116827931
DARK MATTER SEARCH BY THE DAMA EXPERIMENT
119701812
Signals from dark Universe: DAMA/LIBRA at LNGS
The DAMA/LIBRA set-up (about 250 kg highly radiopure NaI(Tl) sensitive mass) is running at the Gran Sasso National Laboratory of the INFN. The first DAMA/LIBRA results point out the presence of a dark matter particle component in the galactic halo, as well as the former DAMA/NaI set-up; cumulatively the data support such evidence at 8.2σ CL and satisfy all the peculiarities of the dark matter annual modulation signature.
17766827
Investigating electron interacting dark matter
Some extensions of the standard model provide dark matter candidate particles which can have a dominant coupling with the lepton sector of the ordinary matter. Thus, such dark matter candidate particles (chi(0)) can be directly detected only through their interaction with electrons in the detectors of a suitable experiment, while they are lost by experiments based on the rejection of the electromagnetic component of the experimental counting rate. These candidates can also offer a possible source of the 511 keV photons observed from the galactic bulge. In this paper this scenario is investigated. Some theoretical arguments are developed and related phenomenological aspects are discussed. Allowed intervals and regions for the characteristic phenomenological parameters of the considered model and of the possible mediator of the interaction are also derived considering the DAMA/NaI data.
117048271
First DAMA/LIBRA Results and Beyond
The DAMA project is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. Its main apparatus is the DAMA/LIBRA set-up, consisting of ≃250 kg highly radiopure NaI(Tl) detectors. Its first results — obtained by exploiting over four annual cycles the model independent annual modulation signature for Dark Matter (DM) particles — confirm by those of the former DAMA/NaI, supporting the evidence for Dark Matter presence in the galactic halo at 8.2 σ C.L.. The DAMA/NaI and DAMA/LIBRA data, in fact, satisfy all the many peculiarities of the DM annual modulation signature. Neither systematic effects nor side reactions able to account for the observed modulation amplitude and to contemporaneously satisfy all the several requirements of the DM signature are available. Future perspectives are also addressed.
118311956
DAMA investigations on Dark Matter at Gran Sasso: results and perspectives
The DAMA/NaI experiment (≃ 100 kg highly radiopure NaI(Tl)) at the Gran Sasso National Laboratory of the I.N.F.N. had the unique feature to effectively investigate the presence of Dark Matter particles in the galactic halo by exploiting the model independent annual modulation signature. A total exposure of more than 105 kg × day, collected over seven annual cycles, has pointed out at 6.3 σ C.L. an effect which satisfies all the many peculiarities of the signature. Neither systematics nor side reactions able to account for the observed effect were found. No experiment whose result can be directly compared in a model independent way with the experimental one of DAMA/NaI is available so far. Searches in space experiments are not in contradiction with DAMA/NaI. Several (but still few with respect to the possibilities) corollary model dependent quests for the candidate particle have also been carried out; others are in progress. At present the second generation DAMA/LIBRA set‐up (≃ 250 kg highly radiopure NaI(...
124862840
DIRECT DETECTION OF DARK MATTER PARTICLES
119292317
Connecting leptonic unitarity triangle to neutrino oscillation
The leptonic unitarity triangle (LUT) provides a geometric description of CP violations in the lepton-neutrino sector and is directly measurable in principle. In this paper, we reveal that the angles in the LUT have definite physical meaning, and demonstrate the exact connection of the LUT to neutrino oscillations. For the first time, we prove that these leptonic angles act as phase shifts in neutrino oscillations, by shifting Delta m(2)L/2E to Delta m(2)L/2E + alpha, where (L, E, alpha) denote the baseline length, neutrino energy and corresponding angle of the LUT. Each LUT has three independent parameters and contains only partial information of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix. We demonstrate that the partial information in each LUT can describe the corresponding neutrino oscillation. Hence, for the first time, we uncover that any given kind of neutrino oscillations contains at most three (rather than four) independent degrees of freedom from the PMNS matrix, and this may provide a cleaner way for fitting the corresponding oscillation data.
102507809
Natural electroweak symmetry breaking from scale invariant Higgs mechanism
We construct a minimal viable extension of the standard model (SM) with classical scale symmetry. Its scalar sector contains a complex singlet in addition to the SM Higgs doublet. The scale-invariant and CP-symmetric Higgs potential generates radiative electroweak symmetry breaking ` a la Coleman-Weinberg, and gives a natural solution to the hierarchy problem, free from fine-tuning. Besides the 125 GeV SM-like Higgs particle, it predicts a new CP-even Higgs (serving as the pseudo-Nambu-Goldstone boson of scale symmetry breaking) and a CP-odd scalar singlet (providing the dark matter candidate) at weak scale. We systematically analyze experimental constraints from direct LHC Higgs searches and electroweak precision tests, as well as theoretical bounds from unitarity, triviality and vacuum stability. We demonstrate the viable parameter space, and discuss implications for new Higgs and dark matter (DM) searches at the upcoming LHC runs and for the on-going direct detections of DM.
6985151
The Structure of electroweak corrections due to extended gauge symmetries
This paper studies models with extended electroweak gauge sectors of the form SU(2) x SU(2) x U(1) x [SU(2) or U(1)]. We establish the general behavior of corrections to precision electroweak observables in this class of theories and connect our results to previous work on specific models whose electroweak sectors are special cases of our extended group.
119110715
GeV SCALE ASYMMETRIC DARK MATTER FROM MIRROR UNIVERSE: DIRECT DETECTION AND LHC SIGNATURES
Mirror universe is a fundamental way to restore parity symmetry in weak interactions. It naturally provides the lightest mirror nucleon as a unique GeV-scale asymmetric dark matter particle candidate. We conjecture that the mirror parity is respected by the fundamental interaction Lagrangian, and its possible soft breaking arises only from non-interaction terms in the gauge-singlet sector. We realize the spontaneous mirror parity violation by minimizing the vacuum Higgs potential, and derive the corresponding Higgs spectrum. We demonstrate that the common origin of CP violation in the visible and mirror neutrino seesaws can generate the right amount of matter and mirror dark matter via leptogenesis. We analyze the direct detections of GeV-scale mirror dark matter by TEXONO and CDEX experiments. We further study the predicted distinctive Higgs signatures at the LHC.
17603783
Oblique Corrections in Deconstructed Higgsless Models
In this talk, using deconstruction, we analyze the form of the corrections to the electroweak interactions in a large class of ``Higgsless'' models of electroweak symmetry breaking, allowing for arbitrary 5-D geometry, position-dependent gauge coupling, and brane kinetic energy terms. Many models considered in the literature, including those most likely to be phenomenologically viable, are in this class. By analyzing the asymptotic behavior of the correlation function of gauge currents at high momentum, we extract the exact form of the relevant correlation functions at tree-level and compute the corrections to precision electroweak observables in terms of the spectrum of heavy vector bosons. We determine when nonoblique corrections due to the interactions of fermions with the heavy vector bosons become important, and specify the form such interactions can take. In particular we find that in this class of models, so long as the theory remains unitary, S - 4 c^2_W T > O(1), where S and T are the usual oblique parameters.