647 research outputs found
The seesaw path to leptonic CP violation
Future experiments such as SHiP and high-intensity colliders will
have a superb sensitivity to heavy Majorana neutrinos with masses below .
We show that the measurement of the mixing to electrons and muons of one such
state could imply the discovery of leptonic CP violation in the context of
seesaw models. We quantify in the minimal model the CP discovery potential of
these future experiments, and demonstrate that a 5 CL discovery of
leptonic CP violation would be possible in a very significant fraction of
parameter space.Comment: An error has been fixed, main conclusions unchange
Long-distance structure of the X(3872)
We investigate heavy quark symmetries for heavy meson hadronic molecules, and
explore the consequences of assuming the X(3872) and as an
isoscalar and an isovector hadronic molecules,
respectively. The symmetry allows to predict new hadronic molecules, in
particular we find an isoscalar bound state with a mass
about 10580 MeV and the isovector charmonium partners of the and
the states. Next, we study the
three body decay. This decay mode is more sensitive to the long-distance
structure of the X(3872) resonance than its and
decays, which are mainly controlled by the short distance part of the X(3872)
molecular wave function. We discuss the final state
interactions, which in some situations become quite important. Indeed in these
cases, a precise measurement of this partial decay width could provide precise
information on the interaction strength between the charm
mesons.Comment: Talk presented at the "XI International Conference on Hyperons, Charm
and Beauty Hadrons (BEACH 2014)", Birmingham (U.K.), July 201
Unitarity of the Leptonic Mixing Matrix
We determine the elements of the leptonic mixing matrix, without assuming
unitarity, combining data from neutrino oscillation experiments and weak
decays. To that end, we first develop a formalism for studying neutrino
oscillations in vacuum and matter when the leptonic mixing matrix is not
unitary. To be conservative, only three light neutrino species are considered,
whose propagation is generically affected by non-unitary effects. Precision
improvements within future facilities are discussed as well.Comment: Standard Model radiative corrections to the invisible Z width
included. Some numerical results modified at the percent level. Updated with
latest bounds on the rare tau decay. Physical conculsions unchange
Renormalization of chiral two pion exchange NN interactions with delta excitations: correlations in the partial wave expansion
In this work we consider the renormalization of the chiral two-pion exchange
potential with explicit delta-excitations for nucleon-nucleon scattering at
next-to-leading (NLO) and next-to-next-to-leading order (N2LO). Due to the
singular nature of the chiral potentials, correlations between different
partial waves are generated. In particular we show that two-body scattering by
a short distance power like singular attractive interaction can be renormalized
in all partial waves with a single counterterm, provided the singularities are
identical. A parallel statement holds in the presence of tensor interactions
when the eigenpotentials in the coupled channel problem also coincide. While
this construction reduces the total number of counterterms to eleven in the
case of nucleon-nucleon scattering with chiral two-pion exchange interactions
with delta degrees of freedom, the differences in the scattering phases as
compared to the case with the uncorrelated partial wave renormalization become
smaller as the angular momentum is increased in the elastic scattering region.Comment: 20 pages, 8 figures, a section has been added discussing cut-off
dependence. Accepted for publication in PR
Are there three Xi(1950) states?
Different experiments on hadron spectroscopy have long suspected the
existence of several cascade states in the region. They
are usually labeled under the common name of . As we argue here,
there are also theoretical reasons supporting the idea of several
resonances. In particular, we propose the existence of three
states: one of these states would be part of a spin-parity decuplet
and the other two probably would belong to the and
octets. We also identify which decay channels are the more appropriate for the
detection of each of the previous states.Comment: 5 pages, 3 tables, final version. Published in Phys. Rev. D 85,
017502 (2012
Thermodynamics of a black hole in a cavity
We present a unified thermodynamical description of the configurations
consisting on self-gravitating radiation with or without a black hole. We
compute the thermal fluctuations and evaluate where will they induce a
transition from metastable configurations towards stable ones. We show that the
probability of finding such a transition is exponentially small. This indicates
that, in a sequence of quasi equilibrium configurations, the system will remain
in the metastable states till it approaches very closely the critical point
beyond which no metastable configuration exists. Near that point, we relate the
divergence of the local temperature fluctuations to the approach of the
instability of the whole system, thereby generalizing the usual fluctuations
analysis in the cases where long range forces are present. When angular
momentum is added to the cavity, the above picture is slightly modified.
Nevertheless, at high angular momentum, the black hole loses most of its mass
before it reaches the critical point at which it evaporates completely.Comment: 27 pages, latex file, contains 3 figures available on request at
[email protected]
EURONU WP6 2009 yearly report: Update of the physics potential of Nufact, superbeams and betabeams
Many studies in the last ten years have shown that we can measure the unknown
angle theta13, discover leptonic CP violation and determine the neutrino
hierarchy in more precise neutrino oscillation experiments, searching for the
subleading channel nue -> numu in the atmospheric range. In this first report
of WP6 activities the following new results are reviewed: (1) Re-evaluation of
the physics reach of the upcoming generation of experiments to measure theta13
and delta; (2) New tools to explore a larger parameter space as needed beyond
the standard scenario; (3) Neutrino Factory: (a) evaluation of the physics
reach of a Nufact regards sterile neutrinos; (b) evaluation of the physics
reach of a Nufact as regards non-standard interactions; (c) evaluation of the
physics reach of a Nufact as regards violation of unitarity; (d) critical
assessment on long baseline tau-detection at Nufact; (e) new physics searches
at a near detector in a Nufact; (4) Beta-beams: (a) choice of ions and location
for a gamma = 100 CERN-based beta-beam; (b) re-evaluation of atmospheric
neutrino background for the gamma = 100 beta-beam scenario; (c) study of a two
baseline beta-beam; (d) measuring absolute neutrino mass with beta-beams; (e)
progress on monochromatic beta-beams; (5) Update of the physics potential of
the SPL super-beam. Eventually, we present an updated comparison of the
sensitivity to theta13, delta and the neutrino mass hierarchy of several of the
different proposed facilities.Comment: 2009 Yearly report of the Working Package 6 (Physics) of the EUROnu
FP7 EU project. 55 pages, 21 figures
Stochastic Norton-Simon-Massagu\ue9 Tumor Growth Modeling: Controlled and Mixed-Effects Uncontrolled Analysis
Tumorigenesis is a complex process that is heterogeneous and affected by numerous sources of variability. This study presents a stochastic extension of a biologically grounded tumor growth model, referred to as the Norton-Simon-Massagu\ue9 (NSM) tumor growth model. We first study the uncontrolled version of the model where the effect of chemotherapeutic drug agent is absent. Conditions on the model\u2019s parameters are derived to guarantee the positivity of the tumor volume and hence the validity of the proposed stochastic NSM model. To calibrate the proposed model we utilize a maximum likelihood- based estimation algorithm and population mixed-effect modeling formulation. The algorithm is tested by fitting previously published tumor volume mice data. Then, we study the controlled version of the model which includes the effect of chemotherapy treatment. Analysis of the influence of adding the control drug agent into the model and how sensitive it is to the stochastic parameters is performed both in open-loop and closed-loop viewpoints through different numerical simulations
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