Measurement of Spin Density Matrix Elements in $\Lambda(1520)$ Photoproduction at 8.2-8.8 GeV

The GlueX collaboration Adhikari, S. ; Akondi, C.S. ; Albrecht, M. ; et al.
Phys.Rev.C 105 (2022) 035201, 2022.
Inspire Record 1892395 DOI 10.17182/hepdata.132920

We report on the measurement of spin density matrix elements of the $\Lambda(1520)$ in the photoproduction reaction $\gamma p\rightarrow \Lambda(1520)K^+$, via its subsequent decay to $K^{-}p$. The measurement was performed as part of the GlueX experimental program in Hall D at Jefferson Lab using a linearly polarized photon beam with $E_\gamma =$ 8.2-8.8 GeV. These are the first such measurements in this photon energy range. Results are presented in bins of momentum transfer squared, $-(t-t_\text{0})$. We compare the results with a Reggeon exchange model and determine that natural exchange amplitudes are dominant in $\Lambda(1520)$ photoproduction.

10 data tables

Numerical results for all presented SDMEs. The first uncertainty is statistical, the second systematic

Numerical results for all presented natural and unnatural combinations, and covariances between $\rho^1_{11}$ and $\rho^1_{33}$. The first uncertainty is statistical, the second systematic

This table contains thinned out samples of the Markov chains used in the parameter estimation of the SDME measurements for $-(t-t_\text{0}) = 0.197\pm0.069~\text{GeV}^2/c^2$, reported in the main article. One in about 250 steps in the chain, which results in 200 different sets of SDMEs, is provided. These values should be used instead of bootstrapping of the results, in order to estimate uncertainties of physics models fitted to this data. To assess how the uncertainties propagate to the model uncertainties, one should evaluate the model under scrutiny for each of the 200 different sets of SDMEs. Plotting all resulting lines in a single plot will create bands which reflect the influence of the uncertainties in the data on the model. This method has the great advantage that all correlations are accurately taken into account.

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The exotic meson $\pi_1(1600)$ with $J^{PC} = 1^{-+}$ and its decay into $\rho(770)\pi$

The COMPASS collaboration Alexeev, M.G. ; Alexeev, G.D. ; Amoroso, A. ; et al.
Phys.Rev.D 105 (2022) 012005, 2022.
Inspire Record 1898933 DOI 10.17182/hepdata.114098

We study the spin-exotic $J^{PC} = 1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV$/c$ pions into $\pi^-\pi^-\pi^+$ using a hydrogen target and confirm the $\pi_1(1600) \to \rho(770) \pi$ amplitude, which interferes with a nonresonant $1^{-+}$ amplitude. We demonstrate that conflicting conclusions from previous studies on these amplitudes can be attributed to different analysis models and different treatment of the dependence of the amplitudes on the squared four-momentum transfer and we thus reconcile their experimental findings. We study the nonresonant contributions to the $\pi^-\pi^-\pi^+$ final state using pseudo-data generated on the basis of a Deck model. Subjecting pseudo-data and real data to the same partial-wave analysis, we find good agreement concerning the spectral shape and its dependence on the squared four-momentum transfer for the $J^{PC} = 1^{-+}$ amplitude and also for amplitudes with other $J^{PC}$ quantum numbers. We investigate for the first time the amplitude of the $\pi^-\pi^+$ subsystem with $J^{PC} = 1^{--}$ in the $3\pi$ amplitude with $J^{PC} = 1^{-+}$ employing the novel freed-isobar analysis scheme. We reveal this $\pi^-\pi^+$ amplitude to be dominated by the $\rho(770)$ for both the $\pi_1(1600)$ and the nonresonant contribution. We determine the $\rho(770)$ resonance parameters within the three-pion final state. These findings largely confirm the underlying assumptions for the isobar model used in all previous partial-wave analyses addressing the $J^{PC} = 1^{-+}$ amplitude.

4 data tables

Results for the spin-exotic $1^{-+}1^+[\pi\pi]_{1^{-\,-}}\pi P$ wave from the free-isobar partial-wave analysis performed in the first $t^\prime$ bin from $0.100$ to $0.141\;(\text{GeV}/c)^2$. The plotted values represent the intensity of the coherent sum of the dynamic isobar amplitudes $\{\mathcal{T}_k^\text{fit}\}$ as a function of $m_{3\pi}$, where the coherent sums run over all $m_{\pi^-\pi^+}$ bins indexed by $k$. These intensity values are given in number of events per $40\;\text{MeV}/c^2$ $m_{3\pi}$ interval and correspond to the orange points in Fig. 8(a). In the "Resources" section of this $t^\prime$ bin, we provide the JSON file named <code>transition_amplitudes_tBin_0.json</code> for download, which contains for each $m_{3\pi}$ bin the values of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, their covariances, and further information. The data in this JSON file are organized in independent bins of $m_{3\pi}$. The information in these bins can be accessed via the key <code>m3pi_bin_<#>_t_prime_bin_0</code>. Each independent $m_{3\pi}$ bin contains <ul> <li>the kinematic ranges of the $(m_{3\pi}, t^\prime)$ cell, which are accessible via the keys <code>m3pi_lower_limit</code>, <code>m3pi_upper_limit</code>, <code>t_prime_lower_limit</code>, and <code>t_prime_upper_limit</code>.</li> <li>the $m_{\pi^-\pi^+}$ bin borders, which are accessible via the keys <code>m2pi_lower_limits</code> and <code>m2pi_upper_limits</code>.</li> <li>the real and imaginary parts of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which are accessible via the keys <code>transition_amplitudes_real_part</code> and <code>transition_amplitudes_imag_part</code>, respectively.</li> <li>the covariance matrix of the real and imaginary parts of the $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>covariance_matrix</code>. Note that this matrix is real-valued and that its rows and columns are indexed such that $(\Re,\Im)$ pairs of the transition amplitudes are arranged with increasing $k$.</li> <li>the normalization factors $\mathcal{N}_a$ in Eq. (13) for all $m_{\pi^-\pi^+}$ bins, which are accessible via the key <code>normalization_factors</code>.</li> <li>the shape of the zero mode, i.e., the values of $\tilde\Delta_k$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>zero_mode_shape</code>.</li> <li>the reference wave, which is accessible via the key <code>reference_wave</code>. Note that this is always the $4^{++}1^+\rho(770)\pi G$ wave.</li> </ul>

Results for the spin-exotic $1^{-+}1^+[\pi\pi]_{1^{-\,-}}\pi P$ wave from the free-isobar partial-wave analysis performed in the second $t^\prime$ bin from $0.141$ to $0.194\;(\text{GeV}/c)^2$. The plotted values represent the intensity of the coherent sum of the dynamic isobar amplitudes $\{\mathcal{T}_k^\text{fit}\}$ as a function of $m_{3\pi}$, where the coherent sums run over all $m_{\pi^-\pi^+}$ bins indexed by $k$. These intensity values are given in number of events per $40\;\text{MeV}/c^2$ $m_{3\pi}$ interval and correspond to the orange points in Fig. 15(a) in the supplemental material of the paper. In the "Resources" section of this $t^\prime$ bin, we provide the JSON file named <code>transition_amplitudes_tBin_1.json</code> for download, which contains for each $m_{3\pi}$ bin the values of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, their covariances, and further information. The data in this JSON file are organized in independent bins of $m_{3\pi}$. The information in these bins can be accessed via the key <code>m3pi_bin_<#>_t_prime_bin_1</code>. Each independent $m_{3\pi}$ bin contains <ul> <li>the kinematic ranges of the $(m_{3\pi}, t^\prime)$ cell, which are accessible via the keys <code>m3pi_lower_limit</code>, <code>m3pi_upper_limit</code>, <code>t_prime_lower_limit</code>, and <code>t_prime_upper_limit</code>.</li> <li>the $m_{\pi^-\pi^+}$ bin borders, which are accessible via the keys <code>m2pi_lower_limits</code> and <code>m2pi_upper_limits</code>.</li> <li>the real and imaginary parts of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which are accessible via the keys <code>transition_amplitudes_real_part</code> and <code>transition_amplitudes_imag_part</code>, respectively.</li> <li>the covariance matrix of the real and imaginary parts of the $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>covariance_matrix</code>. Note that this matrix is real-valued and that its rows and columns are indexed such that $(\Re,\Im)$ pairs of the transition amplitudes are arranged with increasing $k$.</li> <li>the normalization factors $\mathcal{N}_a$ in Eq. (13) for all $m_{\pi^-\pi^+}$ bins, which are accessible via the key <code>normalization_factors</code>.</li> <li>the shape of the zero mode, i.e., the values of $\tilde\Delta_k$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>zero_mode_shape</code>.</li> <li>the reference wave, which is accessible via the key <code>reference_wave</code>. Note that this is always the $4^{++}1^+\rho(770)\pi G$ wave.</li> </ul>

