2,628 research outputs found
Controlled flavor violation in the MSSM from a unified flavor symmetry
We study the phenomenology of a unified supersymmetric theory with a flavor
symmetry . The model accommodates quark and lepton masses, mixing
angles and CP phases. In this model, the Dirac and Majorana mass matrices have
a unified texture zero structure in the entry that leads to the
Gatto-Sartori-Tonin relation between the Cabibbo angle and ratios of the masses
in the quark sectors, and to a natural departure from zero of the
angle in the lepton sector. We derive the flavor structures
of the trilinears and soft mass matrices, and show their general
non-universality. This causes large flavor violating effects. As a consequence,
the parameter space for this model is constrained, allowing it to be
(dis)proven by flavor violation searches in the next decade. Although the
results are model specific, we compare them to previous studies to show similar
flavour effects (and associated constraints) are expected in general in
supersymmetric flavor models, and may be used to distinguish them.Comment: 21 pages, 6 figure
The Chemical Composition of an Extrasolar Minor Planet
We report the relative abundances of 17 elements in the atmosphere of the
white dwarf star GD 362, material that, very probably, was contained previously
in a large asteroid or asteroids with composition similar to the Earth/Moon
system. The asteroid may have once been part of a larger parent body not unlike
one of the terrestrial planets of our solar system.Comment: ApJ, in pres
Leptogenesis in with a Universal Texture Zero
We investigate the possibility of viable leptogenesis in an appealing
model with a universal texture zero in the (1,1) entry. The model
accommodates the mass spectrum, mixing and CP phases for both quarks and
leptons and allows for grand unification. Flavoured Boltzmann equations for the
lepton asymmetries are solved numerically, taking into account both and
right-handed neutrino decays. The -dominated scenario is successful
and the most natural option for the model, with GeV,
and , which constrains the parameter space of the
underlying model and yields lower bounds on the respective Yukawa couplings.
Viable leptogenesis is also possible in the -dominated scenario, with the
asymmetry in the electron flavour protected from washout by the texture
zero. However, this occurs in a region of parameter space which has a stronger
mass hierarchy , and relatively close to , which
is not a natural expectation of the model.Comment: v2: 20 pages, 2 figures. Version accepted in JHE
An Italian expert consensus on the use of opioids for the management of chronic non-oncological pain in clinical practice: focus on buprenorphine
Purpose: The aim of the present work was to evaluate the knowledge and prescriptive habits of clinicians involved in the management of chronic non cancer pain (CNCP), with a special focus on the use of opioids. Methods: A Delphi method was used. A Board of specialists elaborated and discussed a series of statements, based on available literature and personal clinical expertise, about particularly controversial topics on pain pathophysiology and treatment. A Panel of experts in the field of pain management, selected by the Board, was invited to vote the proposed statements, indicating the level of agreement on a 5-point Likert scale (1: strongly disagree; 2: disagree; 3: partially agree; 4: agree; 5: strongly agree). The threshold for consensus was set at minimum 66.6% of the number of respondents with a level of agreement ≥4 (Agree or Strongly agree). Results: The Board included 5 pain therapists, 1 pharmacologist and 1 methodology expert and drew up a total of 36 statements (for a total of 40 requested answers)”. A total of 100 clinicians were included in the Expert Panel. Respondents were 89 (89%). Consensus was achieved for 32 out of 40 answers. Most of the lack of consensus was recorded for statements regarding opioids use, and resulted from a low level of agreement (3 on the Likert scale), suggesting a neutral position deriving from a lack of knowledge rather than a strong contrary opinion. Conclusion: Most of the proposed items reached consensus, suggesting a generally homogeneous approach to CNCP management. However, the lack of consensus recorded for several items regarding opioid use confirms the need to fill important gaps in the knowledge of available agents. A clear explanation of the peculiar pharmacological properties of drugs associated with potential clinical advantages (such as buprenorphine) will help optimize pain treatment in both primary care and hospital settings and improving pain control in CNCP patients
Muon and electron and lepton masses in flavor models
The stringent experimental bound on is compatible
with a simultaneous and sizable new physics contribution to the electron and
muon anomalous magnetic moments (), only if we
assume a non-trivial flavor structure of the dipole operator coefficients. We
propose a mechanism in which the realization of the correction is
manifestly related to the mass generation through a flavor symmetry. A
radiative flavon correction to the fermion mass gives a contribution to the
anomalous magnetic moment. In this framework, we introduce a chiral enhancement
from a non-trivial quartic coupling of the scalar potential.
