Unequal rapidity correlators in the dilute limit of JIMWLK

We study unequal rapidity correlators in the stochastic Langevin picture of Jalilian-Marian– Iancu–McLerran–Weigert–Leonidov–Kovner (JIMWLK) evolution in the Color Glass Conden- sate effective field theory. By separately evolving the Wilson lines in the direct and complex conjugate amplitudes, we use the formalism to study two-particle production at large rapidity separations. We show that the evolution between the rapidities of the two produced particles can be expressed as a linear equa- tion, even in the full nonlinear limit. We also show how the Langevin formalism for two-particle correlations reduces to a BFKL picture in the dilute limit and in momentum space, providing an interpretation of BFKL evolution as a stochastic process for color charges.Peer reviewe

Unequal rapidity correlators in the dilute limit of JIMWLK

We study unequal rapidity correlators in the stochastic Langevin picture of Jalilian-Marian– Iancu–McLerran–Weigert–Leonidov–Kovner (JIMWLK) evolution in the Color Glass Conden- sate effective field theory. By separately evolving the Wilson lines in the direct and complex conjugate amplitudes, we use the formalism to study two-particle production at large rapidity separations. We show that the evolution between the rapidities of the two produced particles can be expressed as a linear equa- tion, even in the full nonlinear limit. We also show how the Langevin formalism for two-particle correlations reduces to a BFKL picture in the dilute limit and in momentum space, providing an interpretation of BFKL evolution as a stochastic process for color charges.Peer reviewe

The dipole picture and the non-relativistic expansion

We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small x, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium light-cone wave function in light-cone gauge. Using these corrections we recover results for the NLO decay width of quarkonium to e+e− and we check that the non-relativistic expansion is consistent with ERBL evolution and with B-JIMWLK evolution of the target. The results presented here will allow computing the exclusive quarkonium production rate at NLO once the one loop photon wave function with massive quarks, currently under investigation, is known. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).Peer reviewe

Wilson line correlator in the MV model: relating the glasma to deep inelastic scattering

In the color glass condensate framework the saturation scale measured in deep inelastic scattering of high energy hadrons and nuclei can be determined from the correlator of Wilson lines in the hadron wavefunction. These same Wilson lines give the initial condition of the classical field computation of the initial gluon multiplicity and energy density in a heavy ion collision. In this paper the Wilson line correlator in both adjoint and fundamental representations is computed using exactly the same numerical procedure that has been used to calculate gluon production in a heavy ion collision. In particular the discretization of the longitudinal coordinate has a large numerical effect on the relation between the color charge density parameter g^2 mu and the saturation scale Qs. Our result for this relation is Qs = 0.6 g^2 mu, which results in the classical Yang-Mills value for the "gluon liberation coefficient" c = 1.1.Comment: 8 pages, 10 figures, RevTEX4, V2: typo corrections, V3: small clarifications, to be published in EPJ

Structure of longitudinal chromomagnetic fields in high energy collisions

Creative Commons License (CC BY 3.0)Peer reviewe

Non-perturbative computation of double inclusive gluon production in the Glasma

The near-side ridge observed in A+A collisions at RHIC has been described as arising from the radial flow of Glasma flux tubes formed at very early times in the collisions. We investigate the viability of this scenario by performing a non-perturbative numerical computation of double inclusive gluon production in the Glasma. Our results support the conjecture that the range of transverse color screening of correlations determining the size of the flux tubes is a semi-hard scale, albeit with non-trivial structure. We discuss our results in the context of ridge correlations in the RHIC heavy ion experiments.Comment: 25 pages, 11 figures, uses JHEP3.cls V2: small clarifications, published in JHE

Ohjusilmatorjunnan kehitykseen vaikuttaneet tekijät sekä kehitysvaiheet ja nykyiset käyttöperiaatteet

