• 검색 결과가 없습니다.

Sum rules for baryon decuplet magnetic moments

N/A
N/A
Protected

Academic year: 2021

Share "Sum rules for baryon decuplet magnetic moments"

Copied!
13
0
0

로드 중.... (전체 텍스트 보기)

전체 글

(1)

Sum rules for baryon decuplet magnetic moments

Soon-Tae Hong*

W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA

and Department of Science Education and Research Institute for Basic Sciences, Ewha Womans University, Seoul 120-750, Korea

(Received 12 April 2007; published 29 November 2007)

In chiral models with SU(3) group structure, baryon decuplet, and octet magnetic moments are evaluated by constructing their sum rules to yield theoretical predictions. In these sum rules we exploit six experimentally known baryon magnetic moments. Sum rules for flavor components and strange form factors of the octet and decuplet magnetic moments and decuplet-to-octet transition magnetic moments are also investigated.

DOI:10.1103/PhysRevD.76.094029 PACS numbers: 12.39.x, 11.30.Hv, 13.40.Em, 21.60.Fw

I. INTRODUCTION

The internal structure of the nucleon is still a subject of great interest to both experimentalists and theorists. In 1933, Frisch and Stern [1] performed the first measurement of the magnetic moment of the proton and obtained the earliest experimental evidence for the internal structure of the nucleon. However, it was not until 40 years later that the quark structure of the nucleon was directly observed in deep inelastic electron scattering experiments and we still lack a quantitative theoretical understanding of these prop-erties including the magnetic moments.

Since Coleman and Glashow [2] predicted the magnetic moments of the baryon octet about 40 years ago, there has been a lot of progress in both the theoretical paradigm and experimental verification for the baryon magnetic mo-ments. The measurements of the baryon decuplet magnetic moments were reported for [3] and [4] to yield a new avenue for understanding the hadron structure. The magnetic moments of baryon decuplet have been theoreti-cally investigated in several models such as the quenched lattice gauge theory [5], the quark models [6], the chiral bag model [7], the chiral perturbation theory [8], the QCD sum rules [9], the chiral quark model [10], and the chiral quark soliton model [11]. Moreover, by including the effect of decuplet intermediate states of spin-3=2 baryons explic-itly, the heavy baryon chiral expansion of baryon octet magnetic moments [12] and charge radii [13] were inves-tigated. The decuplet-to-octet transition magnetic mo-ments have been also analyzed in the 1=Nc expansion of

QCD [14–16] and in the chiral quark soliton model [17]. Quite recently, the SAMPLE Collaboration [18] re-ported the experimental data of the proton strange form factor through parity violating electron scattering [19]. To be more precise, they measured the neutral weak form

factors at a small momentum transfer Q2

S

0:1 GeV=c2 to yield the proton strange magnetic form factor in units of Bohr nuclear magnetons (n.m.) Gs

M

0:37  0:20  0:26  0:07 n:m: [18]. The HAPPEX Collaboration later reported GsM 0:18  0:27 n:m: [20]. Moreover, McKeown [21] has shown that the strange form factor of proton should be positive by using the conjecture that the up-quark effects are generally dominant in the flavor dependence of the nucleon properties. The chiral bag model [22] predicted first the positive value for the proton strange form factor [23].

In this paper, we will exploit the chiral bag model to predict baryon decuplet and octet magnetic moments and their strange form factors. This model calculation can share those of other skyrmion extended models with SU(3) group structure if sum rules are properly used. More specifically, in the chiral models, we will investigate the magnetic moments of baryon decuplet and octet, together with the decuplet-to-octet transition magnetic moments, in terms of their sum rules. We will also study the sum rules for the flavor components and strange form factors of the baryon magnetic moments. In Sec. II, in the adjoint representation we construct the sum rules of the baryon decuplet and octet magnetic moments and the transition magnetic moments in the SU(3) chiral models, and in Sec. III the sum rules for their flavor components and strange form factors in a model independent way at least in the category of the chiral models with the SU(3) flavor group. In the Appendix, we list the u- and d-flavor components of the baryon magnetic moments and transition magnetic mo-ments and their sum rules.

II. MAGNETIC MOMENTS OF BARYON DECUPLET

We start with the chiral bag model with the broken U-spin symmetry whose Lagrangian is of the form *soonhong@ewha.ac.kr

(2)

L  LCS LCSB LFSB; LCS  i@ B 1 2 U 5 B  1 4f 2 trll  1 32e2l; l 2 L WZW   B; LCSB   M B 1 4f 2 m2trU  Uy 2 B; LFSB 1 6f 2 2m2K m2 tr1   3 p 8U  Uy 2 B 1 12f 2 2 1 tr1   3 p 8Ull llUy B; (2.1)

where the quark field has SU(3) flavor degrees of free-dom and the chiral field U  eiaa=f 2 SU3 is

de-scribed by the pseudoscalar meson fields a

(a  1; . . . ; 8) and Gell-Mann matrices a with ab 

2

3ab ifabc dabcc, and B 1  B is the bag

theta function (one inside the bag and zero outside the bag). In the limit of vanishing bag radius, the chiral bag model is reduced to the Skyrmion model. Here l  Uy@U and LWZW stands for the topological Wess-Zumino-Witten (WZW) term. The chiral symmetry (CS) is broken by the quark masses M  diagmu; md; ms and pion mass m in LCSB. Furthermore the SU(3) flavor symmetry breaking (FSB) with mK=m 1 and   fK=f 1 is included in LFSB. Even though the mass terms in LCSB and LFSB break both the SUL3

