Belle experiment

File:Belle Central Drift Chamber.jpg.]]

The experiment was motivated by the search for CP-violation.{{Cite web|last1=Cheng|first1=M. T.|last2=Chu|first2=M. L.|last3=Wang|first3=C. H.|last4=Chen|first4=H. S.|last5=Li|first5=J.|last6=Zhu|first6=Y. C.|last7=Wang|first7=T. J.|last8=Yu|first8=Z. Q.|last9=Kawai|first9=H.|date=1994-01-01|title=Letter of intent for a study of CP violation in B meson decays|url=http://inspirehep.net/record/373239}} However the experiment also performed extensive studies of rare decays, searches for exotic particles and precision measurements of the properties of D mesons, and tau particles. The experiment has resulted in almost 300 publications in physics journals.

Highlights of the Belle experiment include

• an observation of large CP-violation in the neutral B meson system{{Cite journal|last1=Abe|first1=K.|last3=Abe|first3=R.|last4=Adachi|first4=I.|last5=Ahn|first5=Byoung Sup|last6=Aihara|first6=H.|last7=Akatsu|first7=M.|last8=Alimonti|first8=G.|last2=Asai|first2=K.|date=2001-08-14|title=Observation of Large CP Violation in the Neutral B Meson System|journal=Physical Review Letters|language=en|volume=87|issue=9|pages=091802|doi=10.1103/PhysRevLett.87.091802|pmid=11531561|issn=0031-9007|bibcode=2001PhRvL..87i1802A|arxiv = hep-ex/0107061 |s2cid=3197654}}
• measurement of the branching fraction of inclusive $B\backslash to\; X\_\{s\}\backslash gamma$ decays{{Cite journal|last1=Abe|first1=K.|last3=Adachi|first3=I.|last4=Ahn|first4=Byoung Sup|last5=Aihara|first5=H.|last6=Akatsu|first6=M.|last7=Alimonti|first7=G.|last8=Aoki|first8=K.|last2=Asai|first2=K.|date=2001-07-05|title=A measurement of the branching fraction for the inclusive B→Xsγ decays with the Belle detector|journal=Physics Letters B|volume=511|issue=2–4|pages=151–158|doi=10.1016/S0370-2693(01)00626-8|bibcode=2001PhLB..511..151B|arxiv = hep-ex/0103042 |s2cid=119360083}}
• observation of the $b\backslash to\; sl^+l^-$ transition with $B\; \backslash to\; K\; l^+\; l^-${{Cite journal|last1=Abe|first1=K.|last3=Abe|first3=R.|last4=Adachi|first4=I.|last5=Ahn|first5=Byoung Sup|last6=Aihara|first6=H.|last7=Akatsu|first7=M.|last8=Asano|first8=Y.|last2=Aso|first2=T.|year=2002|title=Observation of the Decay B → K l + l −|journal=Physical Review Letters|language=en|volume=88|issue=2|pages=021801|doi=10.1103/PhysRevLett.88.021801|pmid=11801003|issn=0031-9007|bibcode=2002PhRvL..88b1801A|arxiv = hep-ex/0109026 |s2cid=15298752}} and $B\; \backslash to\; K^*\; l^+\; l^-${{Cite journal|last1=Ishikawa|first1=A.|last2=Abe|first2=K.|last3=Abe|first3=K.|last4=Abe|first4=T.|last5=Adachi|first5=I.|last6=Ahn|first6=Byoung Sup|last7=Aihara|first7=H.|last8=Akai|first8=K.|last9=Akatsu|first9=M.|date=2003-12-24|title=Observation of B → K * ℓ + ℓ −|journal=Physical Review Letters|language=en|volume=91|issue=26|pages=261601|doi=10.1103/PhysRevLett.91.261601|pmid=14754037|issn=0031-9007|bibcode=2003PhRvL..91z1601I|arxiv = hep-ex/0308044 |s2cid=26236764}}
• measurement of $\backslash phi\_3$ using the $B\; \backslash to\; D\; K,\; D\; \backslash to\; K\_S\; \backslash pi^+\; \backslash pi^-$ Dalitz plot
• measurement of the CKM quark mixing matrix elements $|V\_\{ub\}|$ and $|V\_\{cb\}|$
• observation of direct CP-violation in $B^0\; \backslash to\; \backslash pi^+\; \backslash pi^-${{Cite journal|last1=Abe|first1=K.|last3=Abe|first3=N.|last4=Abe|first4=T.|last5=Adachi|first5=I.|last6=Aihara|first6=H.|last7=Akai|first7=K.|last8=Akatsu|first8=M.|last2=Akemoto|first2=M.|date=2004-07-06|title=Observation of Large C P Violation and Evidence for Direct C P Violation in B 0 → π + π − Decays|journal=Physical Review Letters|language=en|volume=93|issue=2|pages=021601|doi=10.1103/PhysRevLett.93.021601|pmid=15323897|issn=0031-9007|bibcode=2004PhRvL..93b1601A|arxiv = hep-ex/0401029 |s2cid=23736093}} and $B^0\; \backslash to\; K^-\; \backslash pi^+${{Cite journal|last1=Chao|first1=Y.|last2=Chang|first2=P.|last3=Abe|first3=K.|last4=Abe|first4=K.|last5=Abe|first5=N.|last6=Adachi|first6=I.|last7=Aihara|first7=H.|last8=Akai|first8=K.|last9=Akatsu|first9=M.|date=2004-11-05|title=Evidence for Direct C P Violation in B 0 → K + π − Decays|journal=Physical Review Letters|language=en|volume=93|issue=19|pages=191802|doi=10.1103/PhysRevLett.93.191802|pmid=15600826|issn=0031-9007|bibcode=2004PhRvL..93s1802C|arxiv = hep-ex/0408100 |s2cid=40785991}}
• observation of $b\; \backslash to\; d$ transitions{{Cite journal|last1=Mohapatra|first1=D.|last2=Nakao|first2=M.|last3=Nishida|first3=S.|last4=Abe|first4=K.|last5=Abe|first5=K.|last6=Adachi|first6=I.|last7=Aihara|first7=H.|last8=Anipko|first8=D.|last9=Arinstein|first9=K.|date=2006-06-09|title=Observation of b → d γ and Determination of {{!}} V t d / V t s {{!}}|journal=Physical Review Letters|language=en|volume=96|issue=22|pages=221601|doi=10.1103/PhysRevLett.96.221601|pmid=16803300|issn=0031-9007|bibcode=2006PhRvL..96v1601M|arxiv = hep-ex/0506079 |s2cid=7745694}}
• evidence for $B\; \backslash to\; \backslash tau\; \backslash nu${{Cite journal|last1=Ikado|first1=K.|last2=Abe|first2=K.|last3=Abe|first3=K.|last4=Adachi|first4=I.|last5=Aihara|first5=H.|last6=Akai|first6=K.|last7=Akemoto|first7=M.|last8=Anipko|first8=D.|last9=Arinstein|first9=K.|date=2006-12-22|title=Evidence of the Purely Leptonic Decay B − → τ − ν ¯ τ|journal=Physical Review Letters|language=en|volume=97|issue=25|pages=251802|doi=10.1103/PhysRevLett.97.251802|pmid=17280341|issn=0031-9007|bibcode=2006PhRvL..97y1802I|arxiv = hep-ex/0604018 |s2cid=37468451}}
• observations of a number of new particles including the X(3872){{Cite journal|last1=Choi|first1=S.-K.|last2=Olsen|first2=S. L.|last3=Abe|first3=K.|last4=Abe|first4=T.|last5=Adachi|first5=I.|last6=Ahn|first6=Byoung Sup|last7=Aihara|first7=H.|last8=Akai|first8=K.|last9=Akatsu|first9=M.|date=2003-12-23|title=Observation of a Narrow Charmoniumlike State in Exclusive B ± → K ± π + π − J / ψ Decays|journal=Physical Review Letters|language=en|volume=91|issue=26|pages=262001|doi=10.1103/PhysRevLett.91.262001|pmid=14754041|issn=0031-9007|bibcode=2003PhRvL..91z2001C|arxiv = hep-ex/0309032 |s2cid=1017547}}

