Pub Date : 2020-11-01DOI: 10.1103/PhysRevD.103.L091101
M. Ablikim, M. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, R. Aliberti, A. Amoroso, M. An, Q. An, X. Bai, Y. Bai, O. Bakina, R. Ferroli, I. Balossino, Y. Ban, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. Briere, H. Cai, X. Cai, A. Calcaterra, G. Cao, N. Cao, S. Çetin, J. F. Chang, W. Chang, G. Chelkov, D. Y. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, X. R. Chen, Y. B. Chen, Z. J. Chen, W. Cheng, G. Cibinetto, F. Cossio, X. Cui, H. Dai, X. Dai, A. Dbeyssi, R. de Boer, D. Dedovich, Z. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, C. Dong, J. Dong, L. Dong, M. Dong, X. Dong, S. Du, Y. L. Fan, J. Fang, S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Feng, J. H. Feng, M. Fritsch, C. Fu, Y. Gao, Y. G. Gao, I. Garzia, P. Ge, C. Geng, E. Gersabeck, A. Gilman, K. Goetzen, L. Gong, W. Gong, W. Gradl, M. Greco, L. Gu, M. Gu, S. Gu, Y. Gu, C. Guan, A. Guo, L. B. Guo, R. Guo, Y. P. Guo, A. Guskov, T. Han, W. Han, X. Ha
We report on a comparison of two possible $Lambda_c^+$ spin hypotheses, $J=frac{1}{2}$ and $frac{3}{2}$, via the process $e^+e^-toLambda_c^+barLambda_c^-$, using the angular distributions of $Lambda_c^+$ decays into $pK_S^0$, $Lambdapi^+$, $Sigma^0pi^+$, and $Sigma^+pi^0$. The data were recorded at $sqrt s = 4.6$ GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb$^{-1}$. The $Lambda_c^+$ spin is determined to be $J=frac{1}{2}$, with this value favored over the $frac{3}{2}$ hypothesis with a significance of $7.98$ standard deviations ($sigma$) with a boundary $(7.89sim8.84)sigma$, corresponding to the observed range of systematic variations.
通过$e^+e^-toLambda_c^+barLambda_c^-$的过程,利用$Lambda_c^+$衰变为$pK_S^0$、$Lambdapi^+$、$Sigma^0pi^+$和$Sigma^+pi^0$的角分布,对$J=frac{1}{2}$和$frac{3}{2}$两种可能的自旋假设$Lambda_c^+$进行比较。用BESIII探测器在$sqrt s = 4.6$ GeV记录数据,对应的综合光度为587 pb $^{-1}$。确定$Lambda_c^+$自旋为$J=frac{1}{2}$,该值优于$frac{3}{2}$假设,其显著性为$7.98$标准差($sigma$),边界为$(7.89sim8.84)sigma$,与观察到的系统变化范围相对应。
{"title":"Determination of the $Lambda_c^+$ spin via the reaction $e^+e^-toLambda_c^+barLambda_c^-$","authors":"M. Ablikim, M. Achasov, P. Adlarson, S. Ahmed, M. Albrecht, R. Aliberti, A. Amoroso, M. An, Q. An, X. Bai, Y. Bai, O. Bakina, R. Ferroli, I. Balossino, Y. Ban, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. Briere, H. Cai, X. Cai, A. Calcaterra, G. Cao, N. Cao, S. Çetin, J. F. Chang, W. Chang, G. Chelkov, D. Y. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, X. R. Chen, Y. B. Chen, Z. J. Chen, W. Cheng, G. Cibinetto, F. Cossio, X. Cui, H. Dai, X. Dai, A. Dbeyssi, R. de Boer, D. Dedovich, Z. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, C. Dong, J. Dong, L. Dong, M. Dong, X. Dong, S. Du, Y. L. Fan, J. Fang, S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Feng, J. H. Feng, M. Fritsch, C. Fu, Y. Gao, Y. G. Gao, I. Garzia, P. Ge, C. Geng, E. Gersabeck, A. Gilman, K. Goetzen, L. Gong, W. Gong, W. Gradl, M. Greco, L. Gu, M. Gu, S. Gu, Y. Gu, C. Guan, A. Guo, L. B. Guo, R. Guo, Y. P. Guo, A. Guskov, T. Han, W. Han, X. Ha","doi":"10.1103/PhysRevD.103.L091101","DOIUrl":"https://doi.org/10.1103/PhysRevD.103.L091101","url":null,"abstract":"We report on a comparison of two possible $Lambda_c^+$ spin hypotheses, $J=frac{1}{2}$ and $frac{3}{2}$, via the process $e^+e^-toLambda_c^+barLambda_c^-$, using the angular distributions of $Lambda_c^+$ decays into $pK_S^0$, $Lambdapi^+$, $Sigma^0pi^+$, and $Sigma^+pi^0$. The data were recorded at $sqrt s = 4.6$ GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb$^{-1}$. The $Lambda_c^+$ spin is determined to be $J=frac{1}{2}$, with this value favored over the $frac{3}{2}$ hypothesis with a significance of $7.98$ standard deviations ($sigma$) with a boundary $(7.89sim8.84)sigma$, corresponding to the observed range of systematic variations.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83194620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-27DOI: 10.1103/physrevd.103.012004
L. C. R. Aaij, C. Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C. Aidala, S. Aiola, Z. Ajaltouni, S. Akar, J. Albrecht, Federico Alessio, M. Alexander, A. A. Albero, Z. Aliouche, G. Alkhazov, P. Cartelle, S. Amato, Y. Amhis, L. An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, K. Arzymatov, E. Aslanides, M. Atzeni, B. Audurier, S. Bachmann, M. Bachmayer, J. Back, S. Baker, P. Rodriguez, V. Balagura, W. Baldini, J. B. Leite, R. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H. C. Bernstein, C. Bertella, E. Bertholet, A. Bertolin, C. Betancourt, F. Betti, M. Bettler, I. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M. Bieker, S. Bifani, P. Billoir, M. Birch, F. Bishop, A. Bizzeti, M. Bjørn, M. Blago, T. Blake, F. Blanc, S.