SUR3 and diagonal SU(3) symmetry so that chiral

sym-metry cannot be conserved, these terms without derivatives yield no explicit contribution to the electromagnetic (EM) currents Jand at least in the adjoint representation of the

SU(3) group the EM currents are conserved and of the same form as the chiral limit result JCS to preserve the U-spin symmetry. However the derivative-dependent term inLFSB gives rise to the U-spin symmetry breaking con-served EM currents JFSB so that J J

CS J



FSB. Assuming that the hedgehog classical solution in the meson phase U0  eii^rir (i  1; 2; 3) is embedded in

the SU(2) isospin subgroup of SU(3) and the Fock space in the quark phase is described by the Nc valence quarks

and the vacuum structure composed of quarks filling the negative energy sea, the chiral model generates the zero mode with the collective variable At 2 SU3 by per-forming the slow rotation U ! AU0Ay and ! A on SU(3) group manifold. Given the spinning chiral model ansatz, the EM currents yield the magnetic moment opera-tors ^i ^i3 1

3

p ^i8, where ^ia ^ia CS  ^ ia FSB with ^ iaCS  N D8 ai N 0d ipqD8apT^Rq Nc 2p MD3 8 a8J^i; ^ iaFSB P D8 ai1  D888  Q  3 p 2 dipqD 8 apD88q  RD8 a8D88i; (2.2)

whereM, N , N0,P , Q, and R are the inertia parame-ters calculable in the chiral models [23,24]. Using the theorem that the tensor product of the Wigner D functions can be decomposed into the sum of the single D functions, the isovector and isoscalar parts of the operator ^iaFSB are then rewritten as ^ i3FSB P  4 5D 8 3i 1 4D 10 3i  1 4D  10 3i  3 10D 27 3i   Q 3 10D 8 3i 3 10D 27 3i   R 1 5D 8 3i 7 10D 27 3i  ; ^ i8FSB P  6 5D 8 8i 9 20D 27 8i   Q   3 10D 8 8i 9 20D 27 8i   R  1 5D 8 8i 9 20D 27 8i  : (2.3)

Here one notes that the 1, 10, and 10 irreducible representations (IRs) do not occur in the decuplet baryons while 10 and 10 IRs appear together in the isovector channel of the baryon octet to conserve the hermiticity of the operator.

Using the above operator ^itogether with the decuplet baryon wave function  B

 dim p

D

ab with the quantum

numbers a  Y; I; I3 (Y, hypercharge; I, isospin) and b  YR; J; J3 (YR, right hypercharge; J, spin) and  the

dimension of the representation, the baryon decuplet magnetic moments for 10 (J3 3=2) and transition magnetic moments for 10 J3 1=2 ! 8 J3  1=2   have the following hyperfine structure:

(3)

  1 8M  1 2  N  1 2p N3 03 7P  3 56Q  1 14R;  1 16M  1 4  N  1 2p N3 0 5 21P  1 84Q  1 84R; 0  1 21P  13 168Q  1 21R;   1 16M  1 4  N  1 2p N3 01 7P  1 7Q  3 28R;   1 16M  1 4  N  1 2p N3 019 84P  17 168Q  1 42R; 0  1 84P  1 84Q  1 84R;    1 16M  1 4  N  1 2p N3 017 84P  13 168Q  1 21R; 0   1 42P  17 168Q  1 42R;    1 16M  1 4  N  1 2p N3 011 42P  1 84Q  1 84R;   1 16M  1 4  N  1 2p N3 0 9 28P  3 56Q  1 14R; 1  5 p p 1  5 p n0   2 15  N 2   2 p 8 N 0 4 45P  7 180Q  79 2700R; 1  5 p    2 15  N 2   2 p 8 N 013 90P  1 180Q  1 100R; 1  5 p 00  1 15  N 2   2 p 8 N 0 7 90P  1 45Q  1 90R; 1  5 p   1 90P  7 180Q  29 900R; 1  5 p 00  2 15  N 2   2 p 8 N 0 7 45P  1 180Q  23 2700R; 1  5 p    1 90P  7 180Q  67 2700R; 1  15 p 0   1 15  N 2   2 p 8 N 0 1 18P  1 45Q  11 1350R: (2.4)

Here the coefficients are solely given by the SU(3) group structure of the chiral models and the physical information such as decay constants and masses are included in the above inertia parameters, such asM, N , and so on. Note that the SU(3) group structure in the coefficients is generic property shared by the chiral models which exploit the hedgehog ansatz solution corresponding to the little group SU2 Z2 [25]. In the chiral perturbation theory [8] and in the 1=Nc expansion of QCD [14–16] to which the

hedgehog ansatz does not apply, one can thus see the coefficients different from those in (2.4) even though the

SU(3) flavor group is used in the theory. Now, it seems appropriate to comment on the 1=Nc expansion [25–28]. In the above relations (2.4), the inertia parametersN , N0, P , Q, and R are of order Nc while M is of order Nc1.