Results for the spin-exotic $1^{-+}1^+[\pi\pi]_{1^{-\,-}}\pi P$ wave from the free-isobar partial-wave analysis performed in the third $t^\prime$ bin from $0.194$ to $0.326\;(\text{GeV}/c)^2$. The plotted values represent the intensity of the coherent sum of the dynamic isobar amplitudes $\{\mathcal{T}_k^\text{fit}\}$ as a function of $m_{3\pi}$, where the coherent sums run over all $m_{\pi^-\pi^+}$ bins indexed by $k$. These intensity values are given in number of events per $40\;\text{MeV}/c^2$ $m_{3\pi}$ interval and correspond to the orange points in Fig. 15(b) in the supplemental material of the paper. In the "Resources" section of this $t^\prime$ bin, we provide the JSON file named <code>transition_amplitudes_tBin_2.json</code> for download, which contains for each $m_{3\pi}$ bin the values of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, their covariances, and further information. The data in this JSON file are organized in independent bins of $m_{3\pi}$. The information in these bins can be accessed via the key <code>m3pi_bin_<#>_t_prime_bin_2</code>. Each independent $m_{3\pi}$ bin contains <ul> <li>the kinematic ranges of the $(m_{3\pi}, t^\prime)$ cell, which are accessible via the keys <code>m3pi_lower_limit</code>, <code>m3pi_upper_limit</code>, <code>t_prime_lower_limit</code>, and <code>t_prime_upper_limit</code>.</li> <li>the $m_{\pi^-\pi^+}$ bin borders, which are accessible via the keys <code>m2pi_lower_limits</code> and <code>m2pi_upper_limits</code>.</li> <li>the real and imaginary parts of the transition amplitudes $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which are accessible via the keys <code>transition_amplitudes_real_part</code> and <code>transition_amplitudes_imag_part</code>, respectively.</li> <li>the covariance matrix of the real and imaginary parts of the $\{\mathcal{T}_k^\text{fit}\}$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>covariance_matrix</code>. Note that this matrix is real-valued and that its rows and columns are indexed such that $(\Re,\Im)$ pairs of the transition amplitudes are arranged with increasing $k$.</li> <li>the normalization factors $\mathcal{N}_a$ in Eq. (13) for all $m_{\pi^-\pi^+}$ bins, which are accessible via the key <code>normalization_factors</code>.</li> <li>the shape of the zero mode, i.e., the values of $\tilde\Delta_k$ for all $m_{\pi^-\pi^+}$ bins, which is accessible via the key <code>zero_mode_shape</code>.</li> <li>the reference wave, which is accessible via the key <code>reference_wave</code>. Note that this is always the $4^{++}1^+\rho(770)\pi G$ wave.</li> </ul>

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Measurement of Exclusive $\pi^{+}\pi^{-}$ and $\rho^0$ Meson Photoproduction at HERA

The H1 collaboration Andreev, V. ; Baghdasaryan, A. ; Baty, A. ; et al.
Eur.Phys.J.C 80 (2020) 1189, 2020.
Inspire Record 1798511 DOI 10.17182/hepdata.102569

Exclusive photoproduction of $\rho^0(770)$ mesons is studied using the H1 detector at the $ep$ collider HERA. A sample of about 900000 events is used to measure single- and double-differential cross sections for the reaction $\gamma p \to \pi^{+}\pi^{-}Y$. Reactions where the proton stays intact (${m_Y{=}m_p}$) are statistically separated from those where the proton dissociates to a low-mass hadronic system ($m_p{<}m_Y{<}10$ GeV). The double-differential cross sections are measured as a function of the invariant mass $m_{\pi\pi}$ of the decay pions and the squared $4$-momentum transfer $t$ at the proton vertex. The measurements are presented in various bins of the photon-proton collision energy $W_{\gamma p}$. The phase space restrictions are $0.5 < m_{\pi\pi} < 2.2$ GeV, ${\vert t\vert < 1.5}$ GeV${}^2$, and ${20 < W_{\gamma p} < 80}$ GeV. Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the $m_{\pi\pi}$ dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the $\rho^{0}(770)$ meson mass and width at $m_\rho = 770.8\ {}^{+2.6}_{-2.7}$ (tot) MeV and $\Gamma_\rho = 151.3\ {}^{+2.7}_{-3.6}$ (tot) MeV, respectively. The model is used to extract the $\rho^0(770)$ contribution to the $\pi^{+}\pi^{-}$ cross sections and measure it as a function of $t$ and $W_{\gamma p}$. In a Regge asymptotic limit in which one Regge trajectory $\alpha(t)$ dominates, the intercept $\alpha(t{=}0) = 1.0654\ {}^{+0.0098}_{-0.0067}$ (tot) and the slope $\alpha^\prime(t{=}0) = 0.233\ {}^{+0.067 }_{-0.074 }$ (tot) GeV${}^{-2}$ of the $t$ dependence are extracted for the case $m_Y{=}m_p$.

28 data tables

Elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction off protons, differential in the dipion mass. The tabulated cross sections are $\gamma p$ cross sections but can be converted to $ep$ cross sections using the effective photon flux $\Phi_{\gamma/e}$.

Elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction off protons, differential in the dipion mass --- statistical correlations coefficients $\rho_{ij}$ only. Only one half of the (symmetric) matrix is stored. Bins are identified by their global bin number.

Fit of elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction cross section off protons with a Soeding-inspired analytic function including $\rho$ and $\omega$ meson resonant contributions as well as a continuum background which interfere at the amplitude level. Parameters with subscript "el" and "pd" correspond to elastic and proton-dissociative cross sections, respectively.

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Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at $\sqrt{s} = 200$ GeV with the STAR detector at RHIC

The STAR collaboration Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph ; et al.
JHEP 07 (2020) 178, 2020.
Inspire Record 1792394 DOI 10.17182/hepdata.94264

We report on the measurement of the Central Exclusive Production of charged particle pairs $h^{+}h^{-}$ ($h = \pi, K, p$) with the STAR detector at RHIC in proton-proton collisions at $\sqrt{s} = 200$ GeV. The charged particle pairs produced in the reaction $pp\to p^\prime+h^{+}h^{-}+p^\prime$ are reconstructed from the tracks in the central detector, while the forward-scattered protons are measured in the Roman Pot system. Differential cross sections are measured in the fiducial region, which roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range $0.04~\mbox{GeV}^2 < -t_1 , -t_2 < 0.2~\mbox{GeV}^2$, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range $|\eta|<0.7$. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of $\pi^{+}\pi^{-}$ and $K^{+}K^{-}$ pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to $\pi^{+}\pi^{-}$ production. The fiducial $\pi^+\pi^-$ cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the $f_0(980)$, $f_2(1270)$ and $f_0(1500)$, with a possible small contribution from the $f_0(1370)$. Fits to the extrapolated differential cross section as a function of $t_1$ and $t_2$ enable extraction of the exponential slope parameters in several bins of the invariant mass of $\pi^+\pi^-$ pairs. These parameters are sensitive to the size of the interaction region.

