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1.
We apply a quasi-model-independent strategy ("Sleuth") to search for new high p(T) physics in approximately 100 pb(-1) of pp collisions at square root of (s) = 1.8 TeV collected by the D0 experiment during 1992-1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p(T) physics is observed.  相似文献   

2.
Results on searches for particles and phenomena beyond the Standard Model (new-physics effects) in the D0 experiment at the Tevatron accelerator (FNAL, USA) are examined. These results were obtained on the basis of a statistical sample corresponding to an integrated luminosity of 5 to 7 fb?1 and were published in 2010 and 2011.  相似文献   

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The European Physical Journal C - First results reveal good capabilities of DØ experiment to study B physics. A new tracking system, high reconstruction rate and efficient trigger allow the...  相似文献   

5.
The latest results obtained from searches for particles and phenomena beyond the Standard Model (new physics) in the D0 experiment at the Tevatron [Fermi National Accelerator Laboratory (FNAL), USA] on the basis of a statistical sample corresponding to an accumulated luminosity of 1 to 3 fb−1 in 2008 are considered.  相似文献   

6.
We present the first model-independent measurement of the helicity of W bosons produced in top quark decays, based on a 1 fb(-1) sample of candidate tt events in the dilepton and lepton plus jets channels collected by the D0 detector at the Fermilab Tevatron pp Collider. We reconstruct the angle theta(*) between the momenta of the down-type fermion and the top quark in the W boson rest frame for each top quark decay. A fit of the resulting costheta(*) distribution finds that the fraction of longitudinal W bosons f(0)=0.425+/-0.166(stat)+/-0.102(syst) and the fraction of right-handed W bosons f(+)=0.119+/-0.090(stat)+/-0.053(syst), which is consistent at the 30% C.L. with the standard model.  相似文献   

7.
We suggest that top quark physics can be studied at the LHCb experiment and that top quark production could be observed. Since LHCb covers a large pseudorapidity region in the forward direction, it has unique abilities to probe new physics in the top quark sector. Furthermore, we demonstrate that LHCb may be able to measure a t ?t production rate asymmetry and, thus, indirectly probe an anomalous forward-backward t ?t asymmetry in the forward region, a possibility suggested by the enhanced forward-backward asymmetry reported by the CDF experiment.  相似文献   

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Beta-delayed proton decay of 57Zn has been investigated at the GSI on-line isotope separator. The studied 57Zn nuclei were produced in fusion evaporation reactions by using a 150 MeV 32S beam on a 28Si target. Beta-delayed protons were measured by a charged-particle telescope detector. The observed decay pattern was used to construct the level scheme of 57Cu and to extract the beta feeding distribution. The experimental results are compared with shell-model calculations. An erratum to this article is available at .  相似文献   

10.
The calculations of the time-dependent reactor-antineutrino energy spectrum are presented. Some problems associated with sensitive searches for the neutrino magnetic moment and neutrino oscillations in a reactor-antineutrino flux are considered.  相似文献   

11.
介绍一套新体系的物理实验教材   总被引:1,自引:0,他引:1  
介绍由中国科学技术大学霍剑青、吴泳华等主编,高等教育出版社出版的《大学物理实验》教材,该教材分为四册,对应新实验体系的四级物理实验。  相似文献   

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Scott S. Snyder 《Pramana》2004,62(3):565-568
The status of the Higgs search at the upgraded DØ detector is discussed.  相似文献   

14.
The vast amount of flavor physics data available to date allows probing the presence of physics beyond the standard model through precision measurements of CP violating and CP conserving processes involving B, D, and K mesons. The information extracted from these measurements allows the characterization of physics beyond the standard model in a complementary way with respect to the direct searches at the Tevatron and the LHC. We review the status of the search for new physics with flavor-related observables. We discuss the status of the unitarity triangle analysis beyond the standard model: the inclusion of the recent measurements of Bs decays from the Tevatron experiments point to a discrepancy from the standard model expectation. In addition, we discuss the impact of O(ΛQCD/mb) corrections to the perturbative calculation of charmless hadronic B decays. These corrections can explain the puzzling values of direct CP asymmetries in BKπ decays within the standard model. These corrections cannot explain values of sin2β lower than the standard model value, as observed in bs penguin decays. We conclude with the perspectives of the next generation of flavor-physics experiments, the precision they can reach and their phenomenological impact.  相似文献   