However, since the inertia parameter M is multiplied by an explicit factor Ncin (2.2), the terms withM are of order

N0

c. (For details of further 1=Nc, see [25,28].)

In the SU(3) flavor symmetric limit with the chiral symmetry breaking masses mu md ms, mK m

and decay constants fK f, the magnetic moments of the decuplet baryons are simply given by [29]

(4)

B  QEM 1 16M  1 4  N  1 2p N3 0; (2.5) where QEM is the EM charge. Here one notes that in the chiral model in the adjoint representation the prediction of the baryon magnetic moments with the chiral symmetry is the same as that with the SU(3) flavor symmetry since the mass-dependent term inLCSB andLFSB do not yield any contribution to JFSB so that there are no terms withP , Q, andR in (2.4). Because of the degenerate d- and s-flavor charges in the SU(3) EM charge operator ^QEM, the chiral model possesses the U-spin symmetry relations in the baryon decuplet magnetic moments, similar to those in the octet baryons [30]

      ; 

0 0  0;

  ; (2.6)

which are a subset of the stronger symmetry relations (2.5).

Next, since the SU(3) FSB quark masses do not affect the magnetic moments of the baryon decuplet in the adjoint representation of the chiral model, in the more general SU(3) flavor symmetry broken case with mu md ms, m mK and f fK, the decuplet baryon magnetic moments with all the inertia parameters satisfy the follow-ing symmetric sum rules:

0  1 2 1 2;     0 ; X B2decuplet B 0: (2.7)

Now, in order to predict baryon decuplet magnetic mo-ments we proceed to derive sum rules for the baryon magnetic moments in terms of the experimentally known baryon magnetic moments. To do this, we first consider the baryon octet magnetic moments of the form

p 1 10M  4 15  N 1 2N 0 8 45P  2 45Q  1 45R; n 1 20M  1 5  N 1 2N 01 9P  7 90Q  1 45R;  1 10M  4 15  N 1 2N 013 45P  1 45Q  2 45R; 0   1 40M  1 10  N 1 2N 011 90P  1 36Q  1 45R;   3 20M  1 15  N 1 2N 0 2 45P  7 90Q  4 45R; 0  1 20M  1 5  N 1 2N 011 45P  1 45Q  1 45R;   3 20M  1 15  N 1 2N 0 4 45P  2 45Q  4 45R;   1 40M  1 10  N 1 2N 0 1 10P  1 20Q: (2.8)

Since we have effectively five inertia parameters M, N 1 2N

0,

P , Q, and R, we can derive sum rules for three magnetic moments 0, , and in terms of five experimentally known octet magnetic moments, p, n, , , and 0 as follows: 0  1 2 1 2;    1 3n 8 3 5 3 7 30;  p2 3n 7 6 1 6 4 30: (2.9)

Using the above sum rules we can predict the magnetic moments as in Table I. One notes that the value of  is comparable to the experimental data exp  0:61, while the value of is not so comparable to exp

 0:65. Similarly we can derive sum rules for the decuplet magnetic moments in terms of six experimentally known magnetic moments, p, n, , , 

0, and  to arrive at

(5)

  5 28p 55 168n 5 42 25 84 5 1680 1 2; 0  5 14p 55 84n 5 21 25 42 5 840;   15 28p 55 56n 5 14 25 28 5 560 1 2;    25 14p 235 168n 215 84  65 84 365 1680 1 2; 0   15 28p 5 14n 25 28 5 14 5 70;   5 7p 115 168n 65 84 5 84 125 1680 1 2; 0   10 7 p 115 84 n 65 42 5 42 125 84 0;   25 28p 65 168n 40 21 85 84 235 1680 1 2;   15 14p 5 56n 85 28 55 28 115 56 0 1 2; 1  5 p p  1  5 p n0    1 189 17p2 140  17p3 210  17p6 420  p 173 567  2 p 168  3 p 252  6 p 504  n  3383 11 340  2 p 420  3 p 630  6 p 1260   2189 11 340 13p2 420  13p3 630  13p6 1260    2131 11 340 73p2 840  73p3 1260 73p6 2520  0  1 5  2 p 10  3 p 15  6 p 30  ; 1  5 p     83 630 17p2 140  17p3 210  17p6 420  p   1 378  2 p 168  3 p 252  6 p 504  n  131 756  2 p 420  3 p 630  6 p 1260   107 756 13p2 420  13p3 630  13p6 1260      589 3780 73p2 840  73p3 1260 73p6 2520  0 1 5  2 p 10  3 p 15  6 p 30  ; 1  5 p 00  11 140 17p2 280  17p3 420  17p6 840  p 9 56  2 p 336  3 p 504  6 p 1008  n 19 140  2 p 840  3 p 1260  6 p 2520    37 140 13p2 840  13p3 1260  13p6 2520     13 280 73p2 1680 73p3 2520  73p6 5040  0  1 10  2 p 20  3 p 30  6 p 60  ; 1  5 p   13 45p 35 108n 53 540 209 540 17 2700; 1  5 p 00   667 945 17p2 140  17p3 210  17p6 420  p   451 1134  2 p 168  3 p 252  6 p 504  n  2759 2268  2 p 420  3 p 630  6 p 1260   1385 2268 13p2 420  13p3 630  13p6 1260    8033 11 340 73p2 840  73p3 1260 73p6 2520  0 1 5  2 p 10  3 p 15  6 p 30  ;

