Financial Reporting Frequency and Corporate Innovation

We examine how the regulation of financial reporting frequency affects corporate innovation. We use a difference-in-differences approach based on a sample of treatment firms that experience a change in their reporting frequency and matched industry peers and control firms whose reporting frequency remains unchanged. We find that higher reporting frequency significantly reduces treatment firms’ innovation output, but find no evidence that the net externality effect on industry peers is statistically significant. Together, our results are consistent with the hypothesis that frequent reporting induces managerial myopia and impedes corporate innovation

Correlation dynamics between electrons and ions in the fragmentation of D2_2 molecules by short laser pulses

We studied the recollision dynamics between the electrons and D$_2^+$ ions following the tunneling ionization of D$_2$ molecules in an intense short pulse laser field. The returning electron collisionally excites the D$_2^+$ ion to excited electronic states from there D$_2^+$ can dissociate or be further ionized by the laser field, resulting in D$^+$ + D or D$^+$ + D$^+$, respectively. We modeled the fragmentation dynamics and calculated the resulting kinetic energy spectrum of D$^+$ to compare with recent experiments. Since the recollision time is locked to the tunneling ionization time which occurs only within fraction of an optical cycle, the peaks in the D$^+$ kinetic energy spectra provides a measure of the time when the recollision occurs. This collision dynamics forms the basis of the molecular clock where the clock can be read with attosecond precision, as first proposed by Corkum and coworkers. By analyzing each of the elementary processes leading to the fragmentation quantitatively, we identified how the molecular clock is to be read from the measured kinetic energy spectra of D$^+$ and what laser parameters be used in order to measure the clock more accurately.Comment: 13 pages with 14 figure

Observation of χc1\chi_{c1} decays into vector meson pairs ϕϕ\phi\phi, ωω\omega\omega, and ωϕ\omega\phi

Decays of $\chi_{c1}$ to vector meson pairs $\phi\phi$, $\omega\omega$ and $\omega\phi$ are observed for the first time using $(106\pm4)\times 10^6$ \psip events accumulated at the BESIII detector at the BEPCII $e^+e^-$ collider. The branching fractions are measured to be $(4.4\pm 0.3\pm 0.5)\times 10^{-4}$, $(6.0\pm 0.3\pm 0.7)\times 10^{-4}$, and $(2.2\pm 0.6\pm 0.2)\times 10^{-5}$, for $\chi_{c1}\to \phi\phi$, $\omega\omega$, and $\omega\phi$, respectively. The observation of $\chi_{c1}$ decays into a pair of vector mesons $\phi\phi$, $\omega\omega$ and $\omega\phi$ indicates that the hadron helicity selection rule is significantly violated in $\chi_{cJ}$ decays. In addition, the measurement of $\chi_{cJ}\to \omega\phi$ gives the rate of doubly OZI-suppressed decay. Branching fractions for $\chi_{c0}$ and $\chi_{c2}$ decays into other vector meson pairs are also measured with improved precision.Comment: 4 pages, 2 figure

First Observation of the Decays chi_{cJ} -> pi^0 pi^0 pi^0 pi^0

We present a study of the P-wave spin -triplet charmonium chi_{cJ} decays (J=0,1,2) into pi^0 pi^0 pi^0 pi^0. The analysis is based on 106 million \psiprime decays recorded with the BESIII detector at the BEPCII electron positron collider. The decay into the pi^0 pi^0 pi^0 pi^0 hadronic final state is observed for the first time. We measure the branching fractions B(chi_{c0} -> pi^0 pi^0 pi^0 pi^0)=(3.34 +- 0.06 +- 0.44)*10^{-3}, B(chi_{c1} -> pi^0 pi^0 pi^0 pi^0)=(0.57 +- 0.03 +- 0.08)*10^{-3}, and B(chi_{c2} -> pi^0 pi^0 pi^0 pi^0)=(1.21 +- 0.05 +- 0.16)*10^{-3}, where the uncertainties are statistical and systematical, respectively.Comment: 7 pages, 3 figure

