Hi Gentlemen,
This week we'll discuss the new "exotic hadrons" result from Belle that
Frank suggested (see below). The paper ref is http://arxiv.org/abs/1110.2251,
and rumors in BaBar have it that the interactions newswire post appeared
once the preprint was accepted by PRL.
Dial-in is ReadyTalk 866-740-1260, code 3144955 at 2 PM Eastern as usual.
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]
>
> To unsubscribe from the Interactions News Wire, please email [log in to unmask] with "remove" in the subject line.
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