A search for J^{PC}=1^{-+} exotic mesons in the pi- pi- pi+ and pi- pi0 pi0 systems

A partial wave analysis (PWA) of the pi-pi-pi+ and pi-pi0pi0 systems produced in the reaction pi- p -> (3pi)-p at 18 GeV/c was carried out using an isobar model assumption. This analysis is based on 3.0M pi-pi0pi0 events and 2.6M pi-pi-pi+ events and shows production of the a2(1320), pi2(1670) and \pi(1800) mesons. An earlier analysis of 250K pi-pi-pi+ events from the same experiment showed possible evidence for a J^{PC}=1^{-+}$ exotic meson with a mass of 1.6 GeV/c^2 decaying into rho pi. In this analysis of a higher statistics sample of the (3pi)- system in two charged modes we find no evidence of an exotic meson.Comment: 4 pages, 5 figures, added comment about the negative reflectivity exotic wave

Method of Operational Frost Resistance Monitoring (Assessment) Vibration-Pressed Concrete

Секция III : Ресурсо- и энергосберегающие строительные материалы и технологииВ статье изложены основные положения предлагаемой ускоренной методики определения морозостойкости тяжелого конструкционного мелкозернистого и с крупным заполнителем бетона вибропрессованных изделий для дорожных (тротуарных) покрытий. Она позволяет оценивать показатель морозостойкости бетона непосредственно в изделиях без циклических испытаний замораживанием-оттаиванием. В основе методики – взаимосвязь и взаимозависимость между состоянием структуры бетона (оцениваемой по влагосодержанию в насыщенном водой (раствором 5% NaCl) состоянии), скоростью распространения в нем ультразвукового импульса и установленной (путем прямых экспериментальных испытаний на морозостойкость бетона) закономерностью изменений его морозостойкости, отражаемой соответствующими изменениями скорости ультразвука.=In article basic provisions of the offered accelerated technique of determination of frost resistance heavy constructional fine-grained and with large filler of concrete of the vibropressed products for road (sidewalk) coverings are stated. She allows to estimate an indicator of frost resistance of concrete directly in products without cyclic tests by freezing thawing. At the heart of a technique – interrelation and interdependence between a condition of structure of concrete (estimated on moisture content in a state sated with water (solution of 5% of NaCl)), distribution speed in it an ultrasonic impulse and established (by direct experimental tests for frost resistance of concrete) regularity of changes of its frost resistance reflected by corresponding changes of speed of ultrasound

Method of Operational Frost Resistance Monitoring (Assessment) Vibration-Pressed Concrete

Секция III : Ресурсо- и энергосберегающие строительные материалы и технологииВ статье изложены основные положения предлагаемой ускоренной методики определения морозостойкости тяжелого конструкционного мелкозернистого и с крупным заполнителем бетона вибропрессованных изделий для дорожных (тротуарных) покрытий. Она позволяет оценивать показатель морозостойкости бетона непосредственно в изделиях без циклических испытаний замораживанием-оттаиванием. В основе методики – взаимосвязь и взаимозависимость между состоянием структуры бетона (оцениваемой по влагосодержанию в насыщенном водой (раствором 5% NaCl) состоянии), скоростью распространения в нем ультразвукового импульса и установленной (путем прямых экспериментальных испытаний на морозостойкость бетона) закономерностью изменений его морозостойкости, отражаемой соответствующими изменениями скорости ультразвука.=In article basic provisions of the offered accelerated technique of determination of frost resistance heavy constructional fine-grained and with large filler of concrete of the vibropressed products for road (sidewalk) coverings are stated. She allows to estimate an indicator of frost resistance of concrete directly in products without cyclic tests by freezing thawing. At the heart of a technique – interrelation and interdependence between a condition of structure of concrete (estimated on moisture content in a state sated with water (solution of 5% of NaCl)), distribution speed in it an ultrasonic impulse and established (by direct experimental tests for frost resistance of concrete) regularity of changes of its frost resistance reflected by corresponding changes of speed of ultrasound