15.
We review the search for new physics to be done at Large Hadron Collider,—search for Higgs boson, supersymmetry, and exotic.  相似文献   

16.
即兴物理实验   总被引:1,自引:3,他引:1  
蒋绚  龚晓霞 《物理实验》2003,23(12):30-31
论述了即兴物理实验的优越性,并列举了几个即兴物理实验。  相似文献   

17.
Hypernuclear research will be one of the main topics addressed by the PANDA experiment at the planned Facility for Antiproton and Ion Research FAIR at Darmstadt (Germany). http://www. gsi.de, http://www.gsi.de/fair/ Thanks to the use of stored \(\overline {p}\) beams, copious production of double Λ hypernuclei is expected at the PANDA experiment, which will enable high precision γ spectroscopy of such nuclei for the first time, and consequently a unique chance to explore the hyperon-hyperon interaction. In particular, ambiguities of past experiments in determining the strength of the ΛΛ interaction will be avoided thanks to the excellent energy precision of a few keV (FWHM) achieved by germanium detectors. Such a resolution capability is particularly needed to resolve the small energy spacing of the order of (10–100) keV, which is characteristic from the spin doublet in hypernuclei the so -called ”hypernuclear fine structure”. In comparison to previous experiments, PANDA will benefit from a novel technique to assign the various observable γ-transitions in a unique way to specific double hypernuclei by exploring various light targets. Nevertheless, the ability to carry out unique assignments requires a devoted hypernuclear detector setup. This consists of a primary nuclear target for the production of \({\Xi }^{-}+\overline {\Xi }\) pairs, a secondary active target for the hypernuclei formation and the identification of associated decay products and a germanium array detector to perform γ spectroscopy. Moreover, one of the most challenging issues of this project is the fact that all detector systems need to operate in the presence of a high magnetic field and a large hadronic background. Accordingly, the need of an innovative detector concept will require dramatic improvements to fulfil these conditions and that will likely lead to a new generation of detectors. In the present talk details concerning the current status of the activities related to the detector developments for this challenging programme will be given. Among these improvements is the new concept for a cooling system for the germanium detector based on a electro-mechanical device. In the present work, the cooling efficiency of such devices has been successfully tested, showing their capability to reach liquid nitrogen temperatures and therefore the possibility to use them as a good alternative to the standard liquid nitrogen dewars. Furthermore, since the momentum resolution of low momentum particles is crucial for the unique identification of hypernuclei, an analysis procedure for improving the momentum resolution in few layer silicon based trackers is presented.  相似文献   

18.
The most general momentum independent dynamical r-matrices are described for the standard Lax representation of the degenerate Calogero-Moser models based on gl n and those r-matrices whose dynamical dependence can be gauge d away are selected. In the rational case, a non-dynamical r-matrix resulting from gauge transformation is given explicitly as an antisymmetric solution of the classical Yang-Baxter equation that belongs to the Frobenius subalgebra of gl n consisting of the matrices with vanishing last row.  相似文献   

19.
We present the first general analysis of New Physics contributions to the D0-D[over ](0) lifetime difference (equivalently DeltaGamma(D)). We argue that New Physics (NP) contributions to |DeltaC|=1 processes can dominate the lifetime difference in the flavor SU(3) limit. We provide several specific examples of models that produce sizable effects in DeltaGamma(D) for realistic values of light quark masses, even if such NP contributions are undetectable in the current round of D0 decay experiments. This makes DeltaGamma(D) a viable observable for studies of indirect effects of New Physics.  相似文献   

20.
We describe a search for anomalous production of events with two leptons (e or mu) of the same electric charge in pp[over ] collisions at a center-of-mass energy of 1.96 TeV. Many extensions to the standard model predict the production of two leptons of the same electric charge. This search has a significant increase in sensitivity compared to earlier searches. Using a data sample corresponding to 1 fb(-1) of integrated luminosity recorded by the CDF II detector, we observe no significant excess in an inclusive selection (expect 33.2+/-4.7 events, observe 44) or in a supersymmetry-optimized selection (expect 7.8+/-1.1 events, observe 13.).  相似文献   

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