5,961 research outputs found

### Production of excited charmed mesons at LEP

Studies od the production of orbitally excited charmed and charmed strange
mesons in e+e- collisions, performed by the LEP collaborations are reviewed.
Measurements of the production rates of orbitally excited charmed mesons in
semileptonic b decays are presented. Searches for charmed meson radial
excitations are also briefly discussed.Comment: 4 pasges, 1 figure, HEP99 Tamper

### Review of B Physics Results from the LEP Experiments and SLD

A review of b physics results from the LEP experiments and SLD is presented.
Emphasis is given to the determination of the |Vcb| and |Vub| and to the study
of B meson oscillations, which yield bounds on the unitary triangle.Comment: 14 pages, 9 figures, KAON2001 COnference, Pisa, Italy, June 200

### Review of experimental results on neutral B meson oscillations

The current status of the experimental knowledge of neutral B meson
oscillation is reviewed. The B0d oscillation frequency is precisely measured by
SLD, CDF and the LEP experiments. An overview of the analyses and their
combination is presented. Preliminary measurements and perspectives at the
running B factories are also briefly discussed. The much faster B0s
oscillations have not yet been resolved, despite the progress recently by SLD
and ALEPH. The world combination is presented, together with the expected and
observed lower limit on the B0s oscillation frequency. The "amplitude method",
used to combine the analyses in order to set the limits, is discussed also as a
tool to establish the significance of a possible signal.Comment: 22 pages, 17 figures, Conference Heavy Quarks at Fixed target, Rio de
janeiro, Oct 9-19, 200

### The Bs oscillation amplitude analysis

The properties of the amplitude method for \Bs oscillation analyses are
studied in detail. The world combination of measured amplitudes is converted
into a likelihood profile as a function of oscillation frequency. A procedure
is proposed to estimate the probability that the minimum observed is due to a
statistical fluctuation. This method, applied to the data available at the time
of 1999 Winter Conferences, gives $1 - CL \approx 0.03$ .Comment: 27 pages, 16 figur

### Four Jets as a Probe of O(100 GeV) Physics beyond Standard Model at Hadron Colliders

O(100 GeV) physics beyond the standard model (BSM) could be overlooked
provided that it is hidden in the untouched Higgs sector or jets. The top quark
forward-backward asymmetry measurements and di-jet bump, which is observed in
the associated production with charged lepton plus missing energy (supposed
arising from W decay), may indicate the existence of a new color-octet
axial-vector Z_C with a mass about 145 GeV. Here Z_C only decays into two jets.
In this paper we investigated the possibility to discover Z_C pair via
analyzing the four jets as the final states, which are heavily polluted by huge
QCD background. Our simulation showed that, however, both Tevatron and LHC have
the excellent chance to discover Z_C through analyzing the four jets events in
the current accumulated data.Comment: 15 pages, 11figures and 2 table

### Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing

Limits on the Higgs boson mass restrict CKM mixing of a possible fourth
family beyond the constraints previously obtained from precision electroweak
data alone. Existing experimental and theoretical bounds on the Higgs mass
already significantly restrict the allowed parameter space. Zero CKM mixing is
excluded and mixing of order the Cabibbo angle is allowed. Upper and lower
limits on 3-4 CKM mixing are exhibited as a function of the Higgs mass. We use
the default inputs of the Electroweak Working Group and also explore the
sensitivity of both the three and four family fits to alternative inputs.Comment: Adds discussion of alternative fourth family masses, including new
best fit, and reconciles with published versio

### The $B_{s}$ oscillation amplitude analysis

The properties of the amplitude method for \Bs oscillation analyses are studied in detail. The world combination of measured amplitudes is converted into a likelihood profile as a function of oscillation frequency. A procedure is proposed to estimate the probability that the minimum observed is due to a statistical fluctuation. This method, applied to the data available at the time of 1999 Winter Conferences, gives $1 - CL \approx 0.03$ .The properties of the amplitude method for \Bs oscillation analyses are studied in detail. The world combination of measured amplitudes is converted into a likelihood profile as a function of oscillation frequency. A procedure is proposed to estimate the probability that the minimum observed is due to a statistical fluctuation. This method, applied to the data available at the time of 1999 Winter Conferences, gives $1 - CL \approx 0.03$

### Highlights of the SLD Physics Program at the SLAC Linear Collider

Starting in 1989, and continuing through the 1990s, high-energy physics
witnessed a flowering of precision measurements in general and tests of the
standard model in particular, led by e+e- collider experiments operating at the
Z0 resonance. Key contributions to this work came from the SLD collaboration at
the SLAC Linear Collider. By exploiting the unique capabilities of this
pioneering accelerator and the SLD detector, including a polarized electron
beam, exceptionally small beam dimensions, and a CCD pixel vertex detector, SLD
produced a broad array of electroweak, heavy-flavor, and QCD measurements. Many
of these results are one of a kind or represent the world's standard in
precision. This article reviews the highlights of the SLD physics program, with
an eye toward associated advances in experimental technique, and the
contribution of these measurements to our dramatically improved present
understanding of the standard model and its possible extensions.Comment: To appear in 2001 Annual Review of Nuclear and Particle Science; 78
pages, 31 figures; A version with higher resolution figures can be seen at
http://www.slac.stanford.edu/pubs/slacpubs/8000/slac-pub-8985.html; Second
version incorporates minor changes to the tex

### Top quark physics in hadron collisions

The top quark is the heaviest elementary particle observed to date. Its large
mass makes the top quark an ideal laboratory to test predictions of
perturbation theory concerning heavy quark production at hadron colliders. The
top quark is also a powerful probe for new phenomena beyond the Standard Model
of particle physics. In addition, the top quark mass is a crucial parameter for
scrutinizing the Standard Model in electroweak precision tests and for
predicting the mass of the yet unobserved Higgs boson. Ten years after the
discovery of the top quark at the Fermilab Tevatron top quark physics has
entered an era where detailed measurements of top quark properties are
undertaken. In this review article an introduction to the phenomenology of top
quark production in hadron collisions is given, the lessons learned in Tevatron
Run I are summarized, and first Run II results are discussed. A brief outlook
to the possibilities of top quark research a the Large Hadron Collider,
currently under construction at CERN, is included.Comment: 84 pages, 32 figures, accepted for publication by Reports on Progress
in Physic

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