Study of χcJ\chi_{cJ} radiative decays into a vector meson

The decays $\chi_{cJ}\to\gamma V$ ($V=\phi, \rho^0, \omega$) are studied with a sample of radiative \psip\to\gamma\chi_{cJ} events in a sample of (1.06\pm0.04)\times 10^{8} \psip events collected with the BESIII detector. The branching fractions are determined to be: ${\cal B}(\chi_{c1}\to \gamma\phi)=(25.8\pm 5.2\pm 2.3)\times 10^{-6}$, ${\cal B}(\chi_{c1}\to \gamma\rho^0)=(228\pm 13\pm 22)\times 10^{-6}$, and ${\cal B}(\chi_{c1}\to \gamma\omega)=(69.7\pm 7.2\pm 6.6)\times 10^{-6}$. The decay $\chi_{c1}\to \gamma\phi$ is observed for the first time. Upper limits at the 90% confidence level on the branching fractions for $\chi_{c0}$ and \chict decays into these final states are determined. In addition, the fractions of the transverse polarization component of the vector meson in $\chi_{c1}\to \gamma V$ decays are measured to be $0.29_{-0.12-0.09}^{+0.13+0.10}$ for $\chi_{c1}\to \gamma\phi$, $0.158\pm 0.034^{+0.015}_{-0.014}$ for $\chi_{c1}\to \gamma\rho^0$, and $0.247_{-0.087-0.026}^{+0.090+0.044}$ for $\chi_{c1}\to \gamma\omega$, respectively. The first errors are statistical and the second ones are systematic.Comment: 8 pages, 3 figure

Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0

We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data samples at both resonances collected with the BES III detector in 2009. We measure the corresponding branching fractions with unprecedented precision and provide mass spectra and Dalitz plots. The branching fraction for J/psi -> pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.) +0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4. The J/psi decay is found to be dominated by an intermediate rho(770) state, whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2, leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure

Study of J/ψ→ppˉJ/\psi\to p\bar{p} and J/ψ→nnˉJ/\psi\to n\bar{n}

The decays $J/\psi\to p\bar{p}$ and $J/\psi\to n\bar{n}$ have been investigated with a sample of 225.2 million $J/\psi$ events collected with the BESIII detector at the BEPCII $e^+e^-$ collider. The branching fractions are determined to be $\mathcal{B}(J/\psi\to p\bar{p})=(2.112\pm0.004\pm0.031)\times10^{-3}$ and $\mathcal{B}(J/\psi\to n\bar{n})=(2.07\pm0.01\pm0.17)\times10^{-3}$. Distributions of the angle $\theta$ between the proton or anti-neutron and the beam direction are well described by the form $1+\alpha\cos^2\theta$, and we find $\alpha=0.595\pm0.012\pm0.015$ for $J/\psi\to p\bar{p}$ and $\alpha=0.50\pm0.04\pm0.21$ for $J/\psi\to n\bar{n}$. Our branching-fraction results suggest a large phase angle between the strong and electromagnetic amplitudes describing the $J/\psi\to N\bar{N}$ decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR

First observation of the M1 transition ψ(3686)→γηc(2S)\psi(3686)\to \gamma\eta_c(2S)

Using a sample of 106 million \psi(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: \psi(3686)\to\gamma\eta_c(2S). Analyses of the processes \psi(2S)\to \gamma\eta_c(2S) with \eta_c(2S)\to \K_S^0 K\pi and K^+K^-\pi^0 gave an \eta_c(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the \eta_c(2S) mass (M(\eta_c(2S))=3637.6\pm 2.9_\mathrm{stat}\pm 1.6_\mathrm{sys} MeV/c^2), width (\Gamma(\eta_c(2S))=16.9\pm 6.4_\mathrm{stat}\pm 4.8_\mathrm{sys} MeV), and the product branching fraction (\BR(\psi(3686)\to \gamma\eta_c(2S))\times \BR(\eta_c(2S)\to K\bar K\pi) = (1.30\pm 0.20_\mathrm{stat}\pm 0.30_\mathrm{sys})\times 10^{-5}). Combining our result with a BaBar measurement of \BR(\eta_c(2S)\to K\bar K \pi), we find the branching fraction of the M1 transition to be \BR(\psi(3686)\to\gamma\eta_c(2S)) = (6.8\pm 1.1_\mathrm{stat}\pm 4.5_\mathrm{sys})\times 10^{-4}.Comment: 7 pages, 1 figure, 1 tabl

Higher-order multipole amplitude measurement in ψ(2S)→γχc2\psi(2S)\to\gamma\chi_{c2}

Using $106\times10^6$ $\psi(2S)$ events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition $\psi(2S)\to\gamma\chi_{c2}\to\gamma\pi\pi/\gamma KK$ are measured. A fit to the $\chi_{c2}$ production and decay angular distributions yields $M2=0.046\pm0.010\pm0.013$ and $E3=0.015\pm0.008\pm0.018$, where the first errors are statistical and the second systematic. Here $M2$ denotes the normalized magnetic quadrupole amplitude and $E3$ the normalized electric octupole amplitude. This measurement shows evidence for the existence of the $M2$ signal with $4.4\sigma$ statistical significance and is consistent with the charm quark having no anomalous magnetic moment.Comment: 14 pages, 4 figure