7,984 research outputs found
Higgs Mass and Muon Anomalous Magnetic Moment in Supersymmetric Models with Vector-Like Matters
We study the muon anomalous magnetic moment (muon g-2) and the Higgs boson
mass in a simple extension of the minimal supersymmetric (SUSY) Standard Model
with extra vector-like matters, in the frameworks of gauge mediated SUSY
breaking (GMSB) models and gravity mediation (mSUGRA) models. It is shown that
the deviation of the muon g-2 and a relatively heavy Higgs boson can be
simultaneously explained in large tan-beta region. (i) In GMSB models, the
Higgs mass can be more than 135 GeV (130 GeV) in the region where muon g-2 is
consistent with the experimental value at the 2 sigma (1 sigma) level, while
maintaining the perturbative coupling unification. (ii) In the case of mSUGRA
models with universal soft masses, the Higgs mass can be as large as about 130
GeV when muon g-2 is consistent with the experimental value at the 2 sigma
level. In both cases, the Higgs mass can be above 140 GeV if the g-2 constraint
is not imposed.Comment: 26 pages; 7 figures; corrected typos; minor change
Measuring Muon Reconstruction Efficiency from Data
We suggest a method of measuring the global muon reconstruction efficiency epsilon directly from data, which largely alleviates uncertainties associated with our ability to monitor and reproduce in Monte Carlo simulation all details of the underlying detector performance. With the data corresponding to an integrated luminosity L = 10 fb^-1, the precision of measuring epsilon for muons in the P_T range of 10-100~GeV will be better than 1%
Probing the fourth generation Majorana neutrino dark matter
Heavy fourth generation Majorana neutrino can be stable and contribute to a
small fraction of the relic density of dark matter (DM) in the Universe. Due to
its strong coupling to the standard model particles, it can be probed by the
current direct detection experiments even it is a subdominant component of the
whole halo DM. Assuming that it contributes to the same fraction of the local
halo DM density as that of the DM relic density, we show that the current
Xenon100 data constrain the mass of the stable Majorana neutrino to be greater
than the mass of the top quark. In the mass range between 200 GeV and a few
hundred GeV, the effective spin-independent cross section for the neutrino
elastic scattering off nucleon is insensitive to the neutrino mass and is
predicted to be , which can be reached by the
direct DM search experiments soon. In the same mass region the predicted
effective spin-dependent cross section for the heavy neutrino scattering off
proton is in the range , which
is within the reach of the ongoing IceCube experiment. We demonstrate such
properties in a fourth generation model with the stability of the fourth
Majorana neutrino protected by an additional generation-dependent U(1) gauge
symmetry.Comment: 22 pages, 5 figures, discussions on collider searches included, to
appear in Phys. Rev.
CFRP Dimensional Stability Investigations for Use on the LISA Mission Telescope
The Laser Interferometer Space Antenna (LISA) is a mission designed to detect low frequency gravitational-waves. In order for LISA to succeed in its goal of direct measurement of gravitational waves, many subsystems must work together to measure the distance between proof masses on adjacent spacecraft. One such subsystem, the telescope, plays a critical role as it is the laser transmission and reception link between spacecraft. Not only must the material that makes up the telescope support structure be strong, stiff and light, but it must have a dimensional stability of better than 1 pm Hz(exp -1/2) at 3 mHz and the distance between the primary and the secondary mirrors must change by less than 2.5 micron over the mission lifetime. CFRP is the current baseline materiaL however, it has not been tested to the pico-meter level as required by the LISA mission. In this paper we present dimensional stability results, outgassing effects occurring in the cavity and discuss its feasibility for use as the telescope spacer for the LISA spacecraft
On the presentation of the LHC Higgs Results
We put forth conclusions and suggestions regarding the presentation of the
LHC Higgs results that may help to maximize their impact and their utility to
the whole High Energy Physics community.Comment: Conclusions from the workshops "Likelihoods for the LHC Searches",