47 data tables

Differential fiducial cross section for CEP of $\pi^+\pi^-$ pairs as a function of the invariant mass of the pair. Systematic uncertainties assigned to data points are strongly correlated between bins and should be treated as allowed collective variation of all data points. There are two components of the total systematic uncertainty. The systematic uncertainty related to the experimental tools and analysis method is labeled "syst. (experimental)". The systematic uncertainty related to the integrated luminosity (fully correlated between all data points) is labeled "syst. (luminosity)". Fiducial region definition: * central state $\pi^+$, $\pi^-$ - $p_{\mathrm{T}} > 0.2~\mathrm{GeV}$ - $|\eta| < 0.7$ * intact forward-scattered beam protons $p'$ - $p_x > -0.2~\mathrm{GeV}$ - $0.2~\mathrm{GeV} < |p_{y}| < 0.4~\mathrm{GeV}$ - $(p_x+0.3~\mathrm{GeV})^2 + p_y^2 < 0.25~\mathrm{GeV}^2$

Differential fiducial cross section for CEP of $K^+K^-$ pairs as a function of the invariant mass of the pair. Systematic uncertainties assigned to data points are strongly correlated between bins and should be treated as allowed collective variation of all data points. There are two components of the total systematic uncertainty. The systematic uncertainty related to the experimental tools and analysis method is labeled "syst. (experimental)". The systematic uncertainty related to the integrated luminosity (fully correlated between all data points) is labeled "syst. (luminosity)". Fiducial region definition: * central state $K^+$, $K^-$ - $p_{\mathrm{T}} > 0.3~\mathrm{GeV}$ - $min(p_{\mathrm{T}}(K^+), p_{\mathrm{T}}(K^-)) < 0.7~\mathrm{GeV}$ - $|\eta| < 0.7$ * intact forward-scattered beam protons $p'$ - $p_x > -0.2~\mathrm{GeV}$ - $0.2~\mathrm{GeV} < |p_{y}| < 0.4~\mathrm{GeV}$ - $(p_x+0.3~\mathrm{GeV})^2 + p_y^2 < 0.25~\mathrm{GeV}^2$

Differential fiducial cross section for CEP of $p\bar{p}$ pairs as a function of the invariant mass of the pair. Systematic uncertainties assigned to data points are strongly correlated between bins and should be treated as allowed collective variation of all data points. There are two components of the total systematic uncertainty. The systematic uncertainty related to the experimental tools and analysis method is labeled "syst. (experimental)". The systematic uncertainty related to the integrated luminosity (fully correlated between all data points) is labeled "syst. (luminosity)". Fiducial region definition: * central state $p$, $\bar{p}$ - $p_{\mathrm{T}} > 0.4~\mathrm{GeV}$ - $min(p_{\mathrm{T}}(p), p_{\mathrm{T}}(\bar{p})) < 1.1~\mathrm{GeV}$ - $|\eta| < 0.7$ * intact forward-scattered beam protons $p'$ - $p_x > -0.2~\mathrm{GeV}$ - $0.2~\mathrm{GeV} < |p_{y}| < 0.4~\mathrm{GeV}$ - $(p_x+0.3~\mathrm{GeV})^2 + p_y^2 < 0.25~\mathrm{GeV}^2$

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Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$

The COMPASS collaboration Aghasyan, M. ; Alexeev, M.G. ; Alexeev, G.D. ; et al.
Phys.Rev.D 98 (2018) 092003, 2018.
Inspire Record 1655631 DOI 10.17182/hepdata.82958

We have performed the most comprehensive resonance-model fit of $\pi^-\pi^-\pi^+$ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction $\pi^- + p \to \pi^-\pi^-\pi^+ + p_\text{recoil}$ with a 190 GeV/$c$ pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, $0.5 &lt; m_{3\pi} &lt; 2.5$ GeV/$c^2$, and simultaneously in 11 bins of the reduced four-momentum transfer squared, $0.1 &lt; t' &lt; 1.0$ $($GeV$/c)^2$, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{++}$, $2^{-+}$, $4^{++}$, and spin-exotic $1^{-+}$ quantum numbers. The model contains the well-known resonances $\pi(1800)$, $a_1(1260)$, $a_2(1320)$, $\pi_2(1670)$, $\pi_2(1880)$, and $a_4(2040)$. In addition, it includes the disputed $\pi_1(1600)$, the excited states $a_1(1640)$, $a_2(1700)$, and $\pi_2(2005)$, as well as the resonancelike $a_1(1420)$. We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 $t'$ bins. We extract the relative branching fractions of the $\rho(770) \pi$ and $f_2(1270) \pi$ decays of $a_2(1320)$ and $a_4(2040)$, where the former one is measured for the first time. In a novel approach, we extract the $t'$ dependence of the intensity of the resonances and of their phases. The $t'$ dependence of the intensities of most resonances differs distinctly from the $t'$ dependence of the nonresonant components. For the first time, we determine the $t'$ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances.

2 data tables

Real and imaginary parts of the normalized transition amplitudes $\mathcal{T}_a$ of the 14 selected partial waves in the 1100 $(m_{3\pi}, t')$ cells (see Eq. (12) in the paper). The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the transition amplitudes in the column headers. The $m_{3\pi}$ values that are given in the first column correspond to the bin centers. Each of the 100 $m_{3\pi}$ bins is 20 MeV/$c^2$ wide. Since the 11 $t'$ bins are non-equidistant, the lower and upper bounds of each $t'$ bin are given in the column headers. The transition amplitudes define the spin-density matrix elements $\varrho_{ab}$ for waves $a$ and $b$ according to Eq. (18). The spin-density matrix enters the resonance-model fit via Eqs. (33) and (34). The transition amplitudes are normalized via Eqs. (9), (16), and (17) such that the partial-wave intensities $\varrho_{aa} = |\mathcal{T}_a|^2$ are given in units of acceptance-corrected number of events. The relative phase $\Delta\phi_{ab}$ between two waves $a$ and $b$ is given by $\arg(\varrho_{ab}) = \arg(\mathcal{T}_a) - \arg(\mathcal{T}_b)$. Note that only relative phases are well-defined. The phase of the $1^{++}0^+ \rho(770) \pi S$ wave was set to $0^\circ$ so that the corresponding transition amplitudes are real-valued. In the PWA model, some waves are excluded in the region of low $m_{3\pi}$ (see paper and [Phys. Rev. D 95, 032004 (2017)] for a detailed description of the PWA model). For these waves, the transition amplitudes are set to zero. The tables with the covariance matrices of the transition amplitudes for all 1100 $(m_{3\pi}, t')$ cells can be downloaded via the 'Additional Resources' for this table.

Decay phase-space volume $I_{aa}$ for the 14 selected partial waves as a function of $m_{3\pi}$, normalized such that $I_{aa}(m_{3\pi} = 2.5~\text{GeV}/c^2) = 1$. The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the decay phase-space volume in the column headers. The labels are identical to the ones used in the column headers of the table of the transition amplitudes. $I_{aa}$ is calculated using Monte Carlo integration techniques for fixed $m_{3\pi}$ values, which are given in the first column, in the range from 0.5 to 2.5 GeV/$c^2$ in steps of 10 MeV/$c^2$. The statistical uncertainties given for $I_{aa}$ are due to the finite number of Monte Carlo events. $I_{aa}(m_{3\pi})$ is defined in Eq. (6) in the paper and appears in the resonance model in Eqs. (19) and (20).


Measurement of the I=1/2 $K \pi$ $\mathcal{S}$-wave amplitude from Dalitz plot analyses of $\eta_c \to K \bar K \pi$ in two-photon interactions

The BaBar collaboration Lees, J.P. ; Poireau, V. ; Tisserand, V. ; et al.
Phys.Rev.D 93 (2016) 012005, 2016.
Inspire Record 1403544 DOI 10.17182/hepdata.76968

We study the processes $\gamma \gamma \to K^0_S K^{\pm}\pi^{\mp}$ and $\gamma \gamma \to K^+ K^- \pi^0$ using a data sample of 519~$fb^{-1}$ recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+ e^-$ collider at center-of-mass energies at and near the $\Upsilon(nS)$ ($n = 2,3,4$) resonances. We observe $\eta_c$ decays to both final states and perform Dalitz plot analyses using a model-independent partial wave analysis technique. This allows a model-independent measurement of the mass-dependence of the $I=1/2$ $K \pi$ $\mathcal{S}$-wave amplitude and phase. A comparison between the present measurement and those from previous experiments indicates similar behaviour for the phase up to a mass of 1.5 $GeV/c^2$. In contrast, the amplitudes show very marked differences. The data require the presence of a new $a_0(1950)$ resonance with parameters $m=1931 \pm 14 \pm 22 \ MeV/c^2$ and $\Gamma=271 \pm 22 \pm 29 \ MeV$.