(6)

1  5 p   49 135p 125 324n 181 1620 407 1620 109 8100; 1  15 p 0  215 756 17p2 280  17p3 420  17p6 840  p 1399 4536  2 p 336  3 p 504  6 p 1008  n    3751 11 340  2 p 840  3 p 1260  6 p 2520     1093 11 340 13p2 840  13p3 1260 13p6 2520      5779 22 680 73p2 1680 73p3 2520  73p6 5040  0   1 10  2 p 20  3 p 30  6 p 60  : (2.10)

Here we have used the additional magnetic moment  since we have six inertia parametersM, N , N0,P , Q, andR. We list the predictions for the magnetic moments of the decuplet and octet baryons in TableI, and those for the decuplet-to-octet transition magnetic moments in Table II, by using their sum rules (2.10). Here note that

our prediction of  is comparable to its experimental value exp  1:94. The predicted values of the decuplet-to-octet transition magnetic moments in Table II are also comparable to the previous ones obtained by using the chiral quark soliton model [17].

TABLE II. The transition magnetic moments and their flavor components for 10J3 1=2 !

8J3 1=2  . B8B10 B8B10  s B8B10  u B8B10  d B8B10 p 2:76 0:54 0:76 1:46 n0 2:76 0:54 0:76 1:46  2.24 0.13 2.58 0:47 00 1.01 0.13 1.76 0:88  0:22 0.13 0.94 1:29 00 2.46 0.19 2.72 0:45  0:27 0.19 0.90 1:36 0 2:46 0:54 0:56 1:36

TABLE I. The magnetic moments, their flavor components, and strange form factors of the decuplet and octet baryons. The quantities used as input parameters are indicated by .

B B sB  u B  d B F s 2B  4:52 0.07 4.10 0.35 0:21  2.12 0.07 2.50 0:45 0:21 0 0:29 0.07 0.89 1:25 0:21  2:69 0.07 0:71 2:05 0:21  2.63 0:49 2.84 0.28 0.47 0 0.08 0:49 1.14 0:57 0.47  2:48 0:49 0:57 1:42 0.47 0 0.44 1:15 1.38 0.21 1.45  2:27 1:15 0:43 0:69 1.45  2:06 1:92 0:29 0:15 2.76 p 2:79 0:25 2.94 0.10 0.75 n 1:91 0:25 0:19 1:47 0.75  2:46 0:11 2.72 0:15 0:67 0 0.65 0:11 1.52 0:76 0:67  1:16 0:11 0.31 1:36 0:67 0 1:25 1:32 0.25 0:18 1.95  1:07 1:32 0.37 0:12 1.95  0:51 0:88 0.75 0:38 1.64

(7)

III. STRANGE FLAVOR MAGNETIC MOMENTS OF BARYON DECUPLET

In the SU(3) flavor symmetry broken case we decompose the EM currents into three pieces J  Ju Jd Js

where the q-flavor currents Jq JqCS  JqFSB are given by substituting the charge operator ^Qwith the q-flavor charge operator ^Qq JCSq  Q^ q B  i 2f 2 tr ^Qql  i 8e2 tr ^Qq; l l; l  U $ Uy B  Nc 482  tr ^Q qlll  U $ Uy B; JFSBq  i 12f 2 2 1 tr1   3 p 8U ^Qql lQ^ qUy  U $ Uy B (3.1)

to obtain the baryon magnetic moments and transition magnetic moments in the s-flavor channel

s   7 48M  1 12  N  1 2p N3 0 2 21P  5 168Q  1 84R; s   1 6M  1 126P  1 126Q  1 126R; s   3 16M  1 12  N  1 2p N3 0 2 21P  5 168Q  1 84R; s   5 24M  1 6  N  1 2p N3 0 3 14P  1 28Q  1 21R; sN   7 60M  1 45  N 1 2N 0 1 45P  1 90Q; s  11 60M  1 15  N 1 2N 0 11 135P  1 54Q  2 135R; s  1 5M  4 45  N 1 2N 01 9P  1 45Q  1 45R; s   3 20M  1 15  N 1 2N 0 1 15P  1 30Q; 1  5 p sN  1 6p M;5 1  5 p s   1 6p M 5 2 45  N 2   2 p 8 N 0 7 135P  2 135Q  1 135R; 1  5 p s   1 6p M 5 2 45  N 2   2 p 8 N 0 1 18P  1 90Q  1 90R; 1  15 p s 0   1 6p15M: (3.2)