21-23 January 2013 at CERN, "Implications of the 125 GeV Higgs Boson", 18-22
March 2013 at LPSC Grenoble, and from the 2013 Les Houches "Physics at TeV
Colliders" workshop. 16 pages, 3 figures. Version 2: Comment added on the
first publication of signal strength likelihoods in digital form by ATLA
Note: Silicon Carbide Telescope Dimensional Stability for Space-based Gravitational Wave Detectors
Space-based gravitational wave detectors are conceived to detect gravitational waves in the low frequency range by measuring the distance between proof masses in spacecraft separated by millions of kilometers. One of the key elements is the telescope which has to have a dimensional stability better than 1 pm Hz(exp 1/2) at 3 mHz. In addition, the telescope structure must be light, strong, and stiff. For this reason a potential telescope structure consisting of a silicon carbide quadpod has been designed, constructed, and tested. We present dimensional stability results meeting the requirements at room temperature. Results at 60 C are also shown although the requirements are not met due to temperature fluctuations in the setup
Silicon Carbide Telescope Investigations for the LISA Mission
Space-based gravitational wave (GW) detectors are conceived to detect GWs in the low frequency range (mili-Hertz) by measuring the distance between free-falling proof masses in spacecraft (SC) separated by 5 Gm. The reference in the last decade has been the joint ESA-NASA mission LISA. One of the key elements of LISA is the telescope since it simultaneously gathers the light coming from the far SC (approximately or equal to 100 pW) and expands, collimates and sends the outgoing beam (2 W) to the far SC. Demanding requirements have been imposed on the telescope structure: the dimensional stability of the telescope must be approximately or equal to 1pm Hz(exp1/2) at 3 mHz and the distance between the primary and the secondary mirrors must change by less than 2.5 micrometer over the mission lifetime to prevent defocussing. In addition the telescope structure must be light, strong and stiff. For this reason a potential on-axis telescope structure for LISA consisting of a silicon carbide (SiC) quadpod structure has been designed, constructed and tested. The coefficient of thermal expansion (CTE) in the LISA expected temperature range has been measured with a 1% accuracy which allows us to predict the shrinkage/expansion of the telescope due to temperature changes, and pico-meter dimensional stability has been measured at room temperature and at the expected operating temperature for the LISA telescope (around -6[deg]C). This work is supported by NASA Grants NNX10AJ38G and NX11AO26G
SUSY Survey with Inclusive Muon and Same-Sign Dimuon Accompanied by Jets and MET with CMS
Generic signatures of supersymmetry with R-parity conservation include those of single isolated muons or like-sign isolated dimuon pairs, accompanied with energetic jets and missing transverse energy. The ability of CMS to discover supersymmetry with these signals is estimated for 10 fb^{-1} of data collected with the inclusive single-muon and dimuon High-Level-Trigger paths. The selection criteria are optimized and the systematic effects are studied for a single low-mass benchmark point of the constrained MSSM with m_0 = 60,GeV/c^2, m_{1/2} = 250,GeVc^2, tan beta=10, A_0=0 and mu> 0. Discovery contours in the m_0, m_{1/2}) plane are presented for integrated luminosities ranging from 1 to 100, fb^{-1}
Potential to Discover Supersymmetry in Events with Muons, Jets and Missing Energy in pp Collisions at = 14 TeV with the CMS Detector
Generic signatures of supersymmetry with R-Parity conservation include those of single isolated muons or like-sign isolated dimuon pairs, accompanied with energetic jets and missing transverse energy. The ability of CMS to discover supersymmetry with these signals is estimated for 10 fb^-1 of collected data with the inclusive single- and di-muon High Level Trigger paths. The selection criteria are optimized and the systematic effects are studied for a single low-mass benchmark point of the constrained MSSM with m_0 = 60 GeV/c^2, m_1/2 = 250 GeV/c^2, tan beta = 10, A_0 = 0, and mu > 0. Discovery contours in the (m_0, m_1/2) plane are presented for integrated luminosities ranging from 1 to 100 fb^-1
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