3,324 research outputs found
Measurement of the eta mass at KLOE
An integrated luminosity of 410 pb^(-1), corresponding to ~ 17 million of eta
events, has been analyzed to measure the eta mass using the decay eta to gamma
gamma. The measurement is insensitive to the calorimeter energy calibration and
the systematic error on the measurement is dominated by the uniformity of the
detector response. As a cross check of the method the pi0 mass from the decay
phi to pi0 gamma, pi0 to gamma gamma has been measured and it is in agreement
with the most accurate previous determinations. The result obtained is m(eta) =
547.873 +/- 0.007 (stat.) +/- 0.031 (syst.) MeV, that is today best measurement
of the eta mass.Comment: 7 pages, 8 figures, Contributed paper to Lepton Photon 200
Future circular collider studies
With the end of the High-Luminosity LHC (HL-LHC) run, the
physics potential of pp colliders at an energy of about 14 TeV will be completely exploited. Nevertheless important fundamental questions about the Standard Model, in case of missing evidences of new physics, still would need to be addressed. One possible option to continue the investiagtion of fundamental physics is the building up of higher-energy e+e− and pp machines. The physics potential and motivations
of such machines will be summarised in this contribution
SV-IV Peptide1–16 reduces coagulant power in normal Factor V and Factor V Leiden
Native Factor V is an anticoagulant, but when activated by thrombin, Factor X or platelet proteases, it becomes a procoagulant. Due to these double properties, Factor V plays a crucial role in the regulation of coagulation/anticoagulation balance
A prototype of fine granularity lead-scintillating fiber calorimeter with imaging read out
The construction and tests performed on a smal prototype of lead-scintillating fiber calorimeter instrumented with multianode photomultipliers are reported. The prototype is 15 cm wide, 15 radiation lenghts deep and is made of 200 layers of 50 cm long fibers. One side of the calorimeter has been instrumented with an array of 3 × 5 multianode R8900-M16 Hamamatsu photomultipliers, each segmented with a matrix of 4 × 4 anodes. The read-out granularity is 240 pixels 11 × 11 mm 2 reading about 64 fibers each. They are interfaced to the 6 × 6 mm 2 pixelled photocade with truncated pyramid light guides made of BC-800 plastic, UV transparent. Moreover each photomultiplier provides also the OR information of the last 12 dynodes. This information can be useful for trigger purposes. The response of the individual anodes, their relative gain and cross-talk has been measured with a 404 nm picosecond laser illuminating only a few fibers on the opposite side of the read-out. We also present first results of the calorimeter response to cosmic rays and electron beam data collected at BTF facility in Frascati
Pseudoscalar glueball and mixing
We have performed a dynamical analysis of the mixing in the pseudoscalar
channel with the goal of understanding the existence and behavior of the
pseudoscalar glueball. Our philosophy has not been to predict precise values of
the glueball mass but to exploit an adequate effective theory to the point of
breaking and to analyze which kind of mechanisms restore compatibility with
data. Our study has lead to analytical solutions which allow a clear
understanding of the phenomena. The outcome of our calculation leads to a large
mass glueball MeV, to a large glue content of the
and to mixing angles in agreement with previous numerical studies.Comment: 12 pages, 8 figure
Tuning Local Hydration Enables a Deeper Understanding of Protein-Ligand Binding: The PP1-Src Kinase Case
Water plays a key role in biomolecular recognition and binding. Despite the development of several computational and experimental approaches, it is still challenging to comprehensively characterize water-mediated effects on the binding process. Here, we investigate how water affects the binding of Src kinase to one of its inhibitors, PP1. Src kinase is a target for treating several diseases, including cancer. We use biased molecular dynamics simulations, where the hydration of predetermined regions is tuned at will. This computational technique efficiently accelerates the SRC-PP1 binding simulation and allows us to identify several key and yet unexplored aspects of the solvent's role. This study provides a further perspective on the binding phenomenon, which may advance the current drug design approaches for the development of new kinase inhibitors
An inhibitor of HIV-1 protease modulates constitutive eIF2α dephosphorylation to trigger a specific integrated stress response.
Inhibitors of the HIV aspartyl protease [HIV protease inhibitors (HIV-PIs)] are the cornerstone of treatment for HIV. Beyond their well-defined antiretroviral activity, these drugs have additional effects that modulate cell viability and homeostasis. However, little is known about the virus-independent pathways engaged by these molecules. Here we show that the HIV-PI Nelfinavir decreases translation rates and promotes a transcriptional program characteristic of the integrated stress response (ISR). Mice treated with Nelfinavir display hallmarks of this stress response in the liver, including α subunit of translation initiation factor 2 (eIF2α) phosphorylation, activating transcription factor-4 (ATF4) induction, and increased expression of known downstream targets. Mechanistically, Nelfinavir-mediated ISR bypassed direct activation of the eIF2α stress kinases and instead relied on the inhibition of the constitutive eIF2α dephosphorylation and down-regulation of the phophatase cofactor CReP (Constitutive Repressor of eIF2α Phosphorylation; also known as PPP1R15B). These findings demonstrate that the modulation of eIF2α-specific phosphatase cofactor activity can be a rheostat of cellular homeostasis that initiates a functional ISR and suggest that the HIV-PIs could be repositioned as therapeutics in human diseases to modulate translation rates and stress responses
Measurement of neutron detection efficiency between 22 and 174 MeV using two different kinds of Pb-scintillating fiber sampling calorimeters
We exposed a prototype of the lead-scintillating fiber KLOE calorimeter to
neutron beam of 21, 46 and 174 MeV at The Svedberg Laboratory, Uppsala, to
study its neutron detection efficiency. This has been found larger than what
expected considering the scintillator thickness of the prototype. %To check our
method, we measured also the neutron %detection efficiency of a 5 cm thick
NE110 scintillator. We show preliminary measurement carried out with a
different prototype with a larger lead/fiber ratio, which proves the relevance
of passive material to neutron detection efficiency in this kind of
calorimeters
Measurement of the neutron detection efficiency of a 80% absorber - 20% scintillating fibers calorimeter
The neutron detection efficiency of a sampling calorimeter made of 1 mm
diameter scintillating fibers embedded in a lead/bismuth structure has been
measured at the neutron beam of the The Svedberg Laboratory at Uppsala. A
significant enhancement of the detection efficiency with respect to a bulk
organic scintillator detector with the same thickness is observed.Comment: 10 pages, 7 figure
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