Similarly, in the u- and d-flavor channels of the adjoint representation we obtain the baryon magnetic moments and transition magnetic moments (A1) in the Appendix. Here one notes that in general all the baryon decuplet and octet magnetic moments fulfill the model independent relations in the u- and d-flavor components and the I-spin symmetry of the isomultiplets with the same strangeness in the s-flavor channel

dB Qd Qu u  B ;  s B   s  B ; (3.3)

with Bbeing the isospin conjugate baryon in the isomultiplets of the baryon.

As in the previous sum rules of the magnetic moments (2.9) and (2.10), we find the sum rules of the strange components of the magnetic moments and transition magnetic moments in terms of the six experimentally known magnetic moments:

(8)

s  13 84p 115 504n 83 126 47 252 463 5040 1 6; s   29 42p 50 63n 23 126 8 63 26 630; s   43 84p 445 504n 113 126 103 252 433 5040 1 6; s  8 21p 125 252n 353 126 179 126 569 2520 1 3; sN  2 9n 7 9 1 9 8 90; s  1 3p 5 9n 4 9 2 9 8 90; s  1 3p 2 3n 5 3 2 3 4 30; s  p n; 1  5 p sN    5 p 15p  5 p 9 n 7p5 45   5 p 45 8p5 45 0; 1  5 p s  11 210 17p2 420  17p3 630   5 p 15 17p6 1260  p 3 28  2 p 504  3 p 756  5 p 9   6 p 1512  n  19 210  2 p 1260  3 p 1890 7p5 45   6 p 3780   37 210 13p2 1260  13p3 1890  5 p 45 13p6 3780      13 420 73p2 2520 73p3 3780  8p5 45  73p6 7560  0 1 15  2 p 30  3 p 45  6 p 90  ; 1  5 p s    4 35 17p2 420  17p3 630   5 p 15 17p6 1260  p   1 252  2 p 504  3 p 756  5 p 9   6 p 1512  n  116 315  2 p 1260  3 p 1890 7p5 45   6 p 3780   181 630 13p2 1260  13p3 1890  5 p 45 13p6 3780    241 1260 73p2 2520 73p3 3780  8p5 45  73p6 7560  0 1 15  2 p 30  3 p 45  6 p 90  ; 1  15 p s0    15 p 45 p  15 p 27 n 7p15 135   15 p 135 8p15 135 0: (3.4)

Similarly, the sum rules of the u- and d-flavor components of the magnetic moments and transition magnetic moments are given by (A2) in the Appendix. Here one notes that the flavor components of the transition magnetic moments p and 

n0 satisfy the identities qp 

q

n0; q  u; d; s; (3.5) to yield p  

n0 as in (2.10). The identities (3.5) are consistent with the previous ones in Refs. [14,16]. We list the predictions for the u-, d-, and s-flavor components of the decuplet and octet magnetic moments in TableI, and those for the decuplet-to-octet transition magnetic mo-ments in TableII, by using the sum rules (3.4) and (A2).

Next, the form factors of the decuplet baryons, with internal structure, are defined by the matrix elements of the EM currents hp  qjJjpi  up  qF 1Bq2  i 2mB qF 2Bq2  up; (3.6)

where up is the spinor of the baryons and q is the momentum transfer. Using the s-flavor charge operator in the EM currents as before, in the limit of zero momentum transfer, one can obtain the strange form factors of baryon decuplet and octet

F1Bs0  S; Fs2B0  3sB  S (3.7) in terms of the strangeness quantum number of the baryon S 1  Y (Y, hypercharge) and the strange components of the baryon decuplet and octet magnetic moments sB . The predictions for the strange form factors of the decuplet

(9)

and octet baryons are listed in TableIby using the relation (3.7).

IV. CONCLUSIONS

In summary, we have derived sum rules for the baryon decuplet and octet magnetic moments and the decuplet-to-octet transition magnetic moments, in the chiral models with the SU(3) flavor group. These sum rules are explicitly constructed in terms of the six experimentally known baryon magnetic moments p, n, , , 

0, and  to yield the theoretical predictions for the remnant baryon magnetic moments. Especially in the case of using the experimental data for the six baryon magnetic moments as input data of the sum rules, the predicted value of is comparable to its experimental datum.

