Lithuanian Journal of Physics article / Lietuvos fizikos žurnalo straipsnis

EFFECT OF THE CASIMIR ENERGY ON THE BAG MODEL PHENOMENOLOGY OF LIGHT HADRONS
A. Bernotas^a and V. Šimonis^b
^aFaculty of Physics, Vilnius University, Saulėtekio 9, LT-10222 Vilnius, Lithuania
^bInstitute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto 12, LT-01108 Vilnius, Lithuania
E-mail: vytautas.simonis@tfai.vu.lt

Received 2 July 2012; accepted 20 September 2012

The dependence of light hadron masses and baryon magnetic moments on the magnitude of the Casimir energy is examined in the bag model with centre-of-mass corrections. There are seven free parameters in the model. Six of them are determined from the fit to the masses of certain hadrons, and the last one (Casimir energy parameter) from the best fit to the magnetic moments of light baryons. The predicted magnetic moments are compared with the results obtained in various other models and with experiment data.

Keywords: bag model, Casimir energy, magnetic moments
PACS: 12.39.Ba, 13.40.Em

CASIMIRO ENERGIJOS ĮTAKA LENGVŲJŲ HADRONŲ SAVYBĖMS KVARKŲ MAIŠŲ MODELYJE
A. Bernotas^a, V. Šimonis^b
^aVilniaus universiteto Fizikos fakultetas, Vilnius, Lietuva
^bVilniaus universiteto Teorinės fizikos ir astronomijos institutas, Vilnius, Lietuva

Į modifikuoto kvarkų maišų modelio Hamiltonianą įtrauktas Casimiro energiją atitinkantis narys ir ištirta lengvųjų hadronų, kurių sudėtyje yra u, d bei s kvarkai, masių ir magnetinių momentų priklausomybė nuo šios energijos dydžio. Nustatyta optimali Casimiro energijos parametro Z₀ reikšmė, kada geriausiai su su eksperimentu sutampa suskaičiuoti magnetiniai momentai ir dalelių masės. Rezultatai palyginti su kitų autorių įvertinimais (atliktais naudojant įvairius metodus) bei su eksperimentiniais duomenimis.

