BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2012). Study of X (3915) -> J/psi omega in two-photon collisions. Phys. Rev. D, 86(7), 072002–10pp.
Abstract: We study the process gamma gamma -> J/psi omega using a data sample of 519.2 fb(-1) recorded by the BABAR detector at SLAC at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the gamma(nS) (n = 2, 3, 4) resonances. We confirm the existence of the charmoniumlike resonance X (3915) decaying to J/psi omega with a significance of 7.6 standard deviations, including systematic uncertainties, and measure its mass (3919.4 +/- 2.2 +/- 1.6) MeV/c(2) and width (13 +/- 6 +/- 3) MeV, where the first uncertainty is statistical and the second systematic. A spin-parity analysis supports the assignment J(P) = 0(+) and therefore the identification of the signal as due to the chi(c0)(2P) resonance. In this hypothesis we determine the product between the two-photon width and the final state branching fraction to be (52 +/- 10 +/- 3) eV.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2014). Study of the reaction e(+)e(-) -> psi(2S)pi(+)pi(-) via initial-state radiation at BABAR. Phys. Rev. D, 89(11), 111103–8pp.
Abstract: We study the process e(+)e(-) -> psi(2S)pi(+)pi(-) with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies at and near the (nS) (n = 2, 3, 4) resonances and correspond to an integrated luminosity of 520 fb(-1). We investigate the psi(2S)pi(+)pi(-) mass distribution from 3.95 to 5.95 GeV/c(2), and measure the center-of-mass energy dependence of the associated e(+)e(-) -> psi(2S)pi(+)pi(-) cross section. The mass distribution exhibits evidence of two resonant structures. A fit to the psi(2S)pi(+)pi(-) mass distribution corresponding to the decay mode psi(2S) -> J/psi pi(+)pi(-) yields a mass value of 4340 +/- 16 (stat) +/- 9 (syst) MeV/c(2) and a width of 94 +/- 32 (stat) +/- 13 (syst) MeV for the first resonance, and for the second a mass value of 4669 +/- 21 (stat) +/- 3 (syst) MeV/c(2) and a width of 104 +/- 48 (stat) +/- 10 (syst) MeV. In addition, we show the pi(+)pi(-) mass distributions for these resonant regions.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Initial-state radiation measurement of the e(+)e(-) -> pi(+)pi(-)pi(+)pi(-) cross section. Phys. Rev. D, 85(11), 112009–17pp.
Abstract: We study the process e(+)e(-) -> pi(+)pi(-)pi(+)pi(-)gamma, with a photon emitted from the initial-state electron or positron, using 454.3 fb(-1) of data collected with the BABAR detector at SLAC, corresponding to approximately 260 000 signal events. We use these data to extract the nonradiative sigma(e(+)e(-) -> pi(+)pi(-)pi(+)pi(-)) cross section in the energy range from 0.6 to 4.5 GeV. The total uncertainty of the cross section measurement in the peak region is less than 3%, higher in precision than the corresponding results obtained from energy scan data.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2018). Study of the process e(+)e(-) -> pi(+)pi(-)eta using initial state radiation. Phys. Rev. D, 97(5), 052007–14pp.
Abstract: We study the process e(+)e(-) -> pi(+)pi(-)eta gamma, where the photon is radiated from the initial state. About 8000 fully reconstructed events of this process are selected from the BABAR data sample with an integrated luminosity of 469 fb(-1). Using the pi(+)pi(-)eta invariant mass spectrum, we measure the e(+)e(-) -> pi(+)pi(-)eta cross section in the e(+)e(-) center-of-mass energy range from 1.15 to 3.5 GeV. The cross section is well described by the Vector-Meson dominance model with four.-like states. We observe 49 +/- 9 events of the J/Psi decay to pi(+)pi(-)eta and measure the product Gamma B-J/Psi -> e+e-(J/Psi ->pi+pi-eta) = 2.34 +/- 0.43(stat) +/- 0.16(syst) eV.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Study of the reaction e(+)e(-) -> J/psi pi(+)pi(-) via initial-state radiation at BABAR. Phys. Rev. D, 86(5), 051102–9pp.
Abstract: We study the process e(+)e(-) -> J/psi pi(+)pi(-) with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 fb(-1). We investigate the J/psi pi(+)pi(-) mass distribution in the region from 3.5 to 5.5 GeV/c(2). Below 3.7 GeV/c(2) the psi (2S) signal dominates, and above 4 GeV/c(2) there is a significant peak due to the Y(4260). A fit to the data in the range 3.74-5.50 GeV/c(2) yields a mass value 4245 +/- 5(stat) +/- 4(syst) MeV/c(2) and a width value 114(-15)(+16)(stat) +/- 7(syst) MeV for this state. We do not confirm the report from the Belle Collaboration of a broad structure at 4.01 GeV/c(2). In addition, we investigate the pi(+)pi(-) system which results from Y(4260) decay.