Next, we have extended the above algorithm to flavor components and strange form factors of the baryon dec-uplet and octet magnetic moments to find their sum rules in terms of the six baryon magnetic moments. The sum rules for the decuplet-to-octet transition magnetic moments and their flavor components have also been obtained. It is also shown that all the baryon decuplet and octet magnetic moments fulfill the model independent relations in the u-and d-flavor components u-and the I-spin symmetry of the isomultiplets with the same strangeness in the s-flavor channel. Moreover, the s-flavor components of the decuplet-to-octet transition magnetic moments respect the I-spin symmetry of the isomultiplets with the same strangeness. However, some transition magnetic moments such as up, un0, and u0 do not satisfy the model

independent relations in the u- and d-flavor components. It is also interesting to see that q

p and 

q

n0 are equal to each other in the q-flavor (q  u; d; s) channels, which are consistent with the previous results [14,16].

It would be desirable if the SU(3) representation mixing effects on the baryon magnetic moments [24] could be investigated by exploiting the multiquark structure associ-ated with the highly nontrivial nonlinear symmetry break-ing terms.

ACKNOWLEDGMENTS

The author would like to deeply thank R. D. McKeown for the warm hospitality at Kellogg Radiation Laboratory, Caltech where a part of this work has been done. He is also grateful to G. E. Brown, H. C. Kim, R. D. McKeown, D. P. Min, B. Y. Park, M. Ramsey-Musolf, M. Rho, and P. Wang for helpful discussions and encouragements. This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund), Grant No. KRF-2006-331-C00071, and by the Korea Research Council of Fundamental Science and Technology (KRCF), Grant No. C-RESEARCH-2006-11-NIMS.

APPENDIX

In the u- and d-flavor channels of the adjoint represen-tation, the baryon magnetic moments and transition mag-netic moments are given by

u  2 d   5 12M  1 3  N  1 2p N3 02 7P  1 28Q  1 21R; u  2d 0  3 8M  1 6  N  1 2p N3 010 63P  1 126Q  1 126R; u0  2 d   1 3M  2 63P  13 252Q  2 63R; u  2d   7 24M  1 6  N  1 2p N3 0 2 21P  2 21Q  1 14R; u  2d  3 8M  1 6  N  1 2p N3 0 19 126P  17 252Q  1 63R; u0  2 d 0  1 3M  1 126P  1 126Q  1 126R; u  2 d   7 24M  1 6  N  1 2p N3 0 17 126P  13 252Q  2 63R; u0  2 d   1 3M  1 63P  17 252Q  1 63R; u  2 d 0  7 24M  1 6  N  1 2p N3 011 63P  1 126Q  1 126R; u  2d   7 24M  1 6  N  1 2p N3 0 3 14P  1 28Q  1 21R;

(10)

up  2dn  2 5M  8 45  N 1 2N 0 16 135P  4 135Q  2 135R; un  2dp  11 30M  2 15  N 1 2N 0 2 27P  7 135Q  2 135R; u  2 d   2 5M  8 45  N 1 2N 0 26 135P  2 135Q  4 135R; u0  2 d 0  19 60M  1 15  N 1 2N 0 11 135P  1 54Q  2 135R; u  2d   7 30M  2 45  N 1 2N 0 4 135P  7 135Q  8 135R; u 0  2 d   11 30M  2 15  N 1 2N 0 22 135P  2 135Q  2 135R; u  2 d 0  7 30M  2 45  N 1 2N 0 8 135P  4 135Q  8 135R; u  2d  7 20M  1 15  N 1 2N 0 1 15P  1 30Q; 1  5 p up  1  5 p un0  1 3p M 5 4 45  N 2   2 p 8 N 0 8 135P  7 270Q  79 4050R; 1  5 p u    2  5 p d  1 3p M 5 4 45  N 2   2 p 8 N 0 13 135P  1 270Q  1 150R; 1  5 p u00   2  5 p d00  1 3p M 5 2 45  N 2   2 p 8 N 0 7 135P  2 135Q  1 135R; 1  5 p u   2  5 p d   1 3p M 5 1 135P  7 270Q  29 1350R; 1  5 p u00   2  5 p d  1 3p M 5 4 45  N 2   2 p 8 N 0 14 135P  1 270Q  23 4050R; 1  5 p u    2  5 p d00  1 3p M 5 1 135P  7 270Q  67 4050R; 1  15 p u0  1 3p15M  2 45  N 2   2 p 8 N 0 1 27P  2 135Q  11 2025R; 1  5 p dp  1  5 p dn0   1 6p M 5 2 45  N 2   2 p 8 N 0 4 135P  7 540Q  79 8100R; 1  15 p d 0   1 6p15M  1 45  N 2   2 p 8 N 0 1 54P  1 135Q  11 4050R: (A1)

Next, we list the sum rules of the u- and d-flavor components of the magnetic moments and transition magnetic moments