2 data tables

Measured amplitude and phase values for the $I=1/2$ $K \pi$ $\mathcal{S}$-wave as functions of mass obtained from the Model Independent Partial Wave Analysis (MIPWA) of $\eta_c \to K^0_{\scriptscriptstyle S} K^{\pm}\pi^{\mp}$. The amplitudes and phases in the mass interval 14 are fixed to constant values.

Measured amplitude and phase values for the $I=1/2$ $K \pi$ $\mathcal{S}$-wave as functions of mass obtained from the Model Independent Partial Wave Analysis (MIPWA) of $\eta_c \to K^+ K^- \pi^0$. The amplitudes and phases in the mass interval 14 are fixed to constant values.


Transverse-target-spin asymmetry in exclusive $\omega$-meson electroproduction

The HERMES collaboration Airapetian, A. ; Akopov, N. ; Akopov, Z. ; et al.
Eur.Phys.J.C 75 (2015) 600, 2015.
Inspire Record 1391139 DOI 10.17182/hepdata.75465

Hard exclusive electroproduction of $\omega$ mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive $\pi\omega$ transition form factor.

4 data tables

The amplitudes of the five sine and two cosine modulations as determined in the entire kinematic region. The results receive an additional 8.2% scale uncertainty corresponding to the target-polarization uncertainty.

The definition of intervals and the mean values of the kinematic variables.

Results on the kinematic dependences of the five asymmetry amplitudes $A_{UT}$ and two amplitudes $A_{UU}$. The first two columns correspond to the $-t'$ intervals $0.00 - 0.07 - 0.20$ GeV$^2$ and the last two columns to the $Q^{2}$ intervals $1.00 - 1.85 - 10.00$ GeV$^2$. The results receive an additional 8.2% scale uncertainty corresponding to the target-polarization uncertainty.

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Study of the Reactions $\pi^- p \to K^0 \Sigma^0(1385)$ and $\pi^- p \to K^+ \Sigma^-(1385)$ at 3.95-{GeV}/$c$

The CERN-College de France-Madrid-Stockholm collaboration Aguilar-Benitez, M. ; Albajar, M.C. ; Ferrando, A. ; et al.
Z.Phys.C 6 (1980) 109-123, 1980.
Inspire Record 153921 DOI 10.17182/hepdata.14369

The reactionsπ−p→K0∑0(1385) andπ−p→K+∑−(1385) are studied at an incident momentum of 3.95 GeV/c using data from a high statistics bubble chamber experiment corresponding to approximately 90 events/μb. The total and differential cross sections and the density matrix elements of the Σ(1385) are presented. The results are compared with those obtained for the related processesπpp→K+∑+(1385) and\(K^ -p \to \pi ^ \mp\sum ^ \pm(1385)\) in this energy range. Evidence is presented for the existence of production mechanisms with exotic exchanges in thet channel.

16 data tables

FROM THE CHANNEL PI- P --> LAMBDA K0 PI0 WHICH HAS A CROSS SECTION OF 72 +- 4 MUB.

FROM THE CHANNEL PI- P --> LAMBDA K+ PI- WHICH HAS A CROSS SECTION OF 79 +- 3 MUB.

FORWARD CROSS SECTION.

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Study of the Reactions $\pi^- p \to K^0(890)\Lambda$, $K^0(890) \Sigma^0$ and $K^0(890) \Sigma^0(1385)$ at 3.95-{GeV}/$c$

The CERN-College de France-Madrid-Stockholm collaboration Aguilar-Benitez, M. ; Albajar, M.C. ; Ferrando, A. ; et al.
Z.Phys.C 6 (1980) 195-215, 1980.
Inspire Record 153917 DOI 10.17182/hepdata.1428

The reactionsπ−p→K0(890) Λ,K0(890)Σ0 andK0(890)Σ0 are studied at an incident momentum of 3.95 GeV/c using data from a high statistics bubble chamber experiment corresponding to ∼90 events/μb. The differential cross sections, density matrix elements of the vector meson and hyperon polarizations are presented. A transversity amplitude analysis is performed for each of the reactions. The results are compared with those obtained for the SU(3) related processesK−p→ϕΔ, ϕΣ0, ϕΣ0(1385) andϱ−Σ+(1385) and with predictions of the additive quark model and SU(6) sum rules.

39 data tables

BREIT-WIGNER FIT WITH BACKGROUND POLYNOMIAL.

BACKWARD CROSS SECTION.

TOTAL CROSS SECTION USING SLICING TECHNIQUE. FORWARD (-TP < 1.2 GEV**2) CROSS SECTION IS 25 +- 2 MUB: DOUBLE MASS CUT GIVES 20 +- 7 PCT BACKGROUND CONTAMINATION.

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On $K_L$ - $K_S$ Regeneration in Copper

Bohm, A. ; Darriulat, P. ; Grosso, C. ; et al.
Phys.Lett.B 27 (1968) 594-598, 1968.
Inspire Record 1374884 DOI 10.17182/hepdata.69210

The transmission regeneration amplitude after a thick copper block has been measured. The quantity {∣ƒ(0)- overlineƒ(0)∣ }/{k} varies from 20.0 $\pm$ 1.4 mb at 2.75 GeV/c to 13.6 $\pm$ 1.2 mb at 7.25 GeV/c. Results are in agreement with optical model calculations in which real and imaginary parts of the amplitudes for single nucleon scattering are determined from forward dispersion relations and total cross-sections.

1 data table

Regeneration amplitude.


Observation of k(l) - k(s) regeneration from liquid hydrogen. aachen-cern-turin collaboration,

Darriulat, P. ; Grosso, C. ; Holder, M. ; et al.
Phys.Lett.B 33 (1970) 433-437, 1970.
Inspire Record 69387 DOI 10.17182/hepdata.28718

The K L K S transmission regeneration of a K L beam traversing a liquid hydrogen target has been observed over the momentum interval 3.0–6.0 GeV/ c . Results are in good agreement with predictions based on dispersion relations.

2 data tables

Regeneration amplitude.

No description provided.


Interference between $K_L \to \pi^+ \pi^-$ and $K_S \to \pi^+ \pi^-$ behind a copper regenerator

Faissner, H. ; Foeth, H. ; Staude, A. ; et al.
Phys.Lett.B 30 (1969) 204-208, 1969.
Inspire Record 56677 DOI 10.17182/hepdata.28905

The interference between K L → π + π - and K S → π + π - behind a copper regenerator has been observed in a high statistics experiment. The modulus and the argument of the complex ratio ϱ ( p )/ η +- , where ϱ ( p ) is the regeneration amplitude and η +- = A ( K L → π + π - )/ A (K S → π + π - ) has been measured over the momentum interval from 2.0 GeV/ c to 6.0 GeV/ c . The phase of η +- as deduced from this measurement and from the optical model value of arg [ ϱ ( p )] is 49.3° ± 6.8°. The K L K S mass difference has been found to be Δm/ h ̵ = (0.555 ± 0.020) × 10 10 sec −1 .

1 data table

No description provided.


Parity-Nonconserving Optical Rotation at 876 nm in Bismuth

Macpherson, M.J. ; Stacey, D.N. ; Baird, P.E.G. ; et al.
EPL 4 (1987) 811-816, 1987.
Inspire Record 1408819 DOI 10.17182/hepdata.70515

We have measured parity-nonconserving optical rotation in the vicinity of the M1 absorption transition at 876 nm in bismuth. The result, R = Im(E1PNC/M1) = (-10.0 ± 1.0) centerdot 10-8, is in agreement with calculations based on the standard model of the electroweak interaction. The predicted form of the PNC rotation spectrum has been verified to high accuracy.

1 data table

No description provided.


Transmission regeneration of neutral kaons in hydrogen

Birulev, V.K. ; Genchev, V.I. ; Govorun, N.N. ; et al.
Sov.J.Nucl.Phys. 24 (1976) 390-396, 1976.
Inspire Record 1392573 DOI 10.17182/hepdata.19051

None

1 data table

No description provided.


