12,783 research outputs found

    CP violation in charged Higgs boson decays into tau and neutrino

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    We calculate the CP-violating rate asymmetry of H^\pm decays into tau and neutrino at one loop in the MSSM with complex parameters. We find that the asymmetry is typically of the order of 10^-3, depending mainly on the phases of the trilinear coupling A_\tau and of the gaugino mass M_1.Comment: 9 pages, 3 figures, uses JHEP3.cl

    Advanced Luminescence Imaging of CIGS Solar Cells

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    The importance of CIGS based solar cells for terrestrial application increases steadily. A key issue for a high production yield are efficient inspection tools at the early stage of the production process. The present contribution focuses on imaging characterization of CIGS solar cells including photo and electroluminescence. PL imaging does not need electrical contacts and can be applied after the absorber deposition prior to the TCO deposition and the completion of the module. The effect of heat treatment on thermally evaporated In2S3 buffer layer with respect to the device performance is studied on the absorber amp;buffer stack by PL imaging. The correlation between PL intensity with achieved open circuit voltages of the completed devices has been established. It will be concluded that the quality of the buffer layer and the interface is well detectable at this early stage by PL imaging. The other issue addressed in this contribution is a characterization of graded gap absorbers by EL imaging. It will be demonstrated that luminescence imaging using optical bandpass filters can be used for the evaluation of the bandgap grading of CIGS absorbers fabricated by sequential processes. Furthermore, lateral inhomogeneities with respect to the In Ga intermixing can be detected already after the absorber deposition by the proposed PL imaging metho

    The influence of chiral surface states on the London penetration depth in Sr2_2RuO4_4

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    The London penetration depth for the unconventional superconductor Sr2_2RuO4_4 is analyzed assuming an order parameter which breaks time reversal symmetry and parity simultaneously. Such a superconducting state possesses chiral quasiparticle states with subgap energies at the surface. We show that these subgap states can give a significant contribution to the low-temperature behavior of the London penetration depth yielding a T2 T^2 power-law even though bulk quasiparticle spectrum is gapped. The presence of several electron bands gives rise to interband transition among the subgap surface states and influences the properties of the surface impedance. Furthermore, the surface states lead also to a non-linear Meissner effect.Comment: 4 pages, 1 figure, the definition of the Nambu field operator introduced, and some typos correcte

    The effect of uniaxial pressure on the magnetic anomalies of the heavy-fermion metamagnet CeRu2Si2

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    The effect of uniaxial pressure (P_u) on the magnetic susceptibility (X), magnetization (M), and magnetoresistance (MR) of the heavy-fermion metamagnet CeRu2Si2 has been investigated. For the magnetic field along the tetragonal c axis, it is found that characteristic physical quantities, i.e., the temperature of the susceptibility maximum (T_max), the pagamagnetic Weiss temperature (Q_p), 1/X at 2 K, and the magnetic field of the metamagnetic anomaly (H_M), scale approximately linearly with P_u, indicating that all the quantities are related to the same energy scale, probably of the Kondo temperature. The increase (decrease) of the quantities for P_u || c axis (P_u || a axis) can be attributed to a decrease (increase) in the nearest Ce-Ru distance. Consistently in MR and X, we observed a sign that the anisotropic nature of the hybridization, which is believed to play an important role in the metamagnetic anomaly, can be controlled by applying the uniaxial pressure. PACS numbers: 75.20.Hr, 71.27.+a, 74.62.FjComment: 7 pages, ReVTeX, 6 EPS figures : Will appear in Phys. Rev.

    CP violating asymmetries in single top quark production at the Tevatron p pbar collider

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    Analytic expressions for the angular distributions of the bb-quarks associated with single tt-quark production in ppˉWtbˉbbˉWp \bar p \to W^* \to t \bar b \to b \bar b W and of the leptons from the subsequent decay WlνW \to l\nu are obtained in the laboratory system. CP violation in the tt-production vertex is assumed. Different angular and total cross section CP violating asymmetries are considered. Relations testing CP violation solely in the tt-decay vertex are also obtained. A numerical analysis is performed in the MSSM with a CP violating phase of the trilinear coupling At~A_{\tilde t}. The asymmetries are typically of the order 10310^{-3} - 10410^{-4}.Comment: The numerical results are corrected and some changes that meet the requirements of Phys. Rev. D are mad

    From Double Chooz to Triple Chooz - Neutrino Physics at the Chooz Reactor Complex

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    We discuss the potential of the proposed Double Chooz reactor experiment to measure the neutrino mixing angle sin22θ13\sin^2 2\theta_{13}. We especially consider systematical uncertainties and their partial cancellation in a near and far detector operation, and we discuss implications of a delayed near detector startup. Furthermore, we introduce Triple Chooz, which is a possible upgrade scenario assuming a second, larger far detector, which could start data taking in an existing cavern five years after the first far detector. We review the role of the Chooz reactor experiments in the global context of future neutrino beam experiments. We find that both Double Chooz and Triple Chooz can play a leading role in the search for a finite value of sin22θ13\sin^2 2\theta_{13}. Double Chooz could achieve a sensitivity limit of 2102\sim 2 \cdot 10^{-2} at the 90%~confidence level after 5~years while the Triple Chooz setup could give a sensitivity below 10210^{-2}.Comment: 18 pages, 6 figure

    Physics Analysis Expert PAX: First Applications

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    PAX (Physics Analysis Expert) is a novel, C++ based toolkit designed to assist teams in particle physics data analysis issues. The core of PAX are event interpretation containers, holding relevant information about and possible interpretations of a physics event. Providing this new level of abstraction beyond the results of the detector reconstruction programs, PAX facilitates the buildup and use of modern analysis factories. Class structure and user command syntax of PAX are set up to support expert teams as well as newcomers in preparing for the challenges expected to arise in the data analysis at future hadron colliders.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 10 eps figures. PSN THLT00

    Search for dinucleon decay into pions at Super-Kamiokande

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    A search for dinucleon decay into pions with the Super-Kamiokande detector has been performed with an exposure of 282.1 kiloton-years. Dinucleon decay is a process that violates baryon number by two units. We present the first search for dinucleon decay to pions in a large water Cherenkov detector. The modes 16^{16}O(pp)(pp) \rightarrow 14^{14}Cπ+π+\pi^{+}\pi^{+}, 16^{16}O(pn)(pn) \rightarrow 14^{14}Nπ+π0\pi^{+}\pi^{0}, and 16^{16}O(nn)(nn) \rightarrow 14^{14}Oπ0π0\pi^{0}\pi^{0} are investigated. No significant excess in the Super-Kamiokande data has been found, so a lower limit on the lifetime of the process per oxygen nucleus is determined. These limits are: τppπ+π+>7.22×1031\tau_{pp\rightarrow\pi^{+}\pi^{+}} > 7.22 \times 10^{31} years, τpnπ+π0>1.70×1032\tau_{pn\rightarrow\pi^{+}\pi^{0}} > 1.70 \times 10^{32} years, and τnnπ0π0>4.04×1032\tau_{nn\rightarrow\pi^{0}\pi^{0}} > 4.04 \times 10^{32} years. The lower limits on each mode are about two orders of magnitude better than previous limits from searches for dinucleon decay in iron.Comment: 20 pages, 17 figures. Accepted for publication in Physical Review D on March 30, 201
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