Hadron Spectroscopy with COMPASS at CERN

The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage spectrometer with high momentum resolution, large acceptance, particle identification and calorimetry. A short pilot run in 2004 resulted in the observation of a spin-exotic state with $J^{PC} = 1^{-+}$ consistent with the debated $\pi1(1600)$. In addition, Coulomb production at low momentum transfer data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a world leading data set was collected with hadron beam which is currently being analysed. The large statistics allows for a thorough decomposition of the data into partial waves. The COMPASS hadron data span over a broad range of channels and shed light on several different aspects of QCD.Comment: 4 pages, 5 figure

A Study of the \eta \pi^{0} Spectrum and Search for a J^{PC} = 1^{-+} Exotic Meson

A partial wave analysis (PWA) of the of the $\eta \pi ^0$ system (where $\eta \to \gamma \gamma$) produced in the charge exchange reaction $\pi ^-p\to \eta \pi ^0n$ at an incident momentum of 18 GeV$/c$ is presented as a function of ${\eta \pi ^0}$ invariant mass, $m_{\eta\pi^0}$, and momentum transfer squared, $t_{\pi^{-}\to\eta\pi}$, from the incident $\pi^-$ to the outgoing ${\eta\pi ^0}$ system. $S$, $P$ and $D$ waves were included in the PWA. The $a_0(980)$ and $a_2(1320)$ states are clearly observed in the overall ${\eta\pi ^0}$ effective mass distribution as well as in the amplitudes associated with $S$ wave and $D$ waves respectively after partial wave decomposition. The observed distributions in moments (averages of spherical harmonics) were compared to the results from the PWA and the two are consistent. The distribution in $t_{\pi^{-}\to\eta\pi}$ for individual $D$ waves associated with natural and unnatural parity exchange in the $t$-channel are consistent with Regge phenomenology. Of particular interest in this study is the $P$ wave since this leads to an exotic $J^{PC}=1^{-+}$ for the $\eta \pi$ system. A $P$ wave is present in the data, however attempts to describe the mass dependence of the amplitude and phase motion with respect to the $D$ wave as a Breit-Wigner resonance are problematic. This has implications regarding the existence of a reported exotic $J^{PC} = 1^{-+}$ meson decaying into $\eta \pi^0$ with a mass near 1.4 GeV$/c^2$.Comment: 19 pages, 29 figures, to appear in Phys. Rev.

A spectroscopic analysis of the chemically peculiar star HD207561

In this paper we present a high-resolution spectroscopic analysis of the chemically peculiar star HD207561. During a survey programme to search for new roAp stars in the Northern hemisphere, Joshi et al. (2006) observed significant photometric variability on two consecutive nights in the year 2000. The amplitude spectra of the light curves obtained on these two nights showed oscillations with a frequency of 2.79 mHz [P~6-min]. However, subsequent follow-up observations could not confirm any rapid variability. In order to determine the spectroscopic nature of HD207561, high-resolution spectroscopic and spectro-polarimetric observations were carried out. A reasonable fit of the calculated Hbeta line profile to the observed one yields the effective temperature (Teff) and surface gravity (log g) as 7300 K and 3.7 dex, respectively. The derived projected rotational velocity (vsin i) for HD207561 is 74 km/sec indicative of a relatively fast rotator. The position of HD207561 in the H-R diagram implies that this is slightly evolved from the main-sequence and located well within the delta-Scuti instability strip. The abundance analysis indicates the star has slight under-abundances of Ca and Sc and mild over-abundances of iron-peak elements. The spectro-polarimetric study of HD207561 shows that the effective magnetic field is within the observational error of 100 gauss (G). The spectroscopic analysis revealed that the star has most of the characteristics similar to an Am star, rather than an Ap star, and that it lies in the delta-Scuti instability strip; hence roAp pulsations are not expected in HD207561, but low-overtone modes might be excited.Comment: 8 pages, 7 figures, 3 tables. Accepted for pubblication in MNRA