Measurement of parity non-conserving optical rotation in the 648 nm transition in atomic bismuth

Taylor, J.D. ; Baird, P.E.G. ; Hunt, R.G. ; et al.
J.Phys.B 20 (1987) 5423-5442, 1987.
Inspire Record 1393361 DOI 10.17182/hepdata.38568

Parity non-conserving (PNC) optical rotation has been measured by laser polarimetry in the 648 nm magnetic dipole transition (6p$^{3}J$=$\frac{3}{2}\rightarrow$6p$^{3}J'=\frac{5}{2}$) in atomic bismuth. The experiment involves finding the small differences in rotation between selected frequency points in the vicinity of the F = 6 $\rightarrow$ F' = 7 hyperfine component. Faraday rotation, which can be distinguished from PNC rotation by its wavelength dependence, is used in locking the laser frequency and calibrating the PNC' effect. Results obtained over a six-year period are summarised; a detailed discussion of error sources and associated tests is given. The final result for the PNC parameter of the 648 nm transition is R = (-9.3 $\pm$ 1.4)X10$^{-8}$. This is in agreement with the measurements of Birich et a/ but not with those of Barkov and Zolotorev. It is also consistent with the standard model of the electroweak interaction, but the uncertainty in the atomic theory is now the limiting factor in the comparison.

2 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).


ATOMIC PARITY VIOLATION MEASUREMENTS IN THE HIGHLY FORBIDDEN (6)S(1/2) - (7)S(1/2) CESIUM TRANSITION. 3. DATA ACQUISITION AND PROCESSING. RESULTS AND IMPLICATIONS

Bouchiat, M.A. ; Guena, J. ; Pottier, L. ; et al.
J.Phys.(France) 47 (1986) 1709-1730, 1986.
Inspire Record 232798 DOI 10.17182/hepdata.38588

This paper completes the detailed presentation of our PV experiment on the 6S1/2 - 7S1/2 transition in Cs. A detailed description of the data acquisition and processing is given. The results of two independent measurements made on ΔF = 0 and ΔF =1 hfs components agree, providing an important cross-check. After a complete reanalysis of systematics and calibration, the precision is slightly improved, leading to the weighted average Im Epv 1/β = - 1.52 ± 0.18 mV/cm. Later results from an independent group agree quite well. With the semi-empirical value β = (26.8 ± 0.8) a30, our result yields Epv1 = (- 0.79 ± 0.10) x 10-11 i |e|a0. Coupled with the atomic calculations, this implies that the weak nuclear charge of Cs is Qw = -68 ± 9. This value agrees with the standard electroweak theory and leads to a weak interaction angle sin2 θ W = 0.21 ± 0.04. The complementarity of these measurements with high energy experiments is illustrated.

3 data tables

Revision of the earlier experiment PL 117B, 358. (7s)2S1/2:F=4 --> (6s)2S1/2:F=4 transition.

Revision of the earlier experiment PL 134B, 463. (7s)2S1/2:F=3 --> (6s)2S1/2:F=4 transition.

Combined of the two above measurements following the philosophy: quadratic sum of the statistical and systematic uncertainties and weighting each result by the squared reciprocal of that uncertainty. (7s)2S1/2 --> (6s)2S1/2 transitions.


Observation of parity-violating optical rotation in atomic thallium

Wolfenden, T.D. ; Baird, P.E.G. ; Sandars, P.G.H. ;
EPL 15 (1991) 731-736, 1991.
Inspire Record 331200 DOI 10.17182/hepdata.43748

Parity-violating optical rotation induced by the neutral weak-current interaction has been detected and measured for the first time in atomic thallium vapour. Accurate atomic calculations predicting the size of the rotation are available for this element; thallium also benefits from the Z3 enhancement of the effect. The magnetic-dipole transition 6p1/2-6p3/2 at 1.283 μm was excited using a single-mode semiconductor laser and the small optical rotation was measured using a sensitive polarimeter. The result, expressed in terms of the quantity R = Im E1p.v./M1, is - 12.5(19)10-8 and is consistent with recent calculations based on the standard model.

1 data table

Spin of the Tl nucleus is 1/2.


Angular dependence of k-l k-s regenerative scattering for copper and lead nuclei at high energies

Foeth, H. ; Holder, M. ; Radermacher, E. ; et al.
Phys.Lett.B 31 (1970) 544-548, 1970.
Inspire Record 63172 DOI 10.17182/hepdata.28805

Elastic and inelastic K L  S regenerative scattering on copper and lead nuclei have been observed up to a momentum transfer of 0.17 GeV/ c . The elastic differential cross-section is of a ”diffractive” type. It can be described successfully in terms of an optical model only assuming an appreciable neutron excess in the vicinity of the nuclear surface.

2 data tables

No description provided.

No description provided.


eta-helium quasi-bound states.

Willis, N. ; Le Bornec, Y. ; Zghiche, A. ; et al.
Phys.Lett.B 406 (1997) 14-19, 1997.
Inspire Record 441131 DOI 10.17182/hepdata.40436

The cross section and tensor analysing power t_20 of the d\vec{d}->eta 4He reaction have been measured at six c.m. momenta, 10 < p(eta) < 90 MeV/c. The threshold value of t_20 is consistent with 1/\sqrt{2}, which follows from parity conservation and Bose symmetry. The much slower momentum variation observed for the reaction amplitude, as compared to that for the analogous pd->eta 3He case, suggests strongly the existence of a quasi-bound state in the eta-4He system and optical model fits indicate that this probably also the case for eta-3He.

1 data table

The spin-averaged amplitude squared is defined as follows: ABS(AMP)**2 = (P_deut/P_eta)*D(SIG)/D(OMEGA) and obtained by assuming the angular distributions to be isotropic. The errors in this quantity includes a contribution from Delta(P_eta). The statistical error of about 2% are added quadratically to the systemat ic error.


Further studies of the x (1910) meson

The IHEP-IISN-KEK-LANL-LAPP collaboration Alde, D. ; Binon, F.G. ; Boutemeur, M. ; et al.
Phys.Lett.B 276 (1992) 375-378, 1992.
Inspire Record 322740 DOI 10.17182/hepdata.48134

New data on the ν ′ ν system produced in the π − p charge exchange at 38 GeV c momentum confirm the existence of the narrow ν ′ ν resonance X(1910). The hypothesis of the X(1910) quantum numbers being a J PC = 1 −+ , forbidden for the q[ovbar|q] meson, is proposed to explain the extremely low limits obtained for X(1910) decays through π 0 π 0 , νν and K 0 s K 0 s channels and the flat t -dependence of the X(1910) production cross section.

4 data tables

No description provided.

No description provided.

No description provided.

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Near threshold photoproduction of $\eta$-mesons from the deuteron

Krusche, B. ; Ahrens, J. ; Annand, J.R.M. ; et al.
Phys.Lett.B 358 (1995) 40-46, 1995.
Inspire Record 406946 DOI 10.17182/hepdata.28490

The first measurement of incoherent η-photoproduction from the deuteron in the threshold region is reported. The experiment was carried out at the MAMI accelerator with the TAPS spectrometer. Total and differential inclusive cross sections have been obtained between 627 and 790 MeV. It is found that the reaction is completely dominated by the incoherent part. An upper limit for coherent η-photoproduction on the deuteron is deduced, which is substantially lower than the result from an earlier measurement. The incoherent cross section is reproduced in a participant-spectator approach under the assumption of an energy-independent ratio between the neutron and proton cross sections. Best agreement is found for the ratio σ n σ p ≈ 2 3 . The implications for the isospin components of the electromagnetic excitation of the S 11 (1535) resonance are discussed.

1 data table

The helicity amplitudes A(1/2) = <S11|j(em)|nucleon> are measured.


