Papers by Franco Garibaldi
Nature Physics, 2021
Understanding the nucleon spin structure in the regime where the strong interaction becomes truly... more Understanding the nucleon spin structure in the regime where the strong interaction becomes truly strong poses a challenge to both experiment and theory. At energy scales below the nucleon mass of about 1 GeV, the intense interaction among the quarks and gluons inside the nucleon makes them highly correlated. Their coherent behaviour causes the emergence of effective degrees of freedom, requiring the application of non-perturbative techniques, such as chiral effective field theory [1]. Here, we present measurements of the neutron's generalized spin-polarizabilities that quantify the neutron's spin precession under electromagnetic fields at very low energy-momentum transfer squared down to 0.035 GeV 2. In this regime, chiral effective field theory calculations [2-4] are expected to be applicable. Our data, however, show a strong discrepancy with these predictions, presenting a challenge to the current description of the neutron's spin properties. The nucleon is the basic building block of nature, accounting for about 99% of the universe's
Nuclear Instruments and …, 1992
... [14, C Marchand, These, Uni-ers:te de Paris Sad (u;;puh-lished) 1987; and S. Turck-Chieze, Th... more ... [14, C Marchand, These, Uni-ers:te de Paris Sad (u;;puh-lished) 1987; and S. Turck-Chieze, These, universit de Paris Sud (unpub-lished) 1985. References. ... [14]C. Marchand, These, Université de Paris Sud (1987) (unpublished). S. Turck-Chieze, These (1985) (unpublished). ...
International Journal of STD & AIDS
We present a case of a 48-year-old white HIV-1 positive man who presented an acute myocardial inf... more We present a case of a 48-year-old white HIV-1 positive man who presented an acute myocardial infarction. The patient was on ART for the last ten years with emtricitabine/tenofovir and ritonavir-boosted fosamprenavir. Eplerenone 25 mg/day was also initiated due to a left ventricular dysfunction. A week after discharge a routine laboratory examination revealed severe hyperkalaemia. Due to suspicion of a potential drug–drug interaction, both eplerenone and ARVs were interrupted. Despite daily treatment for hyperkalaemia, serum potassium levels normalized after two weeks. Eplerenone is metabolized by the hepatic P450 cytochrome isoenzyme CYP3A4; therefore, concomitant administration with CYP3A4 inhibitors, like ritonavir, may increase plasma levels of eplerenone and, therefore, the risk of side effects, mainly hyperkalaemia. Based on this case, it is important to alert the medical community of this possible life-threatening drug-drug interaction between eplerenone and ritonavir-boosted...
International Journal of Radiation Oncology*Biology*Physics
Aps Meeting Abstracts, Oct 1, 2001
AIP Conference Proceedings, 1991
ABSTRACT
An experiment is proposed to measure the components of the recoil proton polarization in Real Com... more An experiment is proposed to measure the components of the recoil proton polarization in Real Compton Scattering (RCS) with longitudinally polarized incident photons. Measurements are proposed at s= 9 (GeV/c) 2 for two values of the θ cm p = 90 • and 110 •. The recent JLab RCS experiment, E99-114, demonstrated the feasibility of the experimental technique and produced a remarkable result. Namely, at s= 7 (GeV/c) 2 and θ cm p = 120 • , the longitudinal polarization is in agreement with the handbag description of the process in which the photons interact with a single quark, but is completely inconsistent with a pQCD mechanism which involves three active quarks mediated by two hard gluon exchanges. It is essential to have additional measurements at higher photon energy over a broader kinematic range in order to identify the factorization regime and the reaction mechanism. The experiment utilizes an untagged bremsstrahlung photon beam and the standard cryogenic target. The scattered photon is detected in the BigCal photon spectrometer, recently constructed and used by the GEP-III collaboration. The coincident recoil proton is detected in the Hall A magnetic spectrometer HRS-L or Hall C magnetic spectrometer HMS, and its polarization components are measured in the existing Focal Plane Polarimeters. With 508 hours of beam time in Hall A and 70 hours of beam time in Hall C, each of the three polarization observables, K LL , K LT , and P N , will be measured to a statistical accuracy of ±0.1 at each kinematic point. Such a measurement would be of crucial importance for understanding of the reaction mechanism for this simplest process involving real photon and it is essential base for understanding of other photo-induced exclusive reactions in the JLab energy range.
