89610769
Constraints on natural supersymmetry from electroweak precision tests
A bstractThe observed Higgs boson mass and the naturalness argument leave us a narrow window for the soft mass spectrum in natural supersymmetry that can be studied through the electroweak precision tests (EWPTs). We divide the analysis into the Higgs sector constrained by the charged Higgs mass bound, the neutralino-chargino sector constrained by the chargino mass bound, and the third-generation squark sector tightly constrained by the observed Higgs mass. Total contributions to EWPTs in the MSSM and NMSSM are both presented. It turns out that natural MSSM is excluded at 68% CL but consistent at 95% CL, whereas natural NMSSM with nearly degenerate conditions is excluded at 68% CL but consistent at 99% CL for λ ≤ 0.6.
117134726
Mass Hierarchies with $m_{h}=125$ GeV from Natural SUSY
Our study starts with a sequence of puzzles that include $(a)$ at which level $\mu$ problem involving electroweak symmetry breaking can be solved; $(b)$ in which paradigm masses of superpartners in the third family can be lighter than in the first two families; $(c)$ whether it is possible to accommodate 125 GeV Higgs boson simultaneously; and $(d)$ how natural such paradigm is. These issues are considered in the context of two-site SUSY models. Both the MSSM and NMSSM as low-energy effective theory below the scale of two-site gauge symmetry breaking are investigated. We find that the fine tuning can be indeed reduced in comparison with ordinary MSSM with $m_{h}=125$ GeV. In general, the fine tuning parameter $\Delta$ is in the range of $20-400$.
118398526
Phenomenologies of Higgs messenger models
In this paper, we investigate the phenomenologies of models where the Higgs sector plays the role of messengers in gauge mediation. The minimal Higgs sector and its extension are considered respectively. We find that there exist viable models when an appropriate parity is imposed. Phenomenological features in these kind of models include three approximate sum rules for scalar masses, light gluino as well as one-loop µ and two-loop Bµ terms.
15573749
R-symmetric Gauge Mediation With Fayet-Iliopoulos Term
We have studied R-symmetrc gauge mediation models with Fayet-Iliopoulos terms. We give a concrete example of hidden sector with an U(1)H gauge theory and a Fayet-Iliopoulos term, which can induce distinctive soft terms in the visible sector, and help solving fine tuning problems in models of R-symmetric gauge mediation.
119107259
Electroweak precision tests on the MSSM and NMSSM constrained at the LHC
A bstractFollowing previous works regarding electroweak precision tests in supersymmetry, we continue to explore their implications to the MSSM and NMSSM both of which are tightly constrained by the Higgs mass and its decay experiments at the LHC. We adopt universal squark, slepton mass of three generations, and A-term of all SM fermions. We determine the flows of both MSSM and NMSSM in the S-T plane with increasing tan β and/or γγ rate. Either increasing the value of Rγ or tan β, we find that the benchmark points tend to be pushed outside the contour at 99% CL in the MSSM, however, conversely they tend to shrink towards to the SM reference point in the NMSSM. In particular, our benchmark points suggest that tan β ≳ 50 is excluded at 99% CL by EWPTs for the MSSM in regions of parameter space which predict Rγ ≳ 1.3 due to this behavior. This behavior is also useful to distinguish the NMSSM from the MSSM. A byproduct is that the contributions coming from the neutralinos and charginos should be more suppressed in the MSSM in comparison with the NMSSM.
119198679
Variant supercurrents and linearized supergravity
In this paper, the variant supercurrents based on consistency and completion in off-shell supergravity are studied. We formulate the embedding relations for supersymmetric current and energy tensor into a supercurrent multiplet. Corresponding linearized supergravity is obtained with an appropriate choice of the Wess–Zumino gauge in each gravity supermultiplet.
110549737
Performance evaluation of a hit finding algorithm for the ICARUS detector
Abstract A procedure to filter the ICARUS digitized data is presented. The final multi-kiloton detector will provide raw data at a rate of the order of 100 Gbytes/s and therefore a crucial element of the acquisition chain will be the on-line data reduction system. A filter has been developed to process the signals and to tag the meaningful data. The hit detection efficiency has been evaluated on a sample of signals obtained from cosmic rays events in the 3 t ICARUS prototype. Its robustness has been tested also on simulated events with different signal to noise ratio. The hit finder hardware implementation is also presented.
120427724
ICARUS. A status report
Abstract The latest evolutions of the ICARUS project are reviewed. During the present year the collaboration has been heavily involved into the construction of the first full scale prototypes of the 600 ton ICARUS detector. Cryogenic and purification tests as well as mechanical tests on a wires chamber module, are presently under completion. No major problems were found and we foresee to be ready for the commissioning of the major detector components by the end of the present year. Also, the Long Baseline Neutrino Oscillation program has been subject to a rapid acceleration. Following our formal proposal, submitted and approved at the beginning of this year by the CERN SPSLC, a working group has been formed to study the details of the beam and a sensitive program has been formulated by which first neutrinos can be sent to the Gran Sasso at the end of year 2001.
13975142
Calibration of BC501A liquid scintillator cells with monochromatic neutron beams
Abstract The recoil proton energy response has been measured by exposing cylindrical cells, filled with BC501A BICRON liquid scintillator, to mono-energetic neutron reference fields. We determine the required calibration parameters and report the detailed procedures for the experimental data handling. A dedicated Monte Carlo simulation of the detector response and efficiency has been performed. It showed good agreement with the measured quantities. The results from this calibration are necessary for a detailed study of the neutron spectrum at the underground Gran Sasso Laboratory, with a neutron detector made of 32 liquid scintillator cells, like those used during the calibration.
122659739
The BES upgrade
Abstract The Beijing Spectrometer (BES) detector is a general purpose solenoid detector at the Beijing Electron Positron Collider (BEPC) in Beijing, China, that has collected large numbers of J/ψ, ψ′, D s , D and τ events. In this paper, we describe the recent upgrade of the initial BES detector (BESI) to the improved BESII detector.