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arXiv2007

Measurement of the Branching Fraction for B^0 --> a1(1260)+-pi-+ with 535 Million BBbar Pairs

We present a measurement of the branching fraction for the decay B^0->a1+(1260)pi- with a1+->pi+pi+pi- using a data sample containing 535x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider operating at the Upsilon(4S) resonance. We measure the branching fraction Br(B^0->a1+pi-)Br(a1+->pi+pi+pi-) = (14.9 +- 1.6 +- 2.3)x10^-6, where the first and second errors are statistical and systematic, respectively.

hep-ex↗

arXiv2007

Precision study of K^\pm\toπ^\pmπ^0π^0 and K^\pm\toπ^\pmπ^+π^- Dalitz plot distributions by NA48/2

The NA48/2 experiment at the CERN SPS has collected an unprecedented sample of $K^\pm\to3π$ decays. The high statistics and the good resolution of the detectors allow a unique investigation of the detailed phase space distributions of these decays. The effects of final state pion rescattering observed in the Dalitz plot distribution of the $K^\pm\toπ^\pmπ^0π^0$ decays turned out to be a powerful tool for extraction of the S-wave $ππ$ scattering lengths. The large statistics also allowed a precise measurement of the Dalitz plot slope parameters for the $K^\pm\to3π^\pm$ decays.

hep-ex↗

arXiv2007

A General Search for New Phenomena at HERA

A model-independent search for deviations from the Standard Model prediction is performed in $e^+ p$ and $e^- p$ collisions at HERA II using all high energy data recorded by the H1 experiment. This corresponds to a total integrated luminosity of 337 pb$^{-1}$. All event topologies involving isolated electrons, photons, muons, neutrinos and jets with high transverse momenta are investigated in a single analysis. Events are assigned to exclusive classes according to their final state. A statistical algorithm is used to search for deviations from the Standard Model in distributions of the scalar sum of transverse momenta or invariant mass of final state particles and to quantify their significance. A good agreement with the Standard Model prediction is observed in most of the event classes. The most siginificant deviation is found in the \mujnp channel in $e^+p$ collisions.

hep-ex↗

arXiv2007

Experimental tests of small-x QCD

Current and future experimental studies of the high-energy limit of QCD, dominated by non-linear gluon dynamics in the low-x sector of the hadron wavefunctions, are presented. Results at HERA (proton) and RHIC (nucleus) pointing to the possible onset of parton saturation phenomena, and perspectives at the LHC and new proposed DIS facilities are outlined.

hep-ex↗

arXiv2007

CP violation in the B0s system

In this paper the most recent Tevatron results concerning CP violation in the B0s system are reviewed. These are the measurement of the direct CP asymmetry in the B0s->K-π+ decay performed by CDF and the measurement of ΔΓ_s and ϕ_s performed by D0 in the B0s->J/ψϕdecay.

hep-ex↗

arXiv2007

Calculation of the atmospheric muon flux motivated by the ATIC-2 experiment

We calculate the cosmic ray muon flux at ground level using directly the primary cosmic ray spectrum and composition measured in the ATIC-2 balloon experiment. In order to extend the calculations to high energies, up to 100 TeV, we use the data of the GAMMA experiment as well as Zatsepin and Sokolskaya model. This model, supported by the ATIC-2 data, comprises contributions to the cosmic ray flux of three classes of astrophysical sources - the shocks from exploding stars, nova and supernova of different types. The muon flux computation is based on the method for solution of atmospheric hadron cascade equations in which rising total inelastic cross-sections of hadron-nuclear interactions as well as non-power-law character of the primary cosmic ray spectrum are taken into account. The calculated muon spectrum agrees well with measurements of L3+Cosmic and BESS-TeV, CAPRICE, Frejus, MACRO, LVD as well as other experiments.

astro-ph↗

arXiv2007

Experimental Results on |Vcb| and b -> c l nu Transitions

A review of recent analyses on semileptonic decays of B mesons into charmed final states is given. |Vcb| is extracted both by the Babar and the Belle collaboration from their datasets using inclusively and exclusively reconstructed final states. In addition there are recent results on the determination of exclusive branching fractions to the ground states D and D*, as well as to excited D** states. Those play an important role in understanding the composition of the total decay width. They represent also a sizable fraction of the backgrounds for exclusive analyses and are presented here as well.

hep-ex↗

arXiv2007

Proton Structure Functions at High $Q^{2}$ and High x at HERA

Neutral and charged current deep inelastic scattering cross sections and structure functions are presented. The review also discusses improvements to the parton density measurements using jet cross section data and recent high $Q^{2}$ inclusive cross section measurements. The projected parton density uncertainties using the entire HERA data set are also presented.