2008 IEEE Nuclear Science Symposium Conference Record, 2008
ABSTRACT As a step towards the realization of a γ-ray 8x8 modular imaging probe, the single pixel... more ABSTRACT As a step towards the realization of a γ-ray 8x8 modular imaging probe, the single pixel element has been extensively tested. It consists of a 6.1 mm2 x 3.7 mm CsI(Tl) scintillation crystal optically coupled to the backside of a 3.6 mm2 PiN diode on a 300 um fully depleted silicon wafer. The γ-ray detection system has been irradiated with the radio-isotopes: 241Am, 99mTc, 152Eu and 137Cs to span the energy range between 60 and 1400 keV. The linearity of the response is very good and the total conversion efficiency is 0.45. The dependence of the energy resolution on the electronic noise has been simulated and compared with experimental values. The intrinsic resolution of the crystal is about 6% and the ENC about 200 rms electrons. The resolution on the 140 keV line of the 99mTc and the 660 keV line of the 137Cs are 19% and 7.4%, respectively.
The introduction of a new gamma camera fully dedicated to scintimammography (Single Photon Emissi... more The introduction of a new gamma camera fully dedicated to scintimammography (Single Photon Emission Mammography--SPEM), and more recently with a full breast FoV, allowed to make clinical examination in cranio-caudal projection like in RXmammography, with breast mildly compressed. Such cameras are based on pixellated scintillation array and position sensitive photomultiplier (PSPMT). Reducing the collimator-tumor distance, the geometric spatial resolution and contrast was enhanced. Unfortunately, due to the scintimammographic low counting, poor contrast images are still obtained, in particular for small tumor.
We propose to perform deep inelastic electron scattering of the 3 H and 3 He mirror nuclei with t... more We propose to perform deep inelastic electron scattering of the 3 H and 3 He mirror nuclei with the 11 GeV upgraded beam of Jefferson Lab. The experiment will measure the EMC effect ratio for 3 H and 3 He and will determine the ratio of the neutron to proton inelastic structure functions, F n 2 /F p 2 , and the ratio of the down to up quark distributions in the nucleon, d/u, at medium and large Bjorken x. It will use a cryogenic 3 H and 3 He gas target system operating at 45 K and 15 atm, and the Hall A High Resolution Spectrometers. The required beam time is 31 days at a beam current of 70 µA. The F n 2 /F p 2 ratio will be extracted from the inelastic cross section ratio of the two nuclei by exploiting their mirror symmetry with a minimal theoretical correction. The F n 2 /F p 2 ratio is expected to be almost free of nuclear effects, which introduce a significant uncertainty in its extraction from deep inelastic scattering off the proton and deuteron. The results are expected to test perturbative and non-perturbative mechanisms of spin-flavor symmetry breaking in the nucleon, and constrain the structure function parametrizations needed for the interpretation of high energy hadron collider data. The precision of the expected data for the ratio of the EMC effect for 3 H and 3 He will offer a unique opportunity to test competing parametrizations and calculations of the EMC effect and will provide critical experimental input for the establishment of a unique canonical model for the explanation of its dynamical origin. The Collaboration intends to submit follow-up proposals for measurements of elastic and quasielastic scattering off 3 H at large momentum transfers. The latter measurements will complement similar existing or planned measurements off 3 He and will provide valuable data for our understanding of the structure and dynamics of the three-body nuclear systems.
