Flavor physics of leptons and dipole moments Raidal, M.; van der Schaaf, A.; Bigi, I. ...
European physical journal. C, Particles and fields (Print),
09/2008, Letnik:
57, Številka:
1-2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector ...and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
We consider the production of singly charged Higgs bosons in the Higgs triplet and two Higgs doublet models. We evaluate the cross sections for the pair production and the single production of ...charged Higgs bosons at linear collider. The decay modes of
H
+
and the Standard Model backgrounds are considered. We analyze the possibilities to differentiate between the triplet and two Higgs doublet models.
A
bstract
The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far ...detector, in its first stage a 20 kt LAr double phase TPC and a magnetised iron calorimeter, situated at 2300 km from CERN and a near detector based on a highpressure argon gas TPC. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the
L/E
behaviour, and distinguishing effects arising from
δ
CP
and matter.
In this paper we have reevaluated the physics potential of this setup for determining the mass hierarchy (MH) and discovering CP-violation (CPV), using a conventional neutrino beam from the CERN SPS with a power of 750 kW. We use conservative assumptions on the knowledge of oscillation parameter priors and systematic uncertainties. The impact of each systematic error and the precision of oscillation prior is shown. We demonstrate that the first stage of LBNO can determine unambiguously the MH to
>
5
σ
C.L. over the whole phase space. We show that the statistical treatment of the experiment is of very high importance, resulting in the conclusion that LBNO has ~ 100% probability to determine the MH in at most 4-5 years of running. Since the knowledge of MH is indispensable to extract
δ
CP
from the data, the first LBNO phase can convincingly give evidence for CPV on the 3
σ
C.L. using today’s knowledge on oscillation parameters and realistic assumptions on the systematic uncertainties.
Several supersymmetric models with extended gauge structures predict light doubly-charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying its production ...and decay characteristics.
For over twenty-five years the DAMA/LIBRA experiment has reported an annual modulation signal that is consistent with a dark matter explanation. This signal is, currently, in tension with the null ...results observed by other searches that utilize different target detectors. The COSINUS experiment will perform a model-independent cross-check of the DAMA/LIBRA result by using the same target material, NaI crystals, operated as scintillating calorimeters. By measuring both temperature and light the NaI crystals in COSINUS will be able to distinguish between electron and nuclear recoils on an event-by-event basis. However, background events induced by cosmic-rays, environmental radioactivity or the intrinsic contamination of the materials used in the crystal, shielding and infrastructure can pose an issue to any analysis and must be fully understood. We report on the status of the development of the simulation for an active water Cherenkov muon veto, as well as the results of the beginning radiogenic material screening.
NaI(Tl) based scintillation detectors have become a staple in the field of direct dark matter searches, with the DAMA-LIBRA experiment being the standout for its reported observation of an annually ...modulating WIMP-like signal which is in direct contrast with other results. In order to accurately calibrate the energies of WIMP-induced nuclear recoil signals, precise measurements of the quenching factor of the NaI crystals are essential for each of these experiments, as it is well established that electron recoils and nuclear recoils have dissimilar scintillation light yields. In this contribution, we present first preliminary results of an ongoing systematic study that has been carried out by the COSINUS collaboration and Duke University to measure the quenching factor of Na recoils. Five ultra-pure NaI crystals, manufactured by the Shanghai Institute for Ceramics, each of which have varying Tl dopant concentrations, were irradiated with a mono-energetic neutron beam at the Triangle Universities National Laboratory, North Carolina, USA to extract the quenching factor values in the low recoil energies of 1-30keV
_{nr}
n
r
.
We study the single production of sneutrinos with two leptons (or jets) via γγ collision in an R-parity (Rp) violating supersymmetric model. The subsequent decays of the sneutrino are also ...considered. The single production of sneutrinos may provide a significant test of supersymmetry and Rp-violation with flavour conserving and flavour changing final states. If such processes coming from Rp violation are not detected, the parameter space of the model will be strongly constrained at the future linear collider.
We study the production of neutralinos and charginos at LEP and at a linear collider in the case of spontaneously broken R-parity. We first investigate the constraints on the single neutralino and ...chargino production from the LEP 1 experiments, and then we consider the production at LEP 2 and at a linear collider. We concentrate on the supersymmetric model, where the spontaneous R-parity breaking is inevitable and is associated with the breaking of the LR-symmetry.
We consider the lightest Higgs boson in naturally R-parity conserving supersymmetric left-right models. We obtain an upper bound on the tree-level mass of this lightest Higgs boson. This upper bound ...depends on the
SU(2)
L
and
SU(2)
R
gauge couplings, and the vacuum expectation values of bi-doublet Higgs fields, which are needed to break
SU(2)
L
×
U(1)
Y
. The upper bound does not depend on either the
SU(2)
R
breaking scale or the supersymmetry breaking scale. We evaluate the bound numerically by assuming that the theory remains perturbative up to some scale
Λ. We find that the bound can be considerably larger than in the minimal supersymmetric standard model (MSSM). The dominant radiative corrections to the upper bound due to top-stop and bottom-sbottom systems are of the same form as in the MSSM.
We obtain a relation between right-handed gauge boson mass and soft squark mass in naturally R-parity conserving general supersymmetric left-right models. This relation implies that either
W
R
is ...lighter than twice the soft squark mass, or a ratio of vacuum expectation values (VEVs) in the model, denoted by tan α, is close to its value of unity in the limit of vanishing
D-terms. Generally, we find that for heavy
W
R
tan α is larger than one, and that the right-handed sneutrino VEV, responsible for spontaneous
R-parity breaking, is at most of the order
M
SUSY
h
Δ
R
, where
M
SUSY is supersymmetry breaking scale and
h
Δ
R
is the Yukawa coupling in Majorana mass term for right-handed neutrinos. These constraints follow from
SU(3)
c
and
U(1)
em gauge invariance of the ground state of the theory.
PDF
