TY - JOUR
T1 - A noncritical Ramond-Neveu-Schwarz string with one end fixed
AU - Arapog̃lu, Savaş
AU - Saçliog̃lu, Cihan
PY - 2006/1/10
Y1 - 2006/1/10
N2 - We study a, Ramond-Neveu-Schwarz string with one end fixed on a D0-brane and the other end free as a qualitative guide to the spectrum of hadrons containing one very heavy quark. The mixed boundary conditions break half of the worldsheet supersymmetry and allow only odd α and even d modes in the Ramond sector, while the Neveu-Schwarz oscillators b's become odd-integer moded. Boson-fermion masses can still be matched if space-time is nine-dimensional; thus SO(8) triality still plays a role in the spectrum, although full space-time supersymmetry does not survive. We quantize the system in a temporal-like gauge where X0 ∼ τ. Although the gauge choice eliminates negative-norm states at the outset, there are still even-moded Virasoro and even (odd) moded super-Virasoro constraints to be imposed in the NS(R) sectors. The Casimir energy is now positive in both sectors; there are no tachyons. States for α′M2 ≤ 13/4 are explicitly constructed and found to be organized into SO(8) irreps by (super)constraints, which include a novel "√L0" operator in the Neveu-Schwarz and Γ0 ± I in the Ramond sectors. GSO projections are not allowed. The preconstraint states above the ground state have matching multiplicities, indicating space-time supersymmetry is broken by the (super)constraints. A distinctive physical signature of the system is a, slope twice that of the open RNS string. When both ends are fixed, all leading and subleading trajectories are eliminated, resulting in a spectrum qualitatively similar to the J/ψ and γ particles.
AB - We study a, Ramond-Neveu-Schwarz string with one end fixed on a D0-brane and the other end free as a qualitative guide to the spectrum of hadrons containing one very heavy quark. The mixed boundary conditions break half of the worldsheet supersymmetry and allow only odd α and even d modes in the Ramond sector, while the Neveu-Schwarz oscillators b's become odd-integer moded. Boson-fermion masses can still be matched if space-time is nine-dimensional; thus SO(8) triality still plays a role in the spectrum, although full space-time supersymmetry does not survive. We quantize the system in a temporal-like gauge where X0 ∼ τ. Although the gauge choice eliminates negative-norm states at the outset, there are still even-moded Virasoro and even (odd) moded super-Virasoro constraints to be imposed in the NS(R) sectors. The Casimir energy is now positive in both sectors; there are no tachyons. States for α′M2 ≤ 13/4 are explicitly constructed and found to be organized into SO(8) irreps by (super)constraints, which include a novel "√L0" operator in the Neveu-Schwarz and Γ0 ± I in the Ramond sectors. GSO projections are not allowed. The preconstraint states above the ground state have matching multiplicities, indicating space-time supersymmetry is broken by the (super)constraints. A distinctive physical signature of the system is a, slope twice that of the open RNS string. When both ends are fixed, all leading and subleading trajectories are eliminated, resulting in a spectrum qualitatively similar to the J/ψ and γ particles.
KW - Heavy quark physics
KW - String and brane theory
KW - Supersymmetry phenomenology
UR - http://www.scopus.com/inward/record.url?scp=32644440498&partnerID=8YFLogxK
U2 - 10.1142/S0217751X06022798
DO - 10.1142/S0217751X06022798
M3 - Article
AN - SCOPUS:32644440498
SN - 0217-751X
VL - 21
SP - 185
EP - 204
JO - International Journal of Modern Physics A
JF - International Journal of Modern Physics A
IS - 1
ER -