This document summarizes the status of data preservation in high energy physics. The paradigms and the methodological advances are discussed from a perspective of more than ten years of experience ...with a structured effort at international level. The status and the scientific return related to the preservation of data accumulated at large collider experiments are presented, together with an account of ongoing efforts to ensure long-term analysis capabilities for ongoing and future experiments. Transverse projects aimed at generic solutions, most of which are specifically inspired by open science and FAIR principles, are presented as well. A prospective and an action plan are also indicated.
Status and prospects of the BaBar SVT Re, V.; Bruinsma, M.; Curry, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2006, Letnik:
560, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The
BaBaR Silicon Vertex Tracker (SVT) has been efficiently operated for five years since the start of data taking in 1999. It has met design requirements and no degradation in its performance has ...been observed thus far. However, because of higher than expected background levels, and anticipated further increases in luminosity and dose rates, we have done a thorough study to assess the viability of operating the SVT until the end of the decade.
The Silicon Vertex Tracker (SVT) of the BABAR experiment at SLAC is a crucial tool to measure with precision the decay position of B mesons produced in the PEP-II electron–positron collisions. It is ...structured in five layers made of double-sided, AC coupled silicon microstrip sensors. In this paper, a review of some of the technical solutions chosen in the detector design phase is presented. In particular, we focus here on those elements which turned out to be sources of problems during the installation and the first few years of operation; the solutions adopted to solve the problems are presented together with recommendations and proposals for alternate future designs.
Data preservation is a mandatory specification for any present and future experimental facility and it is a cost-effective way of doing fundamental research by exploiting unique data sets in the ...light of the continuously increasing theoretical understanding. This document summarizes the status of data preservation in high energy physics. The paradigms and the methodological advances are discussed from a perspective of more than ten years of experience with a structured effort at international level. The status and the scientific return related to the preservation of data accumulated at large collider experiments are presented, together with an account of ongoing efforts to ensure long-term analysis capabilities for ongoing and future experiments. Transverse projects aimed at generic solutions, most of which are specifically inspired by open science and FAIR principles, are presented as well. A prospective and an action plan are also indicated.
Using the entire BaBar $\Upsilon(4S)$ data set, the first two-dimensional
unbinned angular analysis of the semileptonic decay $\overline{B} \rightarrow D
\ell^- \overline{\nu}_\ell$ is performed, ...employing hadronic reconstruction of
the tag-side $B$ meson from $\Upsilon(4S)\to B\overline{B}$. Here, $\ell$
denotes the light charged leptons $e$ and $\mu$. A novel data-driven
signal-background separation procedure with minimal dependence on simulation is
developed. This procedure preserves all multi-dimensional correlations present
in the data. The expected $\sin^2\theta_\ell$ dependence of the differential
decay rate in the Standard Model is demonstrated, where $\theta_\ell$ is the
lepton helicity angle. Including input from the latest lattice QCD calculations
and previously available experimental data, the underlying form factors are
extracted using both model-independent (BGL) and dependent (CLN) methods.
Comparisons with lattice calculations show flavor SU(3) symmetry to be a good
approximation in the $B_{(s)}\to D_{(s)}$ sector. Using the BGL results, the
CKM matrix element $|V_{cb}|=(41.09\pm 1.16)\times 10^{-3}$ and the Standard
Model prediction of the lepton-flavor universality violation variable
$\mathcal{R}(D)=0.300\pm 0.004$, are extracted. The value of $|V_{cb}|$ from
$\overline{B} \rightarrow D \ell^- \overline{\nu}_\ell$ tends to be higher than
that extracted using $\overline{B} \rightarrow D \ell^- \overline{\nu}_\ell$.
The Standard Model $\mathcal{R}(D)$ calculation is at a $1.97\sigma$ tension
with the latest HFLAV experimental average.
BaBar forward endcap upgrade Anulli, F.; Baldini, R.; Calcaterra, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2005, Letnik:
539, Številka:
1
Journal Article
Recenzirano
The muon and neutral hadron detector (instrumented flux return or IFR) in the forward endcap of the BaBar detector at SLAC was upgraded by the installation of a new generation of resistive plate ...chambers (RPCs) and by increasing the absorber. The chamber replacement was made necessary by the rapid aging and efficiency loss of the original BaBar RPCs. Based on our experience with those original RPCs and 24 RPCs with thinner linseed oil treatments, improvements in the design, construction, and testing of the new generation RPCs were implemented and are described in detail.
PHYS. REV. D 107, 092001 (2023) A new mechanism has been proposed to simultaneously explain the presence of
dark matter and the matter-antimatter asymmetry in the universe. This scenario
predicts ...exotic $B$ meson decays into a baryon and a dark sector anti-baryon
($\psi_D$) with branching fractions accessible at $B$ factories. We present a
search for $B \rightarrow \Lambda \psi_D$ decays using data collected by the
$BABAR$ experiment at SLAC. This reaction is identified by fully reconstructing
the accompanying $B$ meson and requiring the presence of a single $\Lambda$
baryon in the remaining particles. No significant signal is observed, and
bounds on the $B \rightarrow \Lambda \psi_D$ branching fraction are derived in
the range $0.13 - 5.2\times 10^{-5}$ for $1.0 < m_{\psi_D} < 4.2$ GeV/$c^{2}$.
These results set strong constraints on the parameter space allowed by the
theory.
B a B ar silicon vertex tracker: Status and prospects Re, V.; Bondioli, M.; Bruinsma, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2006, Letnik:
569, Številka:
1
Journal Article
Recenzirano
The
B
a
B
ar Silicon Vertex Tracker (SVT) has been efficiently operated for six years since the start of data taking in 1999. Due to higher than expected background levels some unforeseen effects ...have appeared. We discuss: a shift in the pedestal for the channels of the AToM readout chips that are most exposed to radiation; an anomalous increase in the bias leakage current for the modules in the outer layers. Estimates of future radiation doses and occupancies are shown together with the extrapolated detector performance and lifetime, in light of the new observations.
The silicon vertex tracker (SVT) of the BaBar experiment at PEP-II is described. This is the crucial device for the measurement of the B meson decay vertices to extract charge-conjugation parity (CP) ...asymmetries. It consists of five layers of double-sided ac-coupled silicon strip detectors, read out by a full-custom integrated circuit, capable of simultaneous acquisition, digitization, and transmission of data. It represents the core of the BaBar tracking system, providing position measurements with a precision of 10 /spl mu/m (inner layers) and 30 /spl mu/m (outer layers). The relevant performances of the SVT are presented, and the experience acquired during the construction, installation, and the first five years of data-taking is described. Innovative solutions are highlighted, like the sophisticated alignment procedure, imposed by the design of the silicon tracker, integrated in the beamline elements and mechanically separated from the other parts of BaBar. The harshness of the background conditions in the interaction region required several studies on the radiation damage of the sensors and the front-end chips, whose results are presented. Over the next five years the luminosity is predicted to increase by a factor three, leading to radiation and occupancy levels significantly exceeding the detector design. Extrapolation of future radiation doses and occupancies is shown together with the expected detector performance and lifetime. Upgrade scenarios to deal with the increased luminosity and backgrounds are discussed.
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