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2018). Measurement of the gamma*gamma* -> eta ' transition form factor. Phys. Rev. D, 98(11), 112002–11pp.
Abstract: We study the process e(+)e(-) -> e(+)e(-)eta' in the double-tag mode and measure for the first time the gamma*gamma* -> eta' transition form factor F-eta'(Q(1)(2), Q(2)(2)) in the momentum-transfer range 2 < Q(1)(2), Q(2)(2) < 60 GeV2. The analysis is based on a data sample corresponding to an integrated luminosity of around 469 fb(-1) collected at the PEP-II e(+)e(-) collider with the BABAR detector at center-of-mass energies near 10.6 GeV.
|
Linster, M., Lopez-Pavon, J., & Ziegler, R. (2021). Neutrino observables from a U(2) flavor symmetry. Phys. Rev. D, 103(1), 015020–9pp.
Abstract: We study the predictions for CP phases and absolute neutrino mass scale for broad classes of models with a U(2)-like flavor symmetry. For this purpose we consider the same special textures in neutrino and charged lepton mass matrices that are successful in the quark sector. While in the neutrino sector the U(2) structure enforces two texture zeros, the contribution of the charged lepton sector to the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix can be parametrized by two rotation angles. Restricting to the cases where at least one of these angles is small, we obtain three representative scenarios. In all scenarios we obtain a narrow prediction for the sum of neutrino masses in the range of 60-75 meV, possibly in the reach of upcoming galaxy survey experiments. All scenarios can be excluded if near-future experimental date provide evidence for either neutrinoless double-beta decay or inverted neutrino mass ordering.
|
Ternes, C. A., Gariazzo, S., Hajjar, R., Mena, O., Sorel, M., & Tortola, M. (2019). Neutrino mass ordering at DUNE: An extra nu bonus. Phys. Rev. D, 100(9), 093004–10pp.
Abstract: We study the possibility of extracting the neutrino mass ordering at the future Deep Underground Neutrino Experiment using atmospheric neutrinos, which will be available before the muon neutrino beam starts being operational. The large statistics of the atmospheric muon neutrino and antineutrino samples at the far detector, together with the baselines of thousands of kilometers that these atmospheric (anti) neutrinos travel, provide ideal ingredients to extract the neutrino mass ordering via matter effects in the neutrino propagation through Earth. Crucially, muon capture by argon provides excellent charge tagging, allowing us to disentangle the neutrino and antineutrino signature. This is an important extra benefit of having a liquid argon time projection chamber as a far detector, that could render an similar to 3.5 sigma extraction of the mass ordering after approximately 7 yr of exposure.
|
Gomez Dumm, D., Noguera, S., Scoccola, N. N., & Scopetta, S. (2014). Pion distribution amplitude and the pion-photon transition form factor in a nonlocal chiral quark model. Phys. Rev. D, 89(5), 054031–14pp.
Abstract: We study the pion distribution amplitude (pi DA) in the context of a nonlocal chiral quark model. The corresponding Lagrangian reproduces the phenomenological values of the pion mass and decay constant, as well as the momentum dependence of the quark propagator obtained in lattice calculations. It is found that the obtained pi DA has two symmetric maxima, which arise from the new contributions generated by the nonlocal character of the interactions. This pi DA is applied to leading order and next-to-leading order calculations of the pion-photon transition form factor. Implications of the results are discussed.
|
Parashar, S., Karan, A., Avnish, Bandyopadhyay, P., & Ghosh, K. (2022). Phenomenology of scalar leptoquarks at the LHC in explaining the radiative neutrino masses, muon g-2, and lepton flavor violating observables. Phys. Rev. D, 106(9), 095040–34pp.
Abstract: We study the phenomenology of a particular leptoquark extension of the Standard Model (SM), namely the doublet-singlet scalar leptoquark extension of the SM (DSL-SM). Besides generating Majorana mass for neutrinos, these leptoquarks contribute to muon and electron (g – 2) and various lepton flavor violating processes. Collider signatures of the benchmark points (BPs), consistent with the neutrino oscillation data, anomalous muon/electron magnetic moments, experimental bounds on the charged lepton flavor violation observables, etc., are studied at the LHC/FCC with center-of-mass energies of 14, 27 and 100 TeV. While the two -1=3 charged colored scalars from the singlet and the doublet leptoquark mix with each other, the charge 2=3 colored scalar from the doublet leptoquark remains pure. With a near-degenerate mass spectrum, the pure and mixed leptoquark states are shown to be distinguishable from multiple final states, while discerning between the two mixed states remains very challenging.
|
