What can we learn from the total width of the Higgs boson?

As one of the key properties of the Higgs boson, the Higgs total width is sensitive to the global profile of the Higgs boson couplings, and thus new physics would modify the Higgs width. We investigate the total width in various new physics models, including various scalar extensions, composite Higgs models, and the fraternal twin Higgs model. Typically, the Higgs width is smaller than the standard model value due to mixture with other scalars if the Higgs is elementary, or curved Higgs field space for the composite Higgs. On the other hand, except for the possible invisible decay mode, the enhanced Yukawa coupling in the two Higgs doublet model or the exotic fermion embeddings in the composite Higgs could enhance the Higgs width greatly. The precision measurement of the Higgs total width at the high-luminosity LHC can be used to discriminate certain new physics models.     

What can we learn from the neutron clinical experience for improving ion-beam techniques and high-LET patient selection?

Historically, improvements in radiotherapy have been mainly due to improvements in physical selectivity: beam penetration, collimation, dosimetry, treatment planning; and advances in imaging. Neutrons were the first high-LET (linear energy transfer) radiation to be used clinically and showed improvement in the differential response of radiation resistant tumors and normal tissues. The benefits of fast neutrons (and other forms of high LET radiations) are due to their biological effects: a reduction of the OER, a reduction in the differential cell radiosensitivity related to their position in the mitotic cycle, and a reduction in cellular repair capacity (thus less importance of fractionation). The poor physical selectivity of the early neutron therapy beams introduced a systematic bias in comparison with the photon treatments and created a negative perception for neutron therapy. However, significant improvements in the neutron therapy equipment resulted in a physical selectivity similar to modern MV photon therapy.The tumor types or sites where the best therapeutic results were obtained included inoperable or recurrent salivary gland tumors locally extended prostatic adenocarcinomas, and slowly growing well-differentiated sarcomas. The benefit of neutrons for some other well-defined groups of patients was demonstrated in randomized trials. It was estimated that about 20 % of all radiotherapy patients could benefit from fast neutrons (if neutrons are delivered under satisfactory physical conditions). An important issue for fast neutron therapy is the selection of the types of patients who could most benefit from high-LET radiations. The same issue is raised today with other high-LET radiations (e.g., ¹²C ions). It is reasonable to assume that the same types of patients would benefit from ¹²C irradiation. Of course the better physical selectivity of ion beams enhances the treatment possibilities but this is true for both the high-LET and low-LET radiations (i.e., moving from neutrons to ¹²C ions and from photons to protons, respectively). An important area of research involves developing criteria to identify specific patients suitable for high-LET radiation. One promising technique is to measure the RBE of the cancer cell population in vitro mainly in head and neck tumors. Modern molecular imaging allows the identification of hypoxic or proliferative regions in the tumor. Special MRI examinations are also able to identify hypoxic regions. A promising predictive test recently initiated, is the study of non-repairable double strand breaks but the utility of the technique needs to be confirmed. The extensive experience with fast neutron therapy can greatly assist the transition to high-LET charged-particle therapy.     

What can we learn from the tension between PLANCK and BICEP2 data?

Recently BICEP2 collaboration has announced the detection of the primordial gravitational waves at high confidence level.In light of the results of B-modes power spectrum from BICEP2 and using the basedΛCDM,a constraint on the tensor-to-scalar ratio r=0.20+0.07-0.05(68%C.L.)can be obtained,however,this result is in apparent tension with the limit on standard inflation models from the recent PLANCK measurement,r0.11(95%C.L.).Herein we review the recent progress on the cosmological studies after BICEP2 and discuss on different ways of reconciling the tension between PLANCK and BICEP2 data.We will discuss possible modifications on the standard cosmological model,such as including the running of scalar spectral index or other cosmological parameters correlated with inflationary cosmological parameters,or tilting the primordial power spectrum at large scales by introducing a cut off which can be predicted by bouncing cosmology.We will also comment on another possibility of generating extra B-modes of CMB polarization,namely by a non-zero polarization rotation angle during its transferring from the last scattering surface.     

What can we learn from the energy dependence of strangeness production at RHIC?

Measurements of strange and multi-strange particles with the STAR detector at center of mass energies per nucleon pair () of 62.4 GeV and 200 GeV in ultra-relativistic Au+Au collisions at RHIC are presented. The results are discussed in order to get insight into chemical and dynamical properties of the created medium. The former are obtained by comparison of transverse momentum (p_T) integrated observables such as yields and particle ratios to statistical models, while the latter use p_T dependent quantities such as single particle spectra and elliptic flow measurements to challenge hydrodynamical model calculations and parameterizations. The discussion is orientated towards the energy dependence of these properties by confronting the results at the different RHIC energies but also with the lower SPS energies.     

What can we learn about the spectrum of high-energy stray neutron fields from Bonner sphere measurements?

Extended-Range Bonner sphere spectrometers (ERBSSs) are well suited for measurements in high-energy stray neutron fields, where neutron energies extend from thermal to a few hundred MeV. These fields typically have a thermal peak, a fairly flat intermediate region, a medium energy peak at 1 MeV and a high-energy peak at a few 100 MeV. The data analysis is not straightforward: it requires unfolding with response functions that have a substantial amount of overlap, and the responses of the modified spheres (which provide information about the fluence at high energies) increase dramatically above 100 MeV. In this paper, I try to determine which of the main features of the spectrum are well determined by the data given optimal methods of analysis, and which features are subject to ambiguity. To do this, I analyse ERBSS measurements using two methods of analysis that are particularly useful for this purpose, Bayesian parameter estimation and maximum entropy unfolding.     

Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.     

Comparing kinetic Monte Carlo simulations with cluster dynamics: What can we learn about precipitation? Application to AlZr alloys

Kinetic Monte Carlo simulations of precipitation in AlZr alloys are compared with predictions of cluster dynamics based on an enhanced thermodynamic model. A methodology and various tools are proposed to learn as much as possible from such comparisons. Important deviations between the two methods are investigated and interpreted through the role of different mechanisms.     

What can we learn from high-p<Subscript>T</Subscript> correlations of neutral strange baryons and mesons at RHIC?

We present results on two-particle azimuthal correlations of neutral strange baryons (Λ, Λ̄) and mesons (K_S ⁰) for p_T=2–6 GeV/c associated with non-identified charged particles in d+Au and Au+Au collisions at  =200 GeV measured by the STAR experiment. We investigate in detail the associated yield of charged particles as a function centrality of the collision and transverse momentum of trigger and associated particles to look for possible flavor, baryon/meson and particle/anti-particle differences. We compare our results to the proton and pion triggered correlations as well as to a fragmentation and recombination model. PACS 25.75.-q; 25.75.Gz     

Measurement of στ product of solid state laser materials by an alternative method: Application to Nd3+ doped YVO4 crystal for 4 F 3/2→4 I 11/2 transition

In this paper an alternative approach for measurement of στ product for ⁴ F _3/2→⁴ I _11/2 transition of Nd³⁺ doped YVO₄ crystal is reported. In this method a microchip laser is formed by keeping a small piece of the sample in plane-plane resonator and a diode laser (808 nm) is used for pumping. The pump power induced thermal lensing effect is used to make the cavity stable. The cavity mode area is estimated by measuring the thermal lens focal length at the threshold and the average pump area is measured by Gaussian fit to the intensity profiles of the pump beam. The value of στ product of Nd:YVO₄ crystal obtained by this method is within 10% of the reported values. The advantage of this method is that it is a simple method for direct measurement of στ product of laser crystals.