hep-ex↗

arXiv2007

Determination of Delta G/G from Open Charm events at COMPASS

One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, Delta G/G. It is determined from spin asymmetries in the scattering of 160 GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. A very clean selection of PGF events can be obtained with charmed mesons in the final state. Their detection is based on the reconstruction of D* and D0 mesons in the COMPASS spectrometer. The analysis method for the first measurement of Delta G/G from the open charm channel is described and the result from COMPASS for the 2002-2004 data taking period is presented.

hep-ex↗

arXiv2007

Review of Bu leptonic decays

This paper reviews the status of searches and measurements of Bu leptonic decays, concentrating on the most recent results obtained at B-factories. We will describe studies of decays of the type B+ -> ell+ nu and B+ -> ell+ nu gamma.

hep-ex↗

arXiv2007

Bs Mixing and decays at the Tevatron

This short review reports on recent results from CDF and D0 experiments at the Tevatron collider on Bs mixing and the lifetimes of Bs and Lambdab.

hep-ex↗

arXiv2007

Measurements of the CKM Angle beta/phi_1 at B Factories

We present a review of the measurements of the CKM angle beta (phi_1) by the BaBar and Belle experiments at the asymmetric-energy e+e- B Factories PEP-II and KEKB. The angle beta (phi_1) is measured by time-dependent CP analyses of neutral B meson decays in a Upsilon(4S)->BBbar system, where one B meson is fully reconstructed in a final state that can be accessed to by both B0 and B0bar, usually a CP eigenstate. This angle has been measured at a high precision through B0-> (ccbar)K0 channels. We also review another tree-dominated decay B0-> D(*)0 h0 (h0 = pi0, eta^{'}, omega); tree decays with penguin pollutions, B0->D(*)+-D-+$ and J/psi pi0; and penguin dominated modes, B0-> eta^'K0, K+K-K0, and KsKsKs. A hint of sin2beta (sin2phi_1) in charmless modes less than (ccbar)K0 modes still persists, which may be an indication of possible new physics entering the loop in the penguin diagram.

hep-ex↗

arXiv2007

Charm Dalitz Analyses

A review of recent experimental results of Dalitz analyses of charmed meson decays into three-body final states is presented. These analyses can help in understanding the strong interaction dynamics leading to the observed light mesons spectrum (low mass scalar $σ$, $f_0(980)$, $a_0(980)$). A model for the decay amplitude into such states is very important for the extraction of the angle $γ$ of the CKM unitarity triangle. Implications for such measurement are discussed.

hep-ex↗

arXiv2007

Spin Physics: Session Summary

We summarize the main results of the spin physics Working Group Session of DIS 2007, the 15th International Workshop on ``Deep-Inelastic Scattering and Related Subjects''.

hep-ph↗

arXiv2007

Exotic Searches at the Tevatron

Recent results on searches for new physics at Run II of the Tevatron are reported. The searches cover many different final states and previous hints of signals, but all analyses have at this point led to negative results.

hep-ex↗

arXiv2007

Radiative return physics program within EURIDICE network

A short review of both theoretical and experimental aspects of the radiative return method is presented with the emphasize on the results obtained within the EURIDICE network. It is shown that the method gives not only possibility of an independent from the scan method measurement of the hadronic cross section, but also can provide information concerning details of the hadronic interactions.

hep-ph↗

arXiv2007

Supersymmetry Searches at the Tevatron

CDF and DO detectors have already collected 1.3 fb^{-1} of data delivered by the Tevatron collider at 1.96 TeV center-of-mass energy. We present here the various analyses that are currently testing the possibility of a supersymmetric extension of the Standard Model. No evidence for such processes have been found in luminosities that range from 300 to 800 pb^{-1} and different limits on the different supersymmetric models are set. Constraints coming from indirect searches are also presented.

hep-ex↗

arXiv2007

On the Correlation of Subevents in the ATLAS and CMS/Totem Experiments

We analyze the problem of correlating pp interaction data from the central detectors with a subevent measured in an independent system of leading proton detectors using FP420 as an example. FP420 is an R&D project conducted by a collaboration formed by members of ATLAS and CMS to investigate the possibility of detecting new physics in the central exclusive channel, PP -> P + X + P,where the central system X may be a single particle, for example a Standard Model Higgs boson. With standard LHC optics, the protons emerge from the beam at a distance of 420m from the Interaction Point, for M_X ~ 120 GeV. The mass of the central system can be measured from the outgoing protons alone, with a resolution of order 2 GeV irrespective of the decay products of the central system. In addition, to a very good approximation, only central systems with 0^++ quantum numbers can be produced, meaning that observation of a SM or MSSM Higgs Boson in this channel would lead to a direct determination of the quantum numbers.

hep-ex↗