Thu·Feb 23, 2017Thursday·February 23, 2017

1. 01*

   Twist-2 matching of transverse momentum dependent distributions

   Daniel Gutierrez-Reyes🇪🇸 · Ignazio Scimemi🇪🇸 · Alexey A. Vladimirov🇩🇪

   We systematically study the large-$q_T$ (or small-$b$) matching of transverse momentum dependent (TMD) distributions to the twist-2 integrated parton distributions. Performing operator product expansion for a generic TMD operator at the next-to-leading order (NLO) we found the complete set of TMD distributions that match twist-2. These are unpolarized, helicity, transversity, pretzelosity and linearly polarized gluon distributions. The NLO matching coefficients for these distributions are presented. The pretzelosity matching coefficient is zero at the presented order, however, it is evident that it is non-zero in the following orders. This result offers a natural explanation of the small value of pretzelosity found in phenomenological fits. We also demonstrate that the cancellation of rapidity divergences by the leading order soft factor imposes the necessary requirement on the Lorentz structure of TMD operators, which is supported only by the TMD distributions of leading dynamical twist. Additionally, this requirement puts restrictions on the ${\gamma }_5$-definition in the dimensional regularization.

   ↳ hep-phhep-exnucl-exnucl-thPLB(2017)·51 citations
2. 02*

   Light flavour hadron production in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE

   Raúl Tonatiuh Jiménez Bustamante (for the ALICE collaboration)🇩🇪

   The ALICE detector has excellent Particle IDentification (PID) capabilities in the central barrel ($|\eta |<$ 0.9). This allows identified hadron production to be measured over a wide transverse momentum ($p_{\mathrm{T}}$) range, using different sub-detectors and techniques: their specific energy loss (d$E$/d$x$), the velocity determination via time-of-flight measurement, the Cherenkov angle or their characteristic weak decay topology. Results on identified light flavour hadron production at mid-rapidity measured by ALICE in proton-proton collisions at $\sqrt{s}$ = 13 TeV are presented and compared with previous measurements performed at lower energies. The results cover a wide range of particle species including long-lived hadrons, resonances and multi-strange baryons over the $p_{\mathrm{T}}$ range from 150 MeV/$c$ up to 20 GeV/$c$, depending on the particle species.

   ↳ hep-exnucl-exJ.Phys.Conf.Ser.(2017)·1 citation
3. 03*

   Analysis of recent CLAS data on $f_1(1285)$ photoproduction

   Xiao-Yun Wang🇨🇳 · Jun He🇨🇳

   Based on the experimental data released recently by the CLAS Collaboration, the $f_1(1285)$ photoproduction off a proton target is investigated in an effective Lagrangian approach. In our model, $s$-channel, $u$-channel, and $t$-channel Born terms are included to calculate the differential cross sections, which are compared with the recent CLAS experiment. An interpolating Reggeized treatment is applied to the $t$ channel, and it is found that the $t$-channel contribution is dominant in the $f_1(1285)$ photoproduction and the $u$-channel contribution is responsible for the enhancement at backward angles. The present calculation does not take into account any explicit $s$-channel nucleon-resonance contribution; nevertheless, our model provides a good description of the main features of the data. It suggests small couplings of the $f_1(1285)$ and the nucleon resonances in this energy region.

   ↳ nucl-thhep-phnucl-exPRD(2017)·21 citations
4. 04*

   Multiplicity Dependence of Non-extensive Parameters for Strange and Multi-Strange Particles in Proton-Proton Collisions at $\sqrt{s}=7$ TeV at the LHC

   Arvind Khuntia🇮🇳 · Sushanta Tripathy🇮🇳 · Raghunath Sahoo🇮🇳 · Jean Cleymans🇿🇦

   The transverse momentum ($p_{\mathrm{T}}$) spectra in proton-proton collisions at $\sqrt{s}$ = 7 TeV, measured by the ALICE experiment at the LHC are analyzed with a thermodynamically consistent Tsallis distribution. The information about the freeze-out surface in terms of freeze-out volume, temperature and the non-extenisivity parameter, $q$, for $K_S^0$, $\Lambda +\bar{\Lambda }$, ${\Xi }^{-}+{\bar{\Xi }}^{+}$ and ${\Omega }^{-}+{\bar{\Omega }}^{+}$ are extracted by fitting the $p_{\mathrm{T}}$ spectra with Tsallis distribution function. The freeze-out parameters of these particles are studied as a function of charged particle multiplicity density ($d{N}_{ch}/d\eta$). In addition, we also study these parameters as a function of particle mass to see any possible mass ordering. The strange and multi-strange particles show mass ordering in volume, temperature, non-extensive parameter and also a strong dependence on multiplicity classes. It is observed that with increase in particle multiplicity, the non-extensivity parameter, $q$ decreases, which indicates the tendency of the produced system towards thermodynamic equilibration. The increase in strange particle multiplicity is observed to be due to the increase of temperature and not to the size of the freeze-out volume.

   ↳ hep-phhep-exnucl-exnucl-thEPJA(2017)·52 citations
5. 05*

   Study of $\mathrm{CdMo}{\mathrm{O}}_4$ crystal for a neutrinoless double beta decay experiment with ${}^{116}\mathrm{Cd}$ and ${}^{100}\mathrm{Mo}$ nuclides

   Ming-xuan Xue🇨🇳 · Yun-long Zhang🇨🇳 · Hai-ping Peng🇨🇳 · Zi-zong Xu🇨🇳 · Xiao-lian Wang🇨🇳

   The scintillation properties of a $\mathrm{CdMo}{\mathrm{O}}_4$ crystal have been investigated experimentally. The fluorescence yields and decay times measured from 22 K to 300 K demonstrate that $\mathrm{CdMo}{\mathrm{O}}_4$ crystal is a good candidate for an absorber for a bolometer readout, for both heat and scintillation signals. The results from Monte Carlo studies taking the backgrounds from $2\nu 2\beta$ of ${}_{42}^{100}\mathrm{Mo}$ (${}_{48}^{116}\mathrm{Cd}$) and internal trace nuclides ${}^{214}\mathrm{Bi}$ and ${}^{208}\mathrm{Tl}$ into account show that the expected sensitivity of $\mathrm{CdMo}{\mathrm{O}}_4$ bolometer for neutrinoless double beta decay experiment with an exposure of 100 $\mathrm{kg}\cdot \mathrm{years}$ is one order of magnitude higher than those of the current sets of the $\lim {\mathrm{T}}_{1/2}^{0\nu \beta \beta }$ of ${}_{42}^{100}\mathrm{Mo}$ and ${}_{48}^{116}\mathrm{Cd}$.

   ↳ physics.ins-detnucl-exCPC(2017)·13 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.