Using a proton-proton collision data sample collected by the LHCb experiment, corresponding to an integrated luminosity of 8.5~fb$^{-1}$, the observation of a new excited $Xi_b^0$ resonance decaying to the $Xi_b^-pi^+$ final state is presented. The state, referred to as $Xi_b(6227)^0$, has a measured mass and natural width of $m(Xi_b(6227)^0) = 6227.1^{,+1.4}_{,-1.5}pm0.5$ MeV, $Gamma(Xi_b(6227)^0) = 18.6^{,+5.0}_{,-4.1}pm1.4$ MeV, where the uncertainties are statistical and systematic. The production rate of the $Xi_b(6227)^0$ state relative to that of the $Xi_b^-$ baryon in the kinematic region $2
{"title":"Observation of a new \u0000Ξb0\u0000 state","authors":"L. C. R. Aaij, C. Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C. Aidala, S. Aiola, Z. Ajaltouni, S. Akar, J. Albrecht, Federico Alessio, M. Alexander, A. A. Albero, Z. Aliouche, G. Alkhazov, P. Cartelle, S. Amato, Y. Amhis, L. An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, K. Arzymatov, E. Aslanides, M. Atzeni, B. Audurier, S. Bachmann, M. Bachmayer, J. Back, S. Baker, P. Rodriguez, V. Balagura, W. Baldini, J. B. Leite, R. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H. C. Bernstein, C. Bertella, E. Bertholet, A. Bertolin, C. Betancourt, F. Betti, M. Bettler, I. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M. Bieker, S. Bifani, P. Billoir, M. Birch, F. Bishop, A. Bizzeti, M. Bjørn, M. Blago, T. Blake, F. Blanc, S.","doi":"10.1103/physrevd.103.012004","DOIUrl":"https://doi.org/10.1103/physrevd.103.012004","url":null,"abstract":"Using a proton-proton collision data sample collected by the LHCb experiment, corresponding to an integrated luminosity of 8.5~fb$^{-1}$, the observation of a new excited $Xi_b^0$ resonance decaying to the $Xi_b^-pi^+$ final state is presented. The state, referred to as $Xi_b(6227)^0$, has a measured mass and natural width of $m(Xi_b(6227)^0) = 6227.1^{,+1.4}_{,-1.5}pm0.5$ MeV, $Gamma(Xi_b(6227)^0) = 18.6^{,+5.0}_{,-4.1}pm1.4$ MeV, where the uncertainties are statistical and systematic. The production rate of the $Xi_b(6227)^0$ state relative to that of the $Xi_b^-$ baryon in the kinematic region $2<eta<5$ and $p_{rm T}<30$ GeV is measured to be $frac{f_{Xi_b(6227)^0}}{f_{Xi_b^-}}{mathcal{B}}(Xi_b(6227)^0toXi_b^-pi^+) = 0.045pm0.008pm0.004$, where ${mathcal{B}}(Xi_b(6227)^0toXi_b^-pi^+)$ is the branching fraction of the decay, and $f_{Xi_b(6227)^0}$ and $f_{Xi_b^-}$ represent fragmentation fractions. Improved measurements of the mass and natural width of the previously observed $Xi_b(6227)^-$ state, along with the mass of the $Xi_b^-$ baryon, are also reported. Both measurements are significantly more precise than, and consistent with, previously reported values.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73878414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}