References / Nuorodos

[1] R.F. Lebed and R.H. TerBeek, Baryon magnetic moments in alternate 1/N_c expansions, Phys. Rev. D 83, 016009 (2011),
http://dx.doi.org/10.1103/PhysRevD.83.016009
[2] T. DeGrand, R.L. Jaffe, K. Johnson, and J. Kiskis, Masses and other parameters of the light hadrons, Phys. Rev. D 12, 2060 (1975),
http://dx.doi.org/10.1103/PhysRevD.12.2060
[3] P. Hasenfratz and J. Kuti, The quark bag model, Phys. Rep. 40, 75 (1978),
http://dx.doi.org/10.1016/0370-1573(78)90076-5
[4] P. Miškinis and G. Karlikauskas, Rigid surface bag model, Nucl. Phys. A 683, 339 (2001),
http://dx.doi.org/10.1016/S0375-9474(00)00442-5
[5] R.H. Hackman, N.G. Deshpande, D.A. Dicus, and V.L. Teplitz, M1 transitions in the MIT bag model, Phys. Rev. D 18, 2537 (1978),
http://dx.doi.org/10.1103/PhysRevD.18.2537
[6] A. Halprin and A.K. Kerman, Lepton bags, Phys. Rev. D 26, 2532 (1982),
http://dx.doi.org/10.1103/PhysRevD.26.2532
[7] J. Bartelski, A. Szymacha, Z. Ryzak, L. Mankiewicz, and S. Tatur, The influence of c. m. motion and chiral symmetry on masses and electroweak parameters of hadrons in the bag model, Nucl. Phys. A 424, 484 (1984),
http://dx.doi.org/10.1016/0375-9474(84)90006-X
[8] V. Šimonis, Static properties of hadrons in the improved bag model, Lith. J. Phys. 38, 274 (1998)
[9] A. Bernotas and V. Šimonis, Towards the unified description of light and heavy hadrons in the bag model approach, Nucl. Phys. A 741, 179 (2004),
http://dx.doi.org/10.1016/j.nuclphysa.2004.05.017
[10] C.E. Carlson, T.H. Hansson, and C. Peterson, Meson, baryon, and glueball masses in the MIT bag model, Phys. Rev. D 27, 1556 (1983),
http://dx.doi.org/10.1103/PhysRevD.27.1556
[11] K.A. Milton, New method for the angular-momentum projection, Phys. Rev. D 27, 439 (1983),
http://link.aps.org/doi/10.1103/PhysRevLett.27.439
[12] A. Chodos, R.L. Jaffe, K. Johnson, C.B. Thorn, and V.F. Weisskopf, New extended model of hadrons, Phys. Rev. D 9, 3471 (1974),
http://dx.doi.org/10.1103/PhysRevD.9.3471
[13] J.F. Donoghue and K. Johnson, The pion and an improved static bag model, Phys. Rev. D 21, 1975 (1980), http://dx.doi.org/10.1103/PhysRevD.21.1975
[14] J. Bartelski, A. Szymacha, L. Mankiewicz, and S. Tatur, Center-of-mass corrections to static properties of hadrons in the bag model, Phys. Rev. D 29, 1035 (1984),
http://dx.doi.org/10.1103/PhysRevD.29.1035
[15] D. Tadić and G. Tadić, Center-of-mass corrections and fermions consisting of confined quarks, Phys. Rev. D 31, 1700 (1985),
http://dx.doi.org/10.1103/PhysRevD.31.1700
[16] L.C.L. Hollenberg and B.H.J. McKellar, Improved meson mass spectrum calculation in the static cavity, J. Phys. G 16, 31 (1990),
http://dx.doi.org/10.1088/0954-3899/16/1/006
[17] K.A. Milton, The Casimir Effect (World Scientific, Singapore, 2001),
http://www.worldscibooks.com/physics/4505.html
[18] S. Leseduarte and A. Romeo, Complete zeta-function approach to the electromagnetic Casimir effect for spheres and circles, Ann. Phys. (NY) 250, 448 (1996),
http://dx.doi.org/10.1006/aphy.1996.0101
[19] K. Nakamura et al. (Particle Data Group), Review of particle physics, J. Phys. G 37, 075021 (2010),
http://dx.doi.org/10.1088/0954-3899/37/7A/075021
[20] L.G. Pondrom, Baryon magnetic moments and the quark model reexamined, Phys. Rev. D 53, 5322 (1996),
http://dx.doi.org/10.1103/PhysRevD.53.5322
[21] A.R. Panda, K.C. Roy, and R.K. Sahoo, Static properties of octet baryons in a field-theoretic quark model, Phys. Rev. D 49, 4659 (1994),
http://dx.doi.org/10.1103/PhysRevD.49.4659
[22] R.K. Sahoo, A.R. Panda, and A. Nath, Magnetic moments and charge radii of decuplet baryons in a fieldtheoretic quark model, Phys. Rev. D 52, 4099 (1995),
http://dx.doi.org/10.1103/PhysRevD.52.4099
[23] N. Sharma, H. Dahiya, P.K. Chatley, and M. Gupta, Spin 1/2⁺, spin 3/2⁺, and transition magnetic moments of low lying and charmed baryons, Phys. Rev. D 81, 073001 (2010),
http://dx.doi.org/10.1103/PhysRevD.81.073001
[24] L.S. Geng, J. Martin Camalich, L. Alvarez-Ruso, and M.J. Vicente Vacas, Leading SU(3)-breaking corrections to the baryon magnetic moments in chiral perturbation theory, Phys. Rev. Lett. 101, 222002 (2008),