119230166
Nondecoupling of charged scalars in Higgs decay to two photons and symmetries of the scalar potential
A large class of two- and three-Higgs-doublet models with discrete symmetries has been employed in the literature to address various aspects of flavor physics. We analyze how the precision measurement of the Higgs to diphoton signal strength would severely constrain these scenarios due to the nondecoupling behavior of the charged scalars, to the extent that in the presence of exact discrete symmetry, the number of additional noninert scalar doublets can be constrained no matter how heavy the nonstandard scalars are. We demonstrate that if the scalar potential is endowed with appropriate global continuous symmetries together with soft breaking parameters, decoupling can be achieved thanks to the unitarity constraints on the mass-square differences of the heavy scalars.
118444203
Scalar sector properties of two-Higgs-doublet models with a global U(1) symmetry
A bstractWe analyze the scalar sector properties of a general class of two-Higgs-doublet models which has a global U(1) symmetry in the quartic terms. We find constraints on the parameters of the potential from the considerations of unitarity of scattering amplitudes, the global stability of the potential and the ρ-parameter. We concentrate on the spectrum of the non-standard scalar masses in the decoupling limit which is preferred by the Higgs data at the LHC. We exhibit charged-Higgs induced contributions to the diphoton decay width of the 125 GeV Higgs boson and its correlation with the corresponding Zγ width.
119230769
Performance and First Physics Results of the ALICE Muon Spectrometer
Abstract A precise measurement of the heavy-flavor production cross-sections in pp collisions is an essential baseline for the heavy-ion program. In addition it is a crucial test of pQCD models in the new energy regime at LHC. ALICE measures the muons from the decay of charmonium resonances and from the semileptonic decay of heavy-flavored hadrons in its forward ( − 4.0 η − 2.5 ) Muon Spectrometer. We discuss the status of the detector and present results of data taken in pp collisions at s = 7 TeV .
118826722
IDENTICAL MESON INTERFEROMETRY IN STAR EXPERIMENT
The influence of Bose–Einstein statistics on multi-particle production characterized for various systems and energies by the STAR collaboration provides interesting information about the space-time dynamics of relativistic heavy-ion collisions at RHIC. We present the centrality and transverse mass dependence measurements of the two-pion interferometry in Au+Au collisions at and Cu+Cu collisions at and 200 GeV. We compare the new data with previous STAR measurements from p+p, d+Au and Au+Au collisions at . In all systems and centralities, HBT radii decrease with transverse mass in a similar manner, which is qualitatively consistent with collective flow. The scaling of the apparent freeze-out volume with the number of participants and charged particle multiplicity is studied. Measurements of Au+Au collisions at same centralities and different energies yield different freeze-out volumes, which mean that Npart is not a suitable scaling variable. The multiplicity scaling of the measured HBT radii is found to be independent of colliding system and collision energy.
121418091
Quantum fluctuations near a black-hole singularity
Abstract We present here an investigation of the problem of quantum fluctuations near a black-hole singularity. We show that quantum fluctuations do not vanish near the singularity leading to the conclusion that black-hole singularities are unlikely to exist.
120277549
Exact scalar and spinor solutions in the field of a stationary cosmic string
In this article exact solutions of the Klein–Gordon and Weyl equations in the field of a stationary cosmic string are presented.
120122435
QUANTUM EFFECTS NEAR THE BLACK HOLE SINGULARITY IN KRUSKAL SPACE-TIME
We show that the conclusion by Joshi and Joshi [Class. Quantum Grav.5, L191 (1988)] that there will be infinite quantum fluctuations as the singularity is approached in Kruskal space-time needs modification.