The KEKB accelerator was the world's highest luminosity machine at the time.{{citation needed|date=April 2017}} A large fraction of the data was collected at the {{SubatomicParticle|Upsilon}}(4S). The instantaneous luminosity exceeded {{val|2.11|e=34|u=cm⁻²·s⁻¹}}. The integrated luminosity collected at the {{SubatomicParticle|Upsilon}}(4S) mass was about {{val|710|u=fb⁻¹}} (corresponding to 771 million {{SubatomicParticle|B}}{{SubatomicParticle|AntiB}} meson pairs). About 10% of the data was recorded below the {{SubatomicParticle|Upsilon}}(4S) resonance in order to study backgrounds. In addition, KEKB carried out special runs at the Upsilon meson resonance to study Strange B meson as well as on the Upsilon meson, Upsilon meson and Upsilon meson resonances to search for evidence of Dark Matter and the Higgs Boson. The samples of Upsilon meson, Upsilon meson and Upsilon meson collected by Belle are the world largest samples available.{{citation needed|date=April 2017}}

• B-factory
• B–Bbar oscillation

{{Commons category}}

• [http://belle.kek.jp Official Belle Website]
• [http://belle2.org Belle II Collaboration Website]
• [http://belle2.jp Belle II Public Website]
• Record for [https://inspirehep.net/experiments/1108579 KEK-BF-BELLE] Experiment on INSPIRE-HEP

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Category:Particle experiments

Category:B physics