Artikkelin johdannon mukaan viimeisen kymmenen vuoden aikana on ilmatorjuntaohjuksia käytetty kolmessa sodassa ja niistä saadut kokemukset ovat merkittävästi vaikuttaneet kehitystyöhön. Kirjoittajan toteaa havainneensa, että ohjusilmatorjunnan kehitysvaiheista, kehitykseen vaikuttaneista tekijöistä eikä myöskään taktillisista käyttöperiaatteista ei ole laadittu yhtenäistä kirjallista esitystä edes ulkomailla. Tämä antoi hänelle syyn laatia nyt lyhennelmänä julkaistava tutkimustyö. "Lyhentäminen on kohdistunut painopisteellisesti niihin sotakokemuksiin, jotka ovat vaikuttaneet sekä ohjusilmatorjunnan syntyyn että kehitysvaiheisiin. Teknillistä kehitystä tarkastellaan vain pääpiirtein. Taktilliset käyttöperiaatteet pyritään selvittämään lähitulevaisuuden kehitysnäkymät huomioonottaen. Tutkimustyössä on perustana käytetty pääasiassa ulkomaista lähdekirjallisuutta." Ensimmäinen luku käsittelee ilmatorjuntaohjusten syntyä ja toinen luku ohjusilmatorjunnan kehityksen syitä ja taustatekijöitä toisen maailmansodan jälkeen. Kolmannessa luvussa, "Ohjusilmatorjunnan kehitys toisen maailmansodan jälkeen", tarkastelussa ovat aluksi ohjusilmatorjunnan kehitystendenssit. Lisäksi tarkastellaan havaintoja ohjusilmatorjunnan kehityksestä eri maissa. Kohdemaita ovat Yhdysvallat, Neuvostoliitto, Englanti, Ranska, Ruotsi ja Sveitsi. Perusteiksi selvitetään sotakokemuksia Vietnamin ja Lähi-idän 1967 ja 1973 sodista. Viimeisessä luvussa käsitellään ohjusilmatorjunnan silloisia käyttöperiaatteita Yhdysvalloissa, Neuvostoliitossa, Ruotsissa, Englannissa ja Länsi-Saksassa. Loppusanoissa todetaan muun muassa, että" Kilpailu hyökkäyksellisen ilma-aseen ja puolustuksellisen ohjusilmatorjunta-aseen välillä jatkuu.

Fine morphological assessment of quality of human mature oocytes after slow freezing or vitrification with a closed device: a comparative analysis

BACKGROUND: Human mature oocytes are very susceptible to cryodamage. Several reports demonstrated that vitrification might preserve oocyte better than slow freezing. However, this is still controversial. Thus, larger clinical, biological and experimental trials to confirm this concept are necessary. The aim of the study was to evaluate and compare fine morphological features in human mature oocytes cryopreserved with either slow freezing or vitrification. METHODS: We used 47 supernumerary human mature (metaphase II) oocytes donated by consenting patients, aged 27-32 years, enrolled in an IVF program. Thirtyfive oocytes were cryopreserved using slow freezing with 1.5 M propanediol +0.2 M sucrose concentration (20 oocytes) or a closed vitrification system (CryoTip Irvine Scientific CA) (15 oocytes). Twelve fresh oocytes were used as controls. All samples were prepared for light and transmission electron microscopy evaluation. RESULTS: Control, slow frozen/thawed and vitrified/warmed oocytes (CO, SFO and VO, respectively) were rounded, 90-100 mum in diameter, with normal ooplasm showing uniform distribution of organelles. Mitochondria-smooth endoplasmic reticulum (M-SER) aggregates and small mitochondria-vesicle (MV) complexes were the most numerous structures found in all CO, SFO and VO cultured for 3-4 hours. M-SER aggregates decreased, and large MV complexes increased in those SFO and VO maintained in culture for a prolonged period of time (8-9 hours). A slight to moderate vacuolization was present in the cytoplasm of SFO. Only a slight vacuolization was present in VO, whereas vacuoles were almost completely absent in CO. Amount and density of cortical granules (CG) appeared abnormally reduced in SFO and VO, irrespective of the protocol applied. CONCLUSIONS: Even though, both slow freezing and vitrification ensured a good overall preservation of the oocyte, we found that: 1) prolonged culture activates an intracellular membrane "recycling" that causes the abnormal transformation of the membranes of the small MV complexes and of SER into larger rounded vesicles; 2) vacuolization appears as a recurrent form of cell damage during slow freezing and, at a lesser extent, during vitrification using a closed device; 3) premature CG exocytosis was present in both SFO and VO and may cause zona pellucida hardenin

An analytic study towards instabilities of the glasma

Strong longitudinal color flux fields will be created in the initial stage of high-energy nuclear collisions. We investigate analytically time evolution of such boost-invariant color fields from Abelian-like initial conditions, and next examine stability of the boost-invariant configurations against rapidity dependent fluctuations. We find that the magnetic background field has an instability induced by the lowest Landau level whose amplitude grows exponentially. For the electric background field there is no apparent instability although pair creations due to the Schwinger mechanism should be involved.Comment: 4p, 3figs; poster contribution to QM200