116 research outputs found
Inclusive modes: polarized/unpolarized
The increasing number of flavour anomalies motivates the investigation of new
processes where tensions similar to the observed ones may emerge. It is
necessary to identify observables sensitive to physics beyond the Standard
Model. The analysis which follows concerns the inclusive semileptonic decays of
polarized beauty baryons, computed through the Heavy Quark Expansion at
and at the leading order in . New Physics
interactions have been taken into account, extending the Standard Model low-energy Hamiltonian, where and
, including the full set of operators with
left-handed neutrinos. Among the possible observables one can consider, the
ones depending on the spin of the decaying baryon are very appealing and can be
considered for physics programmes of future facilities, such as FCC-ee.Comment: 6 pages, 3 figures, contribution to QCD@Work - International Workshop
on QCD - Theory and Experiment, 27 - 30 June 202
Inclusive semileptonic decays in the Standard Model and beyond
Inclusive semileptonic decays of beauty baryons are studied using the heavy
quark expansion to , at leading order in . The
case of a polarized decaying baryon is examined, with reference to .
An extension of the Standard Model effective Hamiltonian inducing transitions ( and ) is
considered, which comprises the full set of D=6 semileptonic operators with
left-handed neutrinos. The effects of the new operators in several observables
are described.Comment: 50 pages, 12 figures. Corrected a typo in eq. (B.46
Flavour anomalies, correlations, hadronic uncertainties, and all that
We present a short overview of the so-called flavour anomalies, discussing
their significance and the connections with QCD issues discussed at the HADRON
2023 conference.Comment: LaTeX, 6 pages + references, 3 figures. Plenary talk at HADRON 2023,
Genova 5-9 June 2023. To appear in the proceeding
Dalitz decays
The Dalitz decays of the positive parity charmed mesons,
with and ,
are important processes to investigate the nature of the states.
We analyze the full set of decays, considering the four lightest
mesons as belonging to the heavy quark spin doublets and , with the
spin-parity of the light degrees of freedom in mesons. The description implies
relations among the observables in various modes. We study the decay
distributions in the dilepton invariant mass squared and the distributions in
the angle between the charged lepton momentum and the momentum of the produced
meson, which are expressed in terms of universal form factors and of effective
strong couplings. Such measurements are feasible at the present facilities.Comment: LaTeX, 23 pages, 6 figures. Version to appear on PR
A Modular Lunar Hotel
The aim of this paper is to propose an innovative modular lunar hotel/outpost that can be assembled
using the load capacity of future rockets Space X is at present developing and presumably will be opera-
tional by 2025. In particular, the design is based on the Space X' Starship, that will have the capability
to land large and heavy payloads on the Moon. The lunar building is essentially made of four cylindrical
modules assembled around one central distribution and service hub. These four modules, intended for
housing, have a geodesic dome with large windows to observe the lunar environment surrounding the
outpost. The entry point to the base is in the lower part of the central module, which is the only part of
the building touching the ground and rests on four adjustable legs. The central module will be used for
vertical connections and services as well as for hydroponic laboratories and greenhouses in which to grow
the food the settlers will eat. The whole structure will be about 15m high and will be protected from
cosmic radiation by a magnetic eld generated by a number of electric cables laid on a spherical structure
made of in
atable high pressure tubes. The modules can be made of light material since the protection
form radiation is supplied by the magnetic eld, and need only a thermal insulating layer, which can be
fairly light. The whole structure can thus be carried from Earth without the need of manufacturing it
on site. As an added advantage, large windows can be present, mainly in the a top domes/observatories,
which will be the characteristic elements of the installation. The cylindrical modules have a diameter
of 6m, suitable to be transported in the cargo hold of the Starship. To reach an height of 15m, they
are made in sections and then assembled on site. The modules will be lowered from the hold of the
Starship by means of the crane with which each spaceship is equipped. Before starting the assembly of
the modules, self-propelled cranes and vehicles will be carried to the Moon so that the construction site of
the hotel/outpost can be relatively distant from the landing area. These construction machines will then
remain available for other construction projects on the Moon. A total of about 10 launches are expected
to be required to carry to the Moon all parts needed to build the facility
Modular Lunar Hotel
The aim of this paper is to propose an innovative modular lunar hotel or outpost that can be assembled
using the load capacity of future rockets Space X is at present developing and presumably will be opera-
tional by 2025. In particular, the design is based on the Space X Starship, that will have the capability
to land large and heavy payloads on the Moon. The lunar building is essentially made of four cylindrical
modules assembled around one central distribution and service hub. These four modules, intended for
housing, have a geodesic dome with large windows to observe the lunar environment surrounding the
outpost. The entry point to the base is in the lower part of the central module, which is the only part of
the building touching the ground and rests on four adjustable legs. The central module will be used for
vertical connections and services as well as for hydroponic laboratories and greenhouses in which to grow
the food the settlers will eat. The whole structure will be about 15m high and will be protected from
cosmic radiation by a magnetic eld generated by a number of electric cables laid on a spherical structure
made of in a table high pressure tubes. The modules can be made of light materials since the protection
from radiation is supplied by the magnetic eld, and need only a thermal insulating layer, which can be
fairly light. The whole structure can thus be carried from Earth without the need of manufacturing it
on site. As an added advantage, large windows can be present, mainly in the a top domes/observatories,
which will be the characteristic elements of the installation. The cylindrical modules have a diameter
of 6m, suitable to be transported in the cargo hold of the Starship. To reach an height of 15m, they
are made in sections and then assembled on site. The modules will be lowered from the hold of the
Starship by means of the crane with which each spaceship is equipped. Before starting the assembly of
the modules, self-propelled cranes and vehicles will be carried to the Moon so that the construction site of
the hotel/outpost can be relatively distant from the landing area. These construction machines will then
remain available for other construction projects on the Moon. A total of about 10 launches are expected
to be required to carry to the Moon all parts needed to build the facility
Gleam: the GLAST Large Area Telescope Simulation Framework
This paper presents the simulation of the GLAST high energy gamma-ray
telescope. The simulation package, written in C++, is based on the Geant4
toolkit, and it is integrated into a general framework used to process events.
A detailed simulation of the electronic signals inside Silicon detectors has
been provided and it is used for the particle tracking, which is handled by a
dedicated software. A unique repository for the geometrical description of the
detector has been realized using the XML language and a C++ library to access
this information has been designed and implemented.Comment: 10 pages, Late
A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope
Globular clusters with their large populations of millisecond pulsars (MSPs)
are believed to be potential emitters of high-energy gamma-ray emission. Our
goal is to constrain the millisecond pulsar populations in globular clusters
from analysis of gamma-ray observations. We use 546 days of continuous
sky-survey observations obtained with the Large Area Telescope aboard the Fermi
Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular
clusters. Steady point-like high-energy gamma-ray emission has been
significantly detected towards 8 globular clusters. Five of them (47 Tucanae,
Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices and clear evidence for an exponential cut-off in the range
1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission
from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral
indices , however the presence of an exponential cut-off
can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC
6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral
properties. From the observed gamma-ray luminosities, we estimate the total
number of MSPs that is expected to be present in these globular clusters. We
show that our estimates of the MSP population correlate with the stellar
encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters,
commensurate with previous estimates. The observation of high-energy gamma-ray
emission from a globular cluster thus provides a reliable independent method to
assess their millisecond pulsar populations that can be used to make
constraints on the original neutron star X-ray binary population, essential for
understanding the importance of binary systems in slowing the inevitable core
collapse of globular clusters.Comment: Accepted for publication in A&A. Corresponding authors: J.
Kn\"odlseder, N. Webb, B. Pancraz
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