We show that the muon and electron anomalies can be simultaneously explained in
a vast region of the parameter space with predicted vector-like mediators of
masses as large as ~TeV.Comment: 18 pages, 3 figures, 2 table
Implications of the Muon g-2 result on the flavour structure of the lepton mass matrix
The confirmation of the discrepancy with the Standard Model predictions in
the anomalous magnetic moment by the Muon g-2 experiment at Fermilab points to
a low scale of new physics. Flavour symmetries broken at low energies can
account for this discrepancy but these models are much more restricted, as they
would also generate off-diagonal entries in the dipole moment matrix.
Therefore, if we assume that the observed discrepancy in the muon is
explained by the contributions of a low-energy flavor symmetry, lepton flavour
violating processes can constrain the structure of the lepton mass matrices and
therefore the flavour symmetries themselves predicting these structures. We
apply these ideas to several discrete flavour symmetries popular in the
leptonic sector, such as , , and .Comment: 21 pages; v3: comments added, typos corrected, version accepted for
publication in EPJ
UAS FOR ARCHAEOLOGY. NEW PERSPECTIVES ON AERIAL DOCUMENTATION
In this work some Unmanned Aerial Systems applications are discussed and applied to archaeological sites survey and 3D model reconstructions. Interesting results are shown for three important and different aged sites on north Sardinia (Italy). An easy and simplified procedure has proposed permitting the adoption of multi-rotor aircrafts for daily archaeological survey during excavation and documentation, involving state of art in UAS design, flight control systems, high definition sensor cameras and innovative photogrammetric software tools. Very high quality 3D models results are shown and discussed and how they have been simplified the archaeologist work and decisions
Unusual Abundances from Planetary System Material Polluting the White Dwarf G238-44
Ultraviolet and optical spectra of the hydrogen-dominated atmosphere white
dwarf star G238-44 obtained with FUSE, Keck/HIRES, HST/COS, and HST/STIS reveal
ten elements heavier than helium: C, N, O, Mg, Al, Si, P, S, Ca, and Fe.
G238-44 is only the third white dwarf with nitrogen detected in its atmosphere
from polluting planetary system material. Keck/HIRES data taken on eleven
nights over 24 years show no evidence for variation in the equivalent width of
measured absorption lines, suggesting stable and continuous accretion from a
circumstellar reservoir. From measured abundances and limits on other elements
we find an anomalous abundance pattern and evidence for the presence of
metallic iron. If the pollution is from a single parent body, then it would
have no known counterpart within the solar system. If we allow for two distinct
parent bodies, then we can reproduce the observed abundances with a mix of
iron-rich Mercury-like material and an analog of an icy Kuiper Belt object with
a respective mass ratio of 1.7:1. Such compositionally disparate objects would
provide chemical evidence for both rocky and icy bodies in an exoplanetary
system and would be indicative of a planetary system so strongly perturbed that
G238-44 is able to capture both asteroid- and Kuiper Belt-analog bodies
near-simultaneously within its 100 Myr cooling age.Comment: Accepted to ApJ. 18 pages, 9 figures, 7 table
A Structured Approach to Insider Threat Monitoring for Offensive Security Teams
In many countries, government agencies resort to third parties to acquire security services of many kinds, including Red Team operations to test the effectiveness of own defenses mechanisms. Absolute trust is a key requirement, lest a potentially devastating finding be exploited by a treacherous Red Team against the same entity which commissioned the operation, or sold to its adversaries. In our endeavour as a joint private-academic initiative to address this peculiar market, we observed that a structured approach to this issue is much less common than we would have expected. In this work, we outline the process we are devising to offer customers a verified environment, but integrating it with an evidence-based proof of their correct behavior during the operation, striving to solve the “Quis custodiet ipsos custodes” struggle in an offensive setting
- …