Precise Measurement of Parity Nonconserving Optical Rotation in Atomic Thallium

Edwards, N.H. ; Phipp, S.J. ; Baird, P.E.G. ; et al.
Phys.Rev.Lett. 74 (1995) 2654-2657, 1995.
Inspire Record 943148 DOI 10.17182/hepdata.19660

We report a new measurement of parity nonconserving (PNC) optical rotation on the 6p1/2- 6p3/2 transition in atomic thallium near 1283 nm. The result expressed in terms of the quantity R=Im{E1PNC/M1} is −(15.68±0.45)×10−8, and is consistent with current calculations based on the standard model. In addition, limits have been set on the much smaller nuclear spin-dependent rotation amplitude at RS=(0.04±0.20)×10−8; this is consistent with theoretical estimates which include a nuclear anapole contribution.

1 data table

Spin of the Tl nucleus is 1/2.


Precise test of electroweak theory from a new measurement of parity nonconservation in atomic thallium

Vetter, P.A. ; Meekhof, D.M. ; Majumder, P.K. ; et al.
Phys.Rev.Lett. 74 (1995) 2658-2661, 1995.
Inspire Record 405007 DOI 10.17182/hepdata.19649

We report a new measurement of parity nonconserving (PNC) optical rotation near the 1.28 μm, 6P1/2→6P3/2 magnetic dipole transition in thallium. We find the ratio of the PNC E1 amplitude to the M1 amplitude to be R=(−14.68±0.17)×10−8, which within the present uncertainty of atomic theory yields the thallium weak charge Qw(T205l)=−114.2±3.8 and the electroweak parameter S=−2.2±3.0. Separate measurements on the F=1 and F=0 ground-state hyperfine components of the transition yield R1−R0=(0.15±0.20)×10−8, which limits the size of nuclear spin-dependent PNC in Tl.

1 data table

Spin of the Tl nucleus is 1/2.


Test of low-energy theorems for p(gamma(pol.),pi0)p in the threshold region.

Schmidt, A. ; Achenbach, P. ; Ahrens, J. ; et al.
Phys.Rev.Lett. 87 (2001) 232501, 2001.
Inspire Record 556802 DOI 10.17182/hepdata.31362

The photon asymmetry in the reaction p(\vec{\gamma},\pi^{0})p close to threshold has been measured for the first time with the photon spectrometer TAPS using linearly polarized photons from the tagged-photon facility at the Mainz Microtron MAMI. The total and differential cross sections were also measured simultaneously with the photon asymmetry. This allowed determination of the S-wave and all three P-wave amplitudes. The low-energy theorems based on the parameter-free third-order calculations of heavy-baryon chiral perturbation theory for P1 and P2 agree with the experimental values.

1 data table

Polarized photon beam.


Preliminary Observation of Parity Nonconservation in Atomic Thallium

Conti, R. ; Bucksbaum, P. ; Chu, S. ; et al.
Phys.Rev.Lett. 42 (1979) 343-346, 1979.
Inspire Record 136903 DOI 10.17182/hepdata.20786

Parity nonconservation is observed in the 6P122−7P122 transition in thallium. Absorption of circularly polarized 293-nm photons by 6P122 atoms in an E field results in polarization of the 7P122 state through interference of Stark E1 amplitudes with M1 and parity-nonconserving E1 amplitudes M and Ep. Detection of this polarization yields the circular dichroism δ=+(5.2±2.4)×10−3, which agrees in sign and magnitude with theoretical estimates based on the Weinberg-Salam model.

1 data table

Used 99.999% pure thallium metal with natural isotopic abundances (29.5% Tl203, 70.5% Tl205). SIG(C+), SIG(C-) are the cross sections for absorption of 293-nm photons, with +,- helicity, respectively. Spin of the Tl nucleus is 1/2. Statistical errors only.


PARITY NONCONSERVATION IN ATOMIC THALLIUM

Drell, Persis S. ; Commins, E.D. ;
Phys.Rev.Lett. 53 (1984) 968-971, 1984.
Inspire Record 208341 DOI 10.17182/hepdata.20404

We present new measurements of parity conservation in the 293-nm transition in atomic Tl81205. Linearly polarized 293-nm photons, polarization ε^, are absorbed by 6P122 atoms in crossed electric and magnetic fields. The transition probability for each Zeeman component contains a term proportional to ε^·B→ε^·E→×B→ arising from interference between the Stark E1 amplitude βE and the parity-nonconserving E1 amplitude Ep. Our result, [ImEpβ]expt=−1.73±0.33 mV/cm, is compared with estimates based on the standard electroweak model.

1 data table

Spin of the Tl nucleus is 1/2.


Atomic Beam Measurement of Parity Nonconservation in Cesium

Gilbert, S.L. ; Wieman, Carl E. ;
Phys.Rev.A 34 (1986) 792-803, 1986.
Inspire Record 237319 DOI 10.17182/hepdata.26392

We present a new measurement of parity nonconservation in cesium. In this experiment, a laser excited the 6S→7S transition in an atomic beam in a region of static electric and magnetic fields. The quantity measured was the component of the transition rate arising from the interference between the parity nonconserving amplitude, scrEPNC, and the Stark amplitude, βE. Our results are ImscrEPNC/β=−1.65±0.13 mV/cm and C2p=-2±2, where C2p is the proton-axial-vector–electron-vector neutral-current coupling constant. These results are in agreement with previous less precise measurements in cesium and with the predictions of the electroweak standard model. We give a detailed discussion of the experiment with particular emphasis on the treatment and elimination of systematic errors. This experimental technique will allow future measurements of significantly higher precision.

3 data tables

Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).

Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).

Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).


NEW OBSERVATION OF A PARITY VIOLATION IN CESIUM

Bouchiat, M.A. ; Guena, J. ; Pottier, L. ; et al.
Phys.Lett.B 134 (1984) 463-468, 1984.
Inspire Record 200186 DOI 10.17182/hepdata.30610

The parity violation induced by weak neutral currents is measured in a ΔF =1 hyperfine component of the 6S–7S transition of the Cs atom. The measured value ( Im E PV 1 β ) = −1.78 ± 0.26 (statistical rms deviation) ±0.12 (systematic uncertainty) mV/cm, agrees with our previous measurement in a ΔF =0 component, and constitutes an important cross-check. Our result excludes a parity violation induced by a purely axial hadronic neutral current.

1 data table

(7s)2S1/2:F=3 --> (6s)2S1/2:F=4 transition.


Observation of a Parity Violation in Cesium

Bouchiat, M.A. ; Guena, J. ; Hunter, L. ; et al.
Phys.Lett.B 117 (1982) 358, 1982.
Inspire Record 180105 DOI 10.17182/hepdata.30837

We have measured a parity violation in the 6S–7S transition of Cs in an electric field. Our result is Im E 1 pv β = -1.34 ± 0.22 ( rms statistical deviation ) ± ∼0.11 ( systematic uncertainty ) mV cm; E 1 pv is the parity violating electric dipole amplitude, ß is the vector polarizability. This result is consistent with the Weinberg-Salam prediction.

1 data table

(7s)2S1/2:F=4 --> (6s)2S1/2:F=4 transition.


Search for Parity Nonconservation in Atomic Bismuth

Soreide, D.C. ; Roberts, D.E. ; Lindahl, E.G. ; et al.
Phys.Rev.Lett. 36 (1976) 352-355, 1976.
Inspire Record 112866 DOI 10.17182/hepdata.21089

In a search for optical rotation near the 8755-Å magnetic-dipole absorption line in atomic Bi, our first results set an upper limit F<10−6 on a parity nonconserving amplitude associated with the line. This limit improves upon earlier parity tests in atoms by three orders of magnitude. Further improvement of at least another order of magnitude appears possible by this method which should then provide an exacting test of parity conservation in the neutral weak-current interaction in atoms.

1 data table

No description provided.


PARITY NONCONSERVING OPTICAL ROTATION IN ATOMIC LEAD

Emmons, T.P. ; Reeves, J.M. ; Fortson, E.N. ;
Phys.Rev.Lett. 51 (1983) 2089-2092, 1983.
Inspire Record 200168 DOI 10.17182/hepdata.20506

The search for parity nonconservation in heavy elements has been extended to the 1.28-μm P03→P13 magnetic dipole transition in atomic lead. The experimental result, R=Im(E1M1)=(−9.9±2.5)×10−8, agrees, within the present uncertainties in experiment and atomic theory, with the prediction, R=−13×10−8, derived from the Weinberg-Salam-Glashow theory of weak neutral-current interactions.

