Hi Frank, Peter,
I've got a short doctors appointment at 2:00 PM Eastern tomorrow, so I
wonder if we could meet at 2:30 PM Eastern instead of our usual 2:00 PM
time slot? If that doesn't work, then you two can go ahead and meet
at 2:00 PM as usual and I'll call in as soon as I get out of the
appointment. Peter has the chair code if needed.
Hopefully this week we'll finally get to discuss the new "exotic hadrons" result
from Belle that Frank suggested. The paper is http://arxiv.org/abs/1110.2251,
Dial-in is ReadyTalk 866-740-1260, code 3144955 at 2:30 PM Eastern (I hope).
Thank you,
--Ray
---------- Forwarded message ----------
Date: Tue, 10 Jan 2012 03:00:15 -0600 (CST)
From: Interactions News Wire <[log in to unmask]>
To: [log in to unmask]
Subject: [Interactions News Wire] #02-12 - KEK: Belle Discovers New Heavy
'Exotic Hadrons'
Interactions NewsWire #02-12
10 January 2012 http://www.interactions.org
*******************************************
Source: KEK
Content: Press Release
Date Issued: 10 January 2012
*******************************************
Belle Discovers New Heavy 'Exotic Hadrons'
Two unexpected new hadrons containing bottom quarks have been discovered
by the Belle Experiment using the High Energy Accelerator Research
Organization (KEK)'s B Factory (KEKB), a highly-luminous,
electron?positron collider. These new particles have electric charge and
are thought to be "exotic" hadrons -- non-standard hadrons, containing at
least four quarks. Previously, a series of new and unexpected exotic
hadrons containing charm and anti-charm quarks have been observed. This
latest discovery from Belle demonstrates the existence of exotic hadrons
containing at least four quarks in a particle system including bottom
quarks .
The Belle Experiment has discovered two new unexpected particles at the
KEK B Factory (KEKB). These new particles, termed Z(sub)b, contain both
one 'bottom' quark (the second-heaviest quark among the known six types of
quarks) and one 'anti-bottom' quark (the anti-particle of the bottom
quark). Moreover, they have electric charge and thus are thought to be
hadrons in which at least two additional quarks other than the bottom
quark and anti-bottom quark (at least four quarks in total) are bound
together.
A large amount of data containing particles produced in electron?position
collisions using the KEKB accelerator, which has achieved the world's
highest luminosity, has been obtained. While focusing on 'bottomonia,'
heavy mesons composed of one bottom quark and one anti-bottom quark, we
conducted a detailed analysis of events involving two types of bottomonia,
the Upsilon and the h(sub)b. This analysis revealed two new unanticipated
charged particles that decay into a bottomonium (Upsilon or h(sub)b) and a
charged pi meson (pi ±), which were then called "Z(sub)b(10610)" and
"Z(sub)b(10650)" according to their mass values, 10610 and 10650 MeV/c^2,
respectively. They are approximately eleven times heavier than a proton.
In principle, a bottomonium particle?s charge is zero; therefore, these
charged Z(sub)b particles should have at least two more quarks, e.g. one
'up' quark and one 'anti-down' quark.
Several hundred mesons have been identified to date. All of them are
thought to be bound states of one quark and one anti-quark, with the
binding provided via the strong interaction of elementary particles. Using
the KEKB accelerator, however, the Belle experiment has discovered more
than ten 'exotic hadrons,' including the X(3872), Y(3940), and Z(4430),
which were not anticipated by existing theories. These new particles,
which are about 4?4.5 times heavier than a proton, may be exotic hadrons
consisting of one 'charm' quark and one 'anti-charm' quark plus two more
different types of lighter quarks. These unexpected discoveries have
attracted the attention of researchers around the world. The latest
discovery has revealed the existence of exotic hadrons containing bottom
quarks, which are heavier than charm quarks.
The Belle B Factory experiment, which began in 1999 with the aim of
elucidating the origin of particle?anti-particle symmetry breaking (CP
violation), has contributed to the Nobel Prize in Physics in 2008 awarded
to Drs. Kobayashi and Maskawa. Moreover, data obtained from
electron?positron collisions with the world's highest luminosity achieved
at the KEKB accelerator have resulted in a series of unexpected
discoveries of exotic hadrons, opening a new research frontier in particle
physics. Data taking at the Belle Experiment has already been completed,
but a vast amount of data is still awaiting detailed analysis. Moreover,
an upgraded version of the KEKB/Belle Experiment, called SuperKEKB/Belle
II is currently being prepared. Belle II aims to collect 50 times more
data than the earlier experiment. Researchers are eagerly awaiting the
opportunity to explore the full spectrum of exotic hadrons containing
various types of quarks, including strange quarks, as well as charm and
bottom quarks, which are expected to be discovered in the future at the
SuperKEKB/Belle II Experiment. It is worth noting that quarks are bound by
the strong interaction and confined to composite particles, such as
mesons, and thus cannot exist individually as free particles. The detailed
exploration of exotic hadrons will advance the understanding of how and
what types of hadrons are possible based on the mechanisms defined by
quantum chromodynamics, which describes the strong interaction.
A paper reporting this achievement has been accepted for publication by
Physical Review Letters on December 30, 2011, and will be published
shortly.
Full release, with images and glossary, is available at:
http://www.kek.jp/intra-e/press/2012/011014/
Contact Information
About the details of the present study
Professor Yoshihide Sakai
Co-spokesperson, the Belle Collaboration
The High Energy Accelerator Research Organization
TEL: 81-29-864-5335
FAX: 81-29-864-5340
E-mail: [log in to unmask]
Professor Toru Iijima
Co-spokesperson, the Belle Collaboration
The Center for Experimental Studies, the Kobayashi?Maskawa Institute for
the Origin of Particles and the Universe, Nagoya University
TEL: 81-52-789-2893
FAX: 81-52-782-5752
E-mail: [log in to unmask]
Professor Thomas Browder
Co-spokesperson, the Belle Collaboration
University of Hawaii
TEL: 1-808-956-2936
FAX: 1-808-956-2930
E-mail: [log in to unmask]
Public relations
Yohei Morita
Public Relations Officer
The High Energy Accelerator Research Organization
TEL: 81-29-879-6047
FAX: 81-29-879-6049
E-mail: [log in to unmask]
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