is common
to all low-mass X-ray binaries (LMXBs) in the low-hard state. Studies have
shown that neutron star LMXBs exhibit this behaviour at 0.01-1000 keV
luminosities <=10% of the Eddington limit (L_Edd). However, the unabsorbed
0.3-10 keV XBo 144 luminosity was ~0.30 L_Edd for a 1.4 M_sun neutron star, and
the expected 0.01-1000 keV luminosity is 3-7 times higher. We therefore
identify XBo 144 as a black hole candidate. Furthermore, it is the second black
hole candidate to be consistent with formation via tidal capture of a mean
sequence donor in a GC; such systems were previously though non-existent,
because the donor was thought to be disrupted during the capture process.Comment: Accepted for publication in MRAS letters. Four pages, three figure
The nature and evolution of Nova Cygni 2006
AIMS: Nova Cyg 2006 has been intensively observed throughout its full
outburst. We investigate the energetics and evolution of the central source and
of the expanding ejecta, their chemical abundances and ionization structure,
and the formation of dust. METHOD: We recorded low, medium, and/or
high-resolution spectra (calibrated into accurate absolute fluxes) on 39
nights, along with 2353 photometric UBVRcIc measures on 313 nights, and
complemented them with IR data from the literature. RESULTS: The nova displayed
initially the normal photometric and spectroscopic evolution of a fast nova of
the FeII-type. Pre-maximum, principal, diffuse-enhanced, and Orion absorption
systems developed in a normal way. After the initial outburst, the nova
progressively slowed its fading pace until the decline reversed and a second
maximum was reached (eight months later), accompanied by large spectroscopic
changes. Following the rapid decline from second maximum, the nova finally
entered the nebular phase and formed optically thin dust. We computed the
amount of formed dust and performed a photo-ionization analysis of the
emission-line spectrum during the nebular phase, which showed a strong
enrichment of the ejecta in nitrogen and oxygen, and none in neon, in agreement
with theoretical predictions for the estimated 1.0 Msun white dwarf in Nova Cyg
2006. The similarities with the poorly investigated V1493 Nova Aql 1999a are
discussed.Comment: in press in Astronomy and Astrophysic
Growth of a vortex polycrystal in type II superconductors
We discuss the formation of a vortex polycrystal in type II superconductors
from the competition between pinning and elastic forces. We compute the elastic
energy of a deformed grain boundary, that is strongly non-local, and obtain the
depinning stress for weak and strong pinning. Our estimates for the grain size
dependence on the magnetic field strength are in good agreement with previous
experiments on NbMo. Finally, we discuss the effect of thermal noise on grain
growth.Comment: 4 pages, 2 figure
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