Multiplicity studies and effective energy in ALICE at the LHC

In this work we explore the possibility to perform “effective energy” studies in very high energy collisions at the CERN large hadron collider (LHC). In particular, we focus on the possibility to measure in pp collisions the average charged multiplicity as a function of the effective energy with the ALICE experiment, using its capability to measure the energy of the leading baryons with the zero degree calorimeters. Analyses of this kind have been done at lower centre-of-mass energies and have shown that, once the appropriate kinematic variables are chosen, particle production is characterized by universal properties: no matter the nature of the interacting particles, the final states have identical features. Assuming that this universality picture can be extended to ion–ion collisions, as suggested by recent results from RHIC experiments, a novel approach based on the scaling hypothesis for limiting fragmentation has been used to derive the expected charged event multiplicity in AA interactions at LHC. This leads to scenarios where the multiplicity is significantly lower compared to most of the predictions from the models currently used to describe high energy AA collisions. A mean charged multiplicity of about 1000–2000 per rapidity unit (at η∼0) is expected for the most central Pb–Pb collisions at . In memory of A. Smirnitskiy     

Numerical Simulation of the Yield of α Particles and Neutrons from the 11B(p, 3α) and 11B(p,n)11C Nuclear Reactions Induced by Intense Picosecond Laser Radiation

Journal of Experimental and Theoretical Physics - The yields of alpha particles and neutrons from the promising 11B(p, 3α) fusion reaction and the reference 11B(p, n)11C nuclear reaction,...     

Investigation of the Yield of the Nuclear Reaction $${}^{{11}}$$ B( $${p,3\alpha}$$ ) Initiated by Powerful Picosecond Laser Radiation

Physics of Atomic Nuclei - The results obtained by experimentally and theoretically studying the yield of the promising nuclear-fusion reaction $${}^{11}$$ B( $$p,3\alpha$$ ) initiated by powerful...     

Measurement of cumulative-photon spectra at high transverse momenta in 12C9Be interactions at an energy of 3.2 GeV per nucleon

For ¹²C⁹Be interactions at a kinetic beam energy of 3.2 GeV per nucleon, the spectra of photons at laboratory angles in the range 55°–73° were measured off the kinematical region available to the interaction of single nucleons within colliding nuclei. The use of a fast trigger for selecting events involving the production of high-transverse-momentum photons made it possible to measure spectra off the kinematical boundary of four-nucleon interaction. It is shown that the proposed procedure is adequate to the problem of searches for and investigation of flucton-flucton interaction. In the kinematical region where flucton-flucton interaction can manifest itself, the cross sections in question are on the same order of magnitude as respective model predictions. In order to draw definitive conclusions on the role of flucton-flucton interaction, it is highly desirable to extend the angular range of the measurements toward smaller angles.     

Observation of an anomaly in the angular distribution of cumulative hadrons near the backward direction

The angular distributions of secondary pions, protons, and deuterons originating from π^?Pb interactions at an incident-pion momentum of 5 GeV/c was determined in a new run of measurements relying on track reconstruction. While showing a decrease over a large angular interval with increasing emission angle, the yield of cumulative particles of each species was found to be anomalously large near the backward direction.     

Simultaneous Investigation of the Nuclear Reactions $${}^{11}$$ B $$\boldsymbol{(p,3\alpha)}$$ and $${}^{11}$$ B $$\boldsymbol{(p,n)^{11}}$$ C as a New Tool for Determining the Absolute Yield of Alpha Particles in Picosecond Plasmas

Physics of Atomic Nuclei - The results of experimental investigations devoted to initiating the promising nuclear fusion reaction $${}^{11}$$ B $$(p,3\alpha)$$ in picosecond laser plasmas at a...     

Space charge limited avalanche growth in multigap resistive plate chambers

The European Physical Journal C - The ALICE TOF array will be built using the Multigap Resistive Plate Chamber(MRPC) configured as a double stack. Each stack contains 5 gas gaps with width of...     

Promising lines of research in the realms of laboratory nuclear astrophysics by means of powerful lasers

Basic nuclear-astrophysics problems that can be studied under laboratory conditions at a laserradiation intensity of 10¹⁸ W/cm² or more are specified. These are the lithium problem, the problem of determining neutron sources for s-processes of heavy-element formation, the formation of bypassed stable p-nuclei, and nuclear reactions involving isotopes used by astronomers for diagnostics purposes. The results of experiments at the Neodym laser facility are presented, and proposals for further studies in these realms are formulated.