(11)

u  2 3p 10 9 n 14 9  2 9 16 9 0 2 3; u 11 14p 335 252n 103 63  53 126 443 2520 1 3; u0  19 21p 65 42n 12 7  13 21 73 420; u 43 42p 445 252n 113 63  103 126 433 2520 1 3; u   11 21p 5 28n 137 42  31 42 271 84 0 1 3; u0 13 42p 55 63n 271 126 29 63 142 63 0; u  8 7p 395 252n 131 126 23 126 323 2520 1 3; u0  2 7p 25 126n 163 63  19 63 349 1260; u  53 42p 115 84 n 2 7 19 42 71 840 1 3; u 29 21p 295 252n 59 126 137 126 103 2520 1 3; up  4 3p 10 9 n 14 9  2 9 16 9 0; un  2 3p 16 9 n 14 9  2 9 16 9 0; u 2 3p 10 9 n 20 9  2 9 16 9 0; u 0  2 3p 10 9 n 17 9  5 9 16 9 0; u 2 3p 10 9 n 14 9  8 9 16 9 0; u 0  2 3p 10 9 n 14 9  2 9 22 9 0; u 2 3p 8 9n 2 9 8 9 2 90; u 2 3n 7 3 1 3 8 30; 1  5 p up 1  5 p un0    2 567 17p2 210  17p3 315  2p5 15  17p6 630  p 346 1701  2 p 252  3 p 378 2p5 9   6 p 756  n  3383 17 010  2 p 630  3 p 945 14p5 45   6 p 1890   2189 17 010 13p2 630  13p3 945  2p5 45  13p6 1890    2131 17 010 73p2 1260 73p3 1890  16p5 45  73p6 3780  0   2 15  2 p 15 2p3 45   6 p 45  ;

(12)

1  5 p u    83 945 17p2 210  17p3 315  2p5 15  17p6 630  p   1 567  2 p 252  3 p 378 2p5 9   6 p 756  n  131 1134  2 p 630  3 p 945 14p5 45   6 p 1890   107 1134 13p2 630  13p3 945  2p5 45  13p6 1890      589 5670 73p2 1260 73p3 1890 16p5 45  73p6 3780  0 2 15  2 p 15 2p3 45   6 p 45  ; 1  5 p u00 11 210 17p2 420  17p3 630  2p5 15  17p6 1260  p 3 28  2 p 504  3 p 756 2p5 9   6 p 1512  n  19 210  2 p 1260  3 p 1890 14p5 45   6 p 3780   37 210 13p2 1260 13p3 1890  2p5 45  13p6 3780      13 420 73p2 2520  73p3 3780 16p5 45  73p6 7560  0 1 15  2 p 30  3 p 45  6 p 90  ; 1  5 p u  26 135 2p5 15  p 35 162 2p5 9  n 53 810 14p5 45   209 810 2p5 45   17 405 16p5 45  0; 1  5 p u00  1334 2835 17p2 210  17p3 315  2p5 15  17p6 630  p   451 1701  2 p 252  3 p 378 2p5 9   6 p 756  n  2759 3402  2 p 630  3 p 945 14p5 45   6 p 1890   1385 3402 13p2 630  13p3 945  2p5 45  13p6 1890     8033 17 010 73p2 1260 73p3 1890  16p5 45  73p6 3780  0 2 15  2 p 15 2p3 45   6 p 45  ; 1  5 p u  98 405 2p5 15  p 125 486 2p5 9  n   181 2430 14p5 45   407 2430 2p5 45      109 1215 16p5 45  0; 1  15 p u0 215 1134 17p2 420  17p3 630  17p6 1260 2p15 45  p 1399 6804  2 p 504  3 p 756  6 p 1512 2p15 27  n    3751 17 010  2 p 1260  3 p 1890  6 p 3780 14p15 135     1093 17 010 13p2 1260  13p3 1890  13p6 3780 2p15 135      5779 34 020 73p2 2520  73p3 3780  73p6 7560 16p15 135  0   1 15  2 p 30  3 p 45  6 p 90  ; 1  5 p dp 1  5 p dn0    1 567 17p2 420  17p3 630   5 p 15 17p6 1260  p 173 1701  2 p 504  3 p 756  5 p 9   6 p 1512  n   3383 34 020  2 p 1260  3 p 1890 7p5 45   6 p 3780   2189 34 020 13p2 1260  13p3 1890   5 p 45 13p6 3780     2131 34 020 73p2 2520 73p3 3780  8p5 45  73p6 7560  0   1 15  2 p 30  3 p 45  6 p 90  ;

(13)

1  15 p d0  215 2268 17p2 840  17p3 1260 17p6 2520  15 p 45  p 1399 13 608  2 p 1008  3 p 1512  6 p 3024  15 p 27  n    3751 34 020  2 p 2520  3 p 3780  6 p 7560 7p15 135     1093 34 020 13p2 2520  13p3 3780 13p6 7560   15 p 135      5779 68 040 73p2 5040 73p3 7560 73p6 15120 8p15 135  0   1 30  2 p 60  3 p 90  6 p 180  : (A2)

[1] R. Frisch and O. Stern, Z. Phys. 85, 4 (1933).

[2] S. Coleman and S. L. Glashow, Phys. Rev. Lett. 6, 423 (1961).

