Dayashankar Kulshreshtha | University of Delhi (original) (raw)

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Papers by Dayashankar Kulshreshtha

Research paper thumbnail of How big are the decay constants ƒP of heavy-light mesons?

Physics Letters B, 1991

The quark loop diagram for f;P for a heavy-light (Qq) meson is employed within a Lorentz-invarian... more The quark loop diagram for f;P for a heavy-light (Qq) meson is employed within a Lorentz-invariant framework for addressing a two-fold issue: (i) finite corrections to the asymptotic scaling law (f;P~mQ-1/2) of shifman, Voloshin, Politzer and Wise; (ii) 1/MQ corrections to the static approximation for the heavy-quark propagator in lattice calculations. The loop diagram yields a general two-component structure f;P=f;0+deltaf;

Research paper thumbnail of String Gauge symmetries in the conformally Gauge-Fixed Polyakov D1 Brane action in the presence of background Gauge fields

Journal of Modern Physics, Jan 1, 2012

Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LF... more Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LFQ) of the conformally gauge-fixed Polyakov D1 brane action using the Hamiltonian and path integral formulations. The IFQ is studied in the equal world-sheet time framework on the hyperplanes defined by the world-sheet time σ 0 = τ = constant and the LFQ in the equal light-cone world-sheet time framework, on the hyperplanes of the light-front defined by the light-cone world-sheet time . The light-front theory is seen to be a constrained system in the sense of Dirac in contrast to the instant-form theory. However, owing to the gauge anomalous nature of these theories, both of these theories are seen to lack the usual string gauge symmetries defined by the world-sheet reparametrization invariance (WSRI) and the Weyl invariance (WI). In the present work we show that these theories when considered in the presence of background gauge fields such as the NSNS 2-form gauge field

Research paper thumbnail of c anti-c AND b anti-b SPECTROSCOPY IN THE TWO STEP POTENTIAL MODEL

Research paper thumbnail of The fine and hyperfine structure and dipole transitions of charmonium and bottonium in the two-step potential model

Il Nuovo Cimento A (1971-1996), Jan 1, 1985

... 87A, N. 1 1 Maggie 1985 ... IIALLING, DL ]cIA:RTILL, S. IIOLZNER, M. ITO, J. KANDAS-WAMY, DL ... more ... 87A, N. 1 1 Maggie 1985 ... IIALLING, DL ]cIA:RTILL, S. IIOLZNER, M. ITO, J. KANDAS-WAMY, DL KREINICK, Y. KUBOTA, NB MISTRY, F. MO:RROW, E. NO:RDBE:RG, M. 0GG, A. SILVER:MAN, I ). C. STEIN, S. STONE, I). WEBE:R, R. ~VILCKE, AJ SADDOFF, R. GILES, J. IIASSA ...

Research paper thumbnail of The cc and bb spectroscopy in the two-step potential model

Lettere Al Nuovo Cimento (1971–1985), Jan 1, 1985

Summary We investigate the spectroscopy of the charmonium (cc) and bottomonium (bb) bound states ... more Summary We investigate the spectroscopy of the charmonium (cc) and bottomonium (bb) bound states in a static flavour-independent nonrelativistic quark-antiquark (qq) two-step potential model proposed earlier. Our predictions are in good agreement with ...

Research paper thumbnail of Light-Front Hamiltonian and Path Integral Formulations of the Conformally Gauge-Fixed Polyakov D1 Brane Action

Journal of Modern Physics, Jan 1, 2011

Research paper thumbnail of Light-Front Hamiltonian and Path Integral Formulations of the Conformally Gauge-Fixed Polyakov D1 Brane Action Open Access

Research paper thumbnail of Light-Front Hamiltonian, Path Integral and BRST Formulations of the Chern-Simons Theory under Appropriate Gauge-Fixing

Journal of Modern Physics, Jan 1, 2010

Research paper thumbnail of Light-Front Hamiltonian, Path Integral and BRST Formulations of the Chern-Simons Theory under Appropriate Gauge-Fixing Open Access

Research paper thumbnail of Light-Front Quantization of the Chern-Simons-Higgs Theory

Research paper thumbnail of Light Cone 2010

Research paper thumbnail of How big are the decay constants ƒP of heavy-light mesons?