Recent Achievements and Perspectives in Nuclear Physics - Proceedings of the 5th Italy-Japan Symposium, 2005
The first "systematic&am... more The first "systematic" study of 1 p shell hypernuclei with electromagnetic probes has started in Hall A at Jefferson Lab 5. The aim is to perform hypernuclear high resolution spectroscopy by the electroproduction of strangeness on four 1p-shell targets: 12C, 9Be, 16O, 7Li. The first part of the experiment on 12C and 9Be has been performed in 2004, the second
Proceedings of The IX International Conference on Hypernuclear and Strange Particle Physics, 2007
Results are presented from a new experiment (E94-107) in Hall A of the Thomas Jefferson National ... more Results are presented from a new experiment (E94-107) in Hall A of the Thomas Jefferson National Accelerator Facility (JLab) producing Boron-12-lambda using electroproduction, (e,eâ²K+). In the hypernuclear missing-mass spectrum the experiment achieves very good energy resolution (640 keV FWHM) by exploiting the characteristics of the High Resolution spectrometer pair and the exceptional beam quality available at JLab. The spectrometers were
IEEE Nuclear Science Symposuim & Medical Imaging Conference, 2010
... An endorectal PET-TOF MRI probe, designed here, allows for improved SNR and NECR with respect... more ... An endorectal PET-TOF MRI probe, designed here, allows for improved SNR and NECR with respect to standard imagers, providing better functional diagnosis of prostate diseases. ... This will allow significant reduction of noise allowing increasing of SNR/NECR.. ...
Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications - Proceedings of the 10th Conference, 2008
We have developed a compact, open, Dual Head pinhole SPECT system for high resolution molecular i... more We have developed a compact, open, Dual Head pinhole SPECT system for high resolution molecular imaging with radionuclides of mice, dedicated mainly to preclinical study of stem cells capability to recover myocardial infarction. The gamma detector is made of pinhole tungsten collimators, pixellated scintillators, matrix of multi-anode PMTs and individual channel readout. Measurements have been performed on phantoms and live
2011 IEEE Nuclear Science Symposium Conference Record, 2011
Prostate cancer (PC) is the most common disease in western countries and a leading cause of cance... more Prostate cancer (PC) is the most common disease in western countries and a leading cause of cancer death. Powerful techniques and instruments for diagnosis such as CT, MRI, PET/SPECT suffer from limited spatial resolution, sensitivity and/or specificity. Dedicated detectors and techniques are needed. For this reason a new INFN research project (TOPEM) started with the goal of designing, building and
2011 IEEE Nuclear Science Symposium Conference Record, 2011
In the framework of TOPEM (TOf PEt Mri) R&D program funded by Istituto Nazionale di Fisica Nuclea... more In the framework of TOPEM (TOf PEt Mri) R&D program funded by Istituto Nazionale di Fisica Nucleare (INFN, Italy) a readout system for a matrix of Silicon PhotoMultipliers (SiPM) has been developed. The overall project has been already presented elsewhere: here the main focus is on the readout system that is based on existing components, available in the physic research community. The electronic system completely handles a SiPM matrix made of up to 128 pixels, measuring both timing and charge information for each hit pixel. Although the device has been designed as dedicated unit for the TOPEM internal detector, a coincidence logic has been implemented, permitting to interface an external detector and trigger the data acquisition, implementing a complete, small angle TOF-PET system. The data acquisition is based on Linux PC, interfaced to the controller board using USB 2.0, running up to 25 MByte/s. Moreover, the controller can handle a 2 nd SiPM matrix (or other sensor such as Position Sensitive PhotoMultiplier-PSPMT) which can be used to build a more complicated detector (i.e. dual side scintillator readout for Depth Of Interaction measurement) or the external detector itself. The system is completely running and laboratory tests are ongoing. Finally, the logical "OR" of the outputs is provided for triggering purpose. The test card (Fig. 1 right) is intended to be put in the acquisition system shown, replacing the NINO card. 1) I.N.F.N. Genova-via Dodecaneso, 33-16146-GENOVA (I); 2) I.N.F.N. LNS CATANIA (I); 3) TUM, Muenchen (D); 4) I.N.F.N. BARI (I); 5) I.N.F.N. BOLOGNA (I); 6) INFN Roma1, ROMA (I); 7) Istituto Superiore di Sanità, ROMA, (I); 8) ENEA, ROMA, (I); 9) I.N.F.N. LECCE (I); 10) University of Rome La Sapienza, ROMA (I)
Uploads
Papers by Franco Garibaldi