arXiv subjects

Bhubanjyoti Bhattacharya

Publications and source records attributed to Bhubanjyoti Bhattacharya.

64 records · Page 4Linked to original sources

arXiv2011

Model independent determination of the axial mass parameter in quasielastic neutrino-nucleon scattering

Quasielastic neutrino-nucleon scattering is a basic signal process for neutrino oscillation studies. At accelerator energies, the corresponding cross section is subject to significant uncertainty due to the poorly constrained axial-vector form factor of the nucleon. A model-independent description of the axial-vector form factor is presented. Data from the MiniBooNE experiment for quasielastic neutrino scattering on carbon are analyzed under the assumption of a definite nuclear model. The value of the axial mass parameter, m_A=0.85^{+0.22}_{-0.07} +/- 0.09 GeV, is found to differ significantly from extractions based on traditional form factor models. Implications for future neutrino scattering and pion electroproduction measurements are discussed.

hep-ph↗

arXiv2011

Relative Phases in $D^0\to K^0 K^-π^+$ AND $D^0\to\ok K^+π^-$ Dalitz Plots

The processes $D^0\to K^0 K^-π^+$ and $D^0\to\ok K^+π^-$ involve intermediate vector resonances whose amplitudes and phases are related to each other via flavor SU(3) symmetry. A closer look at Dalitz plots for these two processes is expected to shed light on our understanding of the usefulness of flavor SU(3) symmetry in studying charm decays. In the present work we use data from the BaBar Collaboration's publication in 2002. The goal is to reproduce Dalitz plot amplitudes and phases assuming flavor SU(3) symmetry and compare them with experiment. While an SU(3) fit is able to account for the relative magnitudes of the amplitudes for the decays $D^0 \to K^{*-}K^+$ and $D^0 \to K^{*+}K^-$, the current BaBar sample (based on an integrated luminosity of only 22 fb$^{-1}$) provides only 1--$2 σ$ evidence for the decays $D^0\to K^{*0}\ok$ and $D^0 \to \oks K^0$, with magnitudes and phases not in accord with predictions. The CLEO collaboration could potentially produce an analysis using data with better statistics, and an analysis based on the full BaBar sample (more than 20 times the 2002 value) should definitively settle the question.

hep-ph↗

arXiv2010

Cross ratios between Dalitz plot amplitudes in three-body $D^0$ decays

A recent study of $D^0 \to π^0 K^+ K^-$ and $D^0 \to K_S π^+π^-$ describes a flavor-symmetric approach to calculate relative amplitudes and phases, for characteristic interferences between $D$ decays to a light pseudoscalar $P$ and a light vector $V$, on Dalitz plots for $D \to PPP$ decays. The flavor-symmetric approach used an earlier fit to $D \to P V$ decay rates and was found to agree fairly well with experiments for $D^0 \to π^0 π^+ π^-$ but not as well for $D^0 \to π^0 K^+ K^-$ and $D^0 \to K_S π^+π^-$. The present work extends this investigation to include $D^0 \to K^- π^+ π^0$. We use an SU(3) flavor symmetry relationship between ratios of Cabibbo-favored (CF) $D \to P V$ amplitudes in $D^0 \to K^- π^+ π^0$ and ratios of singly- Cabibbo-suppressed (SCS) $D \to P V$ amplitudes in $D^0 \to π^0 K^+ K^-$ and $D^0 \to π^0 π^+ π^-$. We observe that experimental values for Dalitz plot cross ratios obey this relationship up to discrepancies noted previously. The need for an updated Dalitz plot analysis of $D^0 \to K^- π^+ π^0$ is emphasized.

hep-ph↗

arXiv2010

Relative phases in Dalitz plot amplitudes for $D^0 \to K_S π^+ π^-$ and $D^0 \to π^0 K^+ K^-$

Relative phases of amplitudes for $D$ meson decays to a light pseudoscalar meson $P$ and a light vector meson $V$ decaying to two pseudoscalar mesons will lead to characteristic interferences on the three-body Dalitz plot. These phases may be compared with predictions of a flavor-symmetric treatment which extracts contributing amplitudes and their relative phases from a fit to $D \to PV$ decay rates. Good agreement was found previously for the cases of $D^0 \to K^- π^+ π^0$ and $D^0 \to π^+ π^- π^0$. The present work is devoted to the decays $D^0 \to K_S π^+ π^-$ and $D^0 \to π^0 K^+ K^-$, for which agreement is not found. Several suggestions are offered for this discrepancy.

hep-ph↗

arXiv2010

Effect of $η$--$η'$ mixing on $D \to PV$ decays

Charmed meson decays to a light pseudoscalar ($P$) and light vector ($V$) meson are analyzed taking account of $η$--$η'$ mixing. A frequently-used octet-singlet mixing angle of $19.5^\circ$ is compared with a value of $11.7^\circ$ favored by a recent analysis of $D \to PP$ decays.

hep-ph↗

arXiv2010

Dalitz Plot Structure in $D^0 \to π^+ π^- π^0$

The BaBar Collaboration has pointed out that $D^0 \to π^+ π^- π^0$ is dominated by an isospin-zero final state, leading to nearly complete depletion of the Dalitz plot along all three diagonals. In flavor-SU(3) approaches to charmed particle decays to a light vector and a light pseudoscalar particle, this behavior is seen, but does not appear to have a fundamental origin. Instead, it arises as a result of approximate cancellation of higher-isospin combinations of several types of amplitudes: color-favored tree, color-suppressed tree, and exchange. Interpretation in terms of a direct-channel effect would require an exotic resonance, with spin, parity, and charge-congjugation eigenvalues $J^{PC} = 0^{--}$.

hep-ph↗

arXiv2009

Charmed meson decays to two pseudoscalars

A recent update of data on the decays of $D^0$, $D^+$, and $D_s^+$ to pairs of light pseudoscalars calls for a renewed analysis of key decay amplitudes and tests of flavor symmetry. The present data change our previous understanding of relative phases between amplitudes that describe Cabibbo-favored decays of the charmed mesons. The new data also seem to favor a smaller octet-singlet mixing angle for the $η$ and $η'$ mesons when singly-Cabibbo-suppressed processes are taken into account. We also discuss the effects of the new data on interference between Cabibbo-favored and doubly-Cabibbo-suppressed decays.

hep-ph↗

arXiv2008

Decays of Charmed Mesons to PV Final States

New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to $PV$ final states consisting of a light pseudoscalar meson $P$ and a light vector meson $V$ are analyzed. Following the same methods as in a previous analysis of $D \to PP$ decays, one can test flavor symmetry, extract key key amplitudes, and obtain information on relative strong phases. Analyses are performed for Cabibbo-favored decays and then extended to predict properties of singly- and doubly-Cabibbo-suppressed processes.

hep-ph↗

arXiv2008

Flavor symmetry and decays of charmed mesons to pairs of light pseudoscalars

New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to pairs of light pseudoscalar mesons $P$ allow the testing of flavor symmetry and the extraction of key amplitudes. Information on relative strong phases is obtained. One sees evidence for the expected interference between Cabibbo-favored and doubly-Cabibbo-suppressed decays in the differing patterns of $D^0 \to K_{S,L} π^0$ and $D^+ \to K_{S,L} π^+$ decays.

hep-ph↗

arXiv2007

Flavor Symmetry and Charm Decays

A wealth of new data in charmed particle physics allows the testing of flavor symmetry and the extraction of key amplitudes. Information on relative strong phases is obtained.

hep-ph↗