Physics Letters B, 1991

The quark loop diagram for f;P for a heavy-light (Qq) meson is employed within a Lorentz-invarian... more The quark loop diagram for f;P for a heavy-light (Qq) meson is employed within a Lorentz-invariant framework for addressing a two-fold issue: (i) finite corrections to the asymptotic scaling law (f;P~mQ-1/2) of shifman, Voloshin, Politzer and Wise; (ii) 1/MQ corrections to the static approximation for the heavy-quark propagator in lattice calculations. The loop diagram yields a general two-component structure f;P=f;0+deltaf;

Research paper thumbnail of String Gauge symmetries in the conformally Gauge-Fixed Polyakov D1 Brane action in the presence of background Gauge fields

Journal of Modern Physics, Jan 1, 2012

Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LF... more Recently we have studied the instant-form quantization (IFQ) and the light-front quantization (LFQ) of the conformally gauge-fixed Polyakov D1 brane action using the Hamiltonian and path integral formulations. The IFQ is studied in the equal world-sheet time framework on the hyperplanes defined by the world-sheet time σ 0 = τ = constant and the LFQ in the equal light-cone world-sheet time framework, on the hyperplanes of the light-front defined by the light-cone world-sheet time . The light-front theory is seen to be a constrained system in the sense of Dirac in contrast to the instant-form theory. However, owing to the gauge anomalous nature of these theories, both of these theories are seen to lack the usual string gauge symmetries defined by the world-sheet reparametrization invariance (WSRI) and the Weyl invariance (WI). In the present work we show that these theories when considered in the presence of background gauge fields such as the NSNS 2-form gauge field

Research paper thumbnail of c anti-c AND b anti-b SPECTROSCOPY IN THE TWO STEP POTENTIAL MODEL

Research paper thumbnail of The fine and hyperfine structure and dipole transitions of charmonium and bottonium in the two-step potential model

Il Nuovo Cimento A (1971-1996), Jan 1, 1985

... 87A, N. 1 1 Maggie 1985 ... IIALLING, DL ]cIA:RTILL, S. IIOLZNER, M. ITO, J. KANDAS-WAMY, DL ... more ... 87A, N. 1 1 Maggie 1985 ... IIALLING, DL ]cIA:RTILL, S. IIOLZNER, M. ITO, J. KANDAS-WAMY, DL KREINICK, Y. KUBOTA, NB MISTRY, F. MO:RROW, E. NO:RDBE:RG, M. 0GG, A. SILVER:MAN, I ). C. STEIN, S. STONE, I). WEBE:R, R. ~VILCKE, AJ SADDOFF, R. GILES, J. IIASSA ...

Research paper thumbnail of The cc and bb spectroscopy in the two-step potential model

Lettere Al Nuovo Cimento (1971–1985), Jan 1, 1985

Summary We investigate the spectroscopy of the charmonium (cc) and bottomonium (bb) bound states ... more Summary We investigate the spectroscopy of the charmonium (cc) and bottomonium (bb) bound states in a static flavour-independent nonrelativistic quark-antiquark (qq) two-step potential model proposed earlier. Our predictions are in good agreement with ...

Research paper thumbnail of Light-Front Hamiltonian and Path Integral Formulations of the Conformally Gauge-Fixed Polyakov D1 Brane Action

Journal of Modern Physics, Jan 1, 2011

Research paper thumbnail of Light-Front Hamiltonian and Path Integral Formulations of the Conformally Gauge-Fixed Polyakov D1 Brane Action Open Access

Research paper thumbnail of Light-Front Hamiltonian, Path Integral and BRST Formulations of the Chern-Simons Theory under Appropriate Gauge-Fixing

Journal of Modern Physics, Jan 1, 2010

Research paper thumbnail of Light-Front Hamiltonian, Path Integral and BRST Formulations of the Chern-Simons Theory under Appropriate Gauge-Fixing Open Access

Research paper thumbnail of Light-Front Quantization of the Chern-Simons-Higgs Theory

Research paper thumbnail of Light Cone 2010