[3] A. Bosshard et al., Phys. Rev. D 44, 1962 (1991). [4] H. T. Diehl et al., Phys. Rev. Lett. 67, 804 (1991). [5] D. B. Leinweber, T. Draper, and R. M. Woloshyn, Phys.

Rev. D 46, 3067 (1992).

[6] F. Schlumpf, Phys. Rev. D 48, 4478 (1993); J. Linde and H. Snellman, Phys. Rev. D 53, 2337 (1996).

[7] S. T. Hong and G. E. Brown, Nucl. Phys. A580, 408 (1994).

[8] M. N. Butler, M. J. Savage, and R. P. Springer, Phys. Rev. D 49, 3459 (1994).

[9] F. X. Lee, Phys. Lett. B 419, 14 (1998); Phys. Rev. D 57, 1801 (1998).

[10] J. Linde, T. Ohlsson, and H. Snellman, Phys. Rev. D 57, 5916 (1998).

[11] G. S. Yang, H. C. Kim, M. Praszalowicz, and K. Goeke, Phys. Rev. D 70, 114002 (2004).

[12] E. Jenkins, M. Luke, A. V. Manohar, and M. Savage, Phys. Lett. B 302, 482 (1993).

[13] S. J. Puglia, M. J. Ramsey-Musolf, and S. L. Zhu, Phys. Rev. D 63, 034014 (2001).

[14] E. Jenkins and A. V. Manohar, Phys. Lett. B 335, 452 (1994).

[15] E. Jenkins, X. Ji, and A. V. Manohar, Phys. Rev. Lett. 89, 242001 (2002).

[16] R. F. Lebed and D. R. Martin, Phys. Rev. D 70, 016008 (2004).

[17] H. C. Kim, M. Polyakov, M. Praszalowicz, G. S. Yang, and K. Goeke, Phys. Rev. D 71, 094023 (2005).

[18] D. T. Spayde et al. (SAMPLE Collaboration), Phys. Lett. B 583, 79 (2004).

[19] R. D. McKeown, Phys. Lett. B 219, 140 (1989); E. J. Beise and R. D. McKeown, Comments Nucl. Part. Phys. 20, 105 (1991); R. D. McKeown, in New Directions in Quantum

Chromodynamics, edited by C. R. Ji and D. P. Min (AIP,

Melville, New York, 1999).

[20] A. Acha et al. (HAPPEX Collaboration), Phys. Rev. Lett.

98, 032301 (2007).

[21] R. D. McKeown, arXiv:hep-ph/9607340.

[22] G. E. Brown and M. Rho, Phys. Lett. B 82, 177 (1979).

[23] S. T. Hong and B. Y. Park, Nucl. Phys. A561, 525 (1993); S. T. Hong, B. Y. Park, and D. P. Min, Phys. Lett. B 414, 229 (1997).

[24] S. T. Hong and Y. J. Park, Phys. Rep. 358, 143 (2002), and references therein.

[25] R. F. Dashen, E. Jenkins, and A. V. Manohar, Phys. Rev. D

49, 4713 (1994); R. Dashen, E. Jenkins, and A. V.

Manohar, Phys. Rev. D 51, 3697 (1995); J. Dai, R. Dashen, E. Jenkins, and A. V. Manohar, Phys. Rev. D

53, 273 (1996).

[26] G. ’t Hooft, Nucl. Phys. B72, 461 (1974). [27] E. Witten, Nucl. Phys. B160, 57 (1979).

[28] R. Flores-Mendieta, E. Jenkins, and A. V. Manohar, Phys. Rev. D 58, 094028 (1998).

[29] M. A. B. Beg, B. W. Lee, and A. Pais, Phys. Rev. Lett. 13, 514 (1964).

[30] S. T. Hong and G. E. Brown, Nucl. Phys. A564, 491 (1993).

수치

TABLE II. The transition magnetic moments and their flavor components for 10J 3  1=2 !

참조

관련 문서

Modern Physics for Scientists and Engineers International Edition,

By solving the problem to minimize the sum of compliance costs and administrative costs and introducing a bureaucratic model, it is inferred deductively that

웹 표준을 지원하는 플랫폼에서 큰 수정없이 실행 가능함 패키징을 통해 다양한 기기를 위한 앱을 작성할 수 있음 네이티브 앱과

If the volume of the system is increased at constant temperature, there should be no change in internal energy: since temperature remains constant, the kinetic

Continued to the entropy cycle and energy balance with entropy changes. Reversible cycle consisting of two isothermal branches, AB and CD, and two isentropic branches,

The index is calculated with the latest 5-year auction data of 400 selected Classic, Modern, and Contemporary Chinese painting artists from major auction houses..

The key issue is whether HTS can be defined as the 6th generation of violent extremism. That is, whether it will first safely settle as a locally embedded group

A frame size error in a frame that could alter the state of the entire connection MUST be treated as a connection error (Section 5.4.1); this includes any frame carrying a