Chiral shifts in heavy-light mesons

The mass shifts of the $P$-wave $D_s$ and $B_s$ mesons due to coupling to $DK$ and $BK$ channels are calculated in the coupling channel model without fitting parameters. The strong mass shifts down for $0^+$ and ${1^+}'$ states have been obtained, while ${1^+}"$ and $2^+$ states remain almost in situ. The masses of $0^+$ and ${1^+}'$ states of $B_s$ mesons have been predicted.Comment: to be published in the Proceedings of the 14th International QCD Conference, 7th-12th July 2008, Montpellier, Franc

Nonperturbative hyperfine contribution to the b1b_1 and h1h_1 meson masses

Due to the nonperturbative contribution to the hyperfine splitting the mass of the $n^1P_1$ state is strongly correlated with the center of gravity $M_{\rm cog}(n^3P_J)$ of the $n^3P_J$ multiplet: $M(n^1P_1)$ is less than $M_{\rm cog}(n^3P_J)$ by about 40 MeV (20 MeV) for the 1P (2P) state. For $b_1(1235)$ the agreement with experiment is reached only if $a_0(980)$ belongs to the $1^3P_J$ multiplet. The predicted mass of $b_1(2^1P_1)$ is $\approx 1620$ MeV. For the isoscalar meson a correlation between the mass of $h_1$(1170) $(h_1(1380))$ and $M_{cog}(1^3P_J)$ composed from light (strange) quarks also takes place.Comment: 22 pages RevTe

Ultrafast insulator-metal transition in VO2 nanostructures assisted by picosecond strain pulses

Strain engineering is a powerful technology that exploits the stationary external or internal stress of specific spatial distribution for controlling the fundamental properties of condensed materials and nanostructures. This advanced technique modulates in space the carrier density and mobility, the optical absorption, and in strongly correlated systems, the phase, e.g., insulator-metal or ferromagnetic-paramagnetic. However, while successfully accessing nanometer-length scales, strain engineering is yet to be brought down to ultrafast time scales allowing strain-assisted control of the state of matter at THz frequencies. We demonstrate control of an optically-driven insulator-to-metal phase transition by a picosecond strain pulse, which paves the way to ultrafast strain engineering in nanostructures with phase transitions. This is realized by simultaneous excitation of VO2 nanohillocks by a 170-fs laser and picosecond strain pulses finely timed with each other. By monitoring the transient optical reflectivity of the VO2, we show that strain pulses, depending on the sign of the strain at the moment of optical excitation, increase or decrease the fraction of VO2 that undergoes an ultrafast phase transition. A transient strain of moderate amplitude of approximately 0.1% applied during ultrafast photo-induced nonthermal transition changes the fraction of VO2 in the laser-induced phase by approximately 1%. In contrast, if applied after the photoexcitation when the phase transformations of the material are governed by thermal processes, a transient strain of the same amplitude produces no measurable effect on the phase state

Measurement of Masses and Widths of Excited Charm Mesons D2∗D_2^* and Evidence for Broad States

Using data from the FOCUS experiment we analyze the $D^+\pi^-$ and $D^0\pi^+$ invariant mass distributions. We measure the $D_2^{*0}$ mass M_{D_2^{*0}} = (2464.5 \pm 1.1 \pm 1.9) \mev and width \Gamma_{D_2^{*0}} = (38.7 \pm 5.3 \pm 2.9) \mev, and the $D_2^{*+}$ mass M_{D_2^{*+}} = (2467.6 \pm 1.5 \pm 0.76) \mev and width \Gamma_{D_2^{*+}} = (34.1 \pm 6.5 \pm 4.2) \mev. We find evidence for broad structures over background in both the neutral and charged final state. If each is interpreted as evidence for a single L=1, $j_q=1/2$ excited charm meson resonance, the masses and widths are M_{1/2}^0 =(2407 \pm 21 \pm 35) \mev, \Gamma_{1/2}^0 = (240 \pm 55 \pm 59) \mev, and M_{1/2}^+ = (2403 \pm 14 \pm 35) \mev \Gamma_{1/2}^+ = (283 \pm 24 \pm 34) \mev, respectively.Comment: 15 pages, 4 figures. Submitted to Phys. Lett. B. Added preprint number

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partial-wave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of $P$-matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G-matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determine the natural scale of the density for a possible phase transition into the MQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernova models. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.Comment: 57 pages, 22 figures, 7 tables; RevTeX 4; submitted to Phys. Atom. Nuc

Ultrafast light-induced dynamics of spins and lattice in iron oxides

Contains fulltext : 75624.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 1 april 2009Promotores : Rasing, T.H.M., Pisarev, R.V. Co-promotor : Kirilyuk, Andrei153 p

Charge transfer transitions in multiferroic BiFeO3 and related ferrite insulators

Contains fulltext : 75294.pdf (publisher's version ) (Open Access)16 p

Anomalous optical properties of the mixed-valent lithium cuprate LiCu2O2

Contains fulltext : 36097.pdf (publisher's version ) (Open Access

Ad libitum fluid intakes and thermoregulatory responses of female distance runners in three environments

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Impulsive generation of coherent magnons by linearly polarized light in the easy-plane antiferromagnet FeBO3

Contains fulltext : 34659.pdf (publisher's version ) (Open Access