2 data tables

No description provided.

WE SUM BOTH STATISTICAL AND SYSTEMATIC ERRORS TO OBTAIN A WEIGHTED AVERAGE OF ALL DATA GROUPS. QUOTED ERROR INCLUDES STATISTICAL AND SYSTEMATIC CONTRIBUTIONS.


Observations of Parity Nonconservation in Atomic Thallium

Bucksbaum, P.H. ; Commins, E.D. ; Hunter, L.R. ;
Phys.Rev.D 24 (1981) 1134-1148, 1981.
Inspire Record 166691 DOI 10.17182/hepdata.24054

A detailed account is given of observations of parity nonconservation in the 6P122−7P122 transition in Tl81203,205. Absorption of circularly polarized 293-nm photons by 6P122 atoms in an E field results in polarization of the 7P122 state through interference of the Stark E1 amplitude with M1 and parity-nonconserving E1 amplitudes. This polarization is detected by selective excitation of mF=±1 components of the 7P122 state to the 8S122 state and observation of the ensuing decay fluorescence at 323 nm. Systematic corrections due to imperfect circular polarization, misaligned E fields, and residual magnetic fields are determined precisely by a series of auxiliary experiments. The result is expressed in terms of the circular dichroism δexpt=+(2.8−0.9+1.0)×10−3, to be compared with estimates based on the Weinberg-Salam model for sin2θw=0.23:δtheo=+(2.1±0.7)×10−3.

1 data table

Used 99.999% pure thallium metal with natural isotopic abundances (29.5% Tl203, 70.5% Tl205). SIG(C=+),SIG(C=-) are the cross sections for absorption of 293-nm photons with +- helicity, respectively. Spin of the Tl nucleus is 1/2.


Upper limit on parity nonconserving optical rotation in atomic bismuth

Lewis, L.L. ; Hollister, J.H. ; Soreide, D.C. ; et al.
Phys.Rev.Lett. 39 (1977) 795-798, 1977.
Inspire Record 128258 DOI 10.17182/hepdata.20948

We have searched for optical rotation near the 8757-Å magnetic-dipole absorption line in atomic bismuth vapor. The experiment is sensitive to parity nonconservation in the weak neutral-current interaction between electrons and nucleons in atoms. We find R≡Im(E1M1)=(−0.7±3.2)×10−8, which is considerably smaller than the value R=−2.5×10−7 obtained by central-field calculations for this bismuth line using the Weinberg-Salam theory of neutral currents.

1 data table

No description provided.


Search for parity noncoserving optical rotation in atomic bismuth

Baird, P.E.G ; Brimicombe, S.M. ; Hunt, R.G. ; et al.
Phys.Rev.Lett. 39 (1977) 798-801, 1977.
Inspire Record 128257 DOI 10.17182/hepdata.20929

We report the results of a laser experiment to search for the parity-nonconserving optical rotation in atomic bismuth. We work at wavelengths close to the 648-nm J=32 — J=52 M1 transition from the ground state. We find R=Im(E1M1)=(+2.7±4.7)×10−8, in disagreement with the theoretical value R=−30×10−8 predicted for this transition on the basis of the Weinberg-Salam model of the weak interactions combined with relativistic central-field atomic theory.

1 data table

No description provided.


Observation of Nonconservation of Parity in Atomic Transitions

Barkov, L.M. ; Zolotorev, M.S. ;
JETP Lett. 27 (1978) 357, 1978.
Inspire Record 129724 DOI 10.17182/hepdata.39779

None

1 data table

OPTICAL ROTATION ANGLE DUE TO PARITY NONCONSERVING INTERACTIONS.


PARITY NONCONSERVATION IN BISMUTH ATOMS AND NEUTRAL WEAK INTERACTION CURRENTS

Barkov, L.M. ; Zolotorev, M.S. ;
Sov.Phys.JETP 52 (1980) 360-369, 1980.
Inspire Record 161102 DOI 10.17182/hepdata.27324

None

1 data table

Average value of all Novosibirsk measurements is presented.


NONCONSERVATION OF PARITY IN ATOMIC BISMUTH

Birich, G.N. ; Bogdanov, Yu.V. ; Kanorsky, S.I. ; et al.
Sov.Phys.JETP 60 (1984) 442-449, 1984.
Inspire Record 221351 DOI 10.17182/hepdata.16986

None

1 data table

No description provided.


Precision measurement of parity nonconservation in atomic Cesium: A Low-energy test of the electroweak theory

Noecker, M.C. ; Masterson, B.P. ; Wieman, Carl E. ;
Phys.Rev.Lett. 61 (1988) 310-313, 1988.
Inspire Record 260503 DOI 10.17182/hepdata.20071

We have made an improved measurement of the parity-nonconserving electric-dipole transition amplitude between the 6S and 7S states of atomic cesium. We obtain Im(EPNC)β=−1.576(34) mV/cm, which is in good agreement with the predictions of the standard model and earlier less precise measurements. This places more stringent constraints on alternatives to the standard model. We also see the first evidence of a nuclear-spin-dependent contribution to atomic parity nonconservation. The nuclear-spin dependence observed is in agreement with that predicted to arise from a nuclear anapole moment.

3 data tables

(7s)2S1/2:F=4 --> (6s)2S1/2:F=3 transition.

(7s)2S1/2:F=3 --> (6s)2S1/2:F=4 transition.

Average of (7s)2S1/2:F=4:MF=+-4 --> (6s)2S1/2:F=3:MF=+-3 and (7s)2S1/2:F=3:MF=+-3 --> (7s)2S1/2:F=4:MF=+-4 transitions.


Direct Experimental Reconstruction of the $P P$ Elastic Scattering Amplitudes Between 447-{MeV} and 579-{MeV}

Hausammann, R. ; Heer, E. ; Hess, R. ; et al.
Phys.Rev.D 40 (1989) 22-34, 1989.
Inspire Record 285139 DOI 10.17182/hepdata.23146

A direct experimental reconstruction of the five complex pp elastic-scattering amplitudes has been performed at 447, 497, 517, 539, and 579 MeV. The reconstruction is done over the c.m. angles from 38° to 90° and is based on either 11 or 15 spin observables depending on the angular range. The reconstructed amplitudes are presented and compared to phase-shift analysis. A smooth energy behavior is observed for the amplitudes.

10 data tables

No description provided.

No description provided.

No description provided.

More…

Evidence for Iota (1460) Production in $\pi^- p$ Interactions at 21.4-{GeV}/$c$

Rath, M.G. ; Cason, N.M. ; Bensinger, J.R. ; et al.
Phys.Rev.Lett. 61 (1988) 802, 1988.
Inspire Record 262921 DOI 10.17182/hepdata.20086

The KS0KS0π0 system has been studied in the exclusive reaction π−p→KS0KS0π0n at 21.4 GeV/c. Evidence for the production of the f1(1285) and the η(1460) is presented. The η(1460) is produced away from minimum momentum transfer in the presence of nonresonant K*K (S-wave) production and phase-space background. The observed mass, width, and decay properties of the η(1460) are consistent with those attributed to the ι(1460) observed in radiative Jψ decay.

1 data table

No description provided.


AMPLITUDE ANALYSIS OF PION - NUCLEON SCATTERING AT 40-GeV/c

Siksin, V.V. ;
IFVE-87-64, 1987.
Inspire Record 249408 DOI 10.17182/hepdata.10164

None

2 data tables

No description provided.

No description provided.


Evidence for Two Pseudoscalar Resonances of $\eta \pi^+ \pi^-$ System in the $D(1285)$ and $e$ / Iota Regions

Ando, A. ; Inaba, S. ; Inagaki, T. ; et al.
Phys.Rev.Lett. 57 (1986) 1296, 1986.
Inspire Record 229782 DOI 10.17182/hepdata.20226

High-statistics data on the reaction π−p→ηπ+π−n at 8.06 GeV/c were obtained. An isobarmodel partial-wave analysis was performed for the ηππ system. The η(1275) meson was confirmed as a narrow IJPC=00−+ resonance. It decays through both δπ and εη. A narrow state with IJPC=00−+ was found in an ηππ decay channel at 1.42 GeV. It has a prominent peak in a δπ decay mode. No significant E(1420) signal with IJPC=01++ was found near the mass region of 1.42 GeV.

