3,400 research outputs found
Recent results on charm from E831-FOCUS
E831-FOCUS is a photoproduction experiment which collected data during the
1996/1997 fixed target run at Fermilab. More than 1 million charm particles
have been reconstructed. Using this sample we measure the lifetimes of all the
weakly decaying singly charmed particles, establishing the charm lifetime
hierachy. Then we present recent results on semileptonic decays of charm
mesons, including the new s-wave inteference phenomena in D+ to K-pi+mu+nu, and
high statistics branching ratio and form factor measurements.Comment: Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP
Durham, April 2003 (eConf C0304052). 4 pages LaTeX, 2 eps figure
Charm Hadronic Decays From FOCUS: Lessons Learnt
The FOCUS photoproduction experiment took data in the ninenties and produced
a wealth of results in charm physics. Some of the studies were seminal for
contemporary experiments, and even paved the way for the technology of many
charm and beauty analysis tools.Comment: Presented by S.Bianco at CHARM2010, IHEP Beijing. Six pages, 2
figure
Search for the flavour-changing neutral current decay D0 to mu+mu- in pp collisions at sqrt(s) = 7 TeV with CMS
A search for the flavour-changing neutral current decay D0 to mu+mu- is
performed in pp collisions at sqrt(s) = 7 TeV using 90 pb-1 of data collected
by the CMS experiment at the LHC. No evidence is found for this decay mode. The
upper limit on the branching fraction B(D0 to mu+mu-) is 5.4x10-7 at the 90%
confidence level.Comment: to appear in the proceedings of The 5th International Workshop on
Charm Physics (Charm 2012
A study on the possible merits of using symptomatic cases to trace the development of the COVID-19 pandemic
In a recent work we introduced a novel method to compute the effective
reproduction number and we applied it to describe the development of the
COVID-19 outbreak in Italy. The study is based on the number of daily positive
swabs as reported by the Italian Dipartimento di Protezione Civile. Recently,
the Italian Istituto Superiore di Sanit\`a made available the data relative of
the symptomatic cases, where the reporting date is the date of beginning of
symptoms instead of the date of the reporting of the positive swab. In this
paper we will discuss merits and drawbacks of this data, quantitatively
comparing the quality of the pandemic indicators computed with the two samples
A simplified estimate of the Effective Reproduction Number using its relation with the doubling time and application to Italian COVID-19 data
A simplified method to compute , the Effective Reproduction Number, is
presented. The method relates the value of to the estimation of the
doubling time performed with a local exponential fit. The condition
corresponds to a growth rate equal to zero or equivalently an infinite doubling
time. Different assumptions on the probability distribution of the generation
time are considered. A simple analytical solution is presented in case the
generation time follows a gamma distribution.Comment: Submitted to: The European Physical Journal Plus. Revised version
according to reviewer's comment
Nonleptonic Decays and Lifetimes of b-quark and c-quark Hadrons
We review recent experimental results on lifetimes and hadronic decays of
hadrons that contain and quarks. The theoretical implications of these
results are also considered. An understanding of hadronic decays of heavy
quarks is required to interpret the CP violating asymmetries in decays that
will be observed in experiments planned for the near future.Comment: 74 pages, LATEX format with 12 figures. To appear in Annual Review of
Nuclear and Particle Science, Vol. 46. Also available at
http://www-physics.mps.ohio-state.edu/~phys111/b-physics/bphysics.html and by
anonymous ftp from ftp://pacific.mps.ohio-state.edu/pub/hepex/kh A serious
typographical error on p. 8 is corrected. Other errors and typos are also
correcte
A statistical analysis of death rates in Italy for the years 2015-2020 and a comparison with the casualties reported for the COVID-19 pandemic
We analyze the data about casualties in Italy in the period 01/01/2015 to
30/09/2020 released by the Italian National Institute of Statistics (ISTAT).
The data exhibit a clear sinusoidal behavior, whose fit allows for a robust
subtraction of the baseline trend of casualties in Italy, with a surplus of
mortality in correspondence to the flu epidemics in winter and to the hottest
periods in summer. While these peaks are symmetric in shape, the peak in
coincidence with the COVID-19 pandemics is asymmetric and more pronounced. We
fit the former with a Gaussian function and the latter with a Gompertz
function, in order to quantify number of casualties, the duration and the
position of all causes of excess deaths. The overall quality of the fit to the
data turns out to be very good. We discuss the trend of casualties in Italy by
different classes of ages and for the different genders. We finally compare the
data-subtracted casualties as reported by ISTAT with those reported by the
Italian Department for Civil Protection (DPC) relative to the deaths directly
attributed to COVID-19, and we discuss the differences.Comment: 16 pages, 13 figure
- …