We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled ...particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.
Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, ...extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange
Λ
baryons, selected from weak decays of charm baryons produced in
p
p
collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of
C
P
T
symmetry can be performed by measuring the magnetic dipole moment of
Λ
and
Λ
¯
baryons. For short-lived
Λ
c
+
and
Ξ
c
+
baryons, to be produced in a fixed-target experiment using the 7
TeV
LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.
Electromagnetic dipole moments of short-lived particles are sensitive to physics within and beyond the Standard Model of particle physics but have not been accessible experimentally to date. To ...perform such measurements it has been proposed to exploit the spin precession of channeled particles in bent crystals at the LHC. Progress that enables the first measurement of charm baryon dipole moments is reported. In particular, the design and characterization on beam of silicon and germanium bent crystal prototypes, the optimization of the experimental setup, and advanced analysis techniques are discussed. Sensitivity studies show that first measurements of Λc+ and Ξc+ baryon dipole moments can be performed in two years of data taking with an experimental setup positioned upstream of the LHCb detector.
A novel method for the direct measurement of the elusive magnetic and electric dipole moments of the τ lepton is presented. The experimental approach relies on the production of τ^{+} leptons from ...D_{s}^{+}→τ^{+}ν_{τ} decays, originating in fixed-target collisions at the LHC. A sample of polarized τ^{+} leptons is kinematically selected and subsequently channeled in a bent crystal. The magnetic and electric dipole moments of the τ^{+} lepton are measured by determining the rotation of the spin-polarization vector induced by the intense electromagnetic field between crystal atomic planes. The experimental technique is discussed along with the expected sensitivities.
In this Erratum, an improved simulation of the channeling efficiency of protons and antiprotons as a function of the particle momentum is shown in for different configurations
We present the testbeam results of the first real-time embedded tracking system based on artificial retina algorithm. The tracking system prototype is capable of fast track reconstruction with a ...latency of the response below 1μs and track parameter resolutions that are comparable with the offline results. The artificial retina algorithm was implemented in hardware in a custom data acquisition board based on commercial FPGA. The system was tested successfully using a 180GeV/c proton beam at the CERN SPS with a maximum track rate of about 280kHz. Online track parameters were found in good agreement with offline results and with the simulated response.
•First real-time tracking system based on artificial retina algorithm tested on beam.•Fast track reconstruction within one microsecond latency and offline like quality.•Fast tracking algorithm implemented in commercial FPGAs.
Vertebral fractures occur in over 60% of newly diagnosed multiple myeloma (MM) patients and can cause pain, disability and poor quality of life. Antimyeloma therapy can lead to symptoms improvement, ...but these effects can take time to be perceived. Application of radiotherapy prior to peripheral blood stem cells (PBSC) mobilisation can impair stem cell collection. Percutaneous vertebroplasty has been proposed as a suitable option to rapidly relieve bone pain from vertebral fractures in MM patients, but, little is known about the effects of this procedure on subsequent PBSC mobilisation, collection and transplant. Eighteen patients (10M/8F, median age 64.5 years) with untreated MM and painful vertebral lesions underwent vertebroplasty prior to proceed to the planned transplant program at our Institution. Forty‐one procedures were performed at C2‐L5 levels, eight patients were treated at ≥2 levels. Ninety‐five per cent of the cases obtained a complete or optimal pain control. All the patients successfully mobilised PBSC (median CD34+ cells = 10.8 × 106/kg) and underwent autologous PBSC transplant; both polymorphonucleates and platelets recovery averaged 11 days. Our data seem to suggest that percutaneous vertebroplasty is useful in newly diagnosed MM patients with painful vertebral fractures as it allows rapid and durable achievement of pain control, without interfering with further treatment.
Chordoid glioma is a rare neoplasm occurring in the third ventricle and, as the name implies, having a chordoid appearance. It is currently considered a glial neoplasm of uncertain histogenesis with ...distinct clinicopathologic features. We report three cases of chordoid glioma with a focus on the ultrastructural appearance. The patients were two men and one woman aged, respectively, 34, 40, and 43 years. Immunohistochemically, all tumors showed strong and diffuse reactivity for glial fibrillary acidic protein and vimentin, whereas immunoreactivity for epithelial membrane antigen and cytokeratin was focal. Ultrastructurally, they showed features of ependymal differentiation for the presence of an apical pole with microvilli and a basal pole characterized, as in normal ependyma, by many hemidesmosomelike structures connecting cell membranes to the underlying basal lamina. Constant features were a submicroscopic cell body zonation (i.e., perinuclear, intermediate, subapical, and apical regions) and the presence of secretory granules. These findings were similar to those described for the secretory ependymal cells of the subcommissural organ, a small structure located in a dorsocaudal region of the third ventricle that undergoes regression after birth in humans. Our observations suggest that chordoid glioma may represent a subtype of ependymoma whose cells resemble the highly specialized ependyma of the subcommissural organ.
A narrow pentaquark state, Pc(4312)+, decaying to J/ψp, is discovered with a statistical significance of 7.3σ in a data sample of Λb0→J/ψpK− decays, which is an order of magnitude larger than that ...previously analyzed by the LHCb Collaboration. The Pc(4450)+ pentaquark structure formerly reported by LHCb is confirmed and observed to consist of two narrow overlapping peaks, Pc(4440)+ and Pc(4457)+, where the statistical significance of this two-peak interpretation is 5.4σ. The proximity of the Σc+D¯0 and Σc+D¯*0 thresholds to the observed narrow peaks suggests that they play an important role in the dynamics of these states.
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