{"created":"2023-06-20T13:20:39.684747+00:00","id":698,"links":{},"metadata":{"_buckets":{"deposit":"6345d908-38b7-4224-8644-1a7d23179c1a"},"_deposit":{"created_by":1,"id":"698","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"698"},"status":"published"},"_oai":{"id":"oai:ir.soken.ac.jp:00000698","sets":["2:428:16"]},"author_link":["0","0","0"],"item_1_creator_2":{"attribute_name":"著者名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"中澤, 秀介"}],"nameIdentifiers":[{}]}]},"item_1_creator_3":{"attribute_name":"フリガナ","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"ナカザワ, ヒデユキ"}],"nameIdentifiers":[{}]}]},"item_1_date_granted_11":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2005-03-24"}]},"item_1_degree_grantor_5":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"総合研究大学院大学"}]}]},"item_1_degree_name_6":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（理学）"}]},"item_1_description_12":{"attribute_name":"要旨","attribute_value_mlt":[{"subitem_description":"　We have measured π<SUP>+</SUP>π<SUP>-</SUP> and K<SUP>+</SUP>K<SUP>-</SUP> production in two-photon collisions using 87.7fb<SUP>-1</SUP> of data collected with the Belle detector at the asymmetric energy e<SUP>+</SUP>e-<SUP>-</SUP> collidor KEKB. The cross sections are measured to high precision in the two-photon center-of-mass energy (W) range of 2.4 GeV < W < 4.1 GeV and angular region of |cosθ*| < 0.6. The cross section ratio σ(γγ → K<SUP>+</SUP>K<SUP>-</SUP>) /σ(γγ → π<SUP>+</SUP>π<SUP>-</SUP>) is measured to be 0.89 ± 0.04 ± 0.15 in the range of 3.0 GeV < W < 4.1 GeV, where the ratio is energy independent. We observe a sin<SUP>-4</SUP> θ* behavior of the cross section in the same W range. Production of χ<SUB>c0</SUB> and χ<SUB>c2</SUB> mesons is observed in both γγ → π<SUP>+</SUP>π<SUP>-</SUP> and γγ → K<SUP>+</SUP>K<SUP>-</SUP> modes. The products of the two-photon decay width and the branching ratio are measured to be<br /><br />Γ<SUB>γγ</SUB>(χ<SUB>c0</SUB>)Br(χ<SUB>c0</SUB> → π<SUP>+</SUP>π<SUP>-</SUP>) = 15.1 ± 2.1 ± 2.3 eV<br />Γ<SUB>γγ</SUB>(χ<SUB>c0</SUB>)Br(χ<SUB>c0</SUB> → K<SUP>+</SUP>K<SUP>-</SUP>) = 14.3 ± 1.6 ± 2.3 eV<br />Γ<SUB>γγ</SUB>(χ<SUB>c2</SUB>)Br(χ<SUB>c2</SUB> → π<SUP>+</SUP>π<SUP>-</SUP>) = 0.76 ± 0.14 ± 0.11 eV<br />Γ<SUB>γγ</SUB>(χ<SUB>c2</SUB>)Br(χ<SUB>c2</SUB> → K<SUP>+</SUP>K<SUP>-</SUP>) = 0.44 ± 0.11 ± 0.07 eV<br /><br />which result in the combined two-photon decay width<br /><br />Γ<SUB>γγ</SUB>(χ<SUB>c0</SUB>) = 2.62 ± 0.23 (stat.) ± 0.31 (syst.) ± 0.24 (B) keV<br />Γ<SUB>γγ</SUB>(χ<SUB>c2</SUB>) = 0.44 ± 0.07 (stat.) ± 0.05 (syst.) ± 0.05 (B) keV.","subitem_description_type":"Other"}]},"item_1_description_7":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_description":"総研大甲第852号","subitem_description_type":"Other"}]},"item_1_select_14":{"attribute_name":"所蔵","attribute_value_mlt":[{"subitem_select_item":"有"}]},"item_1_select_8":{"attribute_name":"研究科","attribute_value_mlt":[{"subitem_select_item":"高エネルギー加速器科学研究科"}]},"item_1_select_9":{"attribute_name":"専攻","attribute_value_mlt":[{"subitem_select_item":"14 素粒子原子核専攻"}]},"item_1_text_10":{"attribute_name":"学位授与年度","attribute_value_mlt":[{"subitem_text_value":"2004"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"NAKAZAWA, Hideyuki","creatorNameLang":"en"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-02-17"}],"displaytype":"simple","filename":"甲852_要旨.pdf","filesize":[{"value":"162.6 kB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"要旨・審査要旨","url":"https://ir.soken.ac.jp/record/698/files/甲852_要旨.pdf"},"version_id":"06e5ce00-3679-4199-85d1-e9f9ac0b9163"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Measurement of the processes γγ→π+π-  and γγ→K+K- at enegies of 2.4-4.1GeV","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Measurement of the processes γγ→π+π-  and γγ→K+K- at enegies of 2.4-4.1GeV"},{"subitem_title":"Measurement of the processes γγ→π+π-  and γγ→K+K- at enegies of 2.4-4.1GeV","subitem_title_language":"en"}]},"item_type_id":"1","owner":"1","path":["16"],"pubdate":{"attribute_name":"公開日","attribute_value":"2010-02-22"},"publish_date":"2010-02-22","publish_status":"0","recid":"698","relation_version_is_last":true,"title":["Measurement of the processes γγ→π+π-  and γγ→K+K- at enegies of 2.4-4.1GeV"],"weko_creator_id":"1","weko_shared_id":1},"updated":"2023-06-20T16:01:50.323849+00:00"}