1 data table

No description provided.


A Measurement of $\pi^- p \to K^0(s$) $K^0(s$) $n$ at 22-{GeV}/$c$ and a Systematic Study of the 2++ Meson Spectrum

Longacre, R.S. ; Etkin, A. ; Foley, K.J. ; et al.
Phys.Lett.B 177 (1986) 223-227, 1986.
Inspire Record 230183 DOI 10.17182/hepdata.30232

A coupled channel analysis has been carried out using a new amplitude analysis of the K 0 s K 0 s system produced in the reaction π − p→K 0 s K 0 s n at 22 GeV/ c , which contained about 40 000 new events in the low- t region (| t − t min |<0.1 GeV 2 ). Here only the I G =0 + , J PC =2 ++ amplitude from this analysis is considered, together with available data from other experiments in channels with the same quantum numbers in order to determine which 2 ++ isoscalar mesons have significant pseudoscalar-pseudoscalar couplings. It is found that four poles, f(1270), f'(1525), θ(1690), and f r (1810), are needed, plus a smooth background in order to fit these data; the need for the θ(1690) depends on the J/ψ radiative decay alone, and the f r (1810) is seen only in hadronic production.

1 data table

No description provided.


Measurement of the Reaction $\pi^+$ Polarized $n \to \pi^+ \pi^- p$ at 5.98-{GeV}/$c$ and 11.85-{GeV}/$c$ Using a Transversely Polarized Deuteron Target

de Lesquen, A. ; van Rossum, L. ; Svec, M. ; et al.
Phys.Rev.D 32 (1985) 21, 1985.
Inspire Record 206003 DOI 10.17182/hepdata.3934

In an experiment carried out at the CERN Proton Synchrotron and using the CERN polarized deuteron target, the reaction π+n↑→π+π−p has been measured in the region -t=0.1–1.0 (GeV/c)2 and m(π+π−)=0.36–1.04 GeV at incident momenta of 5.98 and 11.85 GeV/c. We present the m and t dependence of the measured 14 linearly independent spin-density-matrix elements and of the bounds on the moduli squared of the S- and P-wave recoil transversity amplitudes. The results show the presence of ‘‘A1’’ exchange in the unnatural nucleon-helicity-nonflip amplitudes. The natural ‘‘A2’’-exchange amplitudes dominate at large t. In the range 0.2≤-t≤0.4 (GeV/c)2 the mass dependence shows that the unnatural exchange amplitudes with transversity ‘‘down’’ are generally larger than those with transversity ‘‘up.’’ The opposite is true for the natural exchange. In this range of t and at the ρ0 mass, the P-wave unnatural amplitudes with both transversities contribute in equal amounts while the production by natural exchange proceeds entirely with transversity up. We observe rapid changes of the moduli within the ρ0 mass range and variations of the width and the position of the ρ0 peak in spin-averaged partial-wave cross sections. These structures have not been seen in previous polarization experiments and reveal spin dependence of ρ0 production. Our bounds cannot exclude an S-wave resonance in the range 700–800 MeV. The results emphasize the need for a better experimental and theoretical understanding of the mass dependence of the production mechanism.

19 data tables

No description provided.

'Y' components of RHO.

'X' components of RHO.

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PHENOMENOLOGICAL MULTIPOLAR ANALYSIS OF THE REACTION GAMMA p---> p pi0 IN ENERGY INTERVALS FROM THRESHOLD TO e (gamma) = 1200-MeV

Konovalov, O.G. ; Omelaenko, A.S. ; Sorokin, P.V. ;
KhFTI-84-23, 1984.
Inspire Record 211003 DOI 10.17182/hepdata.38330

None

1 data table

No description provided.


THE REACTION P P ---> (LAMBDA0 K+) P AT 50-GEV/C AND 30-GEV/C: PARTIAL WAVE ANALYSIS, DECK MODEL AND DOUBLE REGGE EXCHANGE

Cleland, W.E. ; Delfosse, A. ; Dorsaz, P.-A. ; et al.
Nucl.Phys.B 239 (1984) 27-51, 1984.
Inspire Record 205379 DOI 10.17182/hepdata.33884

We have obtained a sample of 20 465 (2201) events in the channel pp→ ( Λ 0 K + )p at 50 (30) GeV/ c incident momentum with Geneva-Lausanne spectrometer at the CERN SPS. In this analysis we investigate: 1. (i) the production of N ∗ (I = 1 2 ) states in the mass region 1.6 ⩽ M ( Λ 0 K + ) ⩽ 2.6 GeV and momentum transfer 0.06 ⩽ | t | 1.0 (GeV/ c ) 2 , by studing the amplitudes and phases from a moment analysis of the decay angular distribution; 2. (ii) the contribution of the K-exchange Deck model for M ( Λ 0 K + < 2.22 GeV; 3. (iii) the double Regge exchange phenomenology for s Λ 0 K + > 5 GeV 2 and s Λ 0 K + p > 5 GeV 2 .

3 data tables

No description provided.

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The Reactions $K^- p \to \pi^\mp \Sigma^\pm$ (1385) at 8.25-{GeV}/$c$

The Birmingham-CERN-Glasgow-Michigan State-Paris collaboration Baubillier, M. ; Bloodworth, I.J. ; Burns, A. ; et al.
Z.Phys.C 23 (1984) 213, 1984.
Inspire Record 199642 DOI 10.17182/hepdata.16327

The reactionsK−p→π∓Σ(1385)± are studied at an incident laboratory momentum of 8.25 GeV/c using data from a high statistics (≃180 events/μb) bubble chamber experiment. In the case of the reactionK−p→π−Σ(1385)+ an amplitude analysis is performed and the complete Σ(1385)+ spin density matrix is extracted as a function oft′. The results are compared with the predictions of the additive quark model. In the case of the reactionK−p→π+Σ(1385)− the cross-sections for forward and backward production are determined.

7 data tables

No description provided.

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COHERENT REGENERATION IN HYDROGEN FROM 3-GeV/c TO 10-GeV/c

Buchanan, C.D. ; Drickey, Darrell James ; Rudnick, F.D. ; et al.
Phys.Lett.B 37 (1971) 213-216, 1971.
Inspire Record 67654 DOI 10.17182/hepdata.28377

We have studied the proper time distribution of coherent π + π − decays from a 3 – 10 GeV/ c K L o beam incident on a one meter liquid hydrogen target using a wire spark chamber spectrometer in the 3 0 neutral beam at SLAC. We find ∣(ƒ(0) − ƒ (0))/k∣ = 0.43 ± 0.11 mb , φ(ƒ(0) − ƒ (0)) = -101 0 ± 42 0 .

1 data table

No description provided.


Real part of spinless p p-scattering amplitude at zero angle in the energy region from 0.135 to 1.700 gev/c

Amirkhanov, I.V. ; Bystritskii, V.M. ; Vertogradov, L.S. ; et al.
Yad.Fiz. 17 (1973) 1222-1224, 1973.
Inspire Record 85077 DOI 10.17182/hepdata.19177

None

1 data table

FORWARD AMPLITUDE DEDUCED FROM D(SIG)/DOMEGA IN COULOMB-NUCLEAR INTERFERENCE REGION.


Experimental verification of the Kramers-Kronig relation at high energy

Alvensleben, H. ; Becker, U. ; Biggs, P.J. ; et al.
Phys.Rev.Lett. 30 (1973) 328-332, 1973.
Inspire Record 84536 DOI 10.17182/hepdata.21393

The real part of the forward amplitude for Compton scattering on protons was measured through the interference between the Compton and Bethe-Heithler amplitudes by detecting the zero-degree electron pairs asymmetrically. The measurement was made at an average photon energy of 〈k〉=2.2 GeV, and an average momentum transfer to the recoil proton 〈t〉=−0.027 (GeV/c)2. The result confirms the prediction of the Kramers-Kronig relation.

1 data table

No description provided.