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arXiv 1003.4338hep-phnucl-th
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低能和粲重子的自旋1/2^+、自旋3/2^+和跃迁磁矩

Spin 1/2^+, spin 3/2^+ and transition magnetic moments of low lying and charmed baryons

Neetika Sharma, Harleen Dahiya, P. K. Chatley, Manmohan Gupta

摘要:

在SU(4)手征组分夸克模型(\chiCQM)中,考虑c \bar c涨落的贡献,计算了低位和粲化自旋1/2^+和3/2^+重子的磁矩.对价夸克、“夸克海”极化和它们的轨道角动量的贡献进行了显式计算。我们还研究了低自旋3/2^+ \to 1/2^+和1/2^+ \to 1/2^+跃迁以及含粲重子跃迁的磁矩。对于低自旋的1/2^+重子和3/2^+重子,我们的计算结果与实验数据非常吻合。对于自旋为1/2^+和3/2^+的粲重子磁矩,我们的结果与QCD求和规则、光锥求和规则和谱求和规则的预言是一致的.对于“轻”夸克在价结构中占主导地位的情况,海和轨道的贡献被发现是相当重要的,然而,它们在正确的方向上抵消,以给出正确的总磁矩的大小。另一方面,当“重”夸克过剩时,“夸克海”的贡献几乎可以忽略不计。组态混合和夸克质量的影响也进行了研究。

英文摘要:

Magnetic moments of the low lying and charmed spin 1/2^+ and spin 3/2^+ baryons have been calculated in the SU(4) chiral constituent quark model (\chiCQM) by including the contribution from c \bar c fluctuations. Explicit calculations have been carried out for the contribution coming from the valence quarks, "quark sea" polarizations and their orbital angular momentum. The implications of such a model have also been studied for magnetic moments of the low lying spin 3/2^+ \to 1/2^+ and 1/2^+ \to 1/2^+ transitions as well as the transitions involving charmed baryons. We are able to achieve an excellent agreement with data for the case of low lying spin 1/2^+ baryons and spin 3/2^+ baryons. For the spin 1/2^+ and spin 3/2^+ charmed baryon magnetic moments, our results are consistent with the predictions of the QCD sum rules, Light Cone sum rules and Spectral sum rules. For the cases where "light" quarks dominate in the valence structure, the sea and orbital contributions are found to be fairly significant however, they cancel in the right direction to give the correct magnitude of the total magnetic moment. On the other hand, when there is an excess of "heavy" quarks, the contribution of the "quark sea" is almost negligible. The effects of configuration mixing and quark masses have also been investigated.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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