ترغب بنشر مسار تعليمي؟ اضغط هنا

An analysis of charged particles spectra in events with different charged multiplicity

174   0   0.0 ( 0 )
 نشر من قبل Alexander Bylinkin
 تاريخ النشر 2012
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

The shapes of invariant differential cross section for charged particle production as function of transverse momentum measured in $pp$ collisions by the STAR detector are analyzed. The spectra shape varies with the event charged multiplicity changing. To describe this and several other recently observed effects a simple qualitative model for hadroproduction mechanism was proposed.



قيم البحث

اقرأ أيضاً

167 - Yong Zhang , Hui-Qiang Ding , 2021
We study the influence of the in-medium mass difference between boson and antiboson on their spectra. The in-medium mass difference may lead to a difference between the transverse momentum spectra of boson and antiboson. This effect increases with th e increasing in-medium mass difference between boson and antiboson. The difference between the transverse momentum spectra of boson and antiboson increases with the increasing expanding velocity of the source and decreases with the increasing transverse momentum in large transverse mass region (mT > 1:6 GeV). The interactions between the hadron and the medium may increase with the increasing temperature of the medium and the higher freeze-out temperature may lead to a larger mass difference between boson and antiboson, and may give rise to a larger difference between the transverse momentum spectra of boson and antiboson for higher freeze-out temperature.
We construct electrically charged Q-balls and boson stars in a model with a scalar self-interaction potential resulting from gauge mediated supersymmetry breaking. We discuss the properties of these solutions in detail and emphasize the differences t o the uncharged case. We observe that Q-balls can only be constructed up to a maximal value of the charge of the scalar field, while for boson stars the interplay between the attractive gravitational force and the repulsive electromagnetic force determines their behaviour. We find that the vacuum is stable with respect to pair production in the presence of our charged boson stars. We also study the motion of charged, massive test particles in the space-time of boson stars. We find that in contrast to charged black holes the motion of charged test particles in charged boson star space-times is planar, but that the presence of the scalar field plays a crucial role for the qualitative features of the trajectories. Applications of this test particle motion can be made in the study of extreme-mass ratio inspirals (EMRIs) as well as astrophysical plasmas relevant e.g. in the formation of accretion discs and polar jets of compact objects.
We revisit the classical theory of a relativistic massless charged point particle with spin and interacting with an external electromagnetic field. In particular, we give a proper definition of its kinetic energy and its total energy, the latter bein g conserved when the external field is stationary. We also write the conservation laws for the linear and angular momenta. Finally, we find that the particles velocity may differ from $c$ as a result of the spin---electromagnetic field interaction, without jeopardizing Lorentz invariance.
Ultra-peripheral collisions (UPCs) of relativistic ions are an important tool for studying photoproduction at high energies. Vector meson photoproduction is an important tool for nuclear structure measurements and other applications. A future electro n-ion collider (EIC) will allow additional studies, using virtual photons with a wide range of $Q^2$. We propose a significant expansion of the UPC and EIC photoproduction physics programs to include charged final states which may be produced via Reggeon exchange. We consider two examples: $a_2^+(1320)$, which is a conventional $qoverline q$ meson, and the exotic $Z_c^+(4430)$ state (modeled here as a tetraquark). The $Z_c^+(4430)$ cross-section depends on its internal structure, so photoproduction can test whether the $Z_c^+(4430)$ is a tetraquark or other exotic object. We calculate the rates and kinematic distributions for $gamma prightarrow X^+n$ in $pA$ UPCs and $ep$ collisions at an EIC and in UPCs. The rates are large enough for detailed studies of these final states. Because the cross-section for Reggeon exchange is largest near threshold, the final state rapidity distribution depends on the beam energies. At high-energy colliders like the proposed LHeC or $pA$ collisions at the LHC, the final states are produced at far forward rapidities. For lower energy colliders, the systems are produced closer to mid-rapidity, within reach of central detectors.
We use a recent scaling analysis of the quasielastic electron scattering data from $^{12}$C to predict the quasielastic charge-changing neutrino scattering cross sections within an uncertainty band. We use a scaling function extracted from a selectio n of the $(e,e)$ cross section data, and an effective nucleon mass inspired by the relativistic mean-field model of nuclear matter. The corresponding super-scaling analysis with relativistic effective mass (SuSAM*) describes a large amount of the electron data lying inside a phenomenological quasielastic band. The effective mass incorporates the enhancement of the transverse current produced by the relativistic mean field. The scaling function incorporates nuclear effects beyond the impulse approximation, in particular meson-exchange currents and short range correlations producing tails in the scaling function. Besides its simplicity, this model describes the neutrino data as reasonably